1
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Guillen Campos J, Tobin C, Sandlass S, Park M, Wu Y, Gordon M, Read de Alaniz J. Photoactivation of Millimeters Thick Liquid Crystal Elastomers with Broadband Visible Light Using Donor-Acceptor Stenhouse Adducts. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2404932. [PMID: 38899577 DOI: 10.1002/adma.202404932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/05/2024] [Indexed: 06/21/2024]
Abstract
Light-responsive liquid crystal elastomers (LCEs) are stimuli-responsive materials that facilitate the conversion of light energy into a mechanical response. In this work, a novel polysiloxane-based LCE with donor-acceptor Stenhouse adduct (DASA) side-chains is synthesized using a late-stage functionalization strategy. It is demonstrated that this approach does not compromise the molecular alignment observed in the traditional Finkelmann method. This easy, single-batch process provides a robust platform to access well-aligned, light-responsive LCE films with thickness ranging from 400 µm to a 14-layer stack that is 5 mm thick. Upon irradiation with low-intensity broadband visible light (100-200 mW cm-2), these systems undergo 2D planar actuation and complete bleaching. Conversely, exposure to higher-intensity visible light induces bending followed by contraction (300 mW cm-2). These processes are repeatable over several cycles. Finally, it is demonstrated how light intensity and the resulting heat generation influences the photothermal stationary state equilibrium of DASA, thereby controlling its photoresponsive properties. This work establishes the groundwork for advancement of LCE-based actuators beyond thin film and UV-light reliant systems.
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Affiliation(s)
- Jesus Guillen Campos
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Cassidy Tobin
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Sara Sandlass
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Minwook Park
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Yuhang Wu
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Michael Gordon
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Javier Read de Alaniz
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
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2
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Zhang X, Wei J, Qin L, Yu Y. Liquid crystal polymer actuators with complex and multiple actuations. J Mater Chem B 2024; 12:6757-6773. [PMID: 38916076 DOI: 10.1039/d4tb01055h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Deformable liquid crystal polymers (LCPs), which exhibit both entropic elasticity of polymer networks and anisotropic properties originating from ordered mesogens, have gained more and more interest for use as biomedical soft actuators. Especially, LCP actuators with controllable mesogen alignment, sophisticated geometry and reprogrammability are a rising star on the horizon of soft actuators, since they enable complex and multiple actuations. This review focuses on two topics: (1) the regulation of mesogen alignment and geometry of LCP actuators for complex actuations; (2) newly designed reprogrammable LCP materials for multiple actuations. First, basic actuation mechanisms are briefly introduced. Then, LCP actuators with complex actuations are demonstrated. Special attention is devoted to the improvement of fabrication methods, which profoundly influence the available complexity of the mesogen alignment and geometry. Subsequently, reprogrammable LCP actuators featuring dynamic networks or shape memory effects are discussed, with an emphasis on their multiple actuations. Finally, perspectives on the current challenges and potential development trends toward more intelligent LCP actuators are discussed, which may shed light on future investigations in this field.
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Affiliation(s)
- Xiaoyu Zhang
- Department of Materials Science & State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China.
| | - Jia Wei
- Department of Materials Science & State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China.
| | - Lang Qin
- Department of Materials Science & State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China.
| | - Yanlei Yu
- Department of Materials Science & State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China.
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3
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You Y, Golestani YM, Broer DJ, Yang T, Zhou G, Selinger RLB, Yuan D, Liu D. Transforming patterned defects into dynamic poly-regional topographies in liquid crystal oligomers. MATERIALS HORIZONS 2024; 11:3178-3186. [PMID: 38666445 PMCID: PMC11216033 DOI: 10.1039/d4mh00131a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 04/18/2024] [Indexed: 07/02/2024]
Abstract
We create high-aspect-ratio dynamic poly-regional surface topographies in a coating of a main-chain liquid crystal oligomer network (LCON). The topographies form at the topological defects in the director pattern organized in an array which are controlled by photopatterning of the alignment layer. The defect regions are activated by heat and/or light irradiation to form reversible topographic structures. Intrinsically, the LCON is rubbery and sensitive to temperature changes, resulting in shape transformations. We further advanced such system to make it light-responsive by incorporating azobenzene moieties. Actuation reduces the molecular order of the LCON coating that remains firmly adhered to the substrate which gives directional shear stresses around the topological defects. The stresses relax by deforming the surfaces by forming elevations or indents, depending on the type of defects. The formed topographies exhibit various features, including two types of protrusions, ridges and valleys. These poly-regional structures exhibit a large modulation amplitude of close to 60%, which is 6 times larger than the ones formed in liquid crystal networks (LCNs). After cooling or by blue light irradiation, the topographies are erased to the initial flat surface. A finite element method (FEM) model is adopted to simulate structures of surface topographies. These dynamic surface topographies with multilevel textures and large amplitude expand the application range, from haptics, controlled cell growth, to intelligent surfaces with adjustable adhesion and tribology.
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Affiliation(s)
- Yuxin You
- Joint Research Lab of Devices Integrated Responsive Materials (DIRM), South China Normal University, Guangzhou 510006, China.
- Human Interactive Materials (HIM), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands
| | - Youssef M Golestani
- Human Interactive Materials (HIM), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands
| | - Dirk J Broer
- Human Interactive Materials (HIM), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands
| | - Tinghong Yang
- Joint Research Lab of Devices Integrated Responsive Materials (DIRM), South China Normal University, Guangzhou 510006, China.
| | - Guofu Zhou
- Joint Research Lab of Devices Integrated Responsive Materials (DIRM), South China Normal University, Guangzhou 510006, China.
| | - Robin L B Selinger
- Department of Physics, Kent State University, Kent, OH 44242, USA.
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA
| | - Dong Yuan
- Joint Research Lab of Devices Integrated Responsive Materials (DIRM), South China Normal University, Guangzhou 510006, China.
| | - Danqing Liu
- Human Interactive Materials (HIM), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, Eindhoven 5612AE, The Netherlands
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4
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Cheng M, Cai W, Wang Z, Chen L, Yuan D, Ma Z, Bai Z, Kong D, Cen M, Xu S, Srivastava AK, Liu YJ. Responsive Liquid Crystal Network Microstructures with Customized Shapes and Predetermined Morphing for Adaptive Soft Micro-Optics. ACS APPLIED MATERIALS & INTERFACES 2024; 16:31776-31787. [PMID: 38858834 DOI: 10.1021/acsami.4c04275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Stimuli-responsive materials have garnered substantial interest in recent years, particularly liquid crystal networks (LCNs) with sophisticatedly designed structures and morphing capabilities. Extensive efforts have been devoted to LCN structural designs spanning from two-dimensional (2D) to three-dimensional (3D) configurations and their intricate morphing behaviors through designed alignment. However, achieving microscale structures and large-area preparation necessitates the development of novel techniques capable of facilely fabricating LCN microstructures with precise control over both overall shape and alignment, enabling a 3D-to-3D shape change. Herein, a simple and cost-effective in-cell soft lithography (ICSL) technique is proposed to create LCN microstructures with customized shapes and predesigned morphing. The ICSL technique involves two sequential steps: fabricating the desired microstructure as the template by using the photopolymerization-induced phase separation (PIPS) method and reproducing the LCN microstructures through templating. Meanwhile, surface anchoring is employed to design and achieve molecular alignment, accommodating different deformation modes. With the proposed ICSL technique, cylindrical and spherical microlens arrays (CMLAs and SMLAs) have been successfully fabricated with stimulus-driven polarization-dependent focusing effects. This technique offers distinct advantages including high customizability, large-area production, and cost-effectiveness, which pave a new avenue for extensive applications in different fields, exemplified by adaptive soft micro-optics and photonics.
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Affiliation(s)
- Ming Cheng
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Advanced Displays and Optoelectronics Technologies, and Centre for Display Research, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Wenfeng Cai
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhenming Wang
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lei Chen
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Dandan Yuan
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zongjun Ma
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Ziyan Bai
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Delai Kong
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Mengjia Cen
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shaolin Xu
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Abhishek Kumar Srivastava
- State Key Laboratory of Advanced Displays and Optoelectronics Technologies, and Centre for Display Research, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Yan Jun Liu
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Engineering Research Center for High Resolution Light Field Display and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China
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5
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Lu Y, Liu S, Liang J, Wang Z, Hou Y. Self-Propelled Nanomotor for Cancer Precision Combination Therapy. Adv Healthc Mater 2024; 13:e2304212. [PMID: 38259234 DOI: 10.1002/adhm.202304212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Indexed: 01/24/2024]
Abstract
The emergence of nanomotor provides an innovative concept for tumor treatment strategies. Conventional chemotherapeutic agents for tumors exit various therapeutic constraints due to the unique microenvironment of the tumor itself. Calcium overload, the aberrant accumulation of free calcium ions in the cytoplasm, is a well-recognized contributor to damage and even cell death in numerous cell types. Such undesired destructive processes can be a novel means applicable to cancer ion interference therapy. Herein, the chemotherapeutic drug doxorubicin (DOX) and calcium peroxide as the driving force into nanomotors through a facile and understandable experimental scheme are successfully assembled. The modification of nucleic acid aptamer and NIR-II fluorescent molecules on its surface simultaneously strengthens both the active targeting and imaging capability of tumor loci. Therefore, by a comprehensive assessment of nanomotors both in vitro and in vivo experiments, CaO2/DOX@HPS-IR-1061-AS1411 demonstrates superior killing effects on tumor cells, and the intracellular reactive oxygen species produced by nanomotors is verified by molecular biology experiments to induce apoptosis of tumor cells and further achieve tumor therapeutic effects.
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Affiliation(s)
- Yijie Lu
- Spin-X Institute, School of Chemistry and Chemical Engineering, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 511442, China
| | - Shikang Liu
- Spin-X Institute, School of Chemistry and Chemical Engineering, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 511442, China
| | - Jiarong Liang
- Spin-X Institute, School of Chemistry and Chemical Engineering, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 511442, China
| | - Zhiyi Wang
- Spin-X Institute, School of Chemistry and Chemical Engineering, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 511442, China
| | - Yanglong Hou
- Beijing Key Laboratory for Magnetoelectric Materials and Devices, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
- School of Materials, Sun Yat-Sen University, Shenzhen, 518107, China
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6
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Gruzdenko A, Mulder DJ, Schenning APHJ, den Toonder JMJ, Debije MG. Dual-Wavelength Volumetric Microlithography for Rapid Production of 4D Microstructures. ACS APPLIED MATERIALS & INTERFACES 2024; 16:22696-22703. [PMID: 38646711 PMCID: PMC11071039 DOI: 10.1021/acsami.4c01883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/11/2024] [Accepted: 04/11/2024] [Indexed: 04/23/2024]
Abstract
4D microstructured actuators are micro-objects made of stimuli-responsive materials capable of induced shape deformations, with applications ranging from microrobotics to smart micropatterned haptic surfaces. The novel technology dual-wavelength volumetric microlithography (DWVML) realizes rapid printing of high-resolution 3D microstructures and so has the potential to pave the way to feasible manufacturing of 4D microdevices. In this work, DWVML is applied for the first time to printing stimuli-responsive materials, namely, liquid crystal networks (LCNs). An LCN photoresist is developed and characterized, and large arrays of up to 5625 LCN micropillars with programmable shape changes are produced by means of DWVML in the time span of seconds, over areas as large as ∼5.4 mm2. The production rate of 0.24 mm3 h-1 is achieved, exceeding speeds previously reported for additive manufacturing of LCNs by 2 orders of magnitude. Finally, a membrane with tunable, micrometer-sized pores is fabricated to illustrate the potential DWVML holds for real-world applications.
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Affiliation(s)
- Alexandra Gruzdenko
- Stimuli-Responsive
Functional Materials and Devices, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Dirk J. Mulder
- Photosynthetic, De Boelelaan
1085, 1081HV Amsterdam, The Netherlands
| | - Albert P. H. J. Schenning
- Stimuli-Responsive
Functional Materials and Devices, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Jaap M. J. den Toonder
- Microsystems,
Department of Mechanical Engineering, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Michael G. Debije
- Stimuli-Responsive
Functional Materials and Devices, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
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7
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Pinchin NP, Guo H, Meteling H, Deng Z, Priimagi A, Shahsavan H. Liquid Crystal Networks Meet Water: It's Complicated! ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2303740. [PMID: 37392137 DOI: 10.1002/adma.202303740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/21/2023] [Accepted: 06/29/2023] [Indexed: 07/03/2023]
Abstract
Soft robots are composed of compliant materials that facilitate high degrees of freedom, shape-change adaptability, and safer interaction with humans. An attractive choice of material for soft robotics is crosslinked networks of liquid crystal polymers (LCNs), as they are responsive to a wide variety of external stimuli and capable of undergoing fast, programmable, complex shape morphing, which allows for their use in a wide range of soft robotic applications. However, unlike hydrogels, another popular material in soft robotics, LCNs have limited applicability in flooded or aquatic environments. This can be attributed not only to the poor efficiency of common LCN actuation methods underwater but also to the complicated relationship between LCNs and water. In this review, the relationship between water and LCNs is elaborated and the existing body of literature is surveyed where LCNs, both hygroscopic and non-hygroscopic, are utilized in aquatic soft robotic applications. Then the challenges LCNs face in widespread adaptation to aquatic soft robotic applications are discussed and, finally, possible paths forward for their successful use in aquatic environments are envisaged.
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Affiliation(s)
- Natalie P Pinchin
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Hongshuang Guo
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Henning Meteling
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Zixuan Deng
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Arri Priimagi
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Hamed Shahsavan
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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8
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Feng W, He Q, Zhang L. Embedded Physical Intelligence in Liquid Crystalline Polymer Actuators and Robots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2312313. [PMID: 38375751 DOI: 10.1002/adma.202312313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/27/2024] [Indexed: 02/21/2024]
Abstract
Responsive materials possess the inherent capacity to autonomously sense and respond to various external stimuli, demonstrating physical intelligence. Among the diverse array of responsive materials, liquid crystalline polymers (LCPs) stand out for their remarkable reversible stimuli-responsive shape-morphing properties and their potential for creating soft robots. While numerous reviews have extensively detailed the progress in developing LCP-based actuators and robots, there exists a need for comprehensive summaries that elucidate the underlying principles governing actuation and how physical intelligence is embedded within these systems. This review provides a comprehensive overview of recent advancements in developing actuators and robots endowed with physical intelligence using LCPs. This review is structured around the stimulus conditions and categorizes the studies involving responsive LCPs based on the fundamental control and stimulation logic and approach. Specifically, three main categories are examined: systems that respond to changing stimuli, those operating under constant stimuli, and those equip with learning and logic control capabilities. Furthermore, the persisting challenges that need to be addressed are outlined and discuss the future avenues of research in this dynamic field.
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Affiliation(s)
- Wei Feng
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Qiguang He
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Li Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong, China
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9
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Li S, Aizenberg M, Lerch MM, Aizenberg J. Programming Deformations of 3D Microstructures: Opportunities Enabled by Magnetic Alignment of Liquid Crystalline Elastomers. ACCOUNTS OF MATERIALS RESEARCH 2023; 4:1008-1019. [PMID: 38148997 PMCID: PMC10749463 DOI: 10.1021/accountsmr.3c00101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 09/10/2023] [Indexed: 12/28/2023]
Abstract
Synthetic structures that undergo controlled movement are crucial building blocks for developing new technologies applicable to robotics, healthcare, and sustainable self-regulated materials. Yet, programming motion is nontrivial, and particularly at the microscale it remains a fundamental challenge. At the macroscale, movement can be controlled by conventional electric, pneumatic, or combustion-based machinery. At the nanoscale, chemistry has taken strides in enabling molecularly fueled movement. Yet in between, at the microscale, top-down fabrication becomes cumbersome and expensive, while bottom-up chemical self-assembly and amplified molecular motion does not reach the necessary sophistication. Hence, new approaches that converge top-down and bottom-up methods and enable motional complexity at the microscale are urgently needed. Synthetic anisotropic materials (e.g., liquid crystalline elastomers, LCEs) with encoded molecular anisotropy that are shaped into arbitrary geometries by top-down fabrication promise new opportunities to implement controlled actuation at the microscale. In such materials, motional complexity is directly linked to the built-in molecular anisotropy that can be "activated" by external stimuli. So far, encoding the desired patterns of molecular directionality has relied mostly on either mechanical or surface alignment techniques, which do not allow the decoupling of molecular and geometric features, severely restricting achievable material shapes and thus limiting attainable actuation patterns, unless complex multimaterial constructs are fabricated. Electromagnetic fields have recently emerged as possible alternatives to provide 3D control over local anisotropy, independent of the geometry of a given 3D object. The combination of magnetic alignment and soft lithography, in particular, provides a powerful platform for the rapid, practical, and facile production of microscale soft actuators with field-defined local anisotropy. Recent work has established the feasibility of this approach with low magnetic field strengths (in the lower mT range) and comparably simple setups used for the fabrication of the microactuators, in which magnetic fields can be engineered through arrangement of permanent magnets. This workflow gives access to microstructures with unusual spatial patterning of molecular alignment and has enabled a multitude of nontrivial deformation types that would not be possible to program by any other means at the micron scale. A range of "activating" stimuli can be used to put these structures in motion, and the type of the trigger plays a key role too: directional and dynamic stimuli (such as light) make it possible to activate the patterned anisotropic material locally and transiently, which enables one to achieve and further program motional complexity and communication in microactuators. In this Account, we will discuss recent advances in magnetic alignment of molecular anisotropy and its use in soft lithography and related fabrication approaches to create LCE microactuators. We will examine how design choices-from the molecular to the fabrication and the operational levels-control and define the achievable LCE deformations. We then address the role of stimuli in realizing the motional complexity and how one can engineer feedback within and communication between microactuator arrays fabricated by soft lithography. Overall, we outline emerging strategies that make possible a completely new approach to designing for desired sets of motions of active, microscale objects.
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Affiliation(s)
- Shucong Li
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
- Department
of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Michael Aizenberg
- John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Michael M. Lerch
- John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Stratingh
Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Joanna Aizenberg
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
- John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
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10
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Liu M, Fu J, Yang S. Synthesis of Microparticles with Diverse Thermally Responsive Shapes Originated from the Same Janus Liquid Crystalline Microdroplets. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303106. [PMID: 37495936 DOI: 10.1002/smll.202303106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/14/2023] [Indexed: 07/28/2023]
Abstract
Liquid crystalline elastomer (LCE)-based microparticles that can change shapes in response to external stimuli are of great interest for potential applications such as artificial cells, micro-actuators, micro-valves, and smart drug carriers. Here, the synthesis of LCE microparticles with diverse temperature-dependent anisotropic shapes originated from the same Janus microdroplets is reported. The Janus microdroplets, suspended in an aqueous solution of surfactants, are transformed from microdroplets consisting of a mixture of liquid crystal (LC) monomers, oligomers, silicone oil, and an organic solvent, after the removal of the organic solvent. The molecular alignment of the LC part at the interface, whether planar, homeotropic, or hybrid, is dependent on the choice of the surfactants but not affected by the silicone oil. After polymerization and solvent extraction of the unreacted components, LCE microparticles of various shapes are obtained depending on the concentration and composition of the surfactants, the weight ratio of the LC part to the silicone oil part, and the choice of the extraction solvent. The microparticles that undergo different synthetic pathways show distinct thermally responsive shapes, much like how stem cells differentiate in different environmental conditions.
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Affiliation(s)
- Mingzhu Liu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
- School of Chemistry, Beihang University, Beijing, 100191, P. R. China
| | - Jiemin Fu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
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11
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Zhang Y, Wang X, Yang W, Yan H, Zhang X, Han D, He Y, Li C, Sun L. Programmable Complex Shape Changing of Polysiloxane Main-Chain Liquid Crystalline Elastomers. Molecules 2023; 28:4858. [PMID: 37375413 DOI: 10.3390/molecules28124858] [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: 04/20/2023] [Revised: 06/07/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Liquid crystal elastomers (LCEs) are shape-morphing materials whose large and reversible shape transformations are caused by the coupling between the mobile anisotropic properties of liquid crystal (LC) units and the rubber elastic of polymer networks. Their shape-changing behaviors under certain stimuli are largely directed by the LC orientation; therefore, various strategies have been developed to spatially modulate the LC alignments. However, most of these methods are limited as they require complex fabrication technologies or have intrinsic limitations in applicability. To address this issue, programmable complex shape changes in some LCE types, such as polysiloxane side-chain LCEs, thiol-acrylate main-chain LCEs, etc., were achieved by using a mechanical alignment programming process coupled with two-step crosslinking. Here, we report a polysiloxane main-chain LCE with programmable 2- and 3D shape-changing abilities that were created by mechanically programming the polydomain LCE with two crosslinking steps. The resulting LCEs exhibited a reversible thermal-induced shape transformation between the initial and programmed shapes due to the two-way memory between the first and second network structures. Our findings expand on the applications of LCE materials in actuators, soft robotics, and smart structures where arbitrary and easily programmed shape morphing is needed.
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Affiliation(s)
- Yuhe Zhang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Xiuxiu Wang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Wenlong Yang
- Department of Applied Science, Harbin University of Science and Technology, Harbin 150080, China
| | - Huixuan Yan
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Xinyu Zhang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Dongxu Han
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Yifan He
- Institute of Regulatory Science, Beijing Technology and Business University, Beijing 100048, China
| | - Chensha Li
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Liguo Sun
- Key Laboratory of Chemical Engineering Process and Technology for High-Efficiency Conversion School of Chemistry and Material Science, Heilongjiang University, Harbin 150080, China
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12
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Chen M, Gao M, Bai L, Zheng H, Qi HJ, Zhou K. Recent Advances in 4D Printing of Liquid Crystal Elastomers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209566. [PMID: 36461147 DOI: 10.1002/adma.202209566] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/22/2022] [Indexed: 06/09/2023]
Abstract
Liquid crystal elastomers (LCEs) are renowned for their large, reversible, and anisotropic shape change in response to various external stimuli due to their lightly cross-linked polymer networks with an oriented mesogen direction, thus showing great potential for applications in robotics, bio-medics, electronics, optics, and energy. To fully take advantage of the anisotropic stimuli-responsive behaviors of LCEs, it is preferable to achieve a locally controlled mesogen alignment into monodomain orientations. In recent years, the application of 4D printing to LCEs opens new doors for simultaneously programming the mesogen alignment and the 3D geometry, offering more opportunities and higher feasibility for the fabrication of 4D-printed LCE objects with desirable stimuli-responsive properties. Here, the state-of-the-art advances in 4D printing of LCEs are reviewed, with emphasis on both the mechanisms and potential applications. First, the fundamental properties of LCEs and the working principles of the representative 4D printing techniques are briefly introduced. Then, the fabrication of LCEs by 4D printing techniques and the advantages over conventional manufacturing methods are demonstrated. Finally, perspectives on the current challenges and potential development trends toward the 4D printing of LCEs are discussed, which may shed light on future research directions in this new field.
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Affiliation(s)
- Mei Chen
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- HP-NTU Digital Manufacturing Corporate Lab, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Ming Gao
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- HP-NTU Digital Manufacturing Corporate Lab, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Lichun Bai
- School of Traffic and Transportation Engineering, Central South University, Changsha, 410075, China
| | - Han Zheng
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - H Jerry Qi
- School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Kun Zhou
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- HP-NTU Digital Manufacturing Corporate Lab, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
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13
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Zhang P, Debije MG, de Haan LT, Schenning APHJ. Switching between 3D Surface Topographies in Liquid Crystal Elastomer Coatings Using Two-Step Imprint Lithography. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2302051. [PMID: 37189212 DOI: 10.1002/smll.202302051] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/01/2023] [Indexed: 05/17/2023]
Abstract
While dynamic surface topographies are fabricated using liquid crystal (LC) polymers, switching between two distinct 3D topographies remains challenging. In this work, two switchable 3D surface topographies are created in LC elastomer (LCE) coatings using a two-step imprint lithography process. A first imprinting creates a surface microstructure on the LCE coating which is polymerized by a base catalyzed partial thiol-acrylate crosslinking step. The structured coating is then imprinted with a second mold to program the second topography, which is subsequently fully polymerized by light. The resulting LCE coatings display reversible surface switching between the two programmed 3D states. By varying the molds used during the two imprinting steps, diverse dynamic topographies can be achieved. For example, by using grating and rough molds sequentially, switchable surface topographies between a random scatterer and an ordered diffractor are achieved. Additionally, by using negative and positive triangular prism molds consecutively, dynamic surface topographies switching between two 3D structural states are achieved, driven by differential order/disorder transitions in the different areas of the film. It is anticipated that this platform of dynamic 3D topological switching can be used for many applications, including antifouling and biomedical surfaces, switchable friction elements, tunable optics, and beyond.
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Affiliation(s)
- Pei Zhang
- Stimuli-responsive Functional Materials and Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TU/e), Groene Loper, Eindhoven, 5600 MB, The Netherlands
| | - Michael G Debije
- Stimuli-responsive Functional Materials and Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TU/e), Groene Loper, Eindhoven, 5600 MB, The Netherlands
- Interactive Polymer Materials (IPM), Eindhoven University of Technology (TU/e), Groene Loper, Eindhoven, 5600 MB, The Netherlands
| | - Laurens T de Haan
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Albert P H J Schenning
- Stimuli-responsive Functional Materials and Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TU/e), Groene Loper, Eindhoven, 5600 MB, The Netherlands
- Interactive Polymer Materials (IPM), Eindhoven University of Technology (TU/e), Groene Loper, Eindhoven, 5600 MB, The Netherlands
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology (TU/e), Groene Loper, Eindhoven, 5600 MB, The Netherlands
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14
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Zhan Y, Broer DJ, Li J, Xue J, Liu D. A cold-responsive liquid crystal elastomer provides visual signals for monitoring a critical temperature decrease. MATERIALS HORIZONS 2023. [PMID: 37098874 DOI: 10.1039/d3mh00271c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Critical temperature indicators have been extensively utilized in various fields, ranging from healthcare to food safety. However, the majority of the temperature indicators are designed for upper critical temperature monitoring, indicating when the temperature rises and exceeds a predefined limit, whereas stringently demanded low critical temperature indicators are scarcely developed. Herein, we develop a new material and system that monitor temperature decrease, e.g., from ambient temperature to the freezing point, or even to an ultra-low temperature of -20 °C. For this purpose, we create a dynamic membrane which can open and close during temperature cycles from high temperature to low temperature. This membrane consists of a gold-liquid crystal elastomer (Au-LCE) bilayer structure. Unlike the commonly used thermo-responsive LCEs which actuate upon temperature rise, our LCE is cold-responsive. This means that geometric deformations occur when the environmental temperature decreases. Specifically, upon temperature decrease the LCE creates stresses at the gold interface by uniaxial deformation due to expansion along the molecular director and shrinkage perpendicular to it. At a critical stress, optimized to occur at the desired temperature, the brittle Au top layer fractures, which allows contact between the LCE and material on top of the gold layer. Material transport via cracks enables the onset of the visible signal for instance caused by a pH indicator substance. We apply the dynamic Au-LCE membrane for cold-chain applications, indicating the loss of the effectiveness of perishable goods. We anticipate that our newly developed low critical temperature/time indicator will be shortly implemented in supply chains to minimize food and medical product waste.
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Affiliation(s)
- Yuanyuan Zhan
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
| | - Dirk J Broer
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
| | - Junyu Li
- Molecular Materials and Nanosystems, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
| | - Jiuzhi Xue
- Smart Liquid Crystal Technologies Co. Ltd, Jiangsu Industrial Technology Research Institute (JITRI), 280 Huangpujiang Road, Chuangshu, 215556, China
| | - Danqing Liu
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands.
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
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15
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Gablier A, Terentjev EM. Flexible force‐bearing liquid crystalline elastomer component toward a dynamic braille platform. NANO SELECT 2023. [DOI: 10.1002/nano.202300026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023] Open
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16
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Liang H, Wei Y, Ji Y. Magnetic-responsive Covalent Adaptable Networks. Chem Asian J 2023; 18:e202201177. [PMID: 36645376 DOI: 10.1002/asia.202201177] [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: 11/21/2022] [Revised: 01/07/2023] [Accepted: 01/16/2023] [Indexed: 01/17/2023]
Abstract
Covalent adaptable networks (CANs) are reprocessable polymers whose structural arrangement is based on the recombination of dynamic covalent bonds. Composite materials prepared by incorporating magnetic particles into CANs attract much attention due to their remote and precise control, fast response speed, high biological safety and strong penetration of magnetic stimuli. These properties often involve magnetothermal effect and direct magnetic-field guidance. Besides, some of them can also respond to light, electricity or pH values. Thus, they are favorable for soft actuators since various functions are achieved such as magnetic-assisted self-healing (heating or at ambient temperature), welding (on land or under water), shape-morphing, and so on. Although magnetic CANs just start to be studied in recent two years, their advances are promised to expand the practical applications in both cutting-edge academic and engineering fields. This review aims to summarize recent progress in magnetic-responsive CANs, including their design, synthesis and application.
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Affiliation(s)
- Huan Liang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Yen Wei
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.,Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung-Yuan Christian University Chung-Li, 32023, Taiwan, P. R. China
| | - Yan Ji
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
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17
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Chen SJ, Cheng HF, Du B, Liu JS, Shen WB, Zhuo HT. Programming Shape-Morphing Behavior of Zwitterionic Polymer/Liquid Crystal Composite with Humidity-responsive Self-healing Performance. CHINESE JOURNAL OF POLYMER SCIENCE 2023. [DOI: 10.1007/s10118-022-2883-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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18
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Liu M, Jin L, Yang S, Wang Y, Murray CB, Yang S. Shape Morphing Directed by Spatially Encoded, Dually Responsive Liquid Crystalline Elastomer Micro-Actuators. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208613. [PMID: 36341507 DOI: 10.1002/adma.202208613] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Liquid crystalline elastomers (LCEs) with intrinsic molecular anisotropy can be programmed to morph shapes under external stimuli. However, it is difficult to program the position and orientation of individual mesogenic units separately and locally, whether in-plane or out-of-plane, since each mesogen is linked to adjacent ones through the covalently bonded polymer chains. Here, dually responsive, spindle-shaped micro-actuators are synthesized from LCE composites, which can reorient under a magnetic field and change the shape upon heating. When the discrete micro-actuators are embedded in a conventional and nonresponsive elastomer with programmed height distribution and in-plane orientation in local regions, robust and complex shape morphing induced by the cooperative actuations of the locally distributed micro-actuators, which corroborates with finite element analysis, are shown. The spatial encoding of discrete micro-actuators in a nonresponsive matrix allows to decouple the actuators and the matrix, broadening the material palette to program local and global responses to stimuli for applications including soft robotics, smart wearables, and sensors.
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Affiliation(s)
- Mingzhu Liu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Lishuai Jin
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Shengsong Yang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yuchen Wang
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Christopher B Murray
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
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19
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Rogóż M, Dziekan Z, Dradrach K, Zmyślony M, Nałęcz-Jawecki P, Grabowski P, Fabjanowicz B, Podgórska M, Kudzia A, Wasylczyk P. From Light-Powered Motors, to Micro-Grippers, to Crawling Caterpillars, Snails and Beyond-Light-Responsive Oriented Polymers in Action. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8214. [PMID: 36431699 PMCID: PMC9698796 DOI: 10.3390/ma15228214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/12/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
"How would you build a robot, the size of a bacteria, powered by light, that would swim towards the light source, escape from it, or could be controlled by means of different light colors, intensities or polarizations?" This was the question that Professor Diederik Wiersma asked PW on a sunny spring day in 2012, when they first met at LENS-the European Laboratory of Nonlinear Spectroscopy-in Sesto Fiorentino, just outside Florence in northern Italy. It was not just a vague question, as Prof. Wiersma, then the LENS director and leader of one of its research groups, already had an idea (and an ERC grant) about how to actually make such micro-robots, using a class of light-responsive oriented polymers, liquid crystal elastomers (LCEs), combined with the most advanced fabrication technique-two-photon 3D laser photolithography. Indeed, over the next few years, the LCE technology, successfully married with the so-called direct laser writing at LENS, resulted in a 60 micrometer long walker developed in Prof. Wiersma's group (as, surprisingly, walking at that stage proved to be easier than swimming). After completing his post-doc at LENS, PW returned to his home Faculty of Physics at the University of Warsaw, and started experimenting with LCE, both in micrometer and millimeter scales, in his newly established Photonic Nanostructure Facility. This paper is a review of how the ideas of using light-powered soft actuators in micromechanics and micro-robotics have been evolving in Warsaw over the last decade and what the outcomes have been so far.
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20
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Zuo S, Feng W, Liu F, Xu X, Tao X, Wang L, Liu H, Lin S. Polymerization-induced self-assembly of side-chain liquid crystalline copolymers by dissipative particle dynamics simulation. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Javed M, Corazao T, Saed MO, Ambulo CP, Li Y, Kessler MR, Ware TH. Programmable Shape Change in Semicrystalline Liquid Crystal Elastomers. ACS APPLIED MATERIALS & INTERFACES 2022; 14:35087-35096. [PMID: 35866446 DOI: 10.1021/acsami.2c07533] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Liquid crystal elastomers (LCEs) are stimuli-responsive materials capable of reversible and programmable shape change in response to an environmental stimulus. Despite the highly responsive nature of these materials, the modest elastic modulus and blocking stress exhibited by these actuating materials can be limiting in some engineering applications. Here, we engineer a semicrystalline LCE, where the incorporation of semicrystallinity in a lightly cross-linked liquid crystalline network yields tough and highly responsive materials. Directed self-assembly can be employed to program director profiles through the thickness of the semicrystalline LCE. In short, we use the alignment of a liquid crystal monomer phase to pattern the anisotropy of a semicrystalline polymer network. Both the semicrystalline-liquid crystalline and liquid crystalline-isotropic phase transition temperatures provide controllable shape transformations. A planarly aligned sample's normalized dimension parallel to the nematic director decreases from 1 at room temperature to 0.42 at 250 °C. The introduction of the semicrystalline nature also enhances the mechanical properties exhibited by the semicrystalline LCE. Semicrystalline LCEs have a storage modulus of 390 MPa at room temperature, and monodomain samples are capable of generating a contractile stress of 2.7 MPa on heating from 25 to 50 °C, far below the nematic to isotropic transition temperature. The robust mechanical properties of this material combined with the high actuation strain can be leveraged for applications such as soft robotics and actuators capable of doing significant work.
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Affiliation(s)
- Mahjabeen Javed
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Tyler Corazao
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
| | | | - Cedric P Ambulo
- Air Force Research Laboratory, Dayton, Ohio 45433, United States
| | - Yuzhan Li
- University of Science and Technology Beijing, Beijing 100083, China
| | - Michael R Kessler
- North Dakota State University, Fargo, North Dakota 58108, United States
| | - Taylor H Ware
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
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22
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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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23
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Wu Y, Zhang S, Yang Y, Li Z, Wei Y, Ji Y. Locally controllable magnetic soft actuators with reprogrammable contraction-derived motions. SCIENCE ADVANCES 2022; 8:eabo6021. [PMID: 35749490 PMCID: PMC9232107 DOI: 10.1126/sciadv.abo6021] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/10/2022] [Indexed: 06/01/2023]
Abstract
Reprogrammable magneto-responsive soft actuators capable of working in enclosed and confined spaces and adapting functions under changing situations are highly demanded for new-generation smart devices. Despite the promising prospect, the realization of versatile morphing modes (more than bending) and local magnetic control remains challenging but is crucial for further on-demand applications. Here, we address the challenges by maximizing the unexplored potential of magnetothermal responsiveness and covalent adaptable networks (CANs) in liquid crystalline elastomers (LCEs). Various magneto-actuated contraction-derived motions that were hard to achieve previously (e.g., bidirectional shrinkage and dynamic 3D patterns) can be attained, reprogrammed, and assembled seamlessly to endow functional diversity and complexity. By integration of LCEs with different magneto-responsive threshold values, local and sequential magnetic control is readily realized. Many magnetic actuation portfolios are performed by rationally imputing "logic switch" sequences. Meanwhile, our systems exhibit additional favorable performances including stepwise magnetic controllability, multiresponsiveness, self-healing, and remolding ability.
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Affiliation(s)
- Yahe Wu
- The Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Shuai Zhang
- The Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yang Yang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Zhen Li
- Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, China
| | - Yen Wei
- The Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yan Ji
- The Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
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24
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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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Li M, Dai S, Dong X, Jiang Y, Ge J, Xu Y, Yuan N, Ding J. High-Strength, Large-Deformation, Dual Cross-Linking Network Liquid Crystal Elastomers Based on Quadruple Hydrogen Bonds. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:1560-1566. [PMID: 35061400 DOI: 10.1021/acs.langmuir.1c03010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystal elastomers (LCEs) with large deformation under external stimuli have attracted extensive attention in various applications such as soft robotics, 4D printing, and biomedical devices. However, it is still a great challenge to reduce the damage to collimation and enhance the mechanical and actuation properties of LCEs simultaneously. Here, we construct a new method of a double cross-linking network structure to improve the mechanical properties of LCEs. The ureidopyrimidinone (UPy) group with quadruple hydrogen bonds was used as the physical cross-linking unit, and pentaerythritol tetra(3-mercaptopropionate) was used as the chemical cross-link. The LCEs showed a strong mechanical tensile strength of 8.5 MPa and excellent thermally induced deformation (50%). In addition, the introduction of quadruple hydrogen bonds endows self-healing ability to extend the service life of LCEs. This provides a generic strategy for the fabrication of high-strength LCEs, inspiring the development of actuators and artificial muscles.
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Affiliation(s)
- Meng Li
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Shengping Dai
- Institute of Intelligent Flexible Mechatronics, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Xu Dong
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Yaoyao Jiang
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Jun Ge
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Yida Xu
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Ningyi Yuan
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Jianning Ding
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P. R. China
- Institute of Intelligent Flexible Mechatronics, Jiangsu University, Zhenjiang 212013, P. R. China
- Yangzhou University, Yangzhou 225009, P. R. China
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26
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Wang M, Song Y, Bisoyi HK, Yang J, Liu L, Yang H, Li Q. A Liquid Crystal Elastomer-Based Unprecedented Two-Way Shape-Memory Aerogel. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2102674. [PMID: 34569166 PMCID: PMC8596101 DOI: 10.1002/advs.202102674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/17/2021] [Indexed: 05/12/2023]
Abstract
With the advantage of reversible shape-morphing between two different permanent shapes under external stimuli, the two-way shape-memory aerogel is expected to become a preferred aerogel for developing practical applications in actuators, sensors, robotics, and more. Herein, the first two-way shape-memory liquid crystal elastomer (LCE)-based aerogel is prepared by an orthogonal heat and light curing strategy coupled with an intermediate mechanical stretching step. The differential scanning calorimetry, temperature-varied wide-angle X-ray scattering, and polarizing optical microscope results indicate that the aerogel possesses a liquid crystal phase and the insider mesogens are well-oriented along the stretching direction. In addition to having superior compressibility and excellent shape stability, this LCE-based aerogel can perform a reversible shape deformation during the heating/cooling cycles with a shrinkage ratio of 37%. The work, that is disclosed here, realizes a truly two-way shape-memory behavior rather than the one-way shape deformation of traditional polymer aerogel materials, and may promote potential applications of this novel LCE-based aerogel material in control devices, soft actuators, and beyond.
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Affiliation(s)
- Meng Wang
- Institute of Advanced MaterialsSchool of Chemistry and Chemical Engineeringand Jiangsu Hi‐Tech Key Laboratory for Biomedical ResearchSoutheast UniversityNanjing211189China
| | - Ying Song
- Institute of Advanced MaterialsSchool of Chemistry and Chemical Engineeringand Jiangsu Hi‐Tech Key Laboratory for Biomedical ResearchSoutheast UniversityNanjing211189China
| | - Hari Krishna Bisoyi
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary ProgramKent State UniversityKentOH44242USA
| | - Jian‐Feng Yang
- Institute of Advanced MaterialsSchool of Chemistry and Chemical Engineeringand Jiangsu Hi‐Tech Key Laboratory for Biomedical ResearchSoutheast UniversityNanjing211189China
| | - Li Liu
- Institute of Advanced MaterialsSchool of Chemistry and Chemical Engineeringand Jiangsu Hi‐Tech Key Laboratory for Biomedical ResearchSoutheast UniversityNanjing211189China
| | - Hong Yang
- Institute of Advanced MaterialsSchool of Chemistry and Chemical Engineeringand Jiangsu Hi‐Tech Key Laboratory for Biomedical ResearchSoutheast UniversityNanjing211189China
| | - Quan Li
- Institute of Advanced MaterialsSchool of Chemistry and Chemical Engineeringand Jiangsu Hi‐Tech Key Laboratory for Biomedical ResearchSoutheast UniversityNanjing211189China
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary ProgramKent State UniversityKentOH44242USA
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27
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Yin L, Miao TF, Cheng XX, Jiang ZC, Tong X, Zhang W, Zhao Y. Chiral Liquid Crystalline Elastomer for Twisting Motion without Preset Alignment of Mesogens. ACS Macro Lett 2021; 10:690-696. [PMID: 35549093 DOI: 10.1021/acsmacrolett.1c00286] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A chiral liquid crystalline elastomer (CLCE) actuator is demonstrated. The solution-cast polydomain film of CLCE can twist upon order-disorder phase transition without any preset alignment of mesogens. The handedness of twisting is specific to the molecular chirality of the chiral dopant in the CLCE structure, while the degree of twisting, in terms of helical pitch and diameter, is sensitive to the aspect ratio and the thickness of the CLCE strip as well as the chiral dopant content. This phenomenon appears to stem from the local twisting forces and deformations of randomly oriented helical domains, which cannot cancel each other out due to the chirality and thus result in a macroscopic "chiral" force acting on the CLCE actuator. This finding reveals a materials design for preparing twisting LCE actuators.
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Affiliation(s)
- Lu Yin
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou Industrial Park, Suzhou 215123, China
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Teng-Fei Miao
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou Industrial Park, Suzhou 215123, China
| | - Xiao-Xiao Cheng
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou Industrial Park, Suzhou 215123, China
| | - Zhi-Chao Jiang
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Xia Tong
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Wei Zhang
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou Industrial Park, Suzhou 215123, China
| | - Yue Zhao
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
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Zhao J, Yu Y, Xu P, Li K. Wrinkling of liquid-crystal elastomer disks caused by light-driven dynamic contraction. Phys Rev E 2021; 103:L041002. [PMID: 34005964 DOI: 10.1103/physreve.103.l041002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/24/2021] [Indexed: 11/07/2022]
Abstract
The trigger time of light-driven wrinkling is very critical for accurate active control in photo-powered machines. In this paper, the wrinkling of liquid-crystal elastomer disks caused by light-driven dynamic contraction is theoretically studied, and the critical times for appearance and disappearance of the wrinkles are numerically calculated. The light-driven prebuckling stress can be significantly adjusted by changing the contraction coefficient, while controlled within a certain limit by tuning the light intensity and illumination time. There exists a critical contraction coefficient for triggering the wrinkling of the disk, and the second-order mode of wrinkling is the most unstable mode, which is most easily induced for the illumination radius ratio 0.69. The critical times for the appearance and disappearance of wrinkling can be significantly changed by the contraction coefficient, while regulated only within a certain range by the light intensity and the illumination radius ratio. These results have potential applications for accurate active control in the fields of soft robotics, active microlens, smart windows, and tunable surface patterns.
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Affiliation(s)
- Jun Zhao
- Department of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui Province 230601, People's Republic of China
| | - Yong Yu
- Department of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui Province 230601, People's Republic of China
| | - Peibao Xu
- Department of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui Province 230601, People's Republic of China
| | - Kai Li
- Department of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui Province 230601, People's Republic of China
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29
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Tu K, Liu C, He E, Cheng J, Zhang L, Cheng Z. Reduction-Induced Crystallization-Driven Self-Assembly of Main-Chain-Type Alternating Copolymers: Transformation from 1D Lines to 2D Platelets. ACS Macro Lett 2021; 10:564-569. [PMID: 35570758 DOI: 10.1021/acsmacrolett.1c00109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In recent years, crystalline-driven self-assembly (CDSA) has received enormous attention, but almost only for block copolymers (BCPs). Herein, we introduced perfluorocarbon chains into main-chain-type liquid crystalline alternating copolymers (ACPs) to obtain perfluoroalkane-containing ACPs with periodic C-I bonds in polymer backbones via step transfer-addition and radical-termination (START) polymerization, followed by an iodine reduction reaction of C-I bonds to induce CDSA of ACPs and put forward a novel concept of "reduction-induced crystallization-driven self-assembly" (RI-CDSA) of main-chain-type ACPs for the first time. Finally, we proposed the folded-chain model and mechanism to explain the novel RI-CDSA behavior, and its rationality has been proved by the corresponding experimental results.
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Affiliation(s)
- Kai Tu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis; College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Cheng Liu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 21513, China
| | - Enjie He
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis; College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Jiannan Cheng
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis; College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Lifen Zhang
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis; College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Zhenping Cheng
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis; College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
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30
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Wang Z, Cai S. Recent progress in dynamic covalent chemistries for liquid crystal elastomers. J Mater Chem B 2021; 8:6610-6623. [PMID: 32555841 DOI: 10.1039/d0tb00754d] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Liquid crystal elastomers (LCEs) have recently shown great potential in the applications of soft robotics, biomedical devices, active morphing structures, self-regulating systems and biomimetic demonstrations. Physical properties of LCEs highly depend on their crosslinking and the alignment of mesogens in the polymer network. Different strategies have been adopted to control and program the alignment of mesogens in LCEs over the recent decades, including stretching a loosely crosslinked LCE during its second-step crosslinking reaction, application of a strong magnetic or electrical field onto an LCE during its crosslinking process, and crosslinking a LCE thin film on the top of a surface with predesigned molecular texture. In the most recent decade, dynamic covalent bonds, which can undergo exchange reactions with or without external stimuli, have been introduced into LCEs to enable facile programing of mesogen orientation in the elastomer. In addition to the programmability, the LCEs with dynamic covalent bonds have also shown great recyclability, self-healing abilities and reprogrammability. In this article, we will review the recent progress in the synthesis, programming and application of LCEs with dynamic covalent bonds. We will also discuss the challenges and research opportunities in the field.
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Affiliation(s)
- Zhijian Wang
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA.
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31
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Chen Y, Yang J, Zhang X, Feng Y, Zeng H, Wang L, Feng W. Light-driven bimorph soft actuators: design, fabrication, and properties. MATERIALS HORIZONS 2021; 8:728-757. [PMID: 34821314 DOI: 10.1039/d0mh01406k] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Soft robots that can move like living organisms and adapt to their surroundings are currently in the limelight from fundamental studies to technological applications, due to their advances in material flexibility, human-friendly interaction, and biological adaptation that surpass conventional rigid machines. Light-fueled smart actuators based on responsive soft materials are considered to be one of the most promising candidates to promote the field of untethered soft robotics, thereby attracting considerable attention amongst materials scientists and microroboticists to investigate photomechanics, photoswitch, bioinspired design, and actuation realization. In this review, we discuss the recent state-of-the-art advances in light-driven bimorph soft actuators, with the focus on bilayer strategy, i.e., integration between photoactive and passive layers within a single material system. Bilayer structures can endow soft actuators with unprecedented features such as ultrasensitivity, programmability, superior compatibility, robustness, and sophistication in controllability. We begin with an explanation about the working principle of bimorph soft actuators and introduction of a synthesis pathway toward light-responsive materials for soft robotics. Then, photothermal and photochemical bimorph soft actuators are sequentially introduced, with an emphasis on the design strategy, actuation performance, underlying mechanism, and emerging applications. Finally, this review is concluded with a perspective on the existing challenges and future opportunities in this nascent research Frontier.
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Affiliation(s)
- Yuanhao Chen
- School of Materials Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
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32
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Lu X, Ambulo CP, Wang S, Rivera‐Tarazona LK, Kim H, Searles K, Ware TH. 4D‐Printing of Photoswitchable Actuators. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202012618] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xili Lu
- Department of Bioengineering University of Texas at Dallas Richardson TX 75080 USA
- Current address: State Key Laboratory of Polymer Materials Engineering Polymer Research Institute Sichuan University Chengdu 610065 China
| | - Cedric P. Ambulo
- Department of Bioengineering University of Texas at Dallas Richardson TX 75080 USA
| | - Suitu Wang
- Department of Bioengineering University of Texas at Dallas Richardson TX 75080 USA
- Current address: Department of Materials Science and Engineering Texas A&M University College Station TX 77843 USA
| | - Laura K. Rivera‐Tarazona
- Department of Bioengineering University of Texas at Dallas Richardson TX 75080 USA
- Current address: Department of Biomedical Engineering Texas A&M University College Station TX 77843 USA
| | - Hyun Kim
- Department of Bioengineering University of Texas at Dallas Richardson TX 75080 USA
- Current address: Sensors and Electron Devices Directorate CCDC Army Research Laboratory Adelphi MD 20783 USA
| | - Kyle Searles
- Department of Bioengineering University of Texas at Dallas Richardson TX 75080 USA
| | - Taylor H. Ware
- Department of Bioengineering University of Texas at Dallas Richardson TX 75080 USA
- Current address: Department of Biomedical Engineering Texas A&M University College Station TX 77843 USA
- Current address: Department of Materials Science and Engineering Texas A&M University College Station TX 77843 USA
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33
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Lu X, Ambulo CP, Wang S, Rivera-Tarazona LK, Kim H, Searles K, Ware TH. 4D-Printing of Photoswitchable Actuators. Angew Chem Int Ed Engl 2021; 60:5536-5543. [PMID: 33217118 DOI: 10.1002/anie.202012618] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/02/2020] [Indexed: 12/15/2022]
Abstract
Shape-switching behavior, where a transient stimulus induces an indefinitely stable deformation that can be recovered on exposure to another transient stimulus, is critical to building smart structures from responsive polymers as continue power is not needed to maintain deformations. Herein, we 4D-print shape-switching liquid crystalline elastomers (LCEs) functionalized with supramolecular crosslinks, dynamic covalent crosslinks, and azobenzene. The salient property of shape-switching LCEs is that light induces long-lived, deformation that can be recovered on-demand by heating. UV-light isomerizes azobenzene from trans to cis, and temporarily breaks the supramolecular crosslinks, resulting in a programmed deformation. After UV, the shape-switching LCEs fix more than 90 % of the deformation over 3 days by the reformed supramolecular crosslinks. Using the shape-switching properties, we print Braille-like actuators that can be photoswitched to display different letters. This new class of photoswitchable actuators may impact applications such as deployable devices where continuous application of power is impractical.
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Affiliation(s)
- Xili Lu
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA.,Current address: State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu, 610065, China
| | - Cedric P Ambulo
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Suitu Wang
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA.,Current address: Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Laura K Rivera-Tarazona
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA.,Current address: Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Hyun Kim
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA.,Current address: Sensors and Electron Devices Directorate, CCDC Army Research Laboratory, Adelphi, MD, 20783, USA
| | - Kyle Searles
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Taylor H Ware
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA.,Current address: Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA.,Current address: Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA
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34
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He E, Tu K, Cheng J, Lu H, Zhang L, Cheng Z, Zhu X. Multimesophase transitions of main-chain liquid crystalline copolymers with strictly alternating fluorocarbon chains. Polym Chem 2021. [DOI: 10.1039/d0py01644f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Main-chain liquid crystalline perfluoroalkyl-containing alternating copolymers present rare reversible phase transitions from a hexagonal columnar phase to a rectangular columnar phase and finally to a smectic phase with the temperature increasing.
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Affiliation(s)
- Enjie He
- Suzhou key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Kai Tu
- Suzhou key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Jiannan Cheng
- Suzhou key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Huanjun Lu
- Suzhou key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Lifen Zhang
- Suzhou key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Zhenping Cheng
- Suzhou key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Xiulin Zhu
- Suzhou key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
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35
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Chen L, Chu D, Cheng ZA, Wang M, Huang S. Designing seamless-welded liquid-crystalline soft actuators with a “glue-free” method by dynamic boroxines. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122962] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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36
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Ambulo CP, Tasmim S, Wang S, Abdelrahman MK, Zimmern PE, Ware TH. Processing advances in liquid crystal elastomers provide a path to biomedical applications. JOURNAL OF APPLIED PHYSICS 2020; 128:140901. [PMID: 33060862 PMCID: PMC7546753 DOI: 10.1063/5.0021143] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/24/2020] [Indexed: 05/08/2023]
Abstract
Liquid crystal elastomers (LCEs) are a class of stimuli-responsive polymers that undergo reversible shape-change in response to environmental changes. The shape change of LCEs can be programmed during processing by orienting the liquid crystal phase prior to crosslinking. The suite of processing techniques that has been developed has resulted in a myriad of LCEs with different shape-changing behavior and mechanical properties. Aligning LCEs via mechanical straining yields large uniaxial actuators capable of a moderate force output. Magnetic fields are utilized to control the alignment within LCE microstructures. The generation of out-of-plane deformations such as bending, twisting, and coning is enabled by surface alignment techniques within thin films. 4D printing processes have emerged that enable the fabrication of centimeter-scale, 3D LCE structures with a complex alignment. The processing technique also determines, to a large extent, the potential applications of the LCE. For example, 4D printing enables the fabrication of LCE actuators capable of replicating the forces generated by human muscles. Employing surface alignment techniques, LCE films can be designed for use as coatings or as substrates for stretchable electronics. The growth of new processes and strategies opens and strengthens the path for LCEs to be applicable within biomedical device designs.
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Affiliation(s)
- Cedric P Ambulo
- Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas 75080, USA
| | | | | | | | - Philippe E Zimmern
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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37
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Yin L, Han L, Ge F, Tong X, Zhang W, Soldera A, Zhao Y. A Novel Side‐Chain Liquid Crystal Elastomer Exhibiting Anomalous Reversible Shape Change. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lu Yin
- Département de chimie Université de Sherbrooke Sherbrooke Québec J1K 2R1 Canada
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou Industrial Park Suzhou 215123 China
| | - Li Han
- Département de chimie Université de Sherbrooke Sherbrooke Québec J1K 2R1 Canada
| | - Feijie Ge
- Département de chimie Université de Sherbrooke Sherbrooke Québec J1K 2R1 Canada
| | - Xia Tong
- Département de chimie Université de Sherbrooke Sherbrooke Québec J1K 2R1 Canada
| | - Wei Zhang
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou Industrial Park Suzhou 215123 China
| | - Armand Soldera
- Département de chimie Université de Sherbrooke Sherbrooke Québec J1K 2R1 Canada
| | - Yue Zhao
- Département de chimie Université de Sherbrooke Sherbrooke Québec J1K 2R1 Canada
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Zmyślony M, Dradrach K, Haberko J, Nałęcz-Jawecki P, Rogóż M, Wasylczyk P. Optical Pliers: Micrometer-Scale, Light-Driven Tools Grown on Optical Fibers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002779. [PMID: 32627876 DOI: 10.1002/adma.202002779] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/21/2020] [Indexed: 06/11/2023]
Abstract
The ability to grip and handle small objects, from sub-millimeter electronic components to single-micrometer living cells, is vital for numerous ever-shrinking technologies. Mechanical grippers, powered by electric, pneumatic, hydraulic or piezoelectric servos, are well suited for the job at larger scales, but their complexity and need for force transmission prevent their miniaturization and remote control in tight spaces. Using liquid crystal elastomer microstructures that can change shape quickly and reversibly in response to light, a light-powered gripping tool-optical pliers-is built by growing two bending jaws on the tips of optical fibers. By delivering UV light to trigger polymerization via a micrometer-size fiber core, structures of similar size can be made without resorting to any microfabrication technology, such as laser photolithography. The tool is operated using visible light energy supplied through the fibers, with no force transmission. The elastomer growth technique readily offers micrometer-scale, remotely controlled functional structures with different modes of actuation as building blocks for the microtoolbox.
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Affiliation(s)
- Michał Zmyślony
- Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, Warsaw, 02-093, Poland
| | - Klaudia Dradrach
- Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, Warsaw, 02-093, Poland
| | - Jakub Haberko
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, Kraków, 30-059, Poland
| | - Paweł Nałęcz-Jawecki
- Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, Warsaw, 02-093, Poland
| | - Mikołaj Rogóż
- Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, Warsaw, 02-093, Poland
| | - Piotr Wasylczyk
- Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, Warsaw, 02-093, Poland
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39
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Photo-Mechanical Response Dynamics of Liquid Crystal Elastomer Linear Actuators. MATERIALS 2020; 13:ma13132933. [PMID: 32629912 PMCID: PMC7372473 DOI: 10.3390/ma13132933] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/18/2020] [Accepted: 06/26/2020] [Indexed: 11/16/2022]
Abstract
With continuous miniaturization of many technologies, robotics seems to be lagging behind. While the semiconductor technologies operate confidently at the nanometer scale and micro-mechanics of simple structures (MEMS) in micrometers, autonomous devices are struggling to break the centimeter barrier and have hardly colonized smaller scales. One way towards miniaturization of robots involves remotely powered, light-driven soft mechanisms based on photo-responsive materials, such as liquid crystal elastomers (LCEs). While several simple devices have been demonstrated with contracting, bending, twisting, or other, more complex LCE actuators, only their simple behavior in response to light has been studied. Here we characterize the photo-mechanical response of a linear light-driven LCE actuator by measuring its response to laser beams with varying power, pulse duration, pulse energy, and the energy spatial distribution. Light absorption decrease in the actuator over time is also measured. These results are at the foundation of further development of soft, light-driven miniature mechanisms and micro-robots.
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40
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Yin L, Han L, Ge F, Tong X, Zhang W, Soldera A, Zhao Y. A Novel Side-Chain Liquid Crystal Elastomer Exhibiting Anomalous Reversible Shape Change. Angew Chem Int Ed Engl 2020; 59:15129-15134. [PMID: 32449819 DOI: 10.1002/anie.202003904] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/29/2020] [Indexed: 12/11/2022]
Abstract
Liquid crystalline elastomers (LCEs) have been actively investigated as stimuli-controlled actuators and soft robots. The basis of these applications is the ability of LCEs to undergo a reversible shape change upon a liquid crystalline (LC)-isotropic phase transition. Herein, we report the synthesis of a novel LCE based on a side-chain liquid crystalline polymer (SCLCP). In contrast to known LCEs, this LCE exhibits a striking anomalous shape change. Subjecting a mechanically stretched monodomain strip to LC-disorder phase transition, both the length and width of the strip contract in isotropic phase, and both elongate in LC phase. This thermally induced behaviour is the result of a subtle interplay between the relaxation of polymer main chain oriented along the stretching direction and the disordering of side-group mesogens oriented perpendicularly to the stretching direction. This finding points out potential design of LCEs of this peculiar type and possible applications to exploit.
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Affiliation(s)
- Lu Yin
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou Industrial Park, Suzhou, 215123, China
| | - Li Han
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
| | - Feijie Ge
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
| | - Xia Tong
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
| | - Wei Zhang
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou Industrial Park, Suzhou, 215123, China
| | - Armand Soldera
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
| | - Yue Zhao
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
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41
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Zhu C, Lu Y, Sun J, Yu Y. Dynamic Interfacial Regulation by Photodeformable Azobenzene-Containing Liquid Crystal Polymer Micro/Nanostructures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6611-6625. [PMID: 32449856 DOI: 10.1021/acs.langmuir.0c00582] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Photoresponsive materials offer local, temporal, and remote control over their chemical or physical properties under external stimuli, giving new tools for interfacial regulation. Among all, photodeformable azobenzene-containing liquid crystal polymers (azo-LCPs) have received increasing attention because they can be processed into various micro/nanostructures and have the potential to reversibly tune the interfacial properties through chemical and/or morphological variation by light, providing effective dynamic interface regulation. In this feature article, we highlight the milestones in the dynamic regulation of different interfacial properties through micro/nanostructures made of photodeformable azobenzene-containing liquid crystal polymers (azo-LCPs). We describe the preparation of different azo-LCP micro/nanostructures from the aspects of materials and processing techniques and reveal the importance of mesogen orientation toward dynamic interfacial regulation. By introducing our recently developed linear azo-LCP (azo-LLCP) with good mechanical and photoresponsive performances, we discuss the challenge and opportunity with respect to the dynamic light regulation of two- and three-dimensional (2D/3D) micro/nanostructures to tune their related interfacial properties. We have also given our expectation toward exploring photodeformable micro/nanostructures for advanced applications such as in microfluidics, biosensors, and nanotherapeutics.
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Affiliation(s)
- Chongyu Zhu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China
| | - Yao Lu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China
| | - Jiahao Sun
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China
| | - Yanlei Yu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China
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42
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Wang M, Cheng ZW, Zuo B, Chen XM, Huang S, Yang H. Liquid Crystal Elastomer Electric Locomotives. ACS Macro Lett 2020; 9:860-865. [PMID: 35648519 DOI: 10.1021/acsmacrolett.0c00333] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this letter, we present an electro-driven cylindrical actuator system composed of a bilayered liquid crystal elastomer/carbon black (LCE/CB) electro-driven soft actuator and a conductive track. The bilayered LCE/CB electro-driven actuator consists of an inner LCE circular band and several U-shaped CB conductive regions stuck on the outer surface of the LCE ring. Benefiting from the effective Joule heating of CB powder and the consequential inhomogeneous stress generated inside the bilayered LCE/CB film, the cylindrical actuator can roll forward with a rate of 1.6 mm/s along a stationary copper conductive track powered by a 50 V direct current supply. The dynamic connection between the rolling actuator and the conductive track effectively eliminates the limitation of electric wires in the complicated actuation set-ups of the LCE materials. This work might promote the development of electro-driven LCE actuators and have potential applications in the fields of soft robots and electric devices.
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Affiliation(s)
- Meng Wang
- School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Institute of Advanced Materials, Southeast University, Nanjing, 211189, China
| | - Zhi-Wen Cheng
- School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Institute of Advanced Materials, Southeast University, Nanjing, 211189, China
| | - Bo Zuo
- School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Institute of Advanced Materials, Southeast University, Nanjing, 211189, China
| | - Xu-Man Chen
- School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Institute of Advanced Materials, Southeast University, Nanjing, 211189, China
| | - Shuai Huang
- School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Institute of Advanced Materials, Southeast University, Nanjing, 211189, China
| | - Hong Yang
- School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Institute of Advanced Materials, Southeast University, Nanjing, 211189, China
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43
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Wang M, Hu XB, Zuo B, Huang S, Chen XM, Yang H. Liquid crystal elastomer actuator with serpentine locomotion. Chem Commun (Camb) 2020; 56:7597-7600. [PMID: 32514511 DOI: 10.1039/d0cc02823a] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A snake-mimic soft actuator composed of a bilayered liquid crystal elastomer ribbon and two serrated feet is reported in this work. Under repeated on/off near-infrared light irradiation, this actuator can move forward relying on a reversible shape morphing between S-curve structure and reverse S-curve structure, which is similar to the serpentine locomotion of snakes.
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Affiliation(s)
- Meng Wang
- School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, State Key Laboratory of Bioelectronics, Institute of Advanced Materials, Southeast University, Nanjing, 211189, China.
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44
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Zhao D, Liu Y. Light-induced spontaneous bending of a simply supported liquid crystal elastomer rectangular plate. Phys Rev E 2020; 101:042701. [PMID: 32422828 DOI: 10.1103/physreve.101.042701] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 04/07/2020] [Indexed: 11/07/2022]
Abstract
Designing the director alignment of a liquid crystal elastomer (LCE) is a key tuning approach for LCE based smart devices. In this paper, the spontaneous strain of the LCE with arbitrary three-dimensional director orientation is derived, and the governing equation for a simply supported LCE rectangular plate is established. By using the finite difference method, the bending configurations are obtained. Different from the freestanding case, three bending modes, that is, unimodal, bimodal, and trimodal modes, are observed for the simply supported rectangular LCE plate. The relation between the bending modes and the director orientation is established. This paper enhances the understanding and facilitates the design of LCE based intelligent light driven devices.
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Affiliation(s)
- Dong Zhao
- School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Ying Liu
- School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China
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45
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Lee J, Guo Y, Choi YJ, Jung S, Seol D, Choi S, Kim JH, Kim Y, Jeong KU, Ahn SK. Mechanically programmed 2D and 3D liquid crystal elastomers at macro- and microscale via two-step photocrosslinking. SOFT MATTER 2020; 16:2695-2705. [PMID: 32057062 DOI: 10.1039/c9sm02237f] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Liquid crystal elastomers (LCEs) are a unique class of active materials with the largest known reversible shape transformation in the solid state. The shape change of LCEs is directed by programming their molecular orientation, and therefore, several strategies to control LC alignment have been developed. Although mechanical alignment coupled with a two-step crosslinking is commonly adopted for uniaxially-aligned monodomain LCE synthesis, the fabrication of 3D-shaped LCEs at the macro- and microscale has been rarely accomplished. Here, we report a facile processing method for fabricating 2D and 3D-shaped LCEs at the macro- and microscales at room temperature by mechanically programming (i.e., stretching, pressing, embossing and UV-imprinting) the polydomain LCE, and subsequent photocrosslinking. The programmed LCEs exhibited a reversible shape change when exposed to thermal and chemical stimuli. Besides the programmed shape changes, the actuation strain can also be preprogrammed by adjusting the extent of elongation of a polydomain LCE. Furthermore, the LCE micropillar arrays prepared by UV-imprinting displayed a substantial change in pillar height in a reversible manner during thermal actuation. Our convenient method for fabricating reversible 2D and 3D-shaped LCEs from commercially available materials may expedite the potential applications of LCEs in actuators, soft robots, smart coatings, tunable optics and medicine.
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Affiliation(s)
- Jieun Lee
- Department of Polymer Science and Engineering, Pusan National University, Busan, 46241, Korea.
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46
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Vermes B, Czigany T. Non-Conventional Deformations: Materials and Actuation. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E1383. [PMID: 32197533 PMCID: PMC7142986 DOI: 10.3390/ma13061383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/28/2020] [Accepted: 03/13/2020] [Indexed: 11/16/2022]
Abstract
This paper reviews materials and structures displaying non-conventional deformations as a response to different actuations (e.g., electricity, heat and mechanical loading). Due to the various kinds of actuation and targeted irregular deformation modes, the approaches in the literature show great diversity. Methods are systematized and tabulated based on the nature of actuation. Electrically and mechanically actuated shape changing concepts are discussed individually for their significance, while systems actuated by heat, pressure, light and chemicals are condensed in a shared section presenting examples and main research trends. Besides scientific research results, this paper features examples of real-world applicability of shape changing materials, highlighting their industrial value.
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Affiliation(s)
- Bruno Vermes
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary;
- MTA-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Tibor Czigany
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary;
- MTA-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3., H-1111 Budapest, Hungary
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47
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A Review on Liquid Crystal Polymers in Free-Standing Reversible Shape Memory Materials. Molecules 2020; 25:molecules25051241. [PMID: 32164147 PMCID: PMC7179413 DOI: 10.3390/molecules25051241] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/29/2020] [Accepted: 03/03/2020] [Indexed: 01/25/2023] Open
Abstract
Liquid crystal polymers have attracted massive attention as stimuli-responsive shape memory materials due to their unique reversible large-scale and high-speed actuations. These materials can be utilized to fabricate artificial muscles, sensors, and actuators driven by thermal order–disorder phase transition or trans–cis photoisomerization. This review collects most commonly used liquid crystal monomers and techniques to macroscopically order and align liquid crystal materials (monodomain), highlighting the unique materials on the thermal and photo responsive reversible shape memory effects. Challenges and potential future applications are also discussed.
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48
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Dradrach K, Rogóż M, Grabowski P, Xuan C, Węgłowski R, Konieczkowska J, Schab-Balcerzak E, Piecek W, Wasylczyk P. Traveling Wave Rotary Micromotor Based on a Photomechanical Response in Liquid Crystal Polymer Networks. ACS APPLIED MATERIALS & INTERFACES 2020; 12:8681-8686. [PMID: 31994378 PMCID: PMC7497615 DOI: 10.1021/acsami.9b20309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The photomechanical response of liquid crystal polymer networks (LCNs) can be used to directly convert light energy into different forms of mechanical energy. In this study, we demonstrate how a traveling deformation, induced in a liquid crystal polymer ring by a spatially modulated laser beam, can be used to drive the ring (the rotor) to rotate around a stationary element (the stator), thus forming a light-powered micromotor. The photomechanical response of the polymer film is modeled numerically, different LCN molecular configurations are studied, and the performance of a 5.5 mm diameter motor is characterized.
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Affiliation(s)
- Klaudia Dradrach
- Photonic Nanostructure
Facility, Faculty of Physics, University
of Warsaw, ul. Pasteura
5, 02-093, Warsaw, Poland
| | - Mikołaj Rogóż
- Photonic Nanostructure
Facility, Faculty of Physics, University
of Warsaw, ul. Pasteura
5, 02-093, Warsaw, Poland
| | - Przemysław Grabowski
- Photonic Nanostructure
Facility, Faculty of Physics, University
of Warsaw, ul. Pasteura
5, 02-093, Warsaw, Poland
| | - Chen Xuan
- Department of Mathematical Sciences, Xi’an Jiaotong-Liverpool University, 111 Ren’ai Rd, Suzhou 215123, China
| | - Rafał Węgłowski
- Institute of Applied Physics, Military University of Technology, ul. Kaliskiego 2, 01-476 Warsaw, Poland
| | - Jolanta Konieczkowska
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Skłodowskiej 34, 41-819 Zabrze, Poland
| | - Ewa Schab-Balcerzak
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Skłodowskiej 34, 41-819 Zabrze, Poland
| | - Wiktor Piecek
- Institute of Applied Physics, Military University of Technology, ul. Kaliskiego 2, 01-476 Warsaw, Poland
| | - Piotr Wasylczyk
- Photonic Nanostructure
Facility, Faculty of Physics, University
of Warsaw, ul. Pasteura
5, 02-093, Warsaw, Poland
- E-mail:
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Two-Way and Multiple-Way Shape Memory Polymers for Soft Robotics: An Overview. ACTUATORS 2020. [DOI: 10.3390/act9010010] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Shape memory polymers (SMPs) are smart materials capable of changing their shapes in a predefined manner under a proper applied stimulus and have gained considerable interest in several application fields. Particularly, two-way and multiple-way SMPs offer unique opportunities to realize untethered soft robots with programmable morphology and/or properties, repeatable actuation, and advanced multi-functionalities. This review presents the recent progress of soft robots based on two-way and multiple-way thermo-responsive SMPs. All the building blocks important for the design of such robots, i.e., the base materials, manufacturing processes, working mechanisms, and modeling and simulation tools, are covered. Moreover, examples of real-world applications of soft robots and related actuators, challenges, and future directions are discussed.
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50
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Boothby JM, Van Volkenburg T, Le NQ, Ohiri K, Hagedon M, Xia Z. Effects of network structure on the mechanical and thermal responses of liquid crystal elastomers. ACTA ACUST UNITED AC 2020. [DOI: 10.1088/2399-7532/ab6d1e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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