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Zhu QL, Liu W, Khoruzhenko O, Breu J, Bai H, Hong W, Zheng Q, Wu ZL. Closed Twisted Hydrogel Ribbons with Self-Sustained Motions under Static Light Irradiation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2314152. [PMID: 38652466 DOI: 10.1002/adma.202314152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 03/25/2024] [Indexed: 04/25/2024]
Abstract
Self-sustained motions are widespread in biological systems by harvesting energy from surrounding environments, which inspire scientists to develop autonomous soft robots. However, most-existing soft robots require dynamic heterogeneous stimuli or complex fabrication with different components. Recently, control of topological geometry has been promising to afford soft robots with physical intelligence and thus life-like motions. Reported here are a series of closed twisted ribbon robots, which exhibit self-sustained flipping and rotation under constant light irradiation. Both Möbius strip and Seifert ribbon robots are devised for the first time by using an identical hydrogel, which responds to light irradiation on either side. Experiment and simulation results indicate that the self-regulated motions of the hydrogel robots are related to fast and reversible response of muscle-like gel, self-shadowing effect, and topology-facilitated refresh of light-exposed regions. The motion speeds and directions of the hydrogel robots can be tuned over a wide range. These closed twisted ribbon hydrogels are further applied to execute specific tasks in aqueous environments, such as collecting plastic balls, climbing a vertical rod, and transporting objects. This work presents new design principle for autonomous hydrogel robots by benefiting from material response and topology geometry, which may be inspirative for the robotics community.
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Affiliation(s)
- Qing Li Zhu
- Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Weixuan Liu
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Olena Khoruzhenko
- Bavarian Polymer Institute and Department of Chemistry, University of Bayreuth, Universitätsstrasse 30, 95440, Bayreuth, Germany
| | - Josef Breu
- Bavarian Polymer Institute and Department of Chemistry, University of Bayreuth, Universitätsstrasse 30, 95440, Bayreuth, Germany
| | - Huiying Bai
- Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Wei Hong
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Qiang Zheng
- Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Zi Liang Wu
- Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
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2
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Zheng Z, Han J, Shi Q, Demir SO, Jiang W, Sitti M. Single-step precision programming of decoupled multiresponsive soft millirobots. Proc Natl Acad Sci U S A 2024; 121:e2320386121. [PMID: 38513101 PMCID: PMC10990116 DOI: 10.1073/pnas.2320386121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/16/2024] [Indexed: 03/23/2024] Open
Abstract
Stimuli-responsive soft robots offer new capabilities for the fields of medical and rehabilitation robotics, artificial intelligence, and soft electronics. Precisely programming the shape morphing and decoupling the multiresponsiveness of such robots is crucial to enable them with ample degrees of freedom and multifunctionality, while ensuring high fabrication accuracy. However, current designs featuring coupled multiresponsiveness or intricate assembly processes face limitations in executing complex transformations and suffer from a lack of precision. Therefore, we propose a one-stepped strategy to program multistep shape-morphing soft millirobots (MSSMs) in response to decoupled environmental stimuli. Our approach involves employing a multilayered elastomer and laser scanning technology to selectively process the structure of MSSMs, achieving a minimum machining precision of 30 μm. The resulting MSSMs are capable of imitating the shape morphing of plants and hand gestures and resemble kirigami, pop-up, and bistable structures. The decoupled multistimuli responsiveness of the MSSMs allows them to conduct shape morphing during locomotion, perform logic circuit control, and remotely repair circuits in response to humidity, temperature, and magnetic field. This strategy presents a paradigm for the effective design and fabrication of untethered soft miniature robots with physical intelligence, advancing the decoupled multiresponsive materials through modular tailoring of robotic body structures and properties to suit specific applications.
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Affiliation(s)
- Zhiqiang Zheng
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart70569, Germany
| | - Jie Han
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart70569, Germany
- State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an710054, China
- School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an710054, China
| | - Qing Shi
- Intelligent Robotics Institute, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing100081, China
- Key Laboratory of Biomimetic Robots and Systems (Beijing Institute of Technology), Ministry of Education, Beijing100081, China
| | - Sinan Ozgun Demir
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart70569, Germany
| | - Weitao Jiang
- State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an710054, China
- School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an710054, China
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart70569, Germany
- Institute for Biomedical Engineering, ETH Zurich, Zurich8092, Switzerland
- School of Medicine and College of Engineering, Koç University, Istanbul34450, Turkey
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3
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Jin L, Yang S. Engineering Kirigami Frameworks Toward Real-World Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308560. [PMID: 37983878 DOI: 10.1002/adma.202308560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/05/2023] [Indexed: 11/22/2023]
Abstract
The surge in advanced manufacturing techniques has led to a paradigm shift in the realm of material design from developing completely new chemistry to tailoring geometry within existing materials. Kirigami, evolved from a traditional cultural and artistic craft of cutting and folding, has emerged as a powerful framework that endows simple 2D sheets with unique mechanical, thermal, optical, and acoustic properties, as well as shape-shifting capabilities. Given its flexibility, versatility, and ease of fabrication, there are significant efforts in developing kirigami algorithms to create various architectured materials for a wide range of applications. This review summarizes the fundamental mechanisms that govern the transformation of kirigami structures and elucidates how these mechanisms contribute to their distinctive properties, including high stretchability and adaptability, tunable surface topography, programmable shape morphing, and characteristics of bistability and multistability. It then highlights several promising applications enabled by the unique kirigami designs and concludes with an outlook on the future challenges and perspectives of kirigami-inspired metamaterials toward real-world applications.
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Affiliation(s)
- Lishuai Jin
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
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4
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Yu Y, Hu H, Dai Y, Li K. Modeling the light-powered self-rotation of a liquid crystal elastomer fiber-based engine. Phys Rev E 2024; 109:034701. [PMID: 38632774 DOI: 10.1103/physreve.109.034701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 02/08/2024] [Indexed: 04/19/2024]
Abstract
Self-oscillating systems possess the ability to convert ambient energy directly into mechanical work, and new types of self-oscillating systems are worth designing for practical applications in energy harvesters, engines and actuators. Taking inspiration from the four-stroke engine. A concept for a self-rotating engine is presented on the basis of photothermally responsive materials, consisting of a liquid crystal elastomer (LCE) fiber, a hinge and a turnplate, which can self-rotate under steady illumination. Based on the photo-thermal-mechanical model, a nonlinear theoretical model of the LCE-based engine under steady illumination is proposed to investigate its self-rotating behaviors. Numerical calculations reveal that the LCE-based engine experiences a supercritical Hopf bifurcation between the static regime and the self-rotation regime. The self-rotation of the LCE-based engine originates from the photothermally driven strain of the LCE fiber in illumination, and its continuous periodic motion is sustained by the correlation between photothermal energy and damping dissipation. The Hopf bifurcation conditions are also explored in detail, as well as the vital system parameters affecting self-rotation frequency. Compared to the abundant existing self-oscillating systems, this conceptual self-rotating LCE-based engine stands out due to its simple and lightweight structure, customizable dimensions and high speed, and it is expected to offer a broader range of design concepts applicable to soft robotics, energy harvesters, medical instruments, and so on.
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Affiliation(s)
- Yong Yu
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Haoyu Hu
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Yuntong Dai
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Kai Li
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
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5
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Chang S, Koo JH, Yoo J, Kim MS, Choi MK, Kim DH, Song YM. Flexible and Stretchable Light-Emitting Diodes and Photodetectors for Human-Centric Optoelectronics. Chem Rev 2024; 124:768-859. [PMID: 38241488 DOI: 10.1021/acs.chemrev.3c00548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024]
Abstract
Optoelectronic devices with unconventional form factors, such as flexible and stretchable light-emitting or photoresponsive devices, are core elements for the next-generation human-centric optoelectronics. For instance, these deformable devices can be utilized as closely fitted wearable sensors to acquire precise biosignals that are subsequently uploaded to the cloud for immediate examination and diagnosis, and also can be used for vision systems for human-interactive robotics. Their inception was propelled by breakthroughs in novel optoelectronic material technologies and device blueprinting methodologies, endowing flexibility and mechanical resilience to conventional rigid optoelectronic devices. This paper reviews the advancements in such soft optoelectronic device technologies, honing in on various materials, manufacturing techniques, and device design strategies. We will first highlight the general approaches for flexible and stretchable device fabrication, including the appropriate material selection for the substrate, electrodes, and insulation layers. We will then focus on the materials for flexible and stretchable light-emitting diodes, their device integration strategies, and representative application examples. Next, we will move on to the materials for flexible and stretchable photodetectors, highlighting the state-of-the-art materials and device fabrication methods, followed by their representative application examples. At the end, a brief summary will be given, and the potential challenges for further development of functional devices will be discussed as a conclusion.
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Affiliation(s)
- Sehui Chang
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Ja Hoon Koo
- Department of Semiconductor Systems Engineering, Sejong University, Seoul 05006, Republic of Korea
- Institute of Semiconductor and System IC, Sejong University, Seoul 05006, Republic of Korea
| | - Jisu Yoo
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Min Seok Kim
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Moon Kee Choi
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Graduate School of Semiconductor Materials and Devices Engineering, Center for Future Semiconductor Technology (FUST), UNIST, Ulsan 44919, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Dae-Hyeong Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University (SNU), Seoul 08826, Republic of Korea
- Department of Materials Science and Engineering, SNU, Seoul 08826, Republic of Korea
- Interdisciplinary Program for Bioengineering, SNU, Seoul 08826, Republic of Korea
| | - Young Min Song
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Artificial Intelligence (AI) Graduate School, GIST, Gwangju 61005, Republic of Korea
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6
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Zhang Z, Shi Z, Ahmed D. SonoTransformers: Transformable acoustically activated wireless microscale machines. Proc Natl Acad Sci U S A 2024; 121:e2314661121. [PMID: 38289954 PMCID: PMC10861920 DOI: 10.1073/pnas.2314661121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 12/22/2023] [Indexed: 02/01/2024] Open
Abstract
Shape transformation, a key mechanism for organismal survival and adaptation, has gained importance in developing synthetic shape-shifting systems with diverse applications ranging from robotics to bioengineering. However, designing and controlling microscale shape-shifting materials remains a fundamental challenge in various actuation modalities. As materials and structures are scaled down to the microscale, they often exhibit size-dependent characteristics, and the underlying physical mechanisms can be significantly affected or rendered ineffective. Additionally, surface forces such as van der Waals forces and electrostatic forces become dominant at the microscale, resulting in stiction and adhesion between small structures, making them fracture and more difficult to deform. Furthermore, despite various actuation approaches, acoustics have received limited attention despite their potential advantages. Here, we introduce "SonoTransformer," the acoustically activated micromachine that delivers shape transformability using preprogrammed soft hinges with different stiffnesses. When exposed to an acoustic field, these hinges concentrate sound energy through intensified oscillation and provide the necessary force and torque for the transformation of the entire micromachine within milliseconds. We have created machine designs to predetermine the folding state, enabling precise programming and customization of the acoustic transformation. Additionally, we have shown selective shape transformable microrobots by adjusting acoustic power, realizing high degrees of control and functional versatility. Our findings open new research avenues in acoustics, physics, and soft matter, offering new design paradigms and development opportunities in robotics, metamaterials, adaptive optics, flexible electronics, and microtechnology.
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Affiliation(s)
- Zhiyuan Zhang
- Acoustic Robotics Systems Lab, Institute of Robotics and Intelligent Systems, Department of Mechanical and Process Engineering, ETH Zurich, ZurichCH-8803, Switzerland
| | - Zhan Shi
- Acoustic Robotics Systems Lab, Institute of Robotics and Intelligent Systems, Department of Mechanical and Process Engineering, ETH Zurich, ZurichCH-8803, Switzerland
| | - Daniel Ahmed
- Acoustic Robotics Systems Lab, Institute of Robotics and Intelligent Systems, Department of Mechanical and Process Engineering, ETH Zurich, ZurichCH-8803, Switzerland
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7
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Xu L, Zhu C, Lamont S, Zou X, Yang Y, Chen S, Ding J, Vernerey FJ. Programming Motion into Materials Using Electricity-Driven Liquid Crystal Elastomer Actuators. Soft Robot 2024. [PMID: 38265749 DOI: 10.1089/soro.2023.0063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024] Open
Abstract
As thermally driven smart materials capable of large reversible deformations, liquid crystal elastomers (LCEs) have great potential for applications in bionic soft robots, artificial muscles, controllable actuators, and flexible sensors due to their ability to program controllable motion into materials. In this article, we introduce conductive LCE actuators using a liquid metal electrothermal layer and a polyethylene terephthalate substrate. Our LCE actuators can be stimulated at low currents from 2 to 4 A and produce a maximum work density of 9.4 k J ∕ m 3 . We illustrate the potential applications of this system by designing a palm-activated artificial muscle gripper, which can be used to grasp soft objects ranging from 5 to 55 mm in size, and even ring-shaped workpieces with precise external or internal support. Furthermore, inspired by the movement of fruit fly larvae, we designed a new soft robot capable of bioinspired crawling and turning by inducing anisotropic friction with an asymmetric design. Finally, we illustrate advanced motional control by designing an autonomously rotating wheel based on the asymmetric contraction of its spokes. To assist in the production of autonomously moving robots, we provide a thorough characterization of its motion dynamics.
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Affiliation(s)
- Lin Xu
- School of Mechanical Engineering, Jiangsu University, Zhenjiang, PR China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, PR China
| | - Chen Zhu
- School of Mechanical Engineering, Jiangsu University, Zhenjiang, PR China
| | - Samuel Lamont
- Department of Mechanical Engineering and Material Science & Engineering Program, University of Colorado at Boulder, Boulder, Colorado, USA
| | - Xiang Zou
- School of Mechanical Engineering, Jiangsu University, Zhenjiang, PR China
| | - Yabing Yang
- School of Mechanical Engineering, Jiangsu University, Zhenjiang, PR China
| | - Si Chen
- School of Mechanical Engineering, Jiangsu University, Zhenjiang, PR China
| | - Jianning Ding
- School of Mechanical Engineering, Jiangsu University, Zhenjiang, PR China
- School of Mechanical Engineering, Yangzhou University, Yangzhou, PR China
| | - Franck J Vernerey
- Department of Mechanical Engineering and Material Science & Engineering Program, University of Colorado at Boulder, Boulder, Colorado, USA
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8
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Yu J, Xu Z, Wan Q, Shuai Y, Wang J, Mao C, Yang M. Ultrafast Bi-Directional Bending Moisture-Responsive Soft Actuators through Superfine Silk Rod Modified Bio-Mimicking Hierarchical Layered Structure. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2309364. [PMID: 38225691 DOI: 10.1002/smll.202309364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/02/2024] [Indexed: 01/17/2024]
Abstract
Development of stimulus-responsive materials is crucial for novel soft actuators. Among these actuators, the moisture-responsive actuators are known for their accessibility, eco-friendliness, and robust regenerative attributes. A major challenge of moisture-responsive soft actuators (MRSAs) is achieving significant bending curvature within short response times. Many plants naturally perform large deformation through a layered hierarchical structure in response to moisture stimuli. Drawing inspiration from the bionic structure of Delosperma nakurense (D. nakurense) seed capsule, here the fabrication of an ultrafast bi-directional bending MRSAs is reported. Combining a superfine silk fibroin rod (SFR) modified graphene oxide (GO) moisture-responsive layer with a moisture-inert layer of reduced graphene oxide (RGO), this actuator demonstrated large bi-directional bending deformation (-4.06 ± 0.09 to 10.44 ± 0.00 cm-1 ) and ultrafast bending rates (7.06 cm-1 s-1 ). The high deformation rate is achieved by incorporating the SFR into the moisture-responsive layers, facilitating rapid water transmission within the interlayer structure. The complex yet predictable deformations of this actuator are demonstrated that can be utilized in smart switch, robotic arms, and walking device. The proposed SFR modification method is simple and versatile, enhancing the functionality of hierarchical layered actuators. It holds the potential to advance intelligent soft robots for application in confined environments.
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Affiliation(s)
- Jing Yu
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Zongpu Xu
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Quan Wan
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Yajun Shuai
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Jie Wang
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Chuanbin Mao
- School of Materials Science & Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
- Department of Biomedical Engineering, The Chinese University of Hong Kong, ShaTin, Hong Kong, SAR, P. R. China
| | - Mingying Yang
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University, Hangzhou, 310058, P. R. China
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9
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Lei B, Wen ZY, Wang HK, Gao J, Chen LJ. Bioinspired Jumping Soft Actuators of the Liquid Crystal Elastomer Enabled by Photo-Mechanical Coupling. ACS APPLIED MATERIALS & INTERFACES 2024; 16:1596-1604. [PMID: 38153381 DOI: 10.1021/acsami.3c16530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Jumping, a fundamental survival behavior observed in organisms, serves as a vital mechanism for adapting to the surrounding environment and overcoming significant obstacles within a given terrain. Here, we present a light-controlled soft jumping actuator inspired by asphondylia, which employs a closed-loop structure and utilizes a liquid crystal elastomer (LCE). Photo-mechanical coupling highlights the significant influence of the light source on the actuator's jumping behavior. Manipulating the light intensity, the relative position of stimulus and light lock, and the concentration of disperse red 1 (DR1) allows precise control over both the maximum take-off velocity and jump height. Furthermore, tailoring the size of the LCE actuator offers a means of regulating jumping behavior. Upon exposure to 460 nm LED irradiation, our actuator achieves remarkable performance, with a maximum jumping height of 10 body length (BL) and take-off velocity of 62 BL/s. These actuators accumulate and rapidly release energy, enabling the effective transportation of microcargos across substantial distances. Our research yields valuable insights into the realm of soft robotics, underscoring the pivotal importance of photo-mechanical coupling in the field of soft robotics, thereby serving as a catalyst for inspiring continued exploration of agile and capable systems by prestoring elastic energy.
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Affiliation(s)
- Bing Lei
- Department of Electronic Engineering, School of Electronic Science and Engineering, Fujian Key Laboratory of Ultrafast Laser Technology and Applications, Xiamen University, Xiamen 361005, China
| | - Zhi-Yuan Wen
- Department of Electronic Engineering, School of Electronic Science and Engineering, Fujian Key Laboratory of Ultrafast Laser Technology and Applications, Xiamen University, Xiamen 361005, China
| | - Hua-Kun Wang
- Department of Civil Engineering, School of Architecture and Civil Engineering, Fujian Key Laboratory of Digital Simulations for Coastal Civil Engineering, Xiamen University, Xiamen 361005, China
| | - Jing Gao
- Department of Civil Engineering, School of Architecture and Civil Engineering, Fujian Key Laboratory of Digital Simulations for Coastal Civil Engineering, Xiamen University, Xiamen 361005, China
| | - Lu-Jian Chen
- Department of Electronic Engineering, School of Electronic Science and Engineering, Fujian Key Laboratory of Ultrafast Laser Technology and Applications, Xiamen University, Xiamen 361005, China
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10
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Yuan Z, Liu J, Qian G, Dai Y, Li K. Self-Rotation of Electrothermally Responsive Liquid Crystal Elastomer-Based Turntable in Steady-State Circuits. Polymers (Basel) 2023; 15:4598. [PMID: 38232009 PMCID: PMC10708095 DOI: 10.3390/polym15234598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 01/19/2024] Open
Abstract
Self-excited motions, characterized by their ability to harness energy from a consistent environment and self-regulate, exhibit significant potential in micro-devices, autonomous robotics, sensor technology, and energy generation. This study introduces an innovative turntable system based on an electrothermally responsive liquid crystal elastomer (LCE). This system facilitates self-rotation within a steady-state circuit. Employing an electrothermal LCE model, we have modeled and numerically analyzed the nonlinear dynamics of an LCE-rope within steady-state circuits, utilizing the four-order Runge-Kutta method for calculations. The numerical results reveal the emergence of two distinct motion patterns in the turntable system under steady-state conditions: a self-rotation pattern and a static pattern. The self-rotation is initiated when the system's absorbed energy surpasses the energy lost due to damping effects. Furthermore, this paper delves into the critical conditions necessary for initiating self-rotation and examines the influence of various key dimensionless parameters on the system's rotation amplitude and frequency. These parameters include gravitational acceleration, the initial position of the mass ball, elastic stiffness of the LCE and spring, limiting temperature, heating zone angle, thermal shrinkage coefficient, and damping factor. Our computational findings establish that these parameters exert a modulatory impact on the rotation amplitude and period. This research enhances the understanding of self-excited motions and offers promising avenues for applications in energy harvesting, monitoring, soft robotics, medical devices, and micro- and nano-devices.
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Affiliation(s)
- Zongsong Yuan
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (Z.Y.); (G.Q.); (Y.D.)
| | - Junxiu Liu
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (Z.Y.); (G.Q.); (Y.D.)
- Anhui Province Key Laboratory of Building Structure and Underground Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Guqian Qian
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (Z.Y.); (G.Q.); (Y.D.)
| | - Yuntong Dai
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (Z.Y.); (G.Q.); (Y.D.)
| | - Kai Li
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (Z.Y.); (G.Q.); (Y.D.)
- Anhui Province Key Laboratory of Building Structure and Underground Engineering, Anhui Jianzhu University, Hefei 230601, China
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11
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Yu Y, Yang F, Dai Y, Li K. Liquid crystal elastomer self-oscillator with embedded light source. Phys Rev E 2023; 108:054702. [PMID: 38115449 DOI: 10.1103/physreve.108.054702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 10/23/2023] [Indexed: 12/21/2023]
Abstract
Light sources that switch periodically over time have a wide range of application value in life and engineering, and generally require additional controller to periodically switch circuits to achieve periodic lighting. In this paper, a self-oscillating spring oscillator based on optically responsive liquid crystal elastomer (LCE) fiber is constructed, which consists of a embedded light source and a LCE fiber. The spring oscillator can oscillate autonomously to achieve periodic switching of the light source. On the basis of the well-established dynamic LCE model, a nonlinear dynamic model is proposed and its dynamic behavior is studied. Numerical calculations demonstrate that the spring oscillator presents two motion regimes, namely the self-oscillation regime and the static regime. The self-oscillation of spring oscillator is maintained by the energy competition between light energy and damping dissipation. Furthermore, the critical conditions for triggering self-oscillation are also investigated in detail, as well as the key system parameters that affect its frequency and amplitude. Different from the existing abundant self-oscillating systems, this self-oscillating structure with simple structure and convenient fabrication does not require complex controller to obtain periodic lighting, and it is expected to provide more diversified design ideas for soft robots and sensors.
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Affiliation(s)
- Yong Yu
- School of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui 230601, China
| | - Fan Yang
- School of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui 230601, China
| | - Yuntong Dai
- School of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui 230601, China
| | - Kai Li
- School of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui 230601, China
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12
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Li K, Chen J, Hu H, Wu H, Dai Y, Yu Y. A Light-Powered Liquid Crystal Elastomer Roller. Polymers (Basel) 2023; 15:4221. [PMID: 37959899 PMCID: PMC10650120 DOI: 10.3390/polym15214221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/15/2023] [Accepted: 10/18/2023] [Indexed: 11/15/2023] Open
Abstract
Achieving and controlling the desired movements of active machines is generally accomplished through precise control of artificial muscles in a distributed and serialized manner, which is a significant challenge. The emerging motion control strategy based on self-oscillation in active machines has unique advantages, including directly harvesting energy from constant ambient light, and it has no need for complex controllers. Inspired by the roller, we have innovatively developed a self-rolling roller that consists of a roller and a liquid crystal elastomer (LCE) fiber. By utilizing a well-established dynamic LCE model and subjecting it to constant illumination, we have investigated the dynamic behavior of the self-rolling roller. Based on numerical calculations, it has been discovered that the roller, when subjected to steady illumination, exhibits two distinct motion regimes: the static regime and the self-rolling regime. The self-rolling regime, characterized by continuous periodic rolling, is sustained by the interaction between light energy and damping dissipation. The continuous periodic rolling observed in the self-rolling regime is maintained through the interplay between the dissipation of damping and the absorption of light energy. In the static state, the rolling angle of the roller begins to decrease rapidly and then converges to zero. Detailed investigations have been conducted to determine the critical conditions required to initiate self-rolling, as well as the essential system parameters that influence its frequency and amplitude. The proposed self-rolling roller has superiorities in its simple structure, light weight, alternative to manual labor, and speediness. This advancement is expected to inspire greater design diversity in micromachines, soft robotics, energy harvesters, and similar areas.
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Affiliation(s)
| | | | | | | | | | - Yong Yu
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (K.L.); (J.C.); (H.H.); (H.W.); (Y.D.)
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13
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Choi J, Jeon J, Lee J, Nauman A, Lee JG, Cho W, Lee C, Cho Y, Wie JJ, Kim H. Steerable and Agile Light-Fueled Rolling Locomotors by Curvature-Engineered Torsional Torque. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304715. [PMID: 37565602 PMCID: PMC10602523 DOI: 10.1002/advs.202304715] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Indexed: 08/12/2023]
Abstract
On-demand photo-steerable amphibious rolling motions are generated by the structural engineering of monolithic soft locomotors. Photo-morphogenesis of azobenzene-functionalized liquid crystal polymer networks (azo-LCNs) is designed from spiral ribbon to helicoid helices, employing a 270° super-twisted nematic molecular geometry with aspect ratio variations of azo-LCN strips. Unlike the intermittent and biased rolling of spiral ribbon azo-LCNs with center-of-mass shifting, the axial torsional torque of helicoid azo-LCNs enables continuous and straight rolling at high rotation rates (≈720 rpm). Furthermore, center-tapered helicoid structures with wide edges are introduced for effectively accelerating photo-motilities while maintaining directional controllability. Irrespective of surface conditions, the photo-induced rotational torque of center-tapered helicoid azo-LCNs can be transferred to interacting surfaces, as manifested by steep slope climbing and paddle-like swimming multimodal motilities. Finally, the authors demonstrate continuous curvilinear guidance of soft locomotors, bypassing obstacles and reaching desired destinations through real-time on-demand photo-steering.
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Affiliation(s)
- Jun‐Chan Choi
- School of Electronic and Electrical EngineeringKyungpook National University41566DaeguRepublic of Korea
- Soft Hybrid Materials Research CenterKorea Institute of Science and Technology02792SeoulRepublic of Korea
| | - Jisoo Jeon
- Program in Environmental and Polymer EngineeringInha University22212IncheonRepublic of Korea
| | - Jae‐Won Lee
- School of Electronic and Electrical EngineeringKyungpook National University41566DaeguRepublic of Korea
| | - Asad Nauman
- School of Electronic and Electrical EngineeringKyungpook National University41566DaeguRepublic of Korea
| | - Jae Gyeong Lee
- Department of Organic and Nano EngineeringHanyang University04763SeoulRepublic of Korea
- Human‐Tech Convergence ProgramHanyang University04763SeoulRepublic of Korea
| | - Woongbi Cho
- Department of Organic and Nano EngineeringHanyang University04763SeoulRepublic of Korea
- Human‐Tech Convergence ProgramHanyang University04763SeoulRepublic of Korea
| | - Chanwoo Lee
- School of Electronic and Electrical EngineeringKyungpook National University41566DaeguRepublic of Korea
| | - Young‐Min Cho
- School of Electronics EngineeringKyungpook National University41566DaeguRepublic of Korea
| | - Jeong Jae Wie
- Department of Organic and Nano EngineeringHanyang University04763SeoulRepublic of Korea
- Human‐Tech Convergence ProgramHanyang University04763SeoulRepublic of Korea
- Department of Chemical EngineeringHanyang University04763SeoulRepublic of Korea
- Institute of Nano Science and TechnologyHanyang University04763SeoulRepublic of Korea
- The Research Institute of Industrial ScienceHanyang UniversitySeoul04763Republic of Korea
- The Michael M. Szwarc Polymer Research InstituteState University of New York College of Environmental Science and ForestrySyracuseNY13210USA
- Department of Chemical EngineeringState University of New York College of Enviromental Science and ForestrySyracuseNY13210USA
| | - Hak‐Rin Kim
- School of Electronic and Electrical EngineeringKyungpook National University41566DaeguRepublic of Korea
- School of Electronics EngineeringKyungpook National University41566DaeguRepublic of Korea
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14
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Sun J, Lerner E, Tighe B, Middlemist C, Zhao J. Embedded shape morphing for morphologically adaptive robots. Nat Commun 2023; 14:6023. [PMID: 37758737 PMCID: PMC10533550 DOI: 10.1038/s41467-023-41708-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Shape-morphing robots can change their morphology to fulfill different tasks in varying environments, but existing shape-morphing capability is not embedded in a robot's body, requiring bulky supporting equipment. Here, we report an embedded shape-morphing scheme with the shape actuation, sensing, and locking, all embedded in a robot's body. We showcase this embedded scheme using three morphing robotic systems: 1) self-sensing shape-morphing grippers that can adapt to objects for adaptive grasping; 2) a quadrupedal robot that can morph its body shape for different terrestrial locomotion modes (walk, crawl, or horizontal climb); 3) an untethered robot that can morph its limbs' shape for amphibious locomotion. We also create a library of embedded morphing modules to demonstrate the versatile programmable shapes (e.g., torsion, 3D bending, surface morphing, etc.). Our embedded morphing scheme offers a promising avenue for robots to reconfigure their morphology in an embedded manner that can adapt to different environments on demand.
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Affiliation(s)
- Jiefeng Sun
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA.
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, USA.
| | - Elisha Lerner
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA
| | - Brandon Tighe
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA
| | - Clint Middlemist
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA
| | - Jianguo Zhao
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA.
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15
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Duhr P, Meier YA, Damanpack A, Carpenter J, Studart AR, Rafsanjani A, Demirörs AF. Kirigami Makes a Soft Magnetic Sheet Crawl. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301895. [PMID: 37357135 PMCID: PMC10477847 DOI: 10.1002/advs.202301895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/28/2023] [Indexed: 06/27/2023]
Abstract
Limbless crawling on land requires breaking symmetry of the friction with the ground and exploiting an actuation mechanism to generate propulsive forces. Here, kirigami cuts are introduced into a soft magnetic sheet that allow to achieve effective crawling of untethered soft robots upon application of a rotating magnetic field. Bidirectional locomotion is achieved under clockwise and counterclockwise rotating magnetic fields with distinct locomotion patterns and crawling speed in forward and backward propulsions. The crawling and deformation profiles of the robot are experimentally characterized and combined with detailed multiphysics numerical simulations to extract locomotion mechanisms in both directions. It is shown that by changing the shape of the cuts and orientation of the magnet the robot can be steered, and if combined with translational motion of the magnet, complex crawling paths are programed. The proposed magnetic kirigami robot offers a simple approach to developing untethered soft robots with programmable motion.
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Affiliation(s)
- Pierre Duhr
- Complex MaterialsDepartment of MaterialsETH ZurichZurichCH‐8092Switzerland
| | - Yuki A. Meier
- Complex MaterialsDepartment of MaterialsETH ZurichZurichCH‐8092Switzerland
| | - Alireza Damanpack
- Department of Mechanical and Electrical EngineeringUniversity of Southern DenmarkOdense5230Denmark
| | - Julia Carpenter
- Complex MaterialsDepartment of MaterialsETH ZurichZurichCH‐8092Switzerland
| | - André R. Studart
- Complex MaterialsDepartment of MaterialsETH ZurichZurichCH‐8092Switzerland
| | - Ahmad Rafsanjani
- SDU Soft RoboticsSDU BioroboticsThe Maersk Mc‐Kinney Moller InstituteUniversity of Southern DenmarkOdense5230Denmark
| | - Ahmet F. Demirörs
- Complex MaterialsDepartment of MaterialsETH ZurichZurichCH‐8092Switzerland
- Present address:
Department of PhysicsUniversity of FribourgFribourgCH‐1700Switzerland
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16
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Wu H, Dai Y, Li K. Self-Vibration of Liquid Crystal Elastomer Strings under Steady Illumination. Polymers (Basel) 2023; 15:3483. [PMID: 37631540 PMCID: PMC10458575 DOI: 10.3390/polym15163483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/10/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Self-vibrating systems based on active materials have been widely developed, but most of the existing self-oscillating systems are complex and difficult to control. To fulfill the requirements of different functions and applications, it is necessary to construct more self-vibrating systems that are easy to control, simple in material preparation and fast in response. This paper proposes a liquid crystal elastomer (LCE) string-mass structure capable of continuous vibration under steady illumination. Based on the linear elastic model and the dynamic LCE model, the dynamic governing equations of the LCE string-mass system are established. Through numerical calculation, two regimes of the LCE string-mass system, namely the static regime and the self-vibration regime, are obtained. In addition, the light intensity, contraction coefficient and elastic coefficient of the LCE can increase the amplitude and frequency of the self-vibration, while the damping coefficient suppresses the self-oscillation. The LCE string--mass system proposed in this paper has the advantages of simple structure, easy control and customizable size, which has a wide application prospect in the fields of energy harvesting, autonomous robots, bionic instruments and medical equipment.
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Affiliation(s)
| | | | - Kai Li
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (H.W.); (Y.D.)
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17
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Darmawan BA, Park JO, Go G, Choi E. Four-Dimensional-Printed Microrobots and Their Applications: A Review. MICROMACHINES 2023; 14:1607. [PMID: 37630143 PMCID: PMC10456732 DOI: 10.3390/mi14081607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023]
Abstract
Owing to their small size, microrobots have many potential applications. In addition, four-dimensional (4D) printing facilitates reversible shape transformation over time or upon the application of stimuli. By combining the concept of microrobots and 4D printing, it may be possible to realize more sophisticated next-generation microrobot designs that can be actuated by applying various stimuli, and also demonstrates profound implications for various applications, including drug delivery, cells delivery, soft robotics, object release and others. Herein, recent advances in 4D-printed microrobots are reviewed, including strategies for facilitating shape transformations, diverse types of external stimuli, and medical and nonmedical applications of microrobots. Finally, to conclude the paper, the challenges and the prospects of 4D-printed microrobots are highlighted.
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Affiliation(s)
- Bobby Aditya Darmawan
- Korea Institute of Medical Microrobotics, 43-26, Cheomdangwagi-ro 208-beon-gil, Buk-gu, Gwangju 61011, Republic of Korea; (B.A.D.); (J.-O.P.)
| | - Jong-Oh Park
- Korea Institute of Medical Microrobotics, 43-26, Cheomdangwagi-ro 208-beon-gil, Buk-gu, Gwangju 61011, Republic of Korea; (B.A.D.); (J.-O.P.)
| | - Gwangjun Go
- Korea Institute of Medical Microrobotics, 43-26, Cheomdangwagi-ro 208-beon-gil, Buk-gu, Gwangju 61011, Republic of Korea; (B.A.D.); (J.-O.P.)
- Department of Mechanical Engineering, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Eunpyo Choi
- Korea Institute of Medical Microrobotics, 43-26, Cheomdangwagi-ro 208-beon-gil, Buk-gu, Gwangju 61011, Republic of Korea; (B.A.D.); (J.-O.P.)
- School of Mechanical Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Republic of Korea
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18
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Li K, Liu Y, Dai Y, Yu Y. Self-Vibration of a Liquid Crystal Elastomer Fiber-Cantilever System under Steady Illumination. Polymers (Basel) 2023; 15:3397. [PMID: 37631454 PMCID: PMC10458184 DOI: 10.3390/polym15163397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
A new type of self-oscillating system has been developed with the potential to expand its applications in fields such as biomedical engineering, advanced robotics, rescue operations, and military industries. This system is capable of sustaining its own motion by absorbing energy from the stable external environment without the need for an additional controller. The existing self-sustained oscillatory systems are relatively complex in structure and difficult to fabricate and control, thus limited in their implementation in practical and complex scenarios. In this paper, we creatively propose a novel light-powered liquid crystal elastomer (LCE) fiber-cantilever system that can perform self-sustained oscillation under steady illumination. Considering the well-established LCE dynamic model, beam theory, and deflection formula, the control equations for the self-oscillating system are derived to theoretically study the dynamics of self-vibration. The LCE fiber-cantilever system under steady illumination is found to exhibit two motion regimes, namely, the static and self-vibration regimes. The positive work done by the tension of the light-powered LCE fiber provides some compensation against the structural resistance from cantilever and the air damping. In addition, the influences of system parameters on self-vibration amplitude and frequency are also studied. The newly constructed light-powered LCE fiber-cantilever system in this paper has a simple structure, easy assembly/disassembly, easy preparation, and strong expandability as a one-dimensional fiber-based system. It is expected to meet the application requirements of practical complex scenarios and has important application value in fields such as autonomous robots, energy harvesters, autonomous separators, sensors, mechanical logic devices, and biomimetic design.
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Affiliation(s)
| | | | | | - Yong Yu
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
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19
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Li K, Wu H, Zhang B, Dai Y, Yu Y. Heat-Driven Synchronization in Coupled Liquid Crystal Elastomer Spring Self-Oscillators. Polymers (Basel) 2023; 15:3349. [PMID: 37631406 PMCID: PMC10458843 DOI: 10.3390/polym15163349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/06/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Self-oscillating coupled machines are capable of absorbing energy from the external environment to maintain their own motion and have the advantages of autonomy and portability, which also contribute to the exploration of the field of synchronization and clustering. Based on a thermally responsive liquid crystal elastomer (LCE) spring self-oscillator in a linear temperature field, this paper constructs a coupling and synchronization model of two self-oscillators connected by springs. Based on the existing dynamic LCE model, this paper theoretically reveals the self-oscillation mechanism and synchronization mechanism of two self-oscillators. The results show that adjusting the initial conditions and system parameters causes the coupled system to exhibit two synchronization modes: in-phase mode and anti-phase mode. The work conducted by the driving force compensates for the damping dissipation of the system, thus maintaining self-oscillation. The phase diagrams of different system parameters are drawn to illuminate the self-oscillation and synchronization mechanism. For weak interaction, changing the initial conditions may obtain the modes of in-phase and anti-phase. Under conditions of strong interactions, the system consistently exhibits an in-phase mode. Furthermore, an investigation is conducted on the influence of system parameters, such as the LCE elastic coefficient and spring elastic coefficient, on the amplitudes and frequencies of the two synchronization modes. This study aims to enhance the understanding of self-oscillator synchronization and its potential applications in areas such as energy harvesting, power generation, detection, soft robotics, medical devices and micro/nanodevices.
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Affiliation(s)
| | | | | | | | - Yong Yu
- Department of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
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20
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Ge D, Dai Y, Li K. Self-Oscillating Liquid Crystal Elastomer Helical Spring Oscillator with Combined Tension and Torsion. Polymers (Basel) 2023; 15:3294. [PMID: 37571189 PMCID: PMC10422366 DOI: 10.3390/polym15153294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 07/23/2023] [Accepted: 07/30/2023] [Indexed: 08/13/2023] Open
Abstract
Self-oscillation is the autonomous maintenance of continuous periodic motion through energy absorption from non-periodic external stimuli, making it particularly attractive for fabricating soft robots, energy-absorbing devices, mass transport devices, and so on. Inspired by the self-oscillating system that presents high degrees of freedom and diverse complex oscillatory motions, we created a self-oscillating helical spring oscillator with combined tension and torsion under steady illumination, among which a mass block and a liquid crystal elastomer (LCE) helical spring made with LCE wire are included. Considering the well-established helical spring model and the dynamic LCE model, a nonlinear dynamic model of the LCE helical spring oscillator under steady illumination is proposed. From numerical calculation, the helical spring oscillator upon exposure to steady illumination possesses two motion regimes, which are the static regime and the self-tension-torsion regime. Contraction of the LCE wire under illumination is necessary to generate the self-tension-torsion of the helical spring oscillator, with its continuous periodic motion being maintained by the mutual balance between light energy input and damping dissipation. Additionally, the critical conditions for triggering the self-tension-torsion, as well as the vital system parameters affecting its frequencies and amplitudes of the translation and the rotation, were investigated in detail. This self-tension-torsion helical spring oscillator is unique in its customizable mechanical properties via its structural design, small material strain but large structural displacement, and ease of manufacture. We envision a future of novel designs for soft robotics, energy harvesters, active machinery, and so on.
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Affiliation(s)
- Dali Ge
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (D.G.); (Y.D.)
- Institute of Advanced Technology, University of Science and Technology of China, Hefei 230001, China
| | - Yuntong Dai
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (D.G.); (Y.D.)
| | - Kai Li
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China; (D.G.); (Y.D.)
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21
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Shu J, Wang J, Li Z, Tong KYR. Effects of Slit Edge Notches on Mechanical Properties of 3D-Printed PA12 Nylon Kirigami Specimens. Polymers (Basel) 2023; 15:3082. [PMID: 37514471 PMCID: PMC10383772 DOI: 10.3390/polym15143082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/14/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023] Open
Abstract
Kirigami structures, a Japanese paper-cutting art form, has been widely adopted in engineering design, including robotics, biomedicine, energy harvesting, and sensing. This study investigated the effects of slit edge notches on the mechanical properties, particularly the tensile stiffness, of 3D-printed PA12 nylon kirigami specimens. Thirty-five samples were designed with various notch sizes and shapes and printed using a commercial 3D printer with multi-jet fusion (MJF) technique. Finite element analysis (FEA) was employed to determine the mechanical properties of the samples computationally. The results showed that the stiffness of the kirigami samples is positively correlated with the number of edges in the notch shape and quadratically negatively correlated with the notch area of the samples. The mathematical relationship between the stretching tensile stiffness of the samples and their notch area was established and explained from an energy perspective. The relationship established in this study can help fine-tune the stiffness of kirigami-inspired structures without altering the primary parameters of kirigami samples. With the rapid fabrication method (e.g., 3D printing technique), the kirigami samples with suitable mechanical properties can be potentially applied to planar springs for hinge structures or energy-absorbing/harvesting structures. These findings will provide valuable insights into the development and optimization of kirigami-inspired structures for various applications in the future.
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Affiliation(s)
- Jing Shu
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong SAR 999077, China
| | - Junming Wang
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong SAR 999077, China
| | - Zheng Li
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong SAR 999077, China
- Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR 999077, China
| | - Kai-Yu Raymond Tong
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong SAR 999077, China
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22
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Li K, Zhang B, Cheng Q, Dai Y, Yu Y. Light-Fueled Synchronization of Two Coupled Liquid Crystal Elastomer Self-Oscillators. Polymers (Basel) 2023; 15:2886. [PMID: 37447528 DOI: 10.3390/polym15132886] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/27/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
The synchronization and group behaviors of self-excited coupled oscillators are common in nature and deserve to be explored, for self-excited motions have the advantages of actively collecting energy from the environment, being autonomous, making equipment portable, and so on. Based on light-powered self-excited oscillators composed of liquid crystal elastomer (LCE) bars, the synchronization of two self-excited coupled oscillators is theoretically studied. Numerical calculations show that self-excited oscillations of the system have two synchronization modes, in-phase mode and anti-phase mode, which are mainly determined by their interaction. The time histories of various quantities are calculated to elucidate the mechanism of self-excited oscillation and synchronization. For strong interactions, the system always develops into in-phase synchronization mode, while for weak interaction, the system will evolve into anti-phase synchronization mode. Furthermore, the effects of initial conditions, contraction coefficient, light intensity, and damping coefficient on the two synchronization modes of the self-excited oscillation are investigated extensively. The initial condition generally does not affect the synchronization mode and its amplitude. The amplitude of self-oscillation always increases with increasing contraction coefficient, gravitational acceleration, and light intensity, while it decreases with the increasing damping coefficient. This work will deepen people's understanding of the synchronization behaviors of self-excited coupled oscillators, and the theoretical framework could be extended to scenarios involving large-scale synchronization of the systems with numerous interacting oscillators.
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Affiliation(s)
- Kai Li
- Department of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Biao Zhang
- Department of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Quanbao Cheng
- Department of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Yuntong Dai
- Department of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Yong Yu
- Department of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
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23
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Liu J, Yuan Z, Zhao J, Dai Y, Li K. Self-Sustained Oscillation of Electrothermally Responsive Liquid Crystal Elastomer Film in Steady-State Circuits. Polymers (Basel) 2023; 15:2814. [PMID: 37447460 DOI: 10.3390/polym15132814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/22/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
Self-excited oscillations have the advantages of absorbing energy from a stable environment and Self-control; therefore, Self-excited motion patterns have broader applications in micro devices, autonomous robots, sensors and energy-generating devices. In this paper, a Self-sustained curling liquid crystal elastomer (LCE) film-mass system is proposed on the basis of electrothermally responsive materials, which can realize Self-oscillation under a steady-state current. Based on the contact model and dynamic LCE model, a nonlinear dynamics model of LCE film in steady-state circuits is developed and numerical calculations are carried out using the Runge-Kutta method. Through numerical calculations, it is demonstrated that LCE film-mass systems have two motion patterns in steady-state circuits: namely, a Self-oscillation pattern and a stationary pattern. Self-sustained curling of LCE film originates from the fact that the energy absorbed by the system exceeds the energy dissipated due to the damping effect. In addition, the critical conditions for triggering Self-oscillation and the effects of several key dimensionless system parameters on the amplitude and period of Self-oscillation are investigated in detail. Calculation results show that the height of electrolyte solution, gravitational acceleration, elastic modulus of LCE film, limit temperature, curvature coefficient, thermal shrinkage coefficient and damping factor all have a modulating effect on the amplitude and period of Self-oscillation. This research may deepen the understanding of Self-excited oscillation, with promising applications in energy harvesting, power generation, monitoring, soft robotics, medical devices, and micro and nano devices.
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Affiliation(s)
- Junxiu Liu
- Anhui Province Key Laboratory of Building Structure and Underground Engineering, Anhui Jianzhu University, Hefei 230601, China
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Zongsong Yuan
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Junjie Zhao
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Yuntong Dai
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Kai Li
- Anhui Province Key Laboratory of Building Structure and Underground Engineering, Anhui Jianzhu University, Hefei 230601, China
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
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Wang K, Hou C, Cong L, Zhang W, Fan L, Wang X, Dong L. 3D Chiral Micro-Pinwheels Based on Rolling-Up Kirigami Technology. SMALL METHODS 2023:e2201627. [PMID: 37075739 DOI: 10.1002/smtd.202201627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/23/2023] [Indexed: 05/03/2023]
Abstract
Expanding micro-/nanostructures into 3D ones results not only in boosting structural integration level with compact geometry but also enhancing a device's complexity and functionality. Herein, a synergetic 3D micro-/nanoshape transformation is proposed by combining kirigami and rolling-up techniques, or rolling-up kirigami, for the first time. As an example, micro-pinwheels with multiple flabella are patterned on pre-stressed bilayer membranes and rolled up into 3D structures. The flabella are designed when they are patterned on a 2D thin film, facilitating the integration of micro-/nanoelement and other functionalization processes during 2D patterning, which is typically much easier than post-shaping an as-fabricated 3D structure by removing redundant materials or 3D printing. The dynamic rolling-up process is simulated using elastic mechanics with a movable releasing boundary. Mutual competition and cooperation among flabella are observed during the whole release process. More importantly, the mutual conversion between translation and rotation offers a reliable platform for developing parallel microrobots and adaptive 3D micro-antennas. Additionally, 3D chiral micro-pinwheel arrays integrated into a microfluidic chip are successfully applied to detect organic molecules in solution using a terahertz apparatus. With an extra actuation, active micro-pinwheels can potentially serve as a base to functionalize 3D kirigami as tunable devices.
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Affiliation(s)
- Kun Wang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Chaojian Hou
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Longqing Cong
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Wenqi Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Lu Fan
- Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Department of Ocean Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong, 518055, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, 511458, China
| | - Xiaokai Wang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, 999077, China
| | - Lixin Dong
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, 999077, China
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25
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Feng Y, Wei J, Qin L, Yu Y. Three-dimensional liquid crystal polymer actuators assembled by athermal photo-welding. SOFT MATTER 2023; 19:999-1007. [PMID: 36645083 DOI: 10.1039/d2sm01476a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Photodeformable liquid crystal polymers (LCPs) exhibit shape changes of different modes like bending, twisting, and oscillation, which depend on the orientation of liquid crystals. However, it is challenging to create a three-dimensional (3D) actuator with distinct actuation modes due to the difficulty of local orientation in a complex bulk architecture. Here we propose a strategy based on athermal photo-welding to integrate different orientations into a single flexible actuator by the photofluidization of azobenzene-containing linear LCPs. Stretch-induced uniaxial films are cut in different directions and subsequently welded via local photofluidization, during which the LCP transitions from a high-modulus glassy state to a rubbery state upon photoisomerization of azobenzene at room temperature. As a consequence, a cucumber vine-like structure with the opposite handedness and a lifting gripper are constructed by such a cut-and-weld process, demonstrating diverse deformation modes of winding, unwinding, and curling. This strategy provides an athermal process for the fabrication of seamless 3D flexible actuators without structural defects, which have potential applications in micromechanical systems, soft robotics, and artificial muscles.
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Affiliation(s)
- Yaoqing Feng
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China.
| | - Jia Wei
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China.
| | - Lang Qin
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China.
| | - Yanlei Yu
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China.
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu City, Zhejiang 322000, P. R. China
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26
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Chen J, Jiang J, Weber J, Gimenez-Pinto V, Peng C. Shape Morphing by Topological Patterns and Profiles in Laser-Cut Liquid Crystal Elastomer Kirigami. ACS APPLIED MATERIALS & INTERFACES 2023; 15:4538-4548. [PMID: 36637983 DOI: 10.1021/acsami.2c20295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Programming shape changes in soft materials requires precise control of the directionality and magnitude of their mechanical response. Among ordered soft materials, liquid crystal elastomers (LCEs) exhibit remarkable and programmable shape shifting when their molecular order changes. In this work, we synthesized, remotely programmed, and modeled reversible and complex morphing in monolithic LCE kirigami encoded with predesigned topological patterns in its microstructure. We obtained a rich variety of out-of-plane shape transformations, including auxetic structures and undulating morphologies, by combining different topological microstructures and kirigami geometries. The spatiotemporal shape-shifting behaviors are well recapitulated by elastodynamics simulations, revealing that the complex shape changes arise from integrating the custom-cut geometry with local director profiles defined by topological defects inscribed in the material. Different functionalities, such as a bioinspired fluttering butterfly, a flower bud, dual-rotation light mills, and dual-mode locomotion, are further realized. Our proposed LCE kirigami with topological patterns opens opportunities for the future development of multifunctional devices for soft robotics, flexible electronics, and biomedicine.
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Affiliation(s)
- Juan Chen
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jinghua Jiang
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jada Weber
- Department of Physics and Materials Science, The University of Memphis, Memphis, Tennessee 38152, United States
| | - Vianney Gimenez-Pinto
- Physics and Chemistry, Department of Science, Technology and Mathematics, Lincoln University of Missouri, Jefferson City, Missouri 65101, United States
| | - Chenhui Peng
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Physics and Materials Science, The University of Memphis, Memphis, Tennessee 38152, United States
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27
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Liu J, Zhao J, Wu H, Dai Y, Li K. Self-Oscillating Curling of a Liquid Crystal Elastomer Beam under Steady Light. Polymers (Basel) 2023; 15:polym15020344. [PMID: 36679225 PMCID: PMC9863816 DOI: 10.3390/polym15020344] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 01/12/2023] Open
Abstract
Self-oscillation absorbs energy from a steady environment to maintain its own continuous motion, eliminating the need to carry a power supply and controller, which will make the system more lightweight and promising for applications in energy harvesting, soft robotics, and microdevices. In this paper, we present a self-oscillating curling liquid crystal elastomer (LCE) beam-mass system, which is placed on a table and can self-oscillate under steady light. Unlike other self-sustaining systems, the contact surface of the LCE beam with the tabletop exhibits a continuous change in size during self-sustaining curling, resulting in a dynamic boundary problem. Based on the dynamic LCE model, we establish a nonlinear dynamic model of the self-oscillating curling LCE beam considering the dynamic boundary conditions, and numerically calculate its dynamic behavior using the Runge-Kutta method. The existence of two motion patterns in the LCE beam-mass system under steady light are proven by numerical calculation, namely self-curling pattern and stationary pattern. When the energy input to the system exceeds the energy dissipated by air damping, the LCE beam undergoes self-oscillating curling. Furthermore, we investigate the effects of different dimensionless parameters on the critical conditions, the amplitude and the period of the self-curling of LCE beam. Results demonstrate that the light source height, curvature coefficient, light intensity, elastic modulus, damping factor, and gravitational acceleration can modulate the self-curling amplitude and period. The self-curling LCE beam system proposed in this study can be applied to autonomous robots, energy harvesters, and micro-instruments.
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Affiliation(s)
- Junxiu Liu
- Anhui Province Key Laboratory of Building Structure and Underground Engineering, Anhui Jianzhu University, Hefei 230601, China
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Junjie Zhao
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Haiyang Wu
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Yuntong Dai
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Kai Li
- Anhui Province Key Laboratory of Building Structure and Underground Engineering, Anhui Jianzhu University, Hefei 230601, China
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
- Correspondence:
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28
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Ge D, Dai Y, Li K. Self-Sustained Euler Buckling of an Optically Responsive Rod with Different Boundary Constraints. Polymers (Basel) 2023; 15:polym15020316. [PMID: 36679197 PMCID: PMC9862129 DOI: 10.3390/polym15020316] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Self-sustained oscillations can directly absorb energy from the constant environment to maintain its periodic motion by self-regulating. As a classical mechanical instability phenomenon, the Euler compression rod can rapidly release elastic strain energy and undergo large displacement during buckling. In addition, its boundary configuration is usually easy to be modulated. In this paper, we develop a self-sustained Euler buckling system based on optically responsive liquid crystal elastomer (LCE) rod with different boundary constraints. The buckling of LCE rod results from the light-induced expansion and compressive force, and the self-buckling is maintained by the energy competition between the damping dissipation and the net work done by the effective elastic force. Based on the dynamic LCE model, the governing equations for dynamic Euler buckling of the LCE rod is formulated, and the approximate admissible trigonometric functions and Runge-Kutta method are used to solve the dynamic Euler buckling. Under different illumination parameters, there exists two motion modes of the Euler rod: the static mode and the self-buckling mode, including alternating and unilateral self-buckling modes. The triggering conditions, frequency, and amplitude of the self-sustained Euler buckling can be modulated by several system parameters and boundary constraints. Results indicate that strengthening the boundary constraint can increase the frequency and reduce the amplitude. It is anticipated that this system may open new avenues for energy harvesters, signal sensors, mechano-logistic devices, and autonomous robots.
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Affiliation(s)
- Dali Ge
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
- Institute of Advanced Technology, University of Science and Technology of China, Hefei 230001, China
| | - Yuntong Dai
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Kai Li
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
- Correspondence:
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29
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Zhang S, Ke X, Jiang Q, Chai Z, Wu Z, Ding H. Fabrication and Functionality Integration Technologies for Small-Scale Soft Robots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2200671. [PMID: 35732070 DOI: 10.1002/adma.202200671] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 06/12/2022] [Indexed: 06/15/2023]
Abstract
Small-scale soft robots are attracting increasing interest for visible and potential applications owing to their safety and tolerance resulting from their intrinsic soft bodies or compliant structures. However, it is not sufficient that the soft bodies merely provide support or system protection. More importantly, to meet the increasing demands of controllable operation and real-time feedback in unstructured/complicated scenarios, these robots are required to perform simplex and multimodal functionalities for sensing, communicating, and interacting with external environments during large or dynamic deformation with the risk of mismatch or delamination. Challenges are encountered during fabrication and integration, including the selection and fabrication of composite/materials and structures, integration of active/passive functional modules with robust interfaces, particularly with highly deformable soft/stretchable bodies. Here, methods and strategies of fabricating structural soft bodies and integrating them with functional modules for developing small-scale soft robots are investigated. Utilizing templating, 3D printing, transfer printing, and swelling, small-scale soft robots can be endowed with several perceptual capabilities corresponding to diverse stimulus, such as light, heat, magnetism, and force. The integration of sensing and functionalities effectively enhances the agility, adaptability, and universality of soft robots when applied in various fields, including smart manufacturing, medical surgery, biomimetics, and other interdisciplinary sciences.
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Affiliation(s)
- Shuo Zhang
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Xingxing Ke
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Qin Jiang
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Zhiping Chai
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Zhigang Wu
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Han Ding
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
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30
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Gao J, He Y, Cong X, Yi H, Guo J. Reconfigurable Fluorescent Liquid Crystal Elastomers for Integrated Visual and Haptic Information Storage. ACS APPLIED MATERIALS & INTERFACES 2022; 14:53348-53358. [PMID: 36395006 DOI: 10.1021/acsami.2c17494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The rapid advancements in information technology require new information storage and display materials. However, the development of on-demand information storage systems with multiple modes remains a significant challenge. As a pioneering approach, this study designed an integrated visual and haptic information storage and display using a reconfigurable fluorescent liquid crystal elastomer (FLCE) with dynamic covalent bonds. The FLCEs were fabricated in two steps of amine-acrylate aza-Michael addition and photopolymerization, and they simultaneously exhibited phototunable fluorescence caused by the reversible Z/E photoisomerization of the chromophores and a reprogrammable shape owing to the catalyst-free transesterification. In addition, we established various information storage and display modes featuring the characteristics of reversibly photoswitchable fluorescence, shape memory, and thermally reconfigurable shape with a reconfigurable FLCE system. Moreover, a strategy to display the information by incorporating both visual and haptic feedback is implemented for fulfilling the needs of the visually impaired and related users. Such reconfigurable FLCE systems will aid in the development of on-demand information storage, display, and protection devices.
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Affiliation(s)
- Jingjing Gao
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing100029, China
| | - Yanrong He
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing100029, China
| | - Xiaoyang Cong
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing100029, China
| | - Huijie Yi
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing100029, China
| | - Jinbao Guo
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing100029, China
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31
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Zhu F, Du C, Dai Y, Li K. Thermally Driven Continuous Rolling of a Thick-Walled Cylindrical Rod. MICROMACHINES 2022; 13:2035. [PMID: 36422464 PMCID: PMC9698442 DOI: 10.3390/mi13112035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/12/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Self-sustained motion can take advantage of direct energy extraction from a steady external environment to maintain its own motion, and has potential applications in energy harvesting, robotic motion, and transportation. Recent experiments have found that a thermally responsive rod can perform self-sustained rolling on a flat hot plate with an angular velocity determined by the competition between the thermal driving moment and the friction moment. A rod with a hollow cross section tends to greatly reduce the frictional resistance, while promising improvements in thermal conversion efficiency. In this paper, through deriving the equilibrium equations for steady-state self-sustained rolling of the thick-walled cylindrical rod, estimating the temperature field on the rod cross-section, and solving the analytical solution of the thermally induced driving moment, the dynamic behavior of the thermally driven self-sustained rolling of the thick-walled cylindrical rod is theoretically investigated. In addition, we investigate in detail the effects of radius ratio, heat transfer coefficient, heat flux, contact angle, thermal expansion coefficient, and sliding friction coefficient on the angular velocity of the self-sustained rolling of the thick-walled cylindrical rod to obtain the optimal ratio of internal and external radius. The results are instructive for the application of thick-walled cylindrical rods in the fields of waste heat harvesters and soft robotics.
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32
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Engineering Auxetic Cylinders and Intestine to Improve Longitudinal Intestinal Lengthening and Tailoring Procedure. Bioengineering (Basel) 2022; 9:bioengineering9110658. [DOI: 10.3390/bioengineering9110658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/24/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
Auxetic materials can be exploited for coupling different types of tissues. Herein, we designed a material where the microorganism metabolic activity yields the formation of buckled/collapsed bubbles within gelling silicone cylinders thus providing auxetic properties. The finite element model of such hollow auxetic cylinders demonstrated the tubular structure to promote worm-like peristalsis. In this scenario, the described hybrid auxetic structures may be applied to the longitudinal intestinal lengthening and tailoring procedure to promote enteral autonomy in short bowel syndrome. The presented material and analytical design synergistic approach offer a pioneering step for the clinical translation of hybrid auxetic materials.
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33
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Zhang J, Soon RH, Wei Z, Hu W, Sitti M. Liquid Metal-Elastomer Composites with Dual-Energy Transmission Mode for Multifunctional Miniature Untethered Magnetic Robots. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203730. [PMID: 36065052 PMCID: PMC9631051 DOI: 10.1002/advs.202203730] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Miniature untethered robots attract growing interest as they have become more functional and applicable to disruptive biomedical applications recently. Particularly, the soft ones among them exhibit unique merits of compliance, versatility, and agility. With scarce onboard space, these devices mostly harvest energy from environment or physical fields, such as magnetic and acoustic fields and patterned lights. In most cases, one device only utilizes one energy transmission mode (ETM) in powering its activities to achieve programmed tasks, such as locomotion and object manipulation. But real-world tasks demand multifunctional devices that require more energy in various forms. This work reports a liquid metal-elastomer composite with dual-ETM using one magnetic field for miniature untethered multifunctional robots. The first ETM uses the low-frequency (<100 Hz) field component to induce shape-morphing, while the second ETM employs energy transmitted via radio-frequency (20 kHz-300 GHz) induction to power onboard electronics and generate excess heat, enabling new capabilities. These new functions do not disturb the shape-morphing actuated using the first ETM. The reported material enables the integration of electric and thermal functionalities into soft miniature robots, offering a wealth of inspirations for multifunctional miniature robots that leverage developments in electronics to exhibit usefulness beyond self-locomotion.
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Affiliation(s)
- Jiachen Zhang
- Physical Intelligence DepartmentMax Planck Institute for Intelligent Systems70569StuttgartGermany
- Department of Biomedical EngineeringCity University of Hong KongHong Kong SARChina
| | - Ren Hao Soon
- Physical Intelligence DepartmentMax Planck Institute for Intelligent Systems70569StuttgartGermany
| | - Zihan Wei
- Department of Biomedical EngineeringCity University of Hong KongHong Kong SARChina
| | - Wenqi Hu
- Physical Intelligence DepartmentMax Planck Institute for Intelligent Systems70569StuttgartGermany
| | - Metin Sitti
- Physical Intelligence DepartmentMax Planck Institute for Intelligent Systems70569StuttgartGermany
- Institute for Biomedical EngineeringETH ZürichZürich8092Switzerland
- School of Medicine and College of EngineeringKoç UniversityIstanbul34450Turkey
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34
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Wireless Autonomous Soft Crawlers for Adjustable Climbing Actuation. CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2858-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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35
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Li Y, Wu J, Yang P, Song L, Wang J, Xing Z, Zhao J. Multi-Degree-of-Freedom Robots Powered and Controlled by Microwaves. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203305. [PMID: 35986431 PMCID: PMC9561789 DOI: 10.1002/advs.202203305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Microwaves have become a promising wireless driving strategy due to the advantages of transmissivity through obstacles, fast energy targeting, and selective heating. Although there are some studies on microwave powered artificial muscles based on different structures, the lack of studies on microwave control has limited the development of microwave-driven (MWD) robots. Here, a far-field MWD parallel robot controlled by adjusting energy distribution via changing the polarization direction of microwaves at 2.47 GHz is first reported. The parallel robot is based on three double-layer bending actuators composed of wave-absorbing sheets and bimetallic sheets, and it can implement circular and triangular path at a distance of 0.4 m under 700 W transmitting power. The thermal response rate of the actuator under microwaves is studied, and it is found that the electric-field components can provide a faster thermal response at the optimal length of actuator than magnetic-field components. The work of the parallel robot is demonstrated in an enclosed space composed of microwave-transparent materials. This developed method demonstrates the multi-degree-of-freedom controllability for robots using microwaves and offers potential solutions for some engineering cases, such as pipeline/reactors inspection and medical applications.
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Affiliation(s)
- Yongze Li
- Department of Mechanical EngineeringHarbin Institute of TechnologyWeihai264209China
| | - Jianyu Wu
- Department of Mechanical EngineeringHarbin Institute of TechnologyWeihai264209China
| | - Peizhuo Yang
- School of Information Science and EngineeringHarbin Institute of TechnologyWeihai264209China
| | - Lizhong Song
- School of Information Science and EngineeringHarbin Institute of TechnologyWeihai264209China
| | - Jun Wang
- School of Information Science and EngineeringHarbin Institute of TechnologyWeihai264209China
| | - Zhiguang Xing
- Department of Mechanical EngineeringHarbin Institute of TechnologyWeihai264209China
| | - Jianwen Zhao
- Department of Mechanical EngineeringHarbin Institute of TechnologyWeihai264209China
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36
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Ni X, Luan H, Kim JT, Rogge SI, Bai Y, Kwak JW, Liu S, Yang DS, Li S, Li S, Li Z, Zhang Y, Wu C, Ni X, Huang Y, Wang H, Rogers JA. Soft shape-programmable surfaces by fast electromagnetic actuation of liquid metal networks. Nat Commun 2022; 13:5576. [PMID: 36151092 PMCID: PMC9508113 DOI: 10.1038/s41467-022-31092-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 06/01/2022] [Indexed: 11/15/2022] Open
Abstract
Low modulus materials that can shape-morph into different three-dimensional (3D) configurations in response to external stimuli have wide-ranging applications in flexible/stretchable electronics, surgical instruments, soft machines and soft robotics. This paper reports a shape-programmable system that exploits liquid metal microfluidic networks embedded in an elastomer matrix, with electromagnetic forms of actuation, to achieve a unique set of properties. Specifically, this materials structure is capable of fast, continuous morphing into a diverse set of continuous, complex 3D surfaces starting from a two-dimensional (2D) planar configuration, with fully reversible operation. Computational, multi-physics modeling methods and advanced 3D imaging techniques enable rapid, real-time transformations between target shapes. The liquid-solid phase transition of the liquid metal allows for shape fixation and reprogramming on demand. An unusual vibration insensitive, dynamic 3D display screen serves as an application example of this type of morphable surface. Low modulus materials that can change shape in response to external stimuli are promising for a wide range of applications. The authors here introduce a shape-reprogrammable construct, based on liquid metal microfluidic networks and electromagnetic actuation, that supports a unique collection of capabilities.
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Affiliation(s)
- Xinchen Ni
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Haiwen Luan
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Jin-Tae Kim
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Sam I Rogge
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Yun Bai
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA.,Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA.,Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA
| | - Jean Won Kwak
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA.,Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA
| | - Shangliangzi Liu
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Da Som Yang
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Shuo Li
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Shupeng Li
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA
| | - Zhengwei Li
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Yamin Zhang
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Changsheng Wu
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Xiaoyue Ni
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA. .,Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA. .,Department of Biostatistics and Bioinformatics, Duke University, Durham, NC, USA.
| | - Yonggang Huang
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA. .,Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA. .,Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA. .,Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA.
| | - Heling Wang
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA. .,Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA. .,Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA.
| | - John A Rogers
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA. .,Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA. .,Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA. .,Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA. .,Department of Neurological Surgery, Northwestern University, Evanston, IL, USA. .,Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, USA. .,Department of Chemistry, Northwestern University, Evanston, IL, USA.
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37
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Zhou L, Yu W, Li K. Dynamical Behaviors of a Translating Liquid Crystal Elastomer Fiber in a Linear Temperature Field. Polymers (Basel) 2022; 14:polym14153185. [PMID: 35956704 PMCID: PMC9371172 DOI: 10.3390/polym14153185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 02/04/2023] Open
Abstract
Liquid crystal elastomer (LCE) fiber with a fixed end in an inhomogeneous temperature field is capable of self-oscillating because of coupling between heat transfer and deformation, and the dynamics of a translating LCE fiber in an inhomogeneous temperature field are worth investigating to widen its applications. In this paper, we propose a theoretic constitutive model and the asymptotic relationship of a LCE fiber translating in a linear temperature field and investigate the dynamical behaviors of a corresponding fiber-mass system. In the three cases of the frame at rest, uniform, and accelerating translation, the fiber-mass system can still self-oscillate, which is determined by the combination of the heat-transfer characteristic time, the temperature gradient, and the thermal expansion coefficient. The self-oscillation is maintained by the energy input from the ambient linear temperature field to compensate for damping dissipation. Meanwhile, the amplitude and frequency of the self-oscillation are not affected by the translating frame for the three cases. Compared with the cases of the frame at rest, the translating frame can change the equilibrium position of the self-oscillation. The results are expected to provide some useful recommendations for the design and motion control in the fields of micro-robots, energy harvesters, and clinical surgical scenarios.
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Affiliation(s)
- Lin Zhou
- School of Mechanical and Electrical Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Wangyang Yu
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Kai Li
- School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
- Correspondence:
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38
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Xu WC, Liu C, Liang S, Zhang D, Liu Y, Wu S. Designing Rewritable Dual-Mode Patterns using a Stretchable Photoresponsive Polymer via Orthogonal Photopatterning. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202150. [PMID: 35642603 DOI: 10.1002/adma.202202150] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/04/2022] [Indexed: 06/15/2023]
Abstract
The fabrication of dual-mode patterns in the same region of a material is a promising approach for high-density information storage, new anti-counterfeiting technologies, and highly secure encryption. However, dual-mode patterns are difficult to achieve because the two patterns in one material may interfere with each other during fabrication and usage. The development of noninterfering dual-mode patterns requires new materials and patterning techniques. Herein, a novel orthogonal photopatterning technique is reported for the fabrication of noninterfering dual-mode patterns on an azopolymer P1. P1 is a unique material that exhibits both photoinduced reversible solid-to-liquid transitions and good stretchability. In the first step of orthogonal photopatterning, patterned photonic structures are fabricated on a P1 film via masked nanoimprinting controlled by photoinduced reversible solid-to-liquid transitions. In the second step, the P1 film is stretched and irradiated with polarized light through a photomask, which generates a chromatic polarization pattern. In particular, the photonic structures and chromatic polarization in the dual-mode pattern are noninterfering. Another feature of dual-mode patterns is that they are rewritable via photo-, thermal, or solution reprocessing, which are useful for recycling and reprogramming. This study opens an avenue for the development of novel materials and techniques for photopatterning.
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Affiliation(s)
- Wen-Cong Xu
- CAS Key Laboratory of Soft Matter Chemistry, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Chengwei Liu
- CAS Key Laboratory of Soft Matter Chemistry, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Shuofeng Liang
- CAS Key Laboratory of Soft Matter Chemistry, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Dachuan Zhang
- CAS Key Laboratory of Soft Matter Chemistry, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Yazhi Liu
- CAS Key Laboratory of Soft Matter Chemistry, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Si Wu
- CAS Key Laboratory of Soft Matter Chemistry, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
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39
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Synchronization of a Passive Oscillator and a Liquid Crystal Elastomer Self-Oscillator Powered by Steady Illumination. Polymers (Basel) 2022; 14:polym14153058. [PMID: 35956572 PMCID: PMC9370277 DOI: 10.3390/polym14153058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 02/05/2023] Open
Abstract
Self-oscillators have the advantages of actively harvesting energy from external steady environment, autonomy, and portability, and can be adopted as an engine to drive additional working equipment. The synchronous behavior of self-oscillators and passive oscillators may have an important impact on their functions. In this paper, we construct a self-oscillating system composed of a passive oscillator and an active liquid crystal elastomer self-oscillator powered by steady illumination, and theoretically investigate the synchronization of two coupled oscillators. There exist three synchronous regimes of the two coupled oscillators: static, in-phase, and anti-phase. The mechanisms of self-oscillations in in-phase and anti-phase synchronous regimes are elucidated in detail by calculating several key physical parameters. In addition, the effects of spring constant, initial velocity, contraction coefficient, light intensity, and damping coefficient on the self-oscillations of two coupled oscillators are further investigated, and the critical conditions for triggering self-oscillations are obtained. Numerical calculations show that the synchronous regime of self-oscillations is mainly determined by the spring constant, and the amplitudes of self-oscillations of two oscillators increase with increasing contraction coefficient, light intensity, and spring constant, while decrease with increasing damping coefficient. This study deepens the understanding of synchronization between coupled oscillators and may provide new design ideas for energy harvesters, soft robotics, signal detection, active motors, and self-sustained machinery.
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40
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Photothermal-Driven Liquid Crystal Elastomers: Materials, Alignment and Applications. Molecules 2022; 27:molecules27144330. [PMID: 35889204 PMCID: PMC9317631 DOI: 10.3390/molecules27144330] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/02/2022] [Accepted: 07/04/2022] [Indexed: 02/01/2023] Open
Abstract
Liquid crystal elastomers (LCEs) are programmable deformable materials that can respond to physical fields such as light, heat, and electricity. Photothermal-driven LCE has the advantages of accuracy and remote control and avoids the requirement of high photon energy for photochemistry. In this review, we discuss recent advances in photothermal LCE materials and investigate methods for mechanical alignment, external field alignment, and surface-induced alignment. Advances in the synthesis and orientation of LCEs have enabled liquid crystal elastomers to meet applications in optics, robotics, and more. The review concludes with a discussion of current challenges and research opportunities.
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41
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Self-Jumping of a Liquid Crystal Elastomer Balloon under Steady Illumination. Polymers (Basel) 2022; 14:polym14142770. [PMID: 35890544 PMCID: PMC9319439 DOI: 10.3390/polym14142770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 11/17/2022] Open
Abstract
Self-oscillation capable of maintaining periodic motion upon constant stimulus has potential applications in the fields of autonomous robotics, energy-generation devices, mechano-logistic devices, sensors, and so on. Inspired by the active jumping of kangaroos and frogs in nature, we proposed a self-jumping liquid crystal elastomer (LCE) balloon under steady illumination. Based on the balloon contact model and dynamic LCE model, a nonlinear dynamic model of a self-jumping LCE balloon under steady illumination was formulated and numerically calculated by the Runge–Kutta method. The results indicated that there exist two typical motion regimes for LCE balloon under steady illumination: the static regime and the self-jumping regime. The self-jumping of LCE balloon originates from its expansion during contact with a rigid surface, and the self-jumping can be maintained by absorbing light energy to compensate for the damping dissipation. In addition, the critical conditions for triggering self-jumping and the effects of several key system parameters on its frequency and amplitude were investigated in detail. The self-jumping LCE hollow balloon with larger internal space has greater potential to carry goods or equipment, and may open a new insight into the development of mobile robotics, soft robotics, sensors, controlled drug delivery, and other miniature device applications.
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42
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Guan Z, Wang L, Bae J. Advances in 4D printing of liquid crystalline elastomers: materials, techniques, and applications. MATERIALS HORIZONS 2022; 9:1825-1849. [PMID: 35504034 DOI: 10.1039/d2mh00232a] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline elastomers (LCEs) are polymer networks exhibiting anisotropic liquid crystallinity while maintaining elastomeric properties. Owing to diverse polymeric forms and self-alignment molecular behaviors, LCEs have fascinated state-of-the-art efforts in various disciplines other than the traditional low-molar-mass display market. By patterning order to structures, LCEs demonstrate reversible high-speed and large-scale actuations in response to external stimuli, allowing for close integration with 4D printing and architectures of digital devices, which is scarcely observed in homogeneous soft polymer networks. In this review, we collect recent advances in 4D printing of LCEs, with emphases on synthesis and processing methods that enable microscopic changes in the molecular orientation and hence macroscopic changes in the properties of end-use objects. Promising potentials of printed complexes include fields of soft robotics, optics, and biomedical devices. Within this scope, we elucidate the relationships among external stimuli, tailorable morphologies in mesophases of liquid crystals, and programmable topological configurations of printed parts. Lastly, perspectives and potential challenges facing 4D printing of LCEs are discussed.
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Affiliation(s)
- Zhecun Guan
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
| | - Ling Wang
- School of Materials Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
| | - Jinhye Bae
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
- Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
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43
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Chen Y, Kuenstler AS, Hayward RC, Jin L. Formation of rolls from liquid crystal elastomer bistrips. SOFT MATTER 2022; 18:4077-4089. [PMID: 35603603 DOI: 10.1039/d1sm01830b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Formation of desired three-dimensional (3D) shapes from flat thin sheets with programmed non-uniform deformation profiles is an effective strategy to create functional 3D structures. Liquid crystal elastomers (LCEs) are of particular use in programmable shape morphing due to their ability to undergo large, reversible, and anisotropic deformation in response to a stimulus. Here we consider a rectangular monodomain LCE thin sheet divided into one high- and one low-temperature strip, which we dub a 'bistrip'. Upon activation, a discontinuously patterned, anisotropic in-plane stretch profile is generated, and induces buckling of the bistrip into a rolled shape with a transitional bottle neck. Based on the non-Euclidean plate theory, we derive an analytical model to quantitatively capture the formation of the rolled shapes from a flat bistrip with finite thickness by minimizing the total elastic energy involving both stretching and bending energies. Using this analytical model, we identify the critical thickness at which the transition from the unbuckled to buckled configuration occurs. We further study the influence of the anisotropy of the stretch profile on the rolled shapes by first converting prescribed metric tensors with different anisotropy to a unified metric tensor embedded in a bistrip of modified geometry, and then investigating the effect of each parameter in this unified metric tensor on the rolled shapes. Our analysis sheds light on designing shape morphing of LCE thin sheets, and provides quantitative predictions on the 3D shapes that programmed LCE sheets can form upon activation for various applications.
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Affiliation(s)
- Yuzhen Chen
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095, USA.
| | - Alexa S Kuenstler
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO 80309, USA.
| | - Ryan C Hayward
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO 80309, USA.
| | - Lihua Jin
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095, USA.
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44
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Brooks AK, Chakravarty S, Ali M, Yadavalli VK. Kirigami-Inspired Biodesign for Applications in Healthcare. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2109550. [PMID: 35073433 DOI: 10.1002/adma.202109550] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Mechanically flexible and conformable materials and integrated devices have found diverse applications in personalized healthcare as diagnostics and therapeutics, tissue engineering and regenerative medicine constructs, surgical tools, secure systems, and assistive technologies. In order to impart optimal mechanical properties to the (bio)materials used in these applications, various strategies have been explored-from composites to structural engineering. In recent years, geometric cuts inspired by the art of paper-cutting, referred to as kirigami, have provided innovative opportunities for conferring precise mechanical properties via material removal. Kirigami-based approaches have been used for device design in areas ranging from soft bioelectronics to energy storage. In this review, the principles of kirigami-inspired engineering specifically for biomedical applications are discussed. Factors pertinent to their design, including cut geometry, materials, and fabrication, and the effect these parameters have on their properties and configurations are covered. Examples of kirigami designs in healthcare are presented, such as, various form factors of sensors (on skin, wearable), implantable devices, therapeutics, surgical procedures, and cellular scaffolds for regenerative medicine. Finally, the challenges and future scope for the successful translation of these biodesign concepts to broader deployment are discussed.
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Affiliation(s)
- Anne Katherine Brooks
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Sudesna Chakravarty
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Maryam Ali
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Vamsi K Yadavalli
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23284, USA
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45
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Yu Z, Wang Y, Zheng J, Sun S, Fu Y, Chen D, Cai W, Wang D, Zhou H, Li D. Fast-Response Bioinspired Near-Infrared Light-Driven Soft Robot Based on Two-Stage Deformation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:16649-16657. [PMID: 35360897 DOI: 10.1021/acsami.2c01109] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Herein, we report a remotely controlled soft robot employing a photoresponsive nanocomposite synthesized from liquid crystal elastomers (LCEs), high elastic form-stable phase change polymer (HEPCP), and multiwalled carbon nanotubes (MWCNTs). Possessing a two-stage deformation upon exposure to near-infrared (NIR) light, the LCE/HEPCP/MWCNT (LHM) nanocomposite allows the soft robot to exhibit an obvious, fast, and reversible shape change with low detection limitations. In addition to the deformation and bending of the LCE molecular chains itself, the HEPCP in the composite material can also be triggered by a reversible solid-liquid transition due to the temperature rise caused by MWCNTs, which further promotes the change of the LCE. In particular, the proposed photodriven LHM soft robot can bend up to 180° in 2 s upon NIR stimulation (320 mW, distance of 5 cm) and generate recoverable, dramatic, and sensitive deformation to execute various tasks including walking, twisting, and bending. With the capacity of imitating biological behaviors through remote control, the disruptive innovation developed here offers a promising path toward miniaturized untethered robotic systems.
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Affiliation(s)
- Zhaohan Yu
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Yunming Wang
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Jiaqi Zheng
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Shuang Sun
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Yue Fu
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Dan Chen
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Weihao Cai
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Dong Wang
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Huamin Zhou
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
| | - Dequn Li
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China
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46
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A Light-Powered Liquid Crystal Elastomer Spring Oscillator with Self-Shading Coatings. Polymers (Basel) 2022; 14:polym14081525. [PMID: 35458275 PMCID: PMC9028186 DOI: 10.3390/polym14081525] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 02/04/2023] Open
Abstract
The self-oscillating systems based on stimuli-responsive materials, without complex controllers and additional batteries, have great application prospects in the fields of intelligent machines, soft robotics, and light-powered motors. Recently, the periodic oscillation of an LCE fiber with a mass block under periodic illumination was reported. This system requires periodic illumination, which limits the application of self-sustained systems. In this paper, we creatively proposed a light-powered liquid crystal elastomer (LCE) spring oscillator with self-shading coatings, which can self-oscillate continuously under steady illumination. On the basis of the well-established dynamic LCE model, the governing equation of the LCE spring oscillator is formulated, and the self-excited oscillation is studied theoretically. The numerical calculations show that the LCE spring oscillator has two motion modes, static mode and oscillation mode, and the self-oscillation arises from the coupling between the light-driven deformation and its movement. Furthermore, the contraction coefficient, damping coefficient, painting stretch, light intensity, spring constant, and gravitational acceleration all affect the self-excited oscillation of the spring oscillator, and each parameter is a critical value for triggering self-excited oscillation. This work will provide effective help in designing new optically responsive structures for engineering applications.
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47
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Li Y, Liu T, Ambrogi V, Rios O, Xia M, He W, Yang Z. Liquid Crystalline Elastomers Based on Click Chemistry. ACS APPLIED MATERIALS & INTERFACES 2022; 14:14842-14858. [PMID: 35319184 DOI: 10.1021/acsami.1c21096] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline elastomers (LCEs) have emerged as an important class of functional materials that are suitable for a wide range of applications, such as sensors, actuators, and soft robotics. The unique properties of LCEs originate from the combination between liquid crystal and elastomeric network. The control of macroscopic liquid crystalline orientation and network structure is crucial to realizing the useful functionalities of LCEs. A variety of chemistries have been developed to fabricate LCEs, including hydrosilylation, free radical polymerization of acrylate, and polyaddition of epoxy and carboxylic acid. Over the past few years, the use of click chemistry has become a more robust and energy-efficient way to construct LCEs with desired structures. This article provides an overview of emerging LCEs based on click chemistries, including aza-Michael addition between amine and acrylate, radical-mediated thiol-ene and thiol-yne reactions, base-catalyzed thiol-acrylate and thiol-epoxy reactions, copper-catalyzed azide-alkyne cycloaddition, and Diels-Alder cycloaddition. The similarities and differences of these reactions are discussed, with particular attention focused on the strengths and limitations of each reaction for the preparation of LCEs with controlled structures and orientations. The compatibility of these reactions with the traditional and emerging processing techniques, such as surface alignment and additive manufacturing, are surveyed. Finally, the challenges and opportunities of using click chemistry for the design of LCEs with advanced functionalities and applications are discussed.
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Affiliation(s)
- Yuzhan Li
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Tuan Liu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Veronica Ambrogi
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II, Napoli 80125, Italy
| | - Orlando Rios
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Min Xia
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Wanli He
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhou Yang
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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48
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Borchers TH, Topić F, Christopherson JC, Bushuyev OS, Vainauskas J, Titi HM, Friščić T, Barrett CJ. Cold photo-carving of halogen-bonded co-crystals of a dye and a volatile co-former using visible light. Nat Chem 2022; 14:574-581. [PMID: 35361911 DOI: 10.1038/s41557-022-00909-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 02/07/2022] [Indexed: 11/09/2022]
Abstract
The formation of co-crystals by the assembly of molecules with complementary molecular recognition functionalities is a popular strategy to design or improve a range of solid-state properties, including those relevant for pharmaceuticals, photo- or thermoresponsive materials and organic electronics. Here, we report halogen-bonded co-crystals of a fluorinated azobenzene derivative with a volatile component-either dioxane or pyrazine-that can be cut, carved or engraved with low-power visible light. This cold photo-carving process is enabled by the co-crystallization of a light-absorbing azo dye with a volatile component, which gives rise to materials that can be selectively disassembled with micrometre precision using low-power, non-burning laser irradiation or a commercial confocal microscope. The ability to shape co-crystals in three dimensions using laser powers of 0.5-20 mW-substantially lower than those used for metals, ceramics or polymers-is rationalized by photo-carving that targets the disruption of weak supramolecular interactions, rather than the covalent bonds or ionic structures targeted by conventional laser beam or focused ion beam machining processes.
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Affiliation(s)
- T H Borchers
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - F Topić
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | | | - O S Bushuyev
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - J Vainauskas
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - H M Titi
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - T Friščić
- Department of Chemistry, McGill University, Montreal, Quebec, Canada.
| | - C J Barrett
- Department of Chemistry, McGill University, Montreal, Quebec, Canada.
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49
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Programming Soft Shape-Morphing Systems by Harnessing Strain Mismatch and Snap-Through Bistability: A Review. MATERIALS 2022; 15:ma15072397. [PMID: 35407728 PMCID: PMC8999758 DOI: 10.3390/ma15072397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 02/04/2023]
Abstract
Multi-modal and controllable shape-morphing constitutes the cornerstone of the functionalization of soft actuators/robots. Involving heterogeneity through material layout is a widely used strategy to generate internal mismatches in active morphing structures. Once triggered by external stimuli, the entire structure undergoes cooperative deformation by minimizing the potential energy. However, the intrinsic limitation of soft materials emerges when it comes to applications such as soft actuators or load-bearing structures that require fast response and large output force. Many researchers have explored the use of the structural principle of snap-through bistability as the morphing mechanisms. Bistable or multi-stable mechanical systems possess more than one local energy minimum and are capable of resting in any of these equilibrium states without external forces. The snap-through motion could overcome energy barriers to switch among these stable or metastable states with dramatically distinct geometries. Attributed to the energy storage and release mechanism, such snap-through transition is quite highly efficient, accompanied by fast response speed, large displacement magnitude, high manipulation strength, and moderate driving force. For example, the shape-morphing timescale of conventional hydrogel systems is usually tens of minutes, while the activation time of hydrogel actuators using the elastic snapping instability strategy can be reduced to below 1 s. By rationally embedding stimuli-responsive inclusions to offer the required trigger energy, various controllable snap-through actuations could be achieved. This review summarizes the current shape-morphing programming strategies based on mismatch strain induced by material heterogeneity, with emphasis on how to leverage snap-through bistability to broaden the applications of the shape-morphing structures in soft robotics and mechanical metamaterials.
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50
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Zhou GX, Yu YG, Yang ZH, Jia DC, Poulin P, Zhou Y, Zhong J. 3D Printing Graphene Oxide Soft Robotics. ACS NANO 2022; 16:3664-3673. [PMID: 35166113 DOI: 10.1021/acsnano.1c06823] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We propose a universal strategy to 3D printing the graphene oxide (GO) complex structure with GO highly aligned and densely compacted, by the combination of direct ink writing and constrained drying. The constraints not only allow the generation of a huge capillary force accompanied by water evaporation at nanoscale, which induces the high compaction and alignment of GO, but also limit the shrinkage of the extruded filaments only along the wall thickness direction, therefore, successfully maintaining the uniformity of the structure at macroscale. We discover that the shrinkage stress gradually increased during the drying process, with the maximum exceeding ∼0.74 MPa, significantly higher than other colloidal systems. Interestingly, because of the convergence between plates with different orientations of the constraints, a gradient of porosity naturally formed across the thickness direction at the corner. This allows us to 3D print humidity sensitive GO based soft robotics.
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Affiliation(s)
- Guo-Xiang Zhou
- Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, Harbin Institute of Technology, Harbin 150001, China
- Institute for Advanced Ceramics, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
- State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150080, China
| | - Yan-Ge Yu
- Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Zhi-Hua Yang
- Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, Harbin Institute of Technology, Harbin 150001, China
- Institute for Advanced Ceramics, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
- State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150080, China
| | - De-Chang Jia
- Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, Harbin Institute of Technology, Harbin 150001, China
- Institute for Advanced Ceramics, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
- State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150080, China
| | - Philippe Poulin
- Centre de Recherche Paul Pascal - CNRS, Pessac 33600, France
| | - Yu Zhou
- Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, Harbin Institute of Technology, Harbin 150001, China
- Institute for Advanced Ceramics, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
- State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150080, China
| | - Jing Zhong
- Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, Harbin Institute of Technology, Harbin 150001, China
- Key Lab of Structure Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, Harbin 150090, Peoples' Republic of China
- School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, Peoples' Republic of China
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