1
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Jain H, Ghosh S. Imprinting reversible deformations on a compressed soft rod network. SOFT MATTER 2024; 20:5053-5059. [PMID: 38874537 DOI: 10.1039/d4sm00099d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
We present emergent behaviour of storing mechanical deformation in compressed soft cellular materials (a network of soft polymeric rods). Under an applied compressive strain field, the soft cellular material transits from an elastic regime to a 'pseudo-plastic' regime (not to be confused with pseudoplasticity in fluids). In the elastic phase, it is capable of forgetting (or relaxing) any applied indentation once the applied indentation is removed. This relaxation will be determined by the visco-elasticity and internal relaxation timescales in polymeric hyperelastic cellular materials. In the pseudo-plastic phase, however, the material is capable of storing local indentation (or deformation) indefinitely. This deformation can be erased via removal of the external strain field and is therefore reversible. We characterise this behaviour experimentally and present a simple model that makes use of friction for understanding this behavior.
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Affiliation(s)
- Harsh Jain
- Simons Centre for the Study of Living Machines, National Center for Biological Sciences, Bengaluru-560065, India.
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai-400005, India
| | - Shankar Ghosh
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai-400005, India
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2
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Liang H, Zhang Y, He E, Yang Y, Liu Y, Xu H, Yang Z, Wang Y, Wei Y, Ji Y. "Cloth-to-Clothes-Like" Fabrication of Soft Actuators. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2400286. [PMID: 38722690 DOI: 10.1002/adma.202400286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 04/20/2024] [Indexed: 05/16/2024]
Abstract
Inspired by adaptive natural organisms and living matter, soft actuators appeal to a variety of innovative applications such as soft grippers, artificial muscles, wearable electronics, and biomedical devices. However, their fabrication is typically limited in laboratories or a few enterprises since specific instruments, strong stimuli, or specialized operation skills are inevitably involved. Here a straightforward "cloth-to-clothes-like" method to prepare soft actuators with a low threshold by combining the hysteretic behavior of liquid crystal elastomers (LCEs) with the exchange reaction of dynamic covalent bonds, is proposed. Due to the hysteretic behavior, the LCEs (resemble "cloth") effectively retain predefined shapes after stretching and releasing for extended periods. Subsequently, the samples naturally become soft actuators (resemble "clothes") via the exchange reaction at ambient temperatures. As a post-synthesis method, this strategy effectively separates the production of LCEs and soft actuators. LCEs can be mass-produced in bulk by factories or producers and stored as prepared, much like rolls of cloth. When required, these LCEs can be customized into soft actuators as needed. This strategy provides a robust, flexible, and scalable solution to engineer soft actuators, holding great promise for mass production and universal applications.
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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, China
| | - Yubai Zhang
- Research Institute of Petroleum Processing, Beijing, 100083, China
| | - Enjian He
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yang Yang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China
| | - Yawen Liu
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Hongtu Xu
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Zhijun Yang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yixuan Wang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yen Wei
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
- Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung-Yuan Christian University, Chung-Li, Taiwan, 32023, China
| | - Yan Ji
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
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3
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Liu C, Li K, Yu X, Yang J, Wang Z. A Multimodal Self-Propelling Tensegrity Structure. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2314093. [PMID: 38561911 DOI: 10.1002/adma.202314093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 03/22/2024] [Indexed: 04/04/2024]
Abstract
Tensegrity structure is composed of tensile cables and compressive rods, offering high stiffness-to-mass ratio, deploy ability, and excellent energy damping capability. The active and dynamic tensegrity designs demonstrate great potential for soft robots. In previous designs, the movement has relied on carefully controlled input power or manually controlled light irradiation, limiting their potential applications. Here, a hybrid tensegrity structure (HTS) is constructed by integrating thermally responsive cables, nonresponsive cables, and stiff rods. The HTS can self-propel continuously on a hot surface due to its unique geometry. The HTS allows for the easy achievement of multimodal self-propelled locomotive modes, which has been challenging for previously demonstrated self-propelling structures. Additionally, using Velcro tapes to adhere the rods and cables together, a modulable and reassemblable HTS is created. The HTS introduced in this study presents a new strategy and offers a large design space for constructing self-propelling and modulable robots.
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Affiliation(s)
- Changyue Liu
- Key Laboratory of Aerospace Advanced Materials and Performance, Ministry of Education, School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Kai Li
- Department of Civil Engineering, Anhui Jianzhu University, Hefei, Anhui, 230601, China
| | - Xinzi Yu
- Key Laboratory of Aerospace Advanced Materials and Performance, Ministry of Education, School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Jiping Yang
- Key Laboratory of Aerospace Advanced Materials and Performance, Ministry of Education, School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhijian Wang
- Key Laboratory of Aerospace Advanced Materials and Performance, Ministry of Education, School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
- Tianmushan Laboratory, Xixi Octagon City, Yuhang District, Hangzhou, 310023, China
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4
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Jia B, Huang H, Dong Z, Ren X, Lu Y, Wang W, Zhou S, Zhao X, Guo B. Degradable biomedical elastomers: paving the future of tissue repair and regenerative medicine. Chem Soc Rev 2024; 53:4086-4153. [PMID: 38465517 DOI: 10.1039/d3cs00923h] [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: 03/12/2024]
Abstract
Degradable biomedical elastomers (DBE), characterized by controlled biodegradability, excellent biocompatibility, tailored elasticity, and favorable network design and processability, have become indispensable in tissue repair. This review critically examines the recent advances of biodegradable elastomers for tissue repair, focusing mainly on degradation mechanisms and evaluation, synthesis and crosslinking methods, microstructure design, processing techniques, and tissue repair applications. The review explores the material composition and cross-linking methods of elastomers used in tissue repair, addressing chemistry-related challenges and structural design considerations. In addition, this review focuses on the processing methods of two- and three-dimensional structures of elastomers, and systematically discusses the contribution of processing methods such as solvent casting, electrostatic spinning, and three-/four-dimensional printing of DBE. Furthermore, we describe recent advances in tissue repair using DBE, and include advances achieved in regenerating different tissues, including nerves, tendons, muscle, cardiac, and bone, highlighting their efficacy and versatility. The review concludes by discussing the current challenges in material selection, biodegradation, bioactivation, and manufacturing in tissue repair, and suggests future research directions. This concise yet comprehensive analysis aims to provide valuable insights and technical guidance for advances in DBE for tissue engineering.
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Affiliation(s)
- Ben Jia
- School of Civil Aviation, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Heyuan Huang
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Zhicheng Dong
- School of Civil Aviation, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Xiaoyang Ren
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Yanyan Lu
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Wenzhi Wang
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Shaowen Zhou
- Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Xin Zhao
- State Key Laboratory for Mechanical Behavior of Materials, and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Baolin Guo
- State Key Laboratory for Mechanical Behavior of Materials, and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an 710049, China
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5
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Liang Z, Jin B, Zhao H, He Z, Jiang Z, Jiang S. Rotini-like MXene@LCE Actuator with Diverse and Programmable Actuation Based on Dual-mode Synergy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2305371. [PMID: 38018306 DOI: 10.1002/smll.202305371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/22/2023] [Indexed: 11/30/2023]
Abstract
Liquid crystalline elastomer (LCE) exhibits muscle-like actuation upon order-disturbed stimulus, offering ample room for designing soft robotic systems. Multimodal LCE is demonstrated to unleash the potential to perform multitasks. However, each actuation mode is typically isolated. In contrast, coordination between different actuation modes based on an MXene-doped LCE is realized, whose actuation can be triggered either by directly heating/cooling or using near-infrared light due to the photo-thermal effect of MXene. As such, the two activation modes (heat and light) not only can work individually to offer stable actuation under different conditions but also can collaborate synergistically to generate more intelligent motions, such as achieving the brake and turn of an autonomous rolling. The principle therefore can diversify the design principles for multifunctional soft actuators and robotics.
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Affiliation(s)
- Ziwei Liang
- Institute of Safety Science and Engineering, School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou, 510641, China
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, 510641, China
| | - Binjie Jin
- Center for X-Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027, China
| | - Haotian Zhao
- Institute of Safety Science and Engineering, School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou, 510641, China
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, 510641, China
| | - Zhenhua He
- Institute of Safety Science and Engineering, School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou, 510641, China
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, 510641, China
| | - Zhanghe Jiang
- Guangzhou Academy of Special Mechanical and Electrical Equipment Inspection & Testing, Guangzhou, 510180, China
| | - Saihua Jiang
- Institute of Safety Science and Engineering, School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou, 510641, China
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, 510641, China
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6
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Khandagale P, Garcia-Cervera C, deBotton G, Breitzman T, Majidi C, Dayal K. Statistical field theory of polarizable polymer chains with nonlocal dipolar interactions. Phys Rev E 2024; 109:044501. [PMID: 38755880 DOI: 10.1103/physreve.109.044501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 02/14/2024] [Indexed: 05/18/2024]
Abstract
The electromechanical response of polymeric soft matter to applied electric fields is of fundamental scientific interest as well as relevant to technologies for sensing and actuation. Several existing theoretical and numerical approaches for polarizable polymers subject to a combined applied electric field and stretch are based on discrete monomer models. In these models, accounting for the interactions between the induced dipoles on monomers is challenging due to the nonlocality of these interactions. On the other hand, the framework of statistical field theory provides a continuous description of polymer chains that potentially enables a tractable way to account for these interactions. However, prior formulations using this framework have been restricted to the case of weak anisotropy of the monomer polarizability. This paper formulates a general approach based in the framework of statistical field theory to account for the nonlocal nature of the dipolar interactions without any restrictions on the anisotropy or nonlinearity of the polarizability of the monomer. The approach is based on three key elements: (1) the statistical field theory framework, in which the discrete monomers are regularized to a continuous dipole distribution, (2) a replacement of the nonlocal dipole-dipole interactions by the local electrostatics partial differential equation with the continuous dipole distribution as the forcing, and (3) the use of a completely general relation between the polarization and the local electric field. Rather than treat the dipole-dipole interactions directly, the continuous description in the field theory enables the computationally tractable nonlocal-to-local transformation. Further, it enables the use of a realistic statistical-mechanical ensemble wherein the average far-field applied electric field is prescribed, rather than prescribing the applied field at every point in the polymer domain. The model is applied, using the finite element method, to study the electromechanical response of a polymer chain in the ensemble with fixed far-field applied electric field and fixed chain stretch. The nonlocal dipolar interactions are found to increase, over the case where dipole-dipole interactions are neglected, the magnitudes of the polarization and electric field by orders of magnitude as well as significantly change their spatial distributions. Next, the effect of the relative orientation between the applied field and the chain on the local electric field and polarization is studied. The model predicts that the elastic response of the polymer chain is linear, consistent with the Gaussian approximation, and largely unchanged by the orientation of the applied electric field, though the polarization and local electric field distributions are significantly impacted.
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Affiliation(s)
- Pratik Khandagale
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh PA 15213, USA
| | - Carlos Garcia-Cervera
- Department of Mathematics, University of California, Santa Barbara CA 93106, USA
- BCAM, Basque Center for Applied Mathematics, E48009 Bilbao, Basque Country, Spain
| | - Gal deBotton
- Department of Mechanical Engineering, Ben Gurion University, 84105 Beer Sheva, Israel
- Department of Biomedical Engineering, Ben Gurion University, 84105 Beer Sheva, Israel
| | | | - Carmel Majidi
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh PA 15213, USA
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh PA 15213, USA
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh PA 15213, USA
| | - Kaushik Dayal
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh PA 15213, USA
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh PA 15213, USA
- Center for Nonlinear Analysis, Department of Mathematical Sciences, Carnegie Mellon University, Pittsburgh PA 15213, USA
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7
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Kim J, Choi YS, Park G, Kim M, Myung JS, Choi WJ, Park SM, Yoon DK. On-Demand Aligned DNA Hydrogel Via Light Scanning. ACS NANO 2023; 17:22778-22787. [PMID: 37947399 DOI: 10.1021/acsnano.3c07493] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
DNA is an anisotropic, water-attracting, and biocompatible material, an ideal building block for hydrogel. The alignment of the anisotropic DNA chains is essential to maximize hydrogel properties, which has been little explored. Here, we present a method to fabricate the anisotropic DNA hydrogel that allows precise control for the polymerization process of photoreactive cationic monomers. Scanning ultraviolet light enables the uniaxial alignment of DNA chains through the polymerization-induced diffusive mass flow using a concentration gradient. While studying anisotropic mechanical properties and orientation recovery according to the DNA chain alignment direction, we demonstrate the potential of directionally controlled DNA hydrogels as smart materials.
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Affiliation(s)
- Juri Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Yun-Seok Choi
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos 87545, New Mexico, USA
| | - Geonhyeong Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Mingeun Kim
- Chemical Materials Solutions Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Jin Suk Myung
- Chemical Materials Solutions Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Woo Jin Choi
- Chemical Materials Solutions Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Soon Mo Park
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Department of Chemical and Biomolecular Engineering, Cornell University, Ithaca 14853, New York, USA
| | - Dong Ki Yoon
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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8
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LoGrande K, Shankar MR, Dayal K. A dimensionally-reduced nonlinear elasticity model for liquid crystal elastomer strips with transverse curvature. SOFT MATTER 2023; 19:8764-8778. [PMID: 37938345 DOI: 10.1039/d3sm00664f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Liquid crystalline elastomers (LCEs) are active materials that are of interest due to their programmable response to various external stimuli such as light and heat. When exposed to these stimuli, the anisotropy in the response of the material is governed by the nematic director, which is a continuum parameter that is defined as the average local orientation of the mesogens in the liquid crystal phase. This nematic director can be programmed to be heterogeneous in space, creating a vast design space that is useful for applications ranging from artificial ligaments to deployable structures to self-assembling mechanisms. Even when specialized to long and thin strips of LCEs - the focus of this work - the vast design space has required the use of numerical simulations to aid in experimental discovery. To mitigate the computational expense of full 3-d numerical simulations, several dimensionally-reduced rod and ribbon models have been developed for LCE strips, but these have not accounted for the possibility of initial transverse curvature, like carpenter's tape spring. Motivated by recent experiments showing that transversely-curved LCE strips display a rich variety of configurations, this work derives a dimensionally-reduced 1-d model for pre-curved LCE strips. The 1-d model is validated against full 3-d finite element calculations, and it is also shown to capture experimental observations, including tape-spring-like localizations, in activated LCE strips.
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Affiliation(s)
- Kevin LoGrande
- Department of Civil and Environmental Engineering, Carnegie Mellon University, USA.
- Computation and Information Sciences Directorate, CCDC Army Research Lab, USA
| | - M Ravi Shankar
- Department of Industrial Engineering, University of Pittsburgh, USA
| | - Kaushik Dayal
- Department of Civil and Environmental Engineering, Carnegie Mellon University, USA.
- Center for Nonlinear Analysis, Department of Mathematical Sciences, Carnegie Mellon University, USA
- Department of Mechanical Engineering, Carnegie Mellon University, USA
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9
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Ma J, Huo X, Yin J, Cai S, Pang K, Liu Y, Gao C, Xu Z. Axially Encoded Mechano-Metafiber Electronics by Local Strain Engineering. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2305615. [PMID: 37821206 DOI: 10.1002/adma.202305615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/20/2023] [Indexed: 10/13/2023]
Abstract
Multimaterial integration, such as soft elastic and stiff components, exhibits rich deformation and functional behaviors to meet complex needs. Integrating multimaterials in the level of individual fiber is poised to maximize the functional design capacity of smart wearable electronic textiles, but remains unfulfilled. Here, this work continuously integrates stiff and soft elastic components into single fiber to fabricate encoded mechano-metafiber by programmable microfluidic sequence spinning (MSS). The sequences with programmable modulus feature the controllable localization of strain along metafiber length. The mechano-metafibers feature two essential nonlinear deformation modes, which are local strain amplification and retardation. This work extends the sequence-encoded metafiber into fiber networks to exhibit greatly enhanced strain amplification and retardation capability in cascades. Local strain engineering enables the design of highly sensitive strain sensors, stretchable fiber devices to protect brittle components and the fabrication of high-voltage supercapacitors as well as axial electroluminescent arrays. The approach allows the scalably design of multimaterial metafibers with programmable localized mechanical properties for woven metamaterials, smart textiles, and wearable electronics.
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Affiliation(s)
- Jingyu Ma
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, China
| | - Xiaodan Huo
- The State Key Laboratory of Fluid Power and Mechatronic Systems, Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, 310028, China
| | - Jun Yin
- The State Key Laboratory of Fluid Power and Mechatronic Systems, Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, 310028, China
| | - Shengying Cai
- Center for Healthcare Materials, Shaoxing Institute, Zhejiang University, Shaoxing, 312000, China
| | - Kai Pang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, China
| | - Yingjun Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, China
- Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan, 030032, P. R. China
| | - Chao Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, China
- Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan, 030032, P. R. China
| | - Zhen Xu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, China
- Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan, 030032, P. R. China
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10
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Wang Q, Tian X, Zhang D, Zhou Y, Yan W, Li D. Programmable spatial deformation by controllable off-center freestanding 4D printing of continuous fiber reinforced liquid crystal elastomer composites. Nat Commun 2023; 14:3869. [PMID: 37391425 DOI: 10.1038/s41467-023-39566-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 06/16/2023] [Indexed: 07/02/2023] Open
Abstract
Owing to their high deformation ability, 4D printed structures have various applications in origami structures, soft robotics and deployable mechanisms. As a material with programmable molecular chain orientation, liquid crystal elastomer is expected to produce the freestanding, bearable and deformable three-dimensional structure. However, majority of the existing 4D printing methods for liquid crystal elastomers can only fabricate planar structures, which limits their deformation designability and bearing capacity. Here we propose a direct ink writing based 4D printing method for freestanding continuous fiber reinforced composites. Continuous fibers can support freestanding structures during the printing process and improve the mechanical property and deformation ability of 4D printed structures. In this paper, the integration of 4D printed structures with fully impregnated composite interfaces, programmable deformation ability and high bearing capacity are realized by adjusting the off-center distribution of the fibers, and the printed liquid crystal composite can carry a load of up to 2805 times its own weight and achieve a bending deformation curvature of 0.33 mm-1 at 150 °C. This research is expected to open new avenues for creating soft robotics, mechanical metamaterials and artificial muscles.
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Affiliation(s)
- Qingrui Wang
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Xiaoyong Tian
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China.
| | - Daokang Zhang
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Yanli Zhou
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Wanquan Yan
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Dichen Li
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
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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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Becerra D, Jois PR, Hall LM. Coarse-grained modeling of polymers with end-on and side-on liquid crystal moieties: Effect of architecture. J Chem Phys 2023; 158:2895229. [PMID: 37290072 DOI: 10.1063/5.0152817] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 05/19/2023] [Indexed: 06/10/2023] Open
Abstract
Mesogens, which are typically stiff rodlike or disklike molecules, are able to self-organize into liquid crystal (LC) phases in a certain temperature range. Such mesogens, or LC groups, can be attached to polymer chains in various configurations including within the backbone (main-chain LC polymers) or at the ends of side-chains attached to the backbone in an end-on or side-on configuration (side-chain LC polymers or SCLCPs), which can display synergistic properties arising from both their LC and polymeric character. At lower temperatures, chain conformations may be significantly altered due to the mesoscale LC ordering; thus, when heated from the LC ordered state through the LC to isotropic phase transition, the chains return from a more stretched to a more random coil conformation. This can cause macroscopic shape changes, which depend significantly on the type of LC attachment and other architectural properties of the polymer. Here, to study the structure-property relationships for SCLCPs with a range of different architectures, we develop a coarse-grained model that includes torsional potentials along with LC interactions of a Gay-Berne form. We create systems of different side-chain lengths, chain stiffnesses, and LC attachment types and track their structural properties as a function of temperature. Our modeled systems indeed form a variety of well-organized mesophase structures at low temperatures, and we predict higher LC-to-isotropic transition temperatures for the end-on side-chain systems than for analogous side-on side-chain systems. Understanding these phase transitions and their dependence on polymer architecture can be useful in designing materials with reversible and controllable deformations.
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Affiliation(s)
- Diego Becerra
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA
| | - Pranav R Jois
- Department of Mathematics and Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Lisa M Hall
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA
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13
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Yao Y, He E, Xu H, Liu Y, Yang Z, Wei Y, Ji Y. Enabling liquid crystal elastomers with tunable actuation temperature. Nat Commun 2023; 14:3518. [PMID: 37316483 DOI: 10.1038/s41467-023-39238-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 05/31/2023] [Indexed: 06/16/2023] Open
Abstract
Liquid crystalline elastomers are regarded as a kind of desirable soft actuator material for soft robotics and other high-tech areas. The isotropization temperature (Ti) plays an important role as it determines the actuation temperature and other properties, which in turn has a great effect on their applications. In the past, the common physical methods (e.g. annealing) to tune Ti is not applicable to tune the actuation temperature. The new Ti obtained by annealing immediately goes back to the old one once it is heated to a temperature above Ti, while actuation needs a temperature higher than Ti. For a fully cross-linked LCE material, once it is synthesized, the actuation temperature is fixed. Accordingly, the actuation temperature can not be tuned unless the chemical structure is changed, which usually needs to start from the very beginning of the molecular design and material synthesis. Here, we found that different Ti achieved by annealing can be preserved by reversible reactions of dynamic covalent bonds in covalently adaptable LC networks including LC vitrimers. Thus, a variety of soft actuators with different actuation temperatures can be obtained from the same fully cross-linked LCE material. As the tuning of Ti is also reversible, the same actuator can be adjusted for applications with different actuation temperature requirements. Such tuning will also expand the application of LCEs.
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Affiliation(s)
- Yanjin Yao
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Enjian He
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Hongtu Xu
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yawen Liu
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Zhijun Yang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yen Wei
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China
- Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung-Yuan Christian University, Chung-Li, 32023, Taiwan, China
| | - Yan Ji
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China.
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14
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Khandagale P, Breitzman T, Majidi C, Dayal K. Statistical field theory for nonlinear elasticity of polymer networks with excluded volume interactions. Phys Rev E 2023; 107:064501. [PMID: 37464704 DOI: 10.1103/physreve.107.064501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 04/17/2023] [Indexed: 07/20/2023]
Abstract
Polymer networks formed by cross linking flexible polymer chains are ubiquitous in many natural and synthetic soft-matter systems. Current micromechanics models generally do not account for excluded volume interactions except, for instance, through imposing a phenomenological incompressibility constraint at the continuum scale. This work aims to examine the role of excluded volume interactions on the mechanical response. The approach is based on the framework of the self-consistent statistical field theory of polymers, which provides an efficient mesoscale approach that enables the accounting of excluded volume effects without the expense of large-scale molecular modeling. A mesoscale representative volume element is populated with multiple interacting chains, and the macroscale nonlinear elastic deformation is imposed by mapping the end-to-end vectors of the chains by this deformation. In the absence of excluded volume interactions, it recovers the closed-form results of the classical theory of rubber elasticity. With excluded volume interactions, the model is solved numerically in three dimensions using a finite element method to obtain the energy, stresses, and linearized moduli under imposed macroscale deformation. Highlights of the numerical study include: (i) the linearized Poisson's ratio is very close to the incompressible limit without a phenomenological imposition of incompressibility; (ii) despite the harmonic Gaussian chain as a starting point, there is an emergent strain-softening and strain-stiffening response that is characteristic of real polymer networks, driven by the interplay between the entropy and the excluded volume interactions; and (iii) the emergence of a deformation-sensitive localization instability at large excluded volumes.
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Affiliation(s)
- Pratik Khandagale
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Timothy Breitzman
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Carmel Majidi
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Kaushik Dayal
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
- Center for Nonlinear Analysis, Department of Mathematical Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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15
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Zhan Y, Broer DJ, Liu D. Perspiring Soft Robotics Skin Constituted by Dynamic Polarity-Switching Porous Liquid Crystal Membrane. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211143. [PMID: 36608160 DOI: 10.1002/adma.202211143] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/26/2022] [Indexed: 06/17/2023]
Abstract
Secretion of functional fluids is essential for affecting surface properties in ecosystems. The existing polymer membranes that mimic human skin functions are limited to secreting, either apolar or polar, liquid. However, the development of membranes that grant exchange liquid with different polarities remains a grand challenge. This process is prohibited by the mismatch of the polarity between the carrier polymer and the loaded liquid. To conquer this limitation, an innovative strategy is reported to dynamically switch the polarity of the porous membrane, thereby empowering the exchange of apolar liquid with polar liquid and vice versa. This approach incorporates a benzoic acid derivative into the original apolar polymer network. The benzoic acid dimerizes and forms hydrogen bonds, which supports the molecular alignment, but can be broken into the ionic state when subjected to alkaline treatment, changing the polarity of themembrane. Consequently, the apolar liquid can be replaced with a more polar one. This polar liquid is ejected upon safe-dose UV illumination from the membrane. Reabsorption occurs on demand by illumination of visible light or when left in contact with the membrane, spontaneously in the dark. Based on this, the consumed membrane is replenished with the same or different exchanging liquid.
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Affiliation(s)
- Yuanyuan Zhan
- 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
- 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
| | - Danqing Liu
- 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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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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Yasuoka H, Takahashi KZ, Aoyagi T. Impact of molecular architectures on mesogen reorientation relaxation and post-relaxation stress of liquid crystal elastomers under electric fields. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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18
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Hebner TS, McCracken JM, Bowman CN, White TJ. The Contribution of Oligomerization Reaction Chemistry to the Thermomechanical Properties of Surface-Aligned Liquid Crystalline Elastomers. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Tayler S. Hebner
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Joselle M. McCracken
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Christopher N. Bowman
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Timothy J. White
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
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19
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Liu Z, Wang H, Zhou C. Synthesis and Characterization of a Liquid Crystal-Modified Polydimethylsiloxane Rubber with Mechanical Adaptability Based on Chain Extension in the Process of Crosslinking. ACS OMEGA 2022; 7:36590-36597. [PMID: 36278106 PMCID: PMC9583084 DOI: 10.1021/acsomega.2c04560] [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: 07/19/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
The mechanical adaptive material is a kind of functional material that can effectively dissipate energy and suppress the increase of its stress under continuous strain in a large deformation area, which are vital in artificial muscles, connection devices, soft artificial intelligence robots, and other areas. Scientists have been working to broaden the platform of the material's mechanical adaptive platform and improve its mechanical strength by specific structure design. Based on it, we expect to introduce a mechanism of energy dissipation from the molecular chain scale to further improve mechanical adaptability. We developed a liquid crystal-modified polydimethylsiloxane rubber with mechanical adaptability based on chain extension in the process of crosslinking. Results showed that liquid crystal (0.7 mol %)-modified silicone rubber can obviously dissipate energy to achieve mechanical adaptive function, and the energy dissipation ratio of polydimethylsiloxane rubber (MQ), 4-propyl-4'-vinyl-1,1'-bi(cyclohexane)-modified polydimethylsiloxane rubber (3CCV-MQ), and 4-methoxyphenyl-4-(3-butenyloxy) benzoate-modified polydimethylsiloxane rubber (MBB-MQ) gradually decreases from 30 to 24%. Excessive thiol groups of liquid crystal-modified polydimethylsiloxane react with its vinyl group to achieve the chain extension, which significantly improves the mechanical strength from 2.74 to 5.83 MPa and elongation at break from 733 to 1096%. This research offers some new insights into improving the mechanical strength of silicone rubber and is of great significance for the application of the mechanical adaptive material.
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20
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Cang Y, Liu J, Ryu M, Graczykowski B, Morikawa J, Yang S, Fytas G. On the origin of elasticity and heat conduction anisotropy of liquid crystal elastomers at gigahertz frequencies. Nat Commun 2022; 13:5248. [PMID: 36068238 PMCID: PMC9448779 DOI: 10.1038/s41467-022-32865-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 08/18/2022] [Indexed: 11/09/2022] Open
Abstract
Liquid crystal elastomers that offer exceptional load-deformation response at low frequencies often require consideration of the mechanical anisotropy only along the two symmetry directions. However, emerging applications operating at high frequencies require all five true elastic constants. Here, we utilize Brillouin light spectroscopy to obtain the engineering moduli and probe the strain dependence of the elasticity anisotropy at gigahertz frequencies. The Young's modulus anisotropy, E||/E⊥~2.6, is unexpectedly lower than that measured by tensile testing, suggesting disparity between the local mesogenic orientation and the larger scale orientation of the network strands. Unprecedented is the robustness of E||/E⊥ to uniaxial load that it does not comply with continuously transformable director orientation observed in the tensile testing. Likewise, the heat conductivity is directional, κ||/κ⊥~3.0 with κ⊥ = 0.16 Wm-1K-1. Conceptually, this work reveals the different length scales involved in the thermoelastic anisotropy and provides insights for programming liquid crystal elastomers on-demand for high-frequency applications.
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Affiliation(s)
- Yu Cang
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Zhangwu Road 100, Shanghai, 200092, China.,Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany
| | - Jiaqi Liu
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
| | - Meguya Ryu
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan.,National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, 305-8563, Japan
| | - Bartlomiej Graczykowski
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany.,Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznanskiego 2, Poznan, 61-614, Poland
| | - Junko Morikawa
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA.
| | - George Fytas
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany.
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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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Yasuoka H, Takahashi KZ, Aoyagi T. Trade-off effect between the stress and strain range in the soft elasticity of liquid crystalline elastomers. Polym J 2022. [DOI: 10.1038/s41428-022-00641-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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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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24
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Balakrishnan G, Song J, Mou C, Bettinger CJ. Recent Progress in Materials Chemistry to Advance Flexible Bioelectronics in Medicine. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106787. [PMID: 34751987 PMCID: PMC8917047 DOI: 10.1002/adma.202106787] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/15/2021] [Indexed: 05/09/2023]
Abstract
Designing bioelectronic devices that seamlessly integrate with the human body is a technological pursuit of great importance. Bioelectronic medical devices that reliably and chronically interface with the body can advance neuroscience, health monitoring, diagnostics, and therapeutics. Recent major efforts focus on investigating strategies to fabricate flexible, stretchable, and soft electronic devices, and advances in materials chemistry have emerged as fundamental to the creation of the next generation of bioelectronics. This review summarizes contemporary advances and forthcoming technical challenges related to three principal components of bioelectronic devices: i) substrates and structural materials, ii) barrier and encapsulation materials, and iii) conductive materials. Through notable illustrations from the literature, integration and device fabrication strategies and associated challenges for each material class are highlighted.
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Affiliation(s)
| | - Jiwoo Song
- Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA
| | - Chenchen Mou
- Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA
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25
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Liu Z, Wang H, Zhou C. The Effect of Phenyl Content on the Liquid Crystal-Based Organosilicone Elastomers with Mechanical Adaptability. Polymers (Basel) 2022; 14:903. [PMID: 35267724 PMCID: PMC8912632 DOI: 10.3390/polym14050903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 12/02/2022] Open
Abstract
An elastomer with mechanical adaptability is a new kind of polymer material in which the increasing stress under continuous deformation is significantly inhibited in a large deformation area. Liquid crystal-based organosilicone elastomers, which can dissipate energy through reversible internal phase transition under external stimulation and have recoverable large deformation capacity, have drawn much interest as mechanical adaptability materials. However, there is no good way to control the mechanical adaptability at present. For this purpose, we prepared a new liquid crystal-based phenyl silicone rubber (LCMVPQ) using two-step click reactions and systematically explored the effect of phenyl content on its mechanical adaptability to achieve the regulation of mechanical adaptability. With an increase in phenyl content in the LCMVPQs, phenyl can hinder the rearrangement of the mesogenic units along the applied stress direction, which enables the adjustment of mechanical adaptability to meet the needs of different situations. In addition, the introduction of the liquid crystal phase impedes the internal friction of the molecular chain movement of the LCMVPQs and reduces the damping performance of silicone rubber. This research achieves the regulation of elastomers with mechanical adaptability and is expected to be applied in practical application fields.
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Affiliation(s)
| | | | - Chuanjian Zhou
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China; (Z.L.); (H.W.)
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26
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Liu Z, Xiong Y, Hao J, Zhang H, Cheng X, Wang H, Chen W, Zhou C. Liquid Crystal-Based Organosilicone Elastomers with Supreme Mechanical Adaptability. Polymers (Basel) 2022; 14:789. [PMID: 35215702 PMCID: PMC8880581 DOI: 10.3390/polym14040789] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/30/2022] [Accepted: 02/03/2022] [Indexed: 02/04/2023] Open
Abstract
Elastomers with supreme mechanical adaptability where the increasing stress under continuous deformation is significantly inhibited within a large deformation zone, are highly desired in many areas, such as artificial muscles, flexible and wearable electronics, and soft artificial-intelligence robots. Such system comprises the advantages of recoverable elasticity and internal compensation to external mechanical work. To obtain elastomer with supreme mechanical adaptability, a novel liquid crystal-based organosilicon elastomer (LCMQ) is developed in this work, which takes the advantages of reversible strain-induced phase transition of liquid crystal units in polymer matrix and the recoverable nano-sized fillers. The former is responsible for the inhibition of stress increasing during deformation, where the external work is mostly compensated by internal phase transition, and the latter provides tunable and sufficient high tensile strength. Such LCMQs were synthesized with 4-methoxyphenyl 4-(but-3-en-1-yloxy)benzoate (MBB) grafted thiol silicone oil (crosslinker-g-MBB) as crosslinking agent, vinyl terminated polydimethylsiloxane as base adhesive, and fumed silica as reinforcing filler by two-step thiol-ene "click" reaction. The obtained tensile strength and the elongation at break are better than previously reported values. Moreover, the resulting liquid crystal elastomers exhibit different mechanical behavior from conventional silicone rubbers. When the liquid crystal content increases from 1% (w/w) to 4% (w/w), the stress plateau for mechanical adaptability becomes clearer. Moreover, the liquid crystal elastomer has no obvious deformation from 25 °C to 120 °C and is expected to be used in industrial applications. It also provides a new template for the modification of organosilicon elastomers.
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Affiliation(s)
- Zhe Liu
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China; (Z.L.); (J.H.); (H.Z.); (X.C.); (H.W.)
| | - Yuqi Xiong
- CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, China;
| | - Jinghao Hao
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China; (Z.L.); (J.H.); (H.Z.); (X.C.); (H.W.)
| | - Hao Zhang
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China; (Z.L.); (J.H.); (H.Z.); (X.C.); (H.W.)
| | - Xiao Cheng
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China; (Z.L.); (J.H.); (H.Z.); (X.C.); (H.W.)
| | - Hua Wang
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China; (Z.L.); (J.H.); (H.Z.); (X.C.); (H.W.)
| | - Wei Chen
- CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, China;
| | - Chuanjian Zhou
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China; (Z.L.); (J.H.); (H.Z.); (X.C.); (H.W.)
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27
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Astam MO, Zhan Y, Slot TK, Liu D. Active Surfaces Formed in Liquid Crystal Polymer Networks. ACS APPLIED MATERIALS & INTERFACES 2022; 14:22697-22705. [PMID: 35142206 PMCID: PMC9136844 DOI: 10.1021/acsami.1c21024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
There is an increasing interest in animating materials to develop dynamic surfaces. These dynamic surfaces can be utilized for advanced applications, including switchable wetting, friction, and lubrication. Dynamic surfaces can also improve existing technologies, for example, by integrating self-cleaning surfaces on solar cells. In this Spotlight on Applications, we describe our most recent advances in liquid crystal polymer network (LCN) dynamic surfaces, focusing on substrate-based topographies and dynamic porous networks. We discuss our latest insights in the mechanisms of deformation with the "free volume" principle. We illustrate the scope of LCN technology through various examples of photo-/electropatterning, free-volume channeling, oscillating/programmable network distortion, and porous LCNs. Finally, we close by discussing prominent applications of LCNs and their outlook.
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Affiliation(s)
- Mert O. Astam
- Laboratory
of Stimuli-Responsive Functional Materials and Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, The Netherlands
- Institute
for Complex Molecular Systems (ICMS), Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, The Netherlands
| | - Yuanyuan Zhan
- Laboratory
of Stimuli-Responsive Functional Materials and Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, The Netherlands
- Institute
for Complex Molecular Systems (ICMS), Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, The Netherlands
| | - Thierry K. Slot
- Laboratory
of Stimuli-Responsive Functional Materials and Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, The Netherlands
- Institute
for Complex Molecular Systems (ICMS), Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, The Netherlands
| | - Danqing Liu
- Laboratory
of Stimuli-Responsive Functional Materials and Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, The Netherlands
- Institute
for Complex Molecular Systems (ICMS), Eindhoven
University of Technology, Groene Loper 3, Eindhoven AE 5612, 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
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Abstract
In contrast to conventional hard actuators, soft actuators offer many vivid advantages, such as improved flexibility, adaptability, and reconfigurability, which are intrinsic to living systems. These properties make them particularly promising for different applications, including soft electronics, surgery, drug delivery, artificial organs, or prosthesis. The additional degree of freedom for soft actuatoric devices can be provided through the use of intelligent materials, which are able to change their structure, macroscopic properties, and shape under the influence of external signals. The use of such intelligent materials allows a substantial reduction of a device's size, which enables a number of applications that cannot be realized by externally powered systems. This review aims to provide an overview of the properties of intelligent synthetic and living/natural materials used for the fabrication of soft robotic devices. We discuss basic physical/chemical properties of the main kinds of materials (elastomers, gels, shape memory polymers and gels, liquid crystalline elastomers, semicrystalline ferroelectric polymers, gels and hydrogels, other swelling polymers, materials with volume change during melting/crystallization, materials with tunable mechanical properties, and living and naturally derived materials), how they are related to actuation and soft robotic application, and effects of micro/macro structures on shape transformation, fabrication methods, and we highlight selected applications.
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Affiliation(s)
- Indra Apsite
- Faculty of Engineering Science, Department of Biofabrication, University of Bayreuth, Ludwig Thoma Str. 36A, 95447 Bayreuth, Germany
| | - Sahar Salehi
- Department of Biomaterials, Center of Energy Technology und Materials Science, University of Bayreuth, Prof.-Rüdiger-Bormann-Straße 1, 95447 Bayreuth, Germany
| | - Leonid Ionov
- Faculty of Engineering Science, Department of Biofabrication, University of Bayreuth, Ludwig Thoma Str. 36A, 95447 Bayreuth, Germany.,Bavarian Polymer Institute, University of Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany
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29
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Khan M, Liu S, Qi L, Ma C, Munir S, Yu L, Hu Q. Liquid crystal-based sensors for the detection of biomarkers at the aqueous/LC interface. Trends Analyt Chem 2021. [DOI: 10.1016/j.trac.2021.116434] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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30
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Wu J, Yao S, Zhang H, Man W, Bai Z, Zhang F, Wang X, Fang D, Zhang Y. Liquid Crystal Elastomer Metamaterials with Giant Biaxial Thermal Shrinkage for Enhancing Skin Regeneration. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2106175. [PMID: 34561930 DOI: 10.1002/adma.202106175] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Indexed: 06/13/2023]
Abstract
Liquid crystal elastomers (LCEs) are a class of soft active materials of increasing interest, because of their excellent actuation and optical performances. While LCEs show biomimetic mechanical properties (e.g., elastic modulus and strength) that can be matched with those of soft biological tissues, their biointegrated applications have been rarely explored, in part, due to their high actuation temperatures (typically above 60 °C) and low biaxial actuation performances (e.g., actuation strain typically below 10%). Here, unique mechanics-guided designs and fabrication schemes of LCE metamaterials are developed that allow access to unprecedented biaxial actuation strain (-53%) and biaxial coefficient of thermal expansion (-33 125 ppm K-1 ), significantly surpassing those (e.g., -20% and -5950 ppm K-1 ) reported previously. A low-temperature synthesis method with use of optimized composition ratios enables LCE metamaterials to offer reasonably high actuation stresses/strains at a substantially reduced actuation temperature (46 °C). Such biocompatible LCE metamaterials are integrated with medical dressing to develop a breathable, shrinkable, hemostatic patch as a means of noninvasive treatment. In vivo animal experiments of skin repair with both round and cross-shaped wounds demonstrate advantages of the hemostatic patch over conventional strategies (e.g., medical dressing and suturing) in accelerating skin regeneration, while avoiding scar and keloid generation.
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Affiliation(s)
- Jun Wu
- AML, Department of Engineering Mechanics, Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Shenglian Yao
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Hang Zhang
- AML, Department of Engineering Mechanics, Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Weitao Man
- Department of Neurosurgery, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, 102218, P. R. China
| | - Zhili Bai
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Fan Zhang
- AML, Department of Engineering Mechanics, Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Xiumei Wang
- School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Daining Fang
- Institute of Advanced Structure Technology, Beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Yihui Zhang
- AML, Department of Engineering Mechanics, Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
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31
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Guo Y, Zhang J, Hu W, Khan MTA, Sitti M. Shape-programmable liquid crystal elastomer structures with arbitrary three-dimensional director fields and geometries. Nat Commun 2021; 12:5936. [PMID: 34642352 PMCID: PMC8511085 DOI: 10.1038/s41467-021-26136-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 09/08/2021] [Indexed: 11/09/2022] Open
Abstract
Liquid crystal elastomers exhibit large reversible strain and programmable shape transformations, enabling various applications in soft robotics, dynamic optics, and programmable origami and kirigami. The morphing modes of these materials depend on both their geometries and director fields. In two dimensions, a pixel-by-pixel design has been accomplished to attain more flexibility over the spatial resolution of the liquid crystal response. Here we generalize this idea in two steps. First, we create independent, cubic light-responsive voxels, each with a predefined director field orientation. Second, these voxels are in turn assembled to form lines, grids, or skeletal structures that would be rather difficult to obtain from an initially connected material sample. In this way, the orientation of the director fields can be made to vary at voxel resolution to allow for programmable optically- or thermally-triggered anisotropic or heterogeneous material responses and morphology changes in three dimensions that would be impossible or hard to implement otherwise.
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Affiliation(s)
- Yubing Guo
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute of Engineering Medicine, Beijing Institute of Technology, 100081, Beijing, China
| | - Jiachen Zhang
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong SAR, China
| | - Wenqi Hu
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Muhammad Turab Ali Khan
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany.
- Institute for Biomedical Engineering, ETH Zurich, 8092, Zurich, Switzerland.
- School of Medicine and College of Engineering, Koç University, 34450, Istanbul, Turkey.
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32
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Ohzono T, Minamikawa H, Koyama E, Norikane Y. Impact of Crystallites in Nematic Elastomers on Dynamic Mechanical Properties and Adhesion. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01160] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takuya Ohzono
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan
| | - Hiroyuki Minamikawa
- Interdisciplinary Research Center for Catalytic Chemistry, AIST, 1-1-1 Higashi, Tsukuba 305-8565, Japan
| | - Emiko Koyama
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan
| | - Yasuo Norikane
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan
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33
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Cell instructive Liquid Crystalline Networks for myotube formation. iScience 2021; 24:103077. [PMID: 34568797 PMCID: PMC8449234 DOI: 10.1016/j.isci.2021.103077] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/16/2021] [Accepted: 08/29/2021] [Indexed: 02/04/2023] Open
Abstract
Development of biological tissues in vitro is not a trivial task and requires the correct maturation of the selected cell line. To this aim, many attempts were done mainly by mimicking the biological environment using micro/nanopatterned or stimulated scaffolds. However, the obtainment of functional tissues in vitro is still far from being achieved. In contrast with the standard methods, we here present an easy approach for the maturation of myotubes toward the reproduction of muscular tissue. By using liquid crystalline networks with different stiffness and molecular alignment, we demonstrate how the material itself can give favorable interactions with myoblasts helping a correct differentiation. Electrophysiological studies demonstrate that myotubes obtained on these polymers have more adult-like morphology and better functional features with respect to those cultured on standard supports. The study opens to a platform for the differentiation of other cell lines in a simple and scalable way.
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34
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Han WC, Sim GW, Kim YB, Kim DS. Reversible Curvature Reversal of Monolithic Liquid Crystal Elastomer Film and Its Smart Valve Application. Macromol Rapid Commun 2021; 42:e2100404. [PMID: 34418205 DOI: 10.1002/marc.202100404] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/12/2021] [Indexed: 11/11/2022]
Abstract
Beyond a traditional stimuli-responsive soft actuator that shows a single motion by a stimulus, multidirectional actuation reversal with a single stimulus is highly required in applications such as shape morphing sensors and soft robotics. Liquid crystal elastomers (LCEs) are one of the most attractive candidates for the soft actuator due to their capability of stimuli-responsive shape changing in 3D, which is programmable with local orientation of LC mesogens. Here, a simple but effective method to fabricate monolithic LCE actuators that are capable of reversible curvature reversal in bending and twisting deformation by a single stimulus-heat-is reported. The curvature reversal of the LCE film can be programmed by means of asymmetric crosslinking density along the thickness and the orientation of the LC mesogens. The curvature reversal of the monolithic LCE film exhibits highly reversible (more than 100 times) and fast actuation (≈3-5 s) by heating and cooling, allowing new concept of a practical application using LCE material: a self-regulated smart valve that is capable of qualitatively sorting liquids by temperature. It is believed that this system is potentially applied to a self-regulated sorting platform for various endothermic and exothermic chemical or biological reactions.
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Affiliation(s)
- Woong Chan Han
- Department of Polymer Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513, South Korea
| | - Gun Woo Sim
- Department of Polymer Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513, South Korea
| | - Young Been Kim
- Department of Polymer Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513, South Korea
| | - Dae Seok Kim
- Department of Polymer Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513, South Korea
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35
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You R, Kang S, Lee C, Jeon J, Wie JJ, Kim TS, Yoon DK. Programmable Liquid Crystal Defect Arrays via Electric Field Modulation for Mechanically Functional Liquid Crystal Networks. ACS APPLIED MATERIALS & INTERFACES 2021; 13:36253-36261. [PMID: 34310107 DOI: 10.1021/acsami.1c04999] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The arrangement of mesogenic units determines mechanical response of the liquid crystal polymer network (LCN) film to heat. Here, we show an interesting approach to programming three-dimensional patterns of the LCN films with periodic topological defects generated by applying an electric field. The mechanical properties of three representative patterned LCN films were investigated in terms of the arrangement of mesogenic units through tensile testing. Remarkably, it was determined that LCN films showed enhanced toughness and ductility as defects increased in a given area, which is related to the elastic modulus mismatch that mitigates crack propagation. Our platform can also be used to modulate the frictional force of the patterned LCN films by varying the temperature, which can provide insight into the multiplex mechanical properties of LCN films.
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Affiliation(s)
- Ra You
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Sumin Kang
- Department of Mechanical Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - Changjae Lee
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Jisoo Jeon
- Department of Polymer Science and Engineering, Inha University, Incheon 22212, Republic of Korea
- Program in Environmental and Polymer Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Jeong Jae Wie
- Department of Polymer Science and Engineering, Inha University, Incheon 22212, Republic of Korea
- Program in Environmental and Polymer Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Taek-Soo Kim
- Department of Mechanical Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - Dong Ki Yoon
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
- Graduate School of Nanoscience and Technology and KAIST Institute for Nanocentury, KAIST, Daejeon 34141, Republic of Korea
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36
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Zhang M, Shahsavan H, Guo Y, Pena-Francesch A, Zhang Y, Sitti M. Liquid-Crystal-Elastomer-Actuated Reconfigurable Microscale Kirigami Metastructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008605. [PMID: 33987863 PMCID: PMC7612660 DOI: 10.1002/adma.202008605] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/26/2021] [Indexed: 05/02/2023]
Abstract
Programmable actuation of metastructures with predesigned geometrical configurations has recently drawn significant attention in many applications, such as smart structures, medical devices, soft robotics, prosthetics, and wearable devices. Despite remarkable progress in this field, achieving wireless miniaturized reconfigurable metastructures remains a challenge due to the difficult nature of the fabrication and actuation processes at the micrometer scale. Herein, microscale thermo-responsive reconfigurable metasurfaces using stimuli-responsive liquid crystal elastomers (LCEs) is fabricated as an artificial muscle for reconfiguring the 2D microscale kirigami structures. Such structures are fabricated via two-photon polymerization with sub-micrometer precision. Through rationally designed experiments guided by simulations, the optimal formulation of the LCE artificial muscle is explored and the relationship between shape transformation behaviors and geometrical parameters of the kirigami structures is build. As a proof of concept demonstration, the constructs for temperature-dependent switching and information encryption is applied. Such reconfigurable kirigami metastructures have significant potential for boosting the fundamental small-scale metastructure research and the design and fabrication of wireless functional devices, wearables, and soft robots at the microscale as well.
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Affiliation(s)
- Mingchao Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Hamed Shahsavan
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Department of Chemical Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Yubing Guo
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Abdon Pena-Francesch
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Department of Materials Science and Engineering, Macromolecular Science and Engineering, Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yingying Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, Zürich, 8092, Switzerland
- School of Medicine and School of Engineering, Koç University, Istanbul, 34450, Turkey
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37
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Tokumoto H, Zhou H, Takebe A, Kamitani K, Kojio K, Takahara A, Bhattacharya K, Urayama K. Probing the in-plane liquid-like behavior of liquid crystal elastomers. SCIENCE ADVANCES 2021; 7:eabe9495. [PMID: 34144981 PMCID: PMC8213220 DOI: 10.1126/sciadv.abe9495] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 05/05/2021] [Indexed: 06/12/2023]
Abstract
When isotropic solids are unequally stretched in two orthogonal directions, the true stress (force per actual cross-sectional area) in the larger strain direction is typically higher than that in the smaller one. We show that thiol-acrylate liquid crystal elastomers with polydomain texture exhibit an unusual tendency: The true stresses in the two directions are always identical and governed only by the area change in the loading plane, independently of the combination of imposed strains in the two directions. This feature proves a previously unidentified state of matter that can vary its shape freely with no extra mechanical energy like liquids when deformed in the plane. The theory and simulation that explain the unique behavior are also provided. The in-plane liquid-like behavior opens doors for manifold applications, including wrinkle-free membranes and adaptable materials.
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Affiliation(s)
- Haruki Tokumoto
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
| | - Hao Zhou
- Department of Mechanical and Civil Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Asaka Takebe
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
| | - Kazutaka Kamitani
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ken Kojio
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Atsushi Takahara
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kaushik Bhattacharya
- Department of Mechanical and Civil Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Kenji Urayama
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
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38
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Grasinger M, Majidi C, Dayal K. Nonlinear statistical mechanics drives intrinsic electrostriction and volumetric torque in polymer networks. Phys Rev E 2021; 103:042504. [PMID: 34006015 DOI: 10.1103/physreve.103.042504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/08/2021] [Indexed: 11/07/2022]
Abstract
Statistical mechanics is an important tool for understanding polymer electroelasticity because the elasticity of polymers is primarily due to entropy. However, a common approach for the statistical mechanics of polymer chains, the Gaussian chain approximation, misses key physics. By considering the nonlinearities of the problem, we show a strong coupling between the deformation of a polymer chain and its dielectric response, that is, its net dipole. When chains with this coupling are cross linked in an elastomer network and an electric field is applied, the field breaks the symmetry of the elastomer's elastic properties and, combined with electrostatic torque and incompressibility, leads to intrinsic electrostriction. Conversely, deformation can break the symmetry of the dielectric response, leading to volumetric torque and asymmetric actuation. Both phenomena have important implications for designing high-efficiency soft actuators and soft electroactive materials, and the presence of mechanisms for volumetric torque, in particular, can be used to develop higher degree of freedom actuators and to achieve bioinspired locomotion.
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Affiliation(s)
- Matthew Grasinger
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.,Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.,UES, Inc., Dayton, Ohio 45432, USA.,Materials and Manufacturing Directorate, Air Force Research Laboratory, Dayton, Ohio 45433, USA
| | - Carmel Majidi
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.,Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.,Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Kaushik Dayal
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.,Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.,Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.,Center for Nonlinear Analysis, Department of Mathematical Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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39
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Liquid Crystal Elastomers for Biological Applications. NANOMATERIALS 2021; 11:nano11030813. [PMID: 33810173 PMCID: PMC8005174 DOI: 10.3390/nano11030813] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 11/16/2022]
Abstract
The term liquid crystal elastomer (LCE) describes a class of materials that combine the elastic entropy behaviour associated with conventional elastomers with the stimuli responsive properties of anisotropic liquid crystals. LCEs consequently exhibit attributes of both elastomers and liquid crystals, but additionally have unique properties not found in either. Recent developments in LCE synthesis, as well as the understanding of the behaviour of liquid crystal elastomers—namely their mechanical, optical and responsive properties—is of significant relevance to biology and biomedicine. LCEs are abundant in nature, highlighting the potential use of LCEs in biomimetics. Their exceptional tensile properties and biocompatibility have led to research exploring their applications in artificial tissue, biological sensors and cell scaffolds by exploiting their actuation and shock absorption properties. There has also been significant recent interest in using LCEs as a model for morphogenesis. This review provides an overview of some aspects of LCEs which are of relevance in different branches of biology and biomedicine, as well as discussing how recent LCE advances could impact future applications.
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40
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Okamoto S, Sakurai S, Urayama K. Effect of stretching angle on the stress plateau behavior of main-chain liquid crystal elastomers. SOFT MATTER 2021; 17:3128-3136. [PMID: 33599677 DOI: 10.1039/d0sm02244f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The equilibrium nonlinear stress-stretch relationships for a monodomain main-chain nematic elastomer (MNE) are investigated by varying the angle between the stretching and initial director axes (θ0). Angle θ0 has pronounced effects on the ultimate elongation as well as on the width of the low stress plateau regime (Λp) during director rotation, whereas θ0 has no appreciable effect on the plateau stress (σp). In the stretching normal to the initial director (θ0 = 90°), the plateau end exceeds 200% strain. At oblique angles of 90° > θ0≥ 35°, Λp decreases with decreasing θ0, whereas the definite plateau regime vanishes at θ0 < 24°. Wide-angle X-ray scattering and polarized optical microscopy measurements reveal that the director rotates uniformly in the biased direction for the MNE of θ0°≪ 90°, whereas directors rotating clockwise and counterclockwise are coexistent for θ0 = 90°. Over the entire plateau regime, the MNEs exhibit pure shear deformation characterized by a Poisson's ratio of zero in the direction of the rotation axis. The Λp for the corresponding polydomain NE (PNE) undergoing a transition to the monodomain alignment is smaller than that of the MNE of θ0 = 90°, while the σp values for both NEs are almost similar. The semi-soft elasticity concept satisfactorily explains the effects of θ0 on Λp, and the Λp value of the PNE, using a single anisotropy parameter which is evaluated from the degree of thermally induced deformation of MNEs.
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Affiliation(s)
- Suzuka Okamoto
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
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Ohzono T, Katoh K, Minamikawa H, Saed MO, Terentjev EM. Internal constraints and arrested relaxation in main-chain nematic elastomers. Nat Commun 2021; 12:787. [PMID: 33542238 PMCID: PMC7862651 DOI: 10.1038/s41467-021-21036-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/04/2021] [Indexed: 11/16/2022] Open
Abstract
Nematic liquid crystal elastomers (N-LCE) exhibit intriguing mechanical properties, such as reversible actuation and soft elasticity, which manifests as a wide plateau of low nearly-constant stress upon stretching. N-LCE also have a characteristically slow stress relaxation, which sometimes prevents their shape recovery. To understand how the inherent nematic order retards and arrests the equilibration, here we examine hysteretic stress-strain characteristics in a series of specifically designed main-chain N-LCE, investigating both macroscopic mechanical properties and the microscopic nematic director distribution under applied strains. The hysteretic features are attributed to the dynamics of thermodynamically unfavoured hairpins, the sharp folds on anisotropic polymer strands, the creation and transition of which are restricted by the nematic order. These findings provide a new avenue for tuning the hysteretic nature of N-LCE at both macro- and microscopic levels via different designs of polymer networks, toward materials with highly nonlinear mechanical properties and shape-memory applications.
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Affiliation(s)
- Takuya Ohzono
- Research Institute for Electronics and Photonics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.
| | - Kaoru Katoh
- Biomedical Research Institute, AIST, Tsukuba, Japan
| | | | - Mohand O Saed
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
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42
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Xia Y, He Y, Zhang F, Liu Y, Leng J. A Review of Shape Memory Polymers and Composites: Mechanisms, Materials, and Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2000713. [PMID: 32969090 DOI: 10.1002/adma.202000713] [Citation(s) in RCA: 246] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/18/2020] [Indexed: 05/23/2023]
Abstract
Over the past decades, interest in shape memory polymers (SMPs) has persisted, and immense efforts have been dedicated to developing SMPs and their multifunctional composites. As a class of stimuli-responsive polymers, SMPs can return to their initial shape from a programmed temporary shape under external stimuli, such as light, heat, magnetism, and electricity. The introduction of functional materials and nanostructures results in shape memory polymer composites (SMPCs) with large recoverable deformation, enhanced mechanical properties, and controllable remote actuation. Because of these unique features, SMPCs have a broad application prospect in many fields covering aerospace engineering, biomedical devices, flexible electronics, soft robotics, shape memory arrays, and 4D printing. Herein, a comprehensive analysis of the shape recovery mechanisms, multifunctionality, applications, and recent advances in SMPs and SMPCs is presented. Specifically, the combination of functional, reversible, multiple, and controllable shape recovery processes is discussed. Further, established products from such materials are highlighted. Finally, potential directions for the future advancement of SMPs are proposed.
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Affiliation(s)
- Yuliang Xia
- Center for Composite Materials and Structures, Harbin Institute of Technology (HIT), Harbin, 150080, P. R. China
| | - Yang He
- Center for Composite Materials and Structures, Harbin Institute of Technology (HIT), Harbin, 150080, P. R. China
| | - Fenghua Zhang
- Center for Composite Materials and Structures, Harbin Institute of Technology (HIT), Harbin, 150080, P. R. China
| | - Yanju Liu
- Department of Astronautical Science and Mechanics, Harbin Institute of Technology (HIT), Harbin, 150001, P. R. China
| | - Jinsong Leng
- Center for Composite Materials and Structures, Harbin Institute of Technology (HIT), Harbin, 150080, P. R. China
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43
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Martinez AM, Cox LM, Killgore JP, Bongiardina NJ, Riley RD, Bowman CN. Permanent and reversibly programmable shapes in liquid crystal elastomer microparticles capable of shape switching. SOFT MATTER 2021; 17:467-474. [PMID: 33346289 DOI: 10.1039/d0sm01836h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Reversibly programmable liquid crystal elastomer microparticles (LCEMPs), formed as a covalent adaptable network (CAN), with an average diameter of 7 μm ± 2 μm, were synthesized via a thiol-Michael dispersion polymerization. The particles were programmed to a prolate shape via a photoinitiated addition-fragmentation chain-transfer (AFT) exchange reaction by activating the AFT after undergoing compression. Due to the thermotropic nature of the AFT-LCEMPs, shape switching was driven by heating the particles above their nematic-isotropic phase transition temperature (TNI). The programmed particles subsequently displayed cyclable two-way shape switching from prolate to spherical when at low or high temperatures, respectively. Furthermore, the shape programming is reversible, and a second programming step was done to erase the prolate shape by initiating AFT at high temperature while the particles were in their spherical shape. Upon cooling, the particles remained spherical until additional programming steps were taken. Particles were also programmed to maintain a permanent oblate shape. Additionally, the particle surface was programmed with a diffraction grating, demonstrating programmable complex surface topography via AFT activation.
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Affiliation(s)
- Alina M Martinez
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA.
| | - Lewis M Cox
- Department of Mechanical Engineering, Montana State University, Culbertson Hall, 100, Bozeman, MT 59717, USA
| | - Jason P Killgore
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
| | - Nicholas J Bongiardina
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA.
| | - Russell D Riley
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA
| | - Christopher N Bowman
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA. and Department of Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA
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Zhu QL, Dai CF, Wagner D, Daab M, Hong W, Breu J, Zheng Q, Wu ZL. Distributed Electric Field Induces Orientations of Nanosheets to Prepare Hydrogels with Elaborate Ordered Structures and Programmed Deformations. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2005567. [PMID: 33079426 DOI: 10.1002/adma.202005567] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/10/2020] [Indexed: 05/22/2023]
Abstract
Living organisms use musculatures with spatially distributed anisotropic structures to actuate deformations and locomotion with fascinating functions. Replicating such structural features in artificial materials is of great significance yet remains a big challenge. Here, a facile strategy is reported to fabricate hydrogels with elaborate ordered structures of nanosheets (NSs) oriented under a distributed electric field. Multiple electrodes are distributed with various arrangements in the precursor solution containing NSs and gold nanoparticles. A complex electric field induces sophisticated orientations of the NSs that are permanently inscribed by subsequent photo-polymerization. The resultant anisotropic nanocomposite poly(N-isopropylacrylamide) hydrogels exhibit rapid deformation upon heating or photoirradiation, owing to the fast switching of permittivity of the media and electric repulsion between the NSs. The complex alignments of NSs and anisotropic shape change of discrete regions result in programmed deformation of the hydrogels into various configurations. Furthermore, locomotion is realized by a spatiotemporal light stimulation that locally triggers time-variant shape change of the composite hydrogel with complex anisotropic structures. Such a strategy on the basis of the distributed electric-field-generated ordered structures should be applicable to gels, elastomers, and thermosets loaded with other anisotropic particles or liquid crystals, for the design of biomimetic/bioinspired materials with specific functionalities.
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Affiliation(s)
- Qing Li Zhu
- Ministry of Education Key Laboratory of Macromolecular, Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Chen Fei Dai
- Ministry of Education Key Laboratory of Macromolecular, Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Daniel Wagner
- Bavarian Polymer Institute and Department of Chemistry, University of Bayreuth, Universitätsstrasse 30, Bayreuth, 95440, Germany
| | - Matthias Daab
- Bavarian Polymer Institute and Department of Chemistry, University of Bayreuth, Universitätsstrasse 30, Bayreuth, 95440, Germany
| | - Wei Hong
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Josef Breu
- Bavarian Polymer Institute and Department of Chemistry, University of Bayreuth, Universitätsstrasse 30, Bayreuth, 95440, Germany
| | - Qiang Zheng
- Ministry of Education Key Laboratory of Macromolecular, Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Zi Liang Wu
- Ministry of Education Key Laboratory of Macromolecular, Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
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45
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Zolfaghari N, Khandagale P, Ford MJ, Dayal K, Majidi C. Network topologies dictate electromechanical coupling in liquid metal-elastomer composites. SOFT MATTER 2020; 16:8818-8825. [PMID: 32724964 DOI: 10.1039/d0sm01094d] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Elastomers embedded with micro- and nanoscale droplets of liquid metal (LM) alloys like eutectic gallium-indium (EGaIn) can exhibit unique combinations of elastic, thermal, and electrical properties that are difficult to achieve using rigid filler. For composites with sufficient concentrations of liquid metal, the LM droplets can form percolating networks that conduct electricity and deform with the surrounding elastomer as the composite is stretched. Surprisingly, experimental measurements performed on LM-embedded elastomers (LMEEs) show that the total electrical resistance of the composite increases only slightly even as the elastomer is stretched to several times its natural length. In contrast, Pouillet's law would predict an exponential increase in resistance (Ω) with stretch (λ) due to the incompressibility of liquid metal and elastomer. In this manuscript, we perform a computational analysis to examine the unique electromechanical properties of conductive LMEE composites. Our analysis suggests that the gauge factor that quantifies electromechanical coupling (i.e. G = {ΔΩ/Ω0}/λ) decreases with increasing tortuosity of the conductive pathways formed by the connected LM droplets. A dimensionless parameter for path tortuosity can be used to estimate G for statistically homogeneous LMEE composites. These results rationalize experimental observations and provide insight into the influence of liquid metal droplet assembly on the functionality of the composite.
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Affiliation(s)
- Navid Zolfaghari
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Pratik Khandagale
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Michael J Ford
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Kaushik Dayal
- Department of Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA and Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA and Center for Nonlinear Analysis, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Carmel Majidi
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA. and Department of Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA and Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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46
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Grasinger M, Dayal K. Statistical mechanical analysis of the electromechanical coupling in an electrically-responsive polymer chain. SOFT MATTER 2020; 16:6265-6284. [PMID: 32530003 DOI: 10.1039/d0sm00845a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Polymeric materials that couple deformation and electrostatics have the potential for use in soft sensors and actuators with applications ranging from robotic, biomedical, energy, aerospace and automotive technologies. In contrast to the mechanics of polymers that has been studied using statistical mechanics approaches for decades, the coupled response under deformation and electrical field has largely been modeled only phenomenologically at the continuum scale. In this work, we examine the physics of the coupled deformation and electrical response of an electrically-responsive polymer chain using statistical mechanics. We begin with a simple anisotropic model for the electrostatic dipole response to electric field of a single monomer, and use a separation of energy scales between the electrostatic field energy and the induced dipole field energy to reduce the nonlocal and infinite-dimensional statistical averaging to a simpler local finite-dimensional averaging. In this simplified setting, we derive the equations of the most likely monomer orientation density using the maximum term approximation, and a chain free energy is derived using this approximation. These equations are investigated numerically and the results provide insight into the physics of electromechanically coupled elastomer chains. Closed-form approximations are also developed in the limit of small electrical energy with respect to thermal energy; in the limit of small mechanical tension force acting on the chain; and using asymptotic matching for general chain conditions.
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Affiliation(s)
- Matthew Grasinger
- Department of Civil and Environmental Engineering, Carnegie Mellon University, USA.
| | - Kaushik Dayal
- Department of Civil and Environmental Engineering, Carnegie Mellon University, USA. and Center for Nonlinear Analysis, Carnegie Mellon University, USA. and Department of Materials Science and Engineering, Carnegie Mellon University, USA
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47
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Barnes M, Sajadi SM, Parekh S, Rahman MM, Ajayan PM, Verduzco R. Reactive 3D Printing of Shape-Programmable Liquid Crystal Elastomer Actuators. ACS APPLIED MATERIALS & INTERFACES 2020; 12:28692-28699. [PMID: 32484325 DOI: 10.1021/acsami.0c07331] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
3D printed, stimuli-responsive materials that reversibly actuate between programmed shapes are promising for applications ranging from biomedical implants to soft robotics. However, current 3D printing of reversible actuators significantly limits the range of possible shapes and/or shape responses because they couple the print path to mathematically determined director profiles to elicit a desired shape change. Here, we report a reactive 3D-printing method that decouples printing and shape-programming steps, enabling a broad range of complex architectures and virtually any arbitrary shape changes. This method involves first printing liquid crystal elastomer (LCE) precursor solution into a catalyst bath, producing complex architectures defined by printing. Shape changes are then programmed through mechanical deformation and UV irradiation. Upon heating and cooling, the LCE reversibly shape-shifts between printed and programmed shapes, respectively. The potential of this method was demonstrated by programming a variety of arbitrary shape changes in a single printed material, producing auxetic LCE structures and symmetry-breaking shape changes in LCE sheets.
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Affiliation(s)
- Morgan Barnes
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Seyed M Sajadi
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Shaan Parekh
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Muhammad M Rahman
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Pulickel M Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Rafael Verduzco
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
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48
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Li W, Khan M, Lin L, Zhang Q, Feng S, Wu Z, Lin J. Monitoring H
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on the Surface of Single Cells with Liquid Crystal Elastomer Microspheres. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004326] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Weiwei Li
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Mashooq Khan
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Ling Lin
- CAS Key Laboratory of Standardization and Measurement for NanotechnologyCAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology Beijing 100190 China
| | - Qiang Zhang
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Shuo Feng
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Zengnan Wu
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
- CAS Key Laboratory of Standardization and Measurement for NanotechnologyCAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology Beijing 100190 China
| | - Jin‐Ming Lin
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
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49
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Li W, Khan M, Lin L, Zhang Q, Feng S, Wu Z, Lin J. Monitoring H
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on the Surface of Single Cells with Liquid Crystal Elastomer Microspheres. Angew Chem Int Ed Engl 2020; 59:9282-9287. [DOI: 10.1002/anie.202004326] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Indexed: 01/06/2023]
Affiliation(s)
- Weiwei Li
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Mashooq Khan
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Ling Lin
- CAS Key Laboratory of Standardization and Measurement for NanotechnologyCAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology Beijing 100190 China
| | - Qiang Zhang
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Shuo Feng
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
| | - Zengnan Wu
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
- CAS Key Laboratory of Standardization and Measurement for NanotechnologyCAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology Beijing 100190 China
| | - Jin‐Ming Lin
- Department of ChemistryBeijing Key Laboratory of Microanalytical Methods and InstrumentationMOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical BiologyTsinghua University Beijing 100084 China
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50
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Mistry D, Nikkhou M, Raistrick T, Hussain M, Jull EIL, Baker DL, Gleeson HF. Isotropic Liquid Crystal Elastomers as Exceptional Photoelastic Strain Sensors. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02456] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Devesh Mistry
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Maryam Nikkhou
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Thomas Raistrick
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Mariam Hussain
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Ethan I. L. Jull
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Daniel L. Baker
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Helen F. Gleeson
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
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