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Dewang Y, Sharma V, Baliyan VK, Soundappan T, Singla YK. Research Progress in Electroactive Polymers for Soft Robotics and Artificial Muscle Applications. Polymers (Basel) 2025; 17:746. [PMID: 40292598 PMCID: PMC11945207 DOI: 10.3390/polym17060746] [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: 01/20/2025] [Revised: 03/01/2025] [Accepted: 03/04/2025] [Indexed: 04/30/2025] Open
Abstract
Soft robots, constructed from deformable materials, offer significant advantages over rigid robots by mimicking biological tissues and providing enhanced adaptability, safety, and functionality across various applications. Central to these robots are electroactive polymer (EAP) actuators, which allow large deformations in response to external stimuli. This review examines various EAP actuators, including dielectric elastomers, liquid crystal elastomers (LCEs), and ionic polymers, focusing on their potential as artificial muscles. EAPs, particularly ionic and electronic varieties, are noted for their high actuation strain, flexibility, lightweight nature, and energy efficiency, making them ideal for applications in mechatronics, robotics, and biomedical engineering. This review also highlights piezoelectric polymers like polyvinylidene fluoride (PVDF), known for their flexibility, biocompatibility, and ease of fabrication, contributing to tactile and pressure sensing in robotic systems. Additionally, conducting polymers, with their fast actuation speeds and high strain capabilities, are explored, alongside magnetic polymer composites (MPCs) with applications in biomedicine and electronics. The integration of machine learning (ML) and the Internet of Things (IoT) is transforming soft robotics, enhancing actuation, control, and design. Finally, the paper discusses future directions in soft robotics, focusing on self-healing composites, bio-inspired designs, sustainability, and the continued integration of IoT and ML for intelligent, adaptive, and responsive robotic systems.
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Affiliation(s)
- Yogesh Dewang
- Department of Mechanical Engineering, Lakshmi Narain College of Technology, Bhopal 462021, India;
| | - Vipin Sharma
- Department of Mechanical Engineering, Medi-Caps University, Indore 453331, India;
| | - Vijay Kumar Baliyan
- School of Sciences, Sanjeev Agarwal Global Education University, Bhopal 462022, India;
| | | | - Yogesh Kumar Singla
- School of Engineering, Math & Technology, Navajo Technical University, Crownpoint, NM 87313, USA
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2
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Ding H, Yang D, Ding S, Ma F. Reprogrammable Flexible Piezoelectric Actuator Arrays with a High Degree of Freedom for Shape Morphing and Locomotion. Soft Robot 2025. [PMID: 39792479 DOI: 10.1089/soro.2024.0099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2025] Open
Abstract
The high degree of freedom (DoF) shape morphing widely exists in biology for mimicry, camouflage, and locomotion. Currently, a lot of bionic soft/flexible actuators and robots with shape-morphing functions have been developed to realize conformity, grasp, and movement. Among these solutions, two-dimensional responsive materials and structures that can shape morph into different three-dimensional configurations are valuable for creating reversible high DoF shape morphing. However, most existing methods are predetermined through the fabrication process and cannot reprogram their shape, facing limitations on multifunction. Besides, the achievable geometries are very limited due to the device's low integrated level of actuator elements. Here, we develop a polyvinylidene fluoride flexible piezoelectric actuator array based on a row/column addressing (RCA) scheme for reprogrammable high DoF shape morphing and locomotion. The specially designed row/column electrodes form a 6 × 6 array, which contains 36 actuator elements. By developing a high-voltage RCA control system, we can individually control all the elements in the array, leading to a highly reprogrammable array with various sophisticated high DoF shape morphing. We also demonstrate that the array is capable of propelling a robotic fish with various locomotions. This research provides a new method and approach for biomimetic robotics with better mimicry, aero/hydrodynamic efficiency, and maneuverability, as well as haptic display and object manipulation.
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Affiliation(s)
- Hong Ding
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
| | - Dengfei Yang
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
- Advanced Institute of Information Technology, Peking University, Hangzhou, China
| | - Shuo Ding
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Fangyi Ma
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
- School of Electromechanical Engineering & Transportation, Shaoxing Vocational & Technical College, Shaoxing, China
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3
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Feng W, He Q, Zhang L. Embedded Physical Intelligence in Liquid Crystalline Polymer Actuators and Robots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2025; 37:e2312313. [PMID: 38375751 PMCID: PMC11733722 DOI: 10.1002/adma.202312313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/27/2024] [Indexed: 02/21/2024]
Abstract
Responsive materials possess the inherent capacity to autonomously sense and respond to various external stimuli, demonstrating physical intelligence. Among the diverse array of responsive materials, liquid crystalline polymers (LCPs) stand out for their remarkable reversible stimuli-responsive shape-morphing properties and their potential for creating soft robots. While numerous reviews have extensively detailed the progress in developing LCP-based actuators and robots, there exists a need for comprehensive summaries that elucidate the underlying principles governing actuation and how physical intelligence is embedded within these systems. This review provides a comprehensive overview of recent advancements in developing actuators and robots endowed with physical intelligence using LCPs. This review is structured around the stimulus conditions and categorizes the studies involving responsive LCPs based on the fundamental control and stimulation logic and approach. Specifically, three main categories are examined: systems that respond to changing stimuli, those operating under constant stimuli, and those equip with learning and logic control capabilities. Furthermore, the persisting challenges that need to be addressed are outlined and discuss the future avenues of research in this dynamic field.
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Affiliation(s)
- Wei Feng
- Department of Mechanical and Automation EngineeringThe Chinese University of Hong KongHong KongChina
| | - Qiguang He
- Department of Mechanical and Automation EngineeringThe Chinese University of Hong KongHong KongChina
| | - Li Zhang
- Department of Mechanical and Automation EngineeringThe Chinese University of Hong KongHong KongChina
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4
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Zhou X, Jin B, Zhu Z, Wu J, Zhao Q, Chen G. Metal-Ligand Bonds Based Reprogrammable and Re-Processable Supramolecular Liquid Crystal Elastomer Network. Angew Chem Int Ed Engl 2024; 63:e202409182. [PMID: 39086017 DOI: 10.1002/anie.202409182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/30/2024] [Accepted: 07/31/2024] [Indexed: 08/02/2024]
Abstract
Dynamic covalent bonds endow liquid crystal elastomers (LCEs) with network rearrangeability, facilitating the fixation of mesogen alignment induced by external forces and enabling reversible actuation. In comparison, the bond exchange of supramolecular interactions is typically too significant to stably maintain the programmed alignment, particularly under intensified external stimuli. Nevertheless, remaking and recycling of supramolecular interaction-based polymer networks are more accessible than those based on dynamic covalent bonds, as the latter are difficult to completely dissociate. Thus, preparing an LCE that possesses both supramolecular-like exchangeability and covalent bond-level stability remains a significant challenge. In this work, we addressed this issue by employing metal-ligand bonds as the crosslinking points of LCE networks. As such, mesogen alignment can be repeatedly encoded through metal-ligand bond exchange and stably maintained after programming, since the bond exchange rate is sufficiently slow when the programming and actuation temperatures are below the bond dissociation temperature. More importantly, the metal-ligand bonds can be completely dissociated at high temperatures, allowing the LCE network to be dissolved in a solvent and reshaped into desired geometries via solution casting. Building on these properties, our LCEs can be fabricated into versatile actuators, such as reversible folding origami, artificial muscles, and soft robotics.
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Affiliation(s)
- Xiaorui Zhou
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Binjie Jin
- Institute of Emergent Elastomers, School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Zhan Zhu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jingjun Wu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- Ningbo Innovation Center, Zhejiang University, Ningbo, 315807, China
| | - Qian Zhao
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Guancong Chen
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
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5
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Yin S, Yao DR, Song Y, Heng W, Ma X, Han H, Gao W. Wearable and Implantable Soft Robots. Chem Rev 2024; 124:11585-11636. [PMID: 39392765 DOI: 10.1021/acs.chemrev.4c00513] [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: 10/13/2024]
Abstract
Soft robotics presents innovative solutions across different scales. The flexibility and mechanical characteristics of soft robots make them particularly appealing for wearable and implantable applications. The scale and level of invasiveness required for soft robots depend on the extent of human interaction. This review provides a comprehensive overview of wearable and implantable soft robots, including applications in rehabilitation, assistance, organ simulation, surgical tools, and therapy. We discuss challenges such as the complexity of fabrication processes, the integration of responsive materials, and the need for robust control strategies, while focusing on advances in materials, actuation and sensing mechanisms, and fabrication techniques. Finally, we discuss the future outlook, highlighting key challenges and proposing potential solutions.
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Affiliation(s)
- Shukun Yin
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Dickson R Yao
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Yu Song
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Wenzheng Heng
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Xiaotian Ma
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Hong Han
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Wei Gao
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
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6
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He C, Xiao Y, Wang S, Lu H, Li X, Xu L, Wang C, Tu Y. Main-Chain Azobenzene Poly(ether ester) Multiblock Copolymers for Strong and Tough Light-Driven Actuators. ACS APPLIED MATERIALS & INTERFACES 2024; 16:56469-56480. [PMID: 39382379 DOI: 10.1021/acsami.4c13375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2024]
Abstract
The stimulus-responsive polymeric materials have attracted great research interest, especially those remotely manipulated materials with potential applications in actuators and soft robotics. Here we report a photoresponsive main-chain actuator based on azobenzene poly(ether ester) multiblock copolymer (mBCP) thermoplastic elastomers, (PTAD-b-PTMO-b-PTAD)n, which were synthesized by a cascade polycondensation-coupling ring-opening polymerization method using poly(tetramethylene oxide) (PTMO) and azobenzene-containing cyclic oligoesters (COTADs) as monomers. The thermal, mechanical, and microphase separation behaviors of mBCPs could be flexibly tuned by altering the ratios of soft-to-hard segments and block number (n). The oriented azobenzene mBCP fibers were prepared by melt spinning, showing reversible photoresponsive properties with remarkably high strength (∼1000 MPa) and high elongation at break comparable to spider silks. Fast photoinduced bending and contraction were successfully achieved in these fibers with high work and power densities and energy conversion efficiency, enabling it to lift up about 250 times of its own weight. Moreover, it can take out materials inside the tube by UV-light control. These fibers could be applied in light-driven actuators or telecontrolled robot arms.
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Affiliation(s)
- Chong He
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
- Beijing Yanshan Petrochemical High-Tech Company, Ltd., Beijing 102500, China
| | - Yang Xiao
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Sheng Wang
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Huanjun Lu
- Jiangsu Key Laboratory for Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Xiaohong Li
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Lin Xu
- National Engineering Research Center for Synthesis of Novel Rubber and Plastic Materials, SINOPEC (Beijing) Research Institute of Chemical Industry Company, Ltd., Yanshan Branch, Beijing 102500, China
| | - Chao Wang
- National Engineering Research Center for Synthesis of Novel Rubber and Plastic Materials, SINOPEC (Beijing) Research Institute of Chemical Industry Company, Ltd., Yanshan Branch, Beijing 102500, China
| | - Yingfeng Tu
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
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7
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Lee HC, Elder N, Leal M, Stantial S, Vergara Martinez E, Jos S, Cho H, Russo S. A fabrication strategy for millimeter-scale, self-sensing soft-rigid hybrid robots. Nat Commun 2024; 15:8456. [PMID: 39349426 PMCID: PMC11442515 DOI: 10.1038/s41467-024-51137-8] [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: 11/22/2023] [Accepted: 07/31/2024] [Indexed: 10/02/2024] Open
Abstract
Soft robots typically involve manual assembly of core hardware components like actuators, sensors, and controllers. This increases fabrication time and reduces consistency, especially in small-scale soft robots. We present a scalable monolithic fabrication method for millimeter-scale soft-rigid hybrid robots, simplifying the integration of core hardware components. Actuation is provided by soft-foldable polytetrafluoroethylene film-based actuators powered by ionic fluid injection. The desired motion is encoded by integrating a mechanical controller, comprised of rigid-flexible materials. The robot's motion can be self-sensed using an ionic resistive sensor by detecting electrical resistance changes across its body. Our approach is demonstrated by fabricating three distinct soft-rigid hybrid robotic modules, each with unique degrees of freedom: translational, bending, and roto-translational motions. These modules connect to form a soft-rigid hybrid continuum robot with real-time shape-sensing capabilities. We showcase the robot's capabilities by performing object pick-and-place, needle steering and tissue puncturing, and optical fiber steering tasks.
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Affiliation(s)
- Hun Chan Lee
- Department of Mechanical Engineering, Boston University, Boston, MA, USA
| | - Nash Elder
- Department of Mechanical Engineering, Boston University, Boston, MA, USA
| | - Matthew Leal
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sarah Stantial
- Department of Mechanical Engineering, Boston University, Boston, MA, USA
| | | | - Sneha Jos
- Department of Physics, Boston University, Boston, MA, USA
| | - Hyunje Cho
- Department of Mechanical Engineering, Boston University, Boston, MA, USA
| | - Sheila Russo
- Department of Mechanical Engineering, Boston University, Boston, MA, USA.
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8
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An S, Li X, Guo Z, Huang Y, Zhang Y, Jiang H. Energy-efficient dynamic 3D metasurfaces via spatiotemporal jamming interleaved assemblies for tactile interfaces. Nat Commun 2024; 15:7340. [PMID: 39187536 PMCID: PMC11347642 DOI: 10.1038/s41467-024-51865-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 08/19/2024] [Indexed: 08/28/2024] Open
Abstract
Inspired by the natural shape-morphing abilities of biological organisms, we introduce a strategy for creating energy-efficient dynamic 3D metasurfaces through spatiotemporal jamming of interleaved assemblies. Our approach, diverging from traditional shape-morphing techniques reliant on continuous energy inputs, utilizes strategically jammed, paper-based interleaved assemblies. By rapidly altering their stiffness at various spatial points and temporal phases during the relaxation of the soft substrate through jamming, we enable the formation of refreshable, intricate 3D shapes with a desirable load-bearing capability. This process, which does not require ongoing energy consumption, ensures energy-efficient and lasting shape displays. Our theoretical model, linking buckling deformation to residual pre-strain, underpins the inverse design process for an array of interleaved assemblies, facilitating the creation of diverse 3D configurations. This metasurface holds notable potential for tactile displays, particularly for the visually impaired, heralding possibilities in visual impaired education, haptic feedback, and virtual/augmented reality applications.
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Affiliation(s)
- Siqi An
- School of Engineering, Westlake University, Hangzhou, Zhejiang, 310030, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Xiaowen Li
- School of Engineering, Westlake University, Hangzhou, Zhejiang, 310030, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Zengrong Guo
- School of Engineering, Westlake University, Hangzhou, Zhejiang, 310030, China
| | - Yi Huang
- School of Engineering, Westlake University, Hangzhou, Zhejiang, 310030, China
| | - Yanlin Zhang
- School of Engineering, Westlake University, Hangzhou, Zhejiang, 310030, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Hanqing Jiang
- School of Engineering, Westlake University, Hangzhou, Zhejiang, 310030, China.
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.
- Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310030, China.
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9
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Zang T, Fu S, Cheng J, Zhang C, Lu X, Hu J, Xia H, Zhao Y. 4D Printing of Shape-Morphing Liquid Crystal Elastomers. CHEM & BIO ENGINEERING 2024; 1:488-515. [PMID: 39974607 PMCID: PMC11835177 DOI: 10.1021/cbe.4c00027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 02/21/2025]
Abstract
In nature, biological systems can sense environmental changes and alter their performance parameters in real time to adapt to environmental changes. Inspired by these, scientists have developed a range of novel shape-morphing materials. Shape-morphing materials are a kind of "intelligent" materials that exhibit responses to external stimuli in a predetermined way and then display a preset function. Liquid crystal elastomer (LCE) is a typical representative example of shape-morphing materials. The emergence of 4D printing technology can effectively simplify the preparation process of shape-morphing LCEs, by changing the printing material compositions and printing conditions, enabling precise control and macroscopic design of the shape-morphing modes. At the same time, the layer-by-layer stacking method can also endow the shape-morphing LCEs with complex, hierarchical orientation structures, which gives researchers a great degree of design freedom. 4D printing has greatly expanded the application scope of shape-morphing LCEs as soft intelligent materials. This review systematically reports the recent progress of 3D/4D printing of shape-morphing LCEs, discusses various 4D printing technologies, synthesis methods and actuation modes of 3D/4D printed LCEs, and summarizes the opportunities and challenges of 3D/4D printing technologies in preparing shape-morphing LCEs.
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Affiliation(s)
- Tongzhi Zang
- State
Key Laboratory of Polymer Materials Engineering, Polymer Research
Institute, Sichuan University, Chengdu 610065, China
- Center
for Molecular Science and Engineering, College of Science, Northeastern University, Shenyang 110819, China
| | - Shuang Fu
- State
Key Laboratory of Polymer Materials Engineering, Polymer Research
Institute, Sichuan University, Chengdu 610065, China
| | - Junpeng Cheng
- State
Key Laboratory of Polymer Materials Engineering, Polymer Research
Institute, Sichuan University, Chengdu 610065, China
| | - Chun Zhang
- State
Key Laboratory of Polymer Materials Engineering, Polymer Research
Institute, Sichuan University, Chengdu 610065, China
| | - Xili Lu
- State
Key Laboratory of Polymer Materials Engineering, Polymer Research
Institute, Sichuan University, Chengdu 610065, China
| | - Jianshe Hu
- Center
for Molecular Science and Engineering, College of Science, Northeastern University, Shenyang 110819, China
| | - Hesheng Xia
- State
Key Laboratory of Polymer Materials Engineering, Polymer Research
Institute, Sichuan University, Chengdu 610065, China
| | - Yue Zhao
- Département
de chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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10
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Luo B, Lu H, Zhong Y, Zhu K, Wang Y. Carbon Nanotube-Doped 3D-Printed Silicone Electrode for Manufacturing Multilayer Porous Plasticized Polyvinyl Chloride Gel Artificial Muscles. Gels 2024; 10:416. [PMID: 39057440 PMCID: PMC11275437 DOI: 10.3390/gels10070416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 06/15/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Plasticized polyvinyl chloride (PVC) gel has large deformation under an applied external electrical field and high driving stability in air and is a candidate artificial muscle material for manufacturing a flexible actuator. A porous PVC gel actuator consists of a mesh positive pole, a planar negative pole, and a PVC gel core layer. The current casting method is only suitable for manufacturing simple 2D structures, and it is difficult to produce multilayer porous structures. This study investigated the feasibility of a 3D-printed carbon nanotube-doped silicone electrode for manufacturing multilayer porous PVC gel artificial muscle. Carbon nanotube-doped silicone (CNT-PDMS) composite inks were developed for printing electrode layers of PVC gel artificial muscles. The parameters for the printing plane and mesh electrodes were explored theoretically and experimentally. We produced a CNT-PDMS electrode and PVC gel via integrated printing to manufacture multilayer porous PVC artificial muscle and verified its good performance.
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Affiliation(s)
- Bin Luo
- School of Mechanics and Materials, Hohai University, Nanjing 211100, China;
- School of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China; (H.L.); (K.Z.)
- State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, China;
| | - Hanjing Lu
- School of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China; (H.L.); (K.Z.)
| | - Yiding Zhong
- State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, China;
| | - Kejun Zhu
- School of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China; (H.L.); (K.Z.)
| | - Yanjie Wang
- School of Mechanics and Materials, Hohai University, Nanjing 211100, China;
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11
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Jing S, Huang J, Wang H, Wang Y, Xie H, Zhou S. A Solvent-Templated Porous Liquid Crystal Elastomer with Tactile Sensation beyond Reversible Actuation toward Versatile Artificial Muscles. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38692284 DOI: 10.1021/acsami.4c03930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Liquid crystal elastomers (LCEs), as a classical two-way shape-memory material, are good candidates for developing artificial muscles that mimic the contraction, expansion, or rotational behavior of natural muscles. However, biomimicry is currently focused more on the actuation functions of natural muscles dominated by muscle fibers, whereas the tactile sensing functions that are dominated by neuronal receptors and synapses have not been well captured. Very few studies have reported the sensing concept for LCEs, but the signals were still donated by macroscopic actuation, that is, variations in angle or length. Herein, we develop a conductive porous LCE (CPLCE) using a solvent (dimethyl sulfoxide (DMSO))-templated photo-cross-linking strategy, followed by carbon nanotube (CNT) incorporation. The CPLCE has excellent reversible contraction/elongation behavior in a manner similar to the actuation functions of skeletal muscles. Moreover, the CPLCE shows excellent pressure-sensing performance by providing real-time electrical signals and is capable of microtouch sensing, which is very similar to natural tactile sensing. Furthermore, macroscopic actuation and tactile sensation can be integrated into a single system. Proof-of-concept studies reveal that the CPLCE-based artificial muscle is sensitive to external touch while maintaining its excellent actuation performance. The CPLCE with tactile sensation beyond reversible actuation is expected to benefit the development of versatile artificial muscles and intelligent robots.
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Affiliation(s)
- Shirong Jing
- Institute of Biomedical Engineering, College of Medicine, Southwest Jiaotong University, Chengdu 610031, China
- Key Laboratory of Advanced Technologies of Materials Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Jinhui Huang
- Institute of Biomedical Engineering, College of Medicine, Southwest Jiaotong University, Chengdu 610031, China
- Key Laboratory of Advanced Technologies of Materials Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Huan Wang
- Institute of Biomedical Engineering, College of Medicine, Southwest Jiaotong University, Chengdu 610031, China
- Key Laboratory of Advanced Technologies of Materials Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Yilei Wang
- Institute of Biomedical Engineering, College of Medicine, Southwest Jiaotong University, Chengdu 610031, China
| | - Hui Xie
- Institute of Biomedical Engineering, College of Medicine, Southwest Jiaotong University, Chengdu 610031, China
| | - Shaobing Zhou
- Institute of Biomedical Engineering, College of Medicine, Southwest Jiaotong University, Chengdu 610031, China
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12
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Yao DR, Kim I, Yin S, Gao W. Multimodal Soft Robotic Actuation and Locomotion. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308829. [PMID: 38305065 DOI: 10.1002/adma.202308829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/02/2024] [Indexed: 02/03/2024]
Abstract
Diverse and adaptable modes of complex motion observed at different scales in living creatures are challenging to reproduce in robotic systems. Achieving dexterous movement in conventional robots can be difficult due to the many limitations of applying rigid materials. Robots based on soft materials are inherently deformable, compliant, adaptable, and adjustable, making soft robotics conducive to creating machines with complicated actuation and motion gaits. This review examines the mechanisms and modalities of actuation deformation in materials that respond to various stimuli. Then, strategies based on composite materials are considered to build toward actuators that combine multiple actuation modes for sophisticated movements. Examples across literature illustrate the development of soft actuators as free-moving, entirely soft-bodied robots with multiple locomotion gaits via careful manipulation of external stimuli. The review further highlights how the application of soft functional materials into robots with rigid components further enhances their locomotive abilities. Finally, taking advantage of the shape-morphing properties of soft materials, reconfigurable soft robots have shown the capacity for adaptive gaits that enable transition across environments with different locomotive modes for optimal efficiency. Overall, soft materials enable varied multimodal motion in actuators and robots, positioning soft robotics to make real-world applications for intricate and challenging tasks.
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Affiliation(s)
- Dickson R Yao
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Inho Kim
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Shukun Yin
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Wei Gao
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA
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13
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Zhang C, Chen G, Zhang K, Jin B, Zhao Q, Xie T. Repeatedly Programmable Liquid Crystal Dielectric Elastomer with Multimodal Actuation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2313078. [PMID: 38231117 DOI: 10.1002/adma.202313078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/11/2024] [Indexed: 01/18/2024]
Abstract
Dielectric elastomers (DEs) are actuatable under an electric field, whose large strain and fast response speed compare favorably with natural muscles. However, the actuation of DE-based devices is generally limited to a single mode and cannot be reconfigured after fabrication, which pales in comparison to biological counterparts given the ability to alter actuation modes according to external conditions. To address this, liquid crystal dielectric elastomers (LC-DEs) that can alter the dielectric actuation modes based on the thermally triggered shape-changing are prepared. Specifically, the two shapes through the LC phase transition possess different bending stiffness, which leads to distinct actuation modes after an electric field is applied. Moreover, the two shapes can be individually programmed/reprogrammed, that is, the one before the transition is regulated through force-directed solvent evaporation and the one after the transition is via bond exchange-enabled stress relaxation. As such, the multimodal dielectric actuation behaviors upon temperature change can be readily diversified. Meanwhile, the space charge mechanism endows LC-DEs with the significantly reduced driving e-field (8 V µm-1) and bidirectional actuation manners. It is believed this unique adaptivity in the actuation modes under a low electric field shall offer versatile designs for practical soft robots.
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Affiliation(s)
- Chengcheng Zhang
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Guancong Chen
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Kaihang Zhang
- Center for X-Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Binjie Jin
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
- Center for X-Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310058, China
| | - Qian Zhao
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Tao Xie
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
- Department of Colorectal Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310000, China
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14
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Leanza S, Wu S, Sun X, Qi HJ, Zhao RR. Active Materials for Functional Origami. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2302066. [PMID: 37120795 DOI: 10.1002/adma.202302066] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/13/2023] [Indexed: 06/19/2023]
Abstract
In recent decades, origami has been explored to aid in the design of engineering structures. These structures span multiple scales and have been demonstrated to be used toward various areas such as aerospace, metamaterial, biomedical, robotics, and architectural applications. Conventionally, origami or deployable structures have been actuated by hands, motors, or pneumatic actuators, which can result in heavy or bulky structures. On the other hand, active materials, which reconfigure in response to external stimulus, eliminate the need for external mechanical loads and bulky actuation systems. Thus, in recent years, active materials incorporated with deployable structures have shown promise for remote actuation of light weight, programmable origami. In this review, active materials such as shape memory polymers (SMPs) and alloys (SMAs), hydrogels, liquid crystal elastomers (LCEs), magnetic soft materials (MSMs), and covalent adaptable network (CAN) polymers, their actuation mechanisms, as well as how they have been utilized for active origami and where these structures are applicable is discussed. Additionally, the state-of-the-art fabrication methods to construct active origami are highlighted. The existing structural modeling strategies for origami, the constitutive models used to describe active materials, and the largest challenges and future directions for active origami research are summarized.
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Affiliation(s)
- Sophie Leanza
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Shuai Wu
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Xiaohao Sun
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - H Jerry Qi
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Ruike Renee Zhao
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
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15
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Park J, Lee Y, Cho S, Choe A, Yeom J, Ro YG, Kim J, Kang DH, Lee S, Ko H. Soft Sensors and Actuators for Wearable Human-Machine Interfaces. Chem Rev 2024; 124:1464-1534. [PMID: 38314694 DOI: 10.1021/acs.chemrev.3c00356] [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: 02/07/2024]
Abstract
Haptic human-machine interfaces (HHMIs) combine tactile sensation and haptic feedback to allow humans to interact closely with machines and robots, providing immersive experiences and convenient lifestyles. Significant progress has been made in developing wearable sensors that accurately detect physical and electrophysiological stimuli with improved softness, functionality, reliability, and selectivity. In addition, soft actuating systems have been developed to provide high-quality haptic feedback by precisely controlling force, displacement, frequency, and spatial resolution. In this Review, we discuss the latest technological advances of soft sensors and actuators for the demonstration of wearable HHMIs. We particularly focus on highlighting material and structural approaches that enable desired sensing and feedback properties necessary for effective wearable HHMIs. Furthermore, promising practical applications of current HHMI technology in various areas such as the metaverse, robotics, and user-interactive devices are discussed in detail. Finally, this Review further concludes by discussing the outlook for next-generation HHMI technology.
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Affiliation(s)
- Jonghwa Park
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Youngoh Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Seungse Cho
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Ayoung Choe
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Jeonghee Yeom
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Yun Goo Ro
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Jinyoung Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Dong-Hee Kang
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Seungjae Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Hyunhyub Ko
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
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16
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Firoozan M, Baniassadi M, Baghani M, Chortos A. In silico optimization of aligned fiber electrodes for dielectric elastomer actuators. Sci Rep 2024; 14:4703. [PMID: 38409334 PMCID: PMC10897417 DOI: 10.1038/s41598-024-54931-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 02/19/2024] [Indexed: 02/28/2024] Open
Abstract
Dielectric elastomer actuators (DEAs) exhibit fast actuation and high efficiencies, enabling applications in optics, wearable haptics, and insect-scale robotics. However, the non-uniformity and high sheet resistance of traditional soft electrodes based on nanomaterials limit the performance and operating frequency of the devices. In this work, we computationally investigate electrodes composed of arrays of stiff fiber electrodes. Aligning the fibers along one direction creates an electrode layer that exhibits zero stiffness in one direction and is predicted to possess high and uniform sheet resistance. A comprehensive parameter study of the fiber density and dielectric thickness reveals that the fiber density primary determines the electric field localization while the dielectric thickness primarily determines the unit cell stiffness. These trends identify an optimal condition for the actuation performance of the aligned electrode DEAs. This work demonstrates that deterministically designed electrodes composed of stiff materials could provide a new paradigm with the potential to surpass the performance of traditional soft planar electrodes.
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Affiliation(s)
- Mohammadreza Firoozan
- School of Mechanical Engineering, Purdue University, West Lafayette, USA
- School of Mechanical Engineering, University of Tehran, Tehran, Iran
| | - Majid Baniassadi
- School of Mechanical Engineering, University of Tehran, Tehran, Iran
| | - Mostafa Baghani
- School of Mechanical Engineering, University of Tehran, Tehran, Iran
| | - Alex Chortos
- School of Mechanical Engineering, Purdue University, West Lafayette, USA.
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17
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den Hoed FM, Carlotti M, Palagi S, Raffa P, Mattoli V. Evolution of the Microrobots: Stimuli-Responsive Materials and Additive Manufacturing Technologies Turn Small Structures into Microscale Robots. MICROMACHINES 2024; 15:275. [PMID: 38399003 PMCID: PMC10893381 DOI: 10.3390/mi15020275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/02/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024]
Abstract
The development of functional microsystems and microrobots that have characterized the last decade is the result of a synergistic and effective interaction between the progress of fabrication techniques and the increased availability of smart and responsive materials to be employed in the latter. Functional structures on the microscale have been relevant for a vast plethora of technologies that find application in different sectors including automotive, sensing devices, and consumer electronics, but are now also entering medical clinics. Working on or inside the human body requires increasing complexity and functionality on an ever-smaller scale, which is becoming possible as a result of emerging technology and smart materials over the past decades. In recent years, additive manufacturing has risen to the forefront of this evolution as the most prominent method to fabricate complex 3D structures. In this review, we discuss the rapid 3D manufacturing techniques that have emerged and how they have enabled a great leap in microrobotic applications. The arrival of smart materials with inherent functionalities has propelled microrobots to great complexity and complex applications. We focus on which materials are important for actuation and what the possibilities are for supplying the required energy. Furthermore, we provide an updated view of a new generation of microrobots in terms of both materials and fabrication technology. While two-photon lithography may be the state-of-the-art technology at the moment, in terms of resolution and design freedom, new methods such as two-step are on the horizon. In the more distant future, innovations like molecular motors could make microscale robots redundant and bring about nanofabrication.
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Affiliation(s)
- Frank Marco den Hoed
- Center for Materials Interfaces, Istituto Italiano di Tecnologia, Via R. Piaggio 34, 56025 Pontedera, Italy;
- Smart and Sustainable Polymeric Products, Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands;
| | - Marco Carlotti
- Center for Materials Interfaces, Istituto Italiano di Tecnologia, Via R. Piaggio 34, 56025 Pontedera, Italy;
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via Moruzzi 13, 56124 Pisa, Italy
| | - Stefano Palagi
- BioRobotics Institute, Sant’Anna School of Advanced Studies, P.zza Martiri della Libertà 33, 56127 Pisa, Italy;
| | - Patrizio Raffa
- Smart and Sustainable Polymeric Products, Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands;
| | - Virgilio Mattoli
- Center for Materials Interfaces, Istituto Italiano di Tecnologia, Via R. Piaggio 34, 56025 Pontedera, Italy;
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18
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Ren Z, Sitti M. Design and build of small-scale magnetic soft-bodied robots with multimodal locomotion. Nat Protoc 2024; 19:441-486. [PMID: 38097687 DOI: 10.1038/s41596-023-00916-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 09/21/2023] [Indexed: 02/12/2024]
Abstract
Small-scale magnetic soft-bodied robots can be designed to operate based on different locomotion modes to navigate and function inside unstructured, confined and varying environments. These soft millirobots may be useful for medical applications where the robots are tasked with moving inside the human body. Here we cover the entire process of developing small-scale magnetic soft-bodied millirobots with multimodal locomotion capability, including robot design, material preparation, robot fabrication, locomotion control and locomotion optimization. We describe in detail the design, fabrication and control of a sheet-shaped soft millirobot with 12 different locomotion modes for traversing different terrains, an ephyra jellyfish-inspired soft millirobot that can manipulate objects in liquids through various swimming modes, a larval zebrafish-inspired soft millirobot that can adjust its body stiffness for efficient propulsion in different swimming speeds and a dual stimuli-responsive sheet-shaped soft millirobot that can switch its locomotion modes automatically by responding to changes in the environmental temperature. The procedure is aimed at users with basic expertise in soft robot development. The procedure requires from a few days to several weeks to complete, depending on the degree of characterization required.
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Affiliation(s)
- Ziyu Ren
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart, Germany.
- Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland.
- School of Medicine and College of Engineering, Koç University, Istanbul, Turkey.
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19
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Saeed MH, Choi MY, Kim K, Lee JH, Kim K, Kim D, Kim SU, Kim H, Ahn SK, Lan R, Na JH. Electrostatically Powered Multimode Liquid Crystalline Elastomer Actuators. ACS APPLIED MATERIALS & INTERFACES 2023; 15:56285-56292. [PMID: 37991738 DOI: 10.1021/acsami.3c13140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Soft actuators based on liquid crystalline elastomers (LCEs) are captivating significant interest because of their unique properties combining the programmable liquid crystalline molecular order and elasticity of polymeric materials. For practical applications, the ability to perform multimodal shape changes in a single LCE actuator at a subsecond level is a bottleneck. Here, we fabricate a monodomain LCE powered by electrostatic force, which enables fast multidirectional bending, oscillation, rotation, and complex actuation with a high degree of freedom. By tuning the dielectric constant and resistivity in LCE gels, a complete cycle of oscillation and rotation only takes 0.1 s. In addition, monodomain actuators exhibit anisotropic actuation behaviors that promise a more complex deployment in a potential electromechanical system. The presented study will pave the way for electrostatically controllable isothermal manipulation for a fast and multimode soft actuator.
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Affiliation(s)
- Mohsin Hassan Saeed
- Department of Electrical, Electronics and Communication Engineering Education, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Moon-Young Choi
- Department of Convergence System Engineering, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Kitae Kim
- Department of Convergence System Engineering, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Jin-Hyeong Lee
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Keumbee Kim
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Dowon Kim
- Department of Electrical, Electronics and Communication Engineering Education, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Se-Um Kim
- Department of Electrical and Information Engineering, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea
| | - Hyun Kim
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Suk-Kyun Ahn
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
- Department of Polymer Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Ruochen Lan
- Institute of Advanced Materials, Jiangxi Normal University, Nanchang 330022, China
| | - Jun-Hee Na
- Department of Electrical, Electronics and Communication Engineering Education, Chungnam National University, Daejeon 34134, Republic of Korea
- Department of Convergence System Engineering, Chungnam National University, Daejeon 34134, Republic of Korea
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20
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Shan Y, Zhao Y, Wang H, Dong L, Pei C, Jin Z, Sun Y, Liu T. Variable stiffness soft robotic gripper: design, development, and prospects. BIOINSPIRATION & BIOMIMETICS 2023; 19:011001. [PMID: 37948756 DOI: 10.1088/1748-3190/ad0b8c] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 11/10/2023] [Indexed: 11/12/2023]
Abstract
The advent of variable stiffness soft robotic grippers furnishes a conduit for exploration and manipulation within uncharted, non-structured environments. The paper provides a comprehensive review of the necessary technologies for the configuration design of soft robotic grippers with variable stiffness, serving as a reference for innovative gripper design. The design of variable stiffness soft robotic grippers typically encompasses the design of soft robotic grippers and variable stiffness modules. To adapt to unfamiliar environments and grasp unknown objects, a categorization and discussion have been undertaken based on the contact and motion manifestations between the gripper and the things across various dimensions: points contact, lines contact, surfaces contact, and full-bodies contact, elucidating the advantages and characteristics of each gripping type. Furthermore, when designing soft robotic grippers, we must consider the effectiveness of object grasping methods but also the applicability of the actuation in the target environment. The actuation is the propelling force behind the gripping motion, holding utmost significance in shaping the structure of the gripper. Given the challenge of matching the actuation of robotic grippers with the target scenario, we reviewed the actuation of soft robotic grippers. We analyzed the strengths and limitations of various soft actuation, providing insights into the actuation design for soft robotic grippers. As a crucial technique for variable stiffness soft robotic grippers, variable stiffness technology can effectively address issues such as poor load-bearing capacity and instability caused by the softness of materials. Through a retrospective analysis of variable stiffness theory, we comprehensively introduce the development of variable stiffness theory in soft robotic grippers and showcase the application of variable stiffness grasping technology through specific case studies. Finally, we discuss the future prospects of variable stiffness grasping robots from several perspectives of applications and technologies.
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Affiliation(s)
- Yu Shan
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
| | - Yanzhi Zhao
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
| | - Haobo Wang
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
| | - Liming Dong
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
| | - Changlei Pei
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
| | - Zhaopeng Jin
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
| | - Yue Sun
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
| | - Tao Liu
- Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, Hebei Province, People's Republic of China
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21
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Sun J, Lerner E, Tighe B, Middlemist C, Zhao J. Embedded shape morphing for morphologically adaptive robots. Nat Commun 2023; 14:6023. [PMID: 37758737 PMCID: PMC10533550 DOI: 10.1038/s41467-023-41708-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Shape-morphing robots can change their morphology to fulfill different tasks in varying environments, but existing shape-morphing capability is not embedded in a robot's body, requiring bulky supporting equipment. Here, we report an embedded shape-morphing scheme with the shape actuation, sensing, and locking, all embedded in a robot's body. We showcase this embedded scheme using three morphing robotic systems: 1) self-sensing shape-morphing grippers that can adapt to objects for adaptive grasping; 2) a quadrupedal robot that can morph its body shape for different terrestrial locomotion modes (walk, crawl, or horizontal climb); 3) an untethered robot that can morph its limbs' shape for amphibious locomotion. We also create a library of embedded morphing modules to demonstrate the versatile programmable shapes (e.g., torsion, 3D bending, surface morphing, etc.). Our embedded morphing scheme offers a promising avenue for robots to reconfigure their morphology in an embedded manner that can adapt to different environments on demand.
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Affiliation(s)
- Jiefeng Sun
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA.
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, USA.
| | - Elisha Lerner
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA
| | - Brandon Tighe
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA
| | - Clint Middlemist
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA
| | - Jianguo Zhao
- Adaptive Robotics Lab, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA.
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22
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Li Y, Goulbourne NC. Constitutive formulations for intrinsic anisotropy in soft electroelastic materials. Sci Rep 2023; 13:14712. [PMID: 37679342 PMCID: PMC10485073 DOI: 10.1038/s41598-023-37946-9] [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: 02/20/2023] [Accepted: 06/30/2023] [Indexed: 09/09/2023] Open
Abstract
Inspired by biology and engineered soft active material systems, we propose a new constitutive formulation for a soft material consisting of soft contractile fibers embedded in a soft matrix. The mathematical implementation of the model is based on a multi-field invariant formulation within a nonlinear continuum mechanics framework. The coupled constitutive formulation highlights a new electromechanical coupling term that describes the intrinsic (or active) anisotropy due to the contractile units. The model demonstrates the relative role that intrinsic anisotropy plays in the overall stress response. The resulting formulation could be used to design and inspire the development of new soft material systems that seek to replicate three dimensional biological motion.
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Affiliation(s)
- Yali Li
- University of Michigan, Ann Arbor, USA
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23
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Hegde C, Su J, Tan JMR, He K, Chen X, Magdassi S. Sensing in Soft Robotics. ACS NANO 2023; 17:15277-15307. [PMID: 37530475 PMCID: PMC10448757 DOI: 10.1021/acsnano.3c04089] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/26/2023] [Indexed: 08/03/2023]
Abstract
Soft robotics is an exciting field of science and technology that enables robots to manipulate objects with human-like dexterity. Soft robots can handle delicate objects with care, access remote areas, and offer realistic feedback on their handling performance. However, increased dexterity and mechanical compliance of soft robots come with the need for accurate control of the position and shape of these robots. Therefore, soft robots must be equipped with sensors for better perception of their surroundings, location, force, temperature, shape, and other stimuli for effective usage. This review highlights recent progress in sensing feedback technologies for soft robotic applications. It begins with an introduction to actuation technologies and material selection in soft robotics, followed by an in-depth exploration of various types of sensors, their integration methods, and the benefits of multimodal sensing, signal processing, and control strategies. A short description of current market leaders in soft robotics is also included in the review to illustrate the growing demands of this technology. By examining the latest advancements in sensing feedback technologies for soft robots, this review aims to highlight the potential of soft robotics and inspire innovation in the field.
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Affiliation(s)
- Chidanand Hegde
- School
of Materials Science and Engineering, Nanyang
Technological University, Singapore 639798, Singapore
- Singapore-HUJ
alliance for Research and Enterprise (SHARE), Campus for Research Excellence and Technological Enterprise (CREATE) Singapore 138602, Singapore
| | - Jiangtao Su
- School
of Materials Science and Engineering, Nanyang
Technological University, Singapore 639798, Singapore
- Singapore-HUJ
alliance for Research and Enterprise (SHARE), Campus for Research Excellence and Technological Enterprise (CREATE) Singapore 138602, Singapore
| | - Joel Ming Rui Tan
- School
of Materials Science and Engineering, Nanyang
Technological University, Singapore 639798, Singapore
- Singapore-HUJ
alliance for Research and Enterprise (SHARE), Campus for Research Excellence and Technological Enterprise (CREATE) Singapore 138602, Singapore
| | - Ke He
- School
of Materials Science and Engineering, Nanyang
Technological University, Singapore 639798, Singapore
- Singapore-HUJ
alliance for Research and Enterprise (SHARE), Campus for Research Excellence and Technological Enterprise (CREATE) Singapore 138602, Singapore
| | - Xiaodong Chen
- School
of Materials Science and Engineering, Nanyang
Technological University, Singapore 639798, Singapore
- Singapore-HUJ
alliance for Research and Enterprise (SHARE), Campus for Research Excellence and Technological Enterprise (CREATE) Singapore 138602, Singapore
| | - Shlomo Magdassi
- Singapore-HUJ
alliance for Research and Enterprise (SHARE), Campus for Research Excellence and Technological Enterprise (CREATE) Singapore 138602, Singapore
- Casali
Center for Applied Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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24
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Wang J, Sotzing M, Lee M, Chortos A. Passively addressed robotic morphing surface (PARMS) based on machine learning. SCIENCE ADVANCES 2023; 9:eadg8019. [PMID: 37478174 PMCID: PMC10361599 DOI: 10.1126/sciadv.adg8019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/21/2023] [Indexed: 07/23/2023]
Abstract
Reconfigurable morphing surfaces provide new opportunities for advanced human-machine interfaces and bio-inspired robotics. Morphing into arbitrary surfaces on demand requires a device with a sufficiently large number of actuators and an inverse control strategy. Developing compact, efficient control interfaces and algorithms is vital for broader adoption. In this work, we describe a passively addressed robotic morphing surface (PARMS) composed of matrix-arranged ionic actuators. To reduce the complexity of the physical control interface, we introduce passive matrix addressing. Matrix addressing allows the control of N2 independent actuators using only 2N control inputs, which is substantially lower than traditional direct addressing (N2 control inputs). Using machine learning with finite element simulations for training, our control algorithm enables real-time, high-precision forward and inverse control, allowing PARMS to dynamically morph into arbitrary achievable predefined surfaces on demand. These innovations may enable the future implementation of PARMS in wearables, haptics, and augmented reality/virtual reality.
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Affiliation(s)
- Jue Wang
- Department of Mechanical Engineering, Purdue University, 500 Central Dr, Lafayette, IN 47907, USA
| | - Michael Sotzing
- Department of Mechanical Engineering, Purdue University, 500 Central Dr, Lafayette, IN 47907, USA
| | - Mina Lee
- Department of Mechanical Engineering, Purdue University, 500 Central Dr, Lafayette, IN 47907, USA
| | - Alex Chortos
- Department of Mechanical Engineering, Purdue University, 500 Central Dr, Lafayette, IN 47907, USA
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25
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Li Y, Goulbourne NC. Methods for numerical simulation of soft actively contractile materials. Sci Rep 2023; 13:10369. [PMID: 37365212 DOI: 10.1038/s41598-023-36465-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 06/04/2023] [Indexed: 06/28/2023] Open
Abstract
Soft materials that can demonstrate on demand reconfigurability and changing compliance are highly sought after as actuator materials in many fields such as soft robotics and biotechnology. Whilst there are numerous proof of concept materials and devices, rigorous predictive models of deformation have not been well-established or widely adopted. In this paper, we discuss programming complex three-dimensional deformations of a soft intrinsically anisotropic material by controlling the orientation of the contractile units and/or direction of the applied electric field. Programming is achieved by patterning contractile units and/or selectively activating spatial regions. A new constitutive model is derived to describe the soft intrinsic anisotropy of soft materials. The model is developed within a continuum mechanics framework using an invariant-based formulation. Computational implementation allows us to simulate the complex three-dimensional shape response when activated by electric field. Several examples of the achievable Gauss-curved surfaces are demonstrated. Our computational analysis introduces a mechanics-based framework for design when considering soft morphing materials with intrinsic anisotropy, and is meant to inspire the development of new soft active materials.
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Affiliation(s)
- Yali Li
- University of Michigan, Ann Arbor, USA
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26
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Olvera Bernal RA, Olekhnovich RO, Uspenskaya MV. Chitosan/PVA Nanofibers as Potential Material for the Development of Soft Actuators. Polymers (Basel) 2023; 15:polym15092037. [PMID: 37177184 PMCID: PMC10181017 DOI: 10.3390/polym15092037] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
Chitosan/PVA nanofibrous electroresponsive soft actuators were successfully obtained using an electrospinning process, which showed fast speed displacement under an acidic environment. Chitosan/PVA nanofibers were prepared and characterized, and their electroactive response was tested. Chitosan/PVA nanofibers were electrospun from a chitosan/PVA solution at different chitosan contents (2.5, 3, 3.5, and 4 wt.%). Nanofibers samples were characterized using Fourier transform infrared analyses, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), optical microscopy, and tensile test. The electroactive behavior of the nanofiber hydrogels was tested under different HCl pH (2-6) under a constant voltage (10 V). The electroactive response test showed a dependence between the nanofiber's chitosan content and pH with the bending speed displacement, reaching a maximum speed displacement of 1.86 mm-1 in a pH 3 sample with a chitosan content of 4 wt.%. The results of the electroactive response were further supported by the determination of the proportion of free amine groups, though deconvoluting the FTIR spectra in the range of 3000-3700 cm-1. Deconvolution results showed that the proportion of free amine increased as the chitosan content was higher, being 3.6% and 4.59% for nanofibers with chitosan content of 2.5 and 4 wt.%, respectively.
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27
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Liao W, Yang Z. 3D printing programmable liquid crystal elastomer soft pneumatic actuators. MATERIALS HORIZONS 2023; 10:576-584. [PMID: 36468657 DOI: 10.1039/d2mh01001a] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Soft pneumatic actuators (SPAs) rely on anisotropic mechanical properties to generate specific motions after inflation. To achieve mechanical anisotropy, additional stiff materials or heterogeneous structures are typically introduced in isotropic base materials. However, the inherent limitations of these strategies may lead to potential interfacial problems or inefficient material usage. Herein, we develop a new strategy for fabricating SPAs based on an aligned liquid crystal elastomer (LCE) by a modified 3D printing technology. A rotating substrate enables the one-step fabrication of tubular LCE-SPAs with designed alignments in three dimensions. The alignment can be precisely programmed through printing, resulting in intrinsic mechanical anisotropy of the LCE. With a specially designed alignment, LCE-SPAs can achieve basic motions-contraction, elongation, bending, and twisting-and accomplish diverse tasks, e.g., grabbing objects and mixing water. This study provides a new perspective for the design and fabrication of SPAs.
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Affiliation(s)
- Wei Liao
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, China.
| | - Zhongqiang Yang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, China.
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, China
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28
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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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29
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Dominici S, Kamranikia K, Mougin K, Spangenberg A. Smart Nematic Liquid Crystal Polymers for Micromachining Advances. MICROMACHINES 2023; 14:124. [PMID: 36677185 PMCID: PMC9860665 DOI: 10.3390/mi14010124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/22/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
The miniaturization of tools is an important step in human evolution to create faster devices as well as precise micromachines. Studies around this topic have allowed the creation of small-scale objects capable of a wide range of deformation to achieve complex tasks. Molecular arrangements have been investigated through liquid crystal polymer (LCP) to program such a movement. Smart polymers and hereby liquid crystal matrices are materials of interest for their easy structuration properties and their response to external stimuli. However, up until very recently, their employment at the microscale was mainly limited to 2D structuration. Among the numerous issues, one concerns the ability to 3D structure the material while controlling the molecular orientation during the polymerization process. This review aims to report recent efforts focused on the microstructuration of LCP, in particular those dealing with 3D microfabrication via two-photon polymerization (TPP). Indeed, the latter has revolutionized the production of 3D complex micro-objects and is nowadays recognized as the gold standard for 3D micro-printing. After a short introduction highlighting the interest in micromachines, some basic principles of liquid crystals are recalled from the molecular aspect to their implementation. Finally, the possibilities offered by TPP as well as the way to monitor the motion into the fabricated microrobots are highlighted.
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Affiliation(s)
- Sébastien Dominici
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS–UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France
- Université de Strasbourg, 67000 Strasbourg, France
| | - Keynaz Kamranikia
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS–UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France
- Université de Strasbourg, 67000 Strasbourg, France
| | - Karine Mougin
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS–UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France
- Université de Strasbourg, 67000 Strasbourg, France
| | - Arnaud Spangenberg
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS–UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France
- Université de Strasbourg, 67000 Strasbourg, France
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30
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Zhang C, Jin B, Cao X, Chen Z, Miao W, Yang X, Luo Y, Li T, Xie T. Dielectric Polymer with Designable Large Motion under Low Electric Field. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2206393. [PMID: 36189869 DOI: 10.1002/adma.202206393] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Dielectric elastomers (DEs) can demonstrate fast and large in-plane expansion/contraction due to electric field (e-field)-induced Maxwell stress. For robotic applications, it is often necessary that the in-plane actuation is converted into out-of-plane motions with mechanical frames. Despite their performance appeal, their high driving e-field (20-100 V µm-1 ) demands bulky power accessories and severely compromises their durability. Here, a dielectric polymer that can be programmed into diverse motions actuated under a low e-field (2-10 V µm-1 ) is reported. The material is a crystalline dynamic covalent network that can be reconfigured into arbitrary 3D geometries. This gives rise to a geometric effect that markedly amplifies the actuation, leading to designable large motions when the dielectric polymer is heated above its melting temperature to become a DE. Additionally, the crystallization transition enables dynamic multimodal motions and active deployability. These attributes result in unique design versatility for soft robots.
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Affiliation(s)
- Chengcheng Zhang
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Binjie Jin
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- Center for X-Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027, China
| | - Xunuo Cao
- Center for X-Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027, China
| | - Zheqi Chen
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Wusha Miao
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xuxu Yang
- Center for X-Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027, China
| | - Yingwu Luo
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Tiefeng Li
- Center for X-Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027, China
| | - Tao Xie
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- Department of Colorectal Surgery and Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310027, China
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31
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Emerging 4D printing strategies for on-demand local actuation & micro printing of soft materials. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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32
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Pinchin NP, Lin CH, Kinane CA, Yamada N, Pena-Francesch A, Shahsavan H. Plasticized liquid crystal networks and chemical motors for the active control of power transmission in mechanical devices. SOFT MATTER 2022; 18:8063-8070. [PMID: 35969176 DOI: 10.1039/d2sm00826b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The miniaturization of mechanical devices poses new challenges in powering, actuation, and control since traditional approaches cannot be used due to inherent size limitations. This is particularly challenging in untethered small-scale machines where independent actuation of multicomponent and multifunctional complex systems is required. This work showcases the integration of self-powered chemical motors and liquid crystal networks into a powertrain transmission device to achieve orthogonal untethered actuation for power and control. Driving gears with a protein-based chemical motor were used to power the transmission system with Marangoni propulsive forces, while photothermal liquid crystal networks were used as a photoresponsive clutch to engage/disengage the gear system. Liquid crystal networks were plasticized for optimized photothermal bending actuation to break the surface tension of water and achieve reversible immersion/resurfacing at the air-water interface. This concept is demonstrated in a milliscale transmission gear system and offers potential solutions for aquatic soft robots whose powering and control mechanisms must be necessarily decoupled.
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Affiliation(s)
- Natalie P Pinchin
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - Chia-Heng Lin
- Department of Materials Science and Engineering, Macromolecular Science and Engineering, Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Cecelia A Kinane
- Department of Materials Science and Engineering, Macromolecular Science and Engineering, Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Naoki Yamada
- Department of System Innovation, Osaka University, Osaka, 560-0043, Japan
| | - Abdon Pena-Francesch
- Department of Materials Science and Engineering, Macromolecular Science and Engineering, Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Hamed Shahsavan
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
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33
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Dong X, Luo X, Zhao H, Qiao C, Li J, Yi J, Yang L, Oropeza FJ, Hu TS, Xu Q, Zeng H. Recent advances in biomimetic soft robotics: fabrication approaches, driven strategies and applications. SOFT MATTER 2022; 18:7699-7734. [PMID: 36205123 DOI: 10.1039/d2sm01067d] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Compared to traditional rigid-bodied robots, soft robots are constructed using physically flexible/elastic bodies and electronics to mimic nature and enable novel applications in industry, healthcare, aviation, military, etc. Recently, the fabrication of robots on soft matter with great flexibility and compliance has enabled smooth and sophisticated 'multi-degree-of-freedom' 3D actuation to seamlessly interact with humans, other organisms and non-idealized environments in a highly complex and controllable manner. Herein, we summarize the fabrication approaches, driving strategies, novel applications, and future trends of soft robots. Firstly, we introduce the different fabrication approaches to prepare soft robots and compare and systematically discuss their advantages and disadvantages. Then, we present the actuator-based and material-based driving strategies of soft robotics and their characteristics. The representative applications of soft robotics in artificial intelligence, medicine, sensors, and engineering are summarized. Also, some remaining challenges and future perspectives in soft robotics are provided. This work highlights the recent advances of soft robotics in terms of functional material selection, structure design, control strategies and biomimicry, providing useful insights into the development of next-generation functional soft robotics.
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Affiliation(s)
- Xiaoxiao Dong
- College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, Beijing 102249, China.
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton T6G 1H9, Canada.
| | - Xiaohang Luo
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum-Beijing, Beijing 102249, China
| | - Hong Zhao
- College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, Beijing 102249, China.
| | - Chenyu Qiao
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton T6G 1H9, Canada.
| | - Jiapeng Li
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum-Beijing, Beijing 102249, China
| | - Jianhong Yi
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China.
| | - Li Yang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton T6G 1H9, Canada.
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China.
| | - Francisco J Oropeza
- Department of Mechanical Engineering, California State University, Los Angeles, California 90032, USA
| | - Travis Shihao Hu
- Department of Mechanical Engineering, California State University, Los Angeles, California 90032, USA
| | - Quan Xu
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum-Beijing, Beijing 102249, China
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton T6G 1H9, Canada.
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34
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Jin L, Yeager M, Lee YJ, O’Brien DJ, Yang S. Shape-morphing into 3D curved surfaces with nacre-like composite architectures. SCIENCE ADVANCES 2022; 8:eabq3248. [PMID: 36223460 PMCID: PMC9555776 DOI: 10.1126/sciadv.abq3248] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Inhomogeneous in-plane deformation of soft materials or cutting and folding of inextensible flat sheets enables shape-morphing from two dimensional (2D) to three-dimensional (3D), while the resulting structures often have weakened mechanical strength. Shells like nacre are known for the superior fracture toughness due to the "brick and mortar" composite layers, enabling stress redistribution and crack stopping. Here, we report an optimal and universal cutting and stacking strategy that transforms composite plies into 3D doubly curved shapes with nacre-like architectures. The multilayered laminate exhibits staggered cut distributions, while the interlaminar shear mitigates the cut-induced mechanical weakness. The experimentally consolidated hemispherical shells exhibit, on average, 37 and 69% increases of compression peak forces, versus those with random cut distributions, when compressed in different directions. Our approach opens a previously unidentified paradigm for shape-conforming arbitrarily curved surfaces while achieving high mechanical performance.
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Affiliation(s)
- Lishuai Jin
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104, USA
| | - Michael Yeager
- DEVCOM Army Research Laboratory, Aberdeen Proving Ground, MD 21005, USA
| | - Young-Joo Lee
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104, USA
| | - Daniel J. O’Brien
- DEVCOM Army Research Laboratory, Aberdeen Proving Ground, MD 21005, USA
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104, USA
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35
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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: 5] [Impact Index Per Article: 1.7] [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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36
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Cai F, Yang B, Lv X, Feng W, Yu H. Mechanically mutable polymer enabled by light. SCIENCE ADVANCES 2022; 8:eabo1626. [PMID: 36001666 PMCID: PMC9401616 DOI: 10.1126/sciadv.abo1626] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 07/13/2022] [Indexed: 05/25/2023]
Abstract
Human skin is a remarkable example of a biological material that displays unique mechanical characters of both soft elasticity and stretchability. However, mimicking these features has been absent in photoresponsive soft matters. Here, we present one synthetic ABA-type triblock copolymer consisting of polystyrene as end blocks and one photoresponsive azopolymer as the middle block, which is stiffness at room temperature and shows a phototunable transition to soft elastics athermally. We have synthesized an elastics we term "photoinduced soft elastomer," where the photo-evocable soft midblock of azopolymer and the glassy polystyrene domains act as elastic matrix and physical cross-linking junctions, respectively. On the basis of the photoswitchable transformation between stiffness and elasticity at room temperature, we demonstrated precise control over nanopatterns on nonplanar substrates especially adaptable in the human skin and fabrication of packaged perovskite solar cells, enabling the simple, human-friendly, and controllable approach to be promising for mechanically adaptable soft photonic and electronic packaging applications.
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Affiliation(s)
- Feng Cai
- School of Materials Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, P. R. China
| | - Bowen Yang
- School of Materials Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, P. R. China
| | - Xuande Lv
- School of Materials Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, P. R. China
| | - Wei Feng
- School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, P. R. China
| | - Haifeng Yu
- School of Materials Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, P. R. China
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37
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Xiao YY, Jiang ZC, Hou JB, Chen XS, Zhao Y. Electrically driven liquid crystal network actuators. SOFT MATTER 2022; 18:4850-4867. [PMID: 35730498 DOI: 10.1039/d2sm00544a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Soft actuators based on liquid crystal networks (LCNs) have aroused great scientific interest for use as stimuli-controlled shape-changing and moving components for robotic devices due to their fast, large, programmable and solvent-free actuation responses. Recently, various LCN actuators have been implemented in soft robotics using stimulus sources such as heat, light, humidity and chemical reactions. Among them, electrically driven LCN actuators allow easy modulation and programming of the input electrical signals (amplitude, phase, and frequency) as well as stimulation throughout the volume, rendering them promising actuators for practical applications. Herein, the progress of electrically driven LCN actuators regarding their construction, actuation mechanisms, actuation performance, actuation programmability and the design strategies for intelligent systems is elucidated. We also discuss new robotic functions and advanced actuation control. Finally, an outlook is provided, highlighting the research challenges faced with this type of actuator.
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Affiliation(s)
- Yao-Yu Xiao
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| | - Zhi-Chao Jiang
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| | - Jun-Bo Hou
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| | - Xin-Shi Chen
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| | - Yue Zhao
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec, Canada.
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38
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Guan Z, Wang L, Bae J. Advances in 4D printing of liquid crystalline elastomers: materials, techniques, and applications. MATERIALS HORIZONS 2022; 9:1825-1849. [PMID: 35504034 DOI: 10.1039/d2mh00232a] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline elastomers (LCEs) are polymer networks exhibiting anisotropic liquid crystallinity while maintaining elastomeric properties. Owing to diverse polymeric forms and self-alignment molecular behaviors, LCEs have fascinated state-of-the-art efforts in various disciplines other than the traditional low-molar-mass display market. By patterning order to structures, LCEs demonstrate reversible high-speed and large-scale actuations in response to external stimuli, allowing for close integration with 4D printing and architectures of digital devices, which is scarcely observed in homogeneous soft polymer networks. In this review, we collect recent advances in 4D printing of LCEs, with emphases on synthesis and processing methods that enable microscopic changes in the molecular orientation and hence macroscopic changes in the properties of end-use objects. Promising potentials of printed complexes include fields of soft robotics, optics, and biomedical devices. Within this scope, we elucidate the relationships among external stimuli, tailorable morphologies in mesophases of liquid crystals, and programmable topological configurations of printed parts. Lastly, perspectives and potential challenges facing 4D printing of LCEs are discussed.
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Affiliation(s)
- Zhecun Guan
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
| | - Ling Wang
- School of Materials Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
| | - Jinhye Bae
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
- Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
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39
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Xiao M, Mao J, Kollosche M, Hwang V, Clarke DR, Manoharan VN. Voltage-tunable elastomer composites that use shape instabilities for rapid structural color changes. MATERIALS HORIZONS 2022; 9:1954-1961. [PMID: 35579252 DOI: 10.1039/d2mh00374k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Structurally colored materials can switch colors in response to external stimuli, which makes them potentially useful as colorimetric sensors, dynamic displays, and camouflage. However, their applications are limited by the angular dependence, slow response, and absence of synchronous control in time and space. In addition, out-of-plane deformation from shape instability easily occurs in photonic films, leading to inhomogeneous colors in photonic-crystal materials. To address these challenges, we combine structurally colored photonic glasses and dielectric elastomer actuators. We use an external voltage signal to tune color changes quickly (much less than 0.1 s). The photonic glassses produce colors with low angular dependence, so that their colors are homogeneous even when they become curved due to voltage-triggered instabilities (buckling or wrinkling). As proof of concept, we present a pixelated display in which segments can be independently and rapidly turned on and off. This wide-angle, instability-tolerant, color-changing platform could be used in next-generation soft and curved color displays, camouflage with both shape and color changes, and multifunctional sensors.
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Affiliation(s)
- Ming Xiao
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
- College of Polymer Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Jie Mao
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
- College of Chemical Engineering, Ningxia University, Yinchuan City, 750021, China
| | - Matthias Kollosche
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
| | - Victoria Hwang
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
| | - David R Clarke
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
| | - Vinothan N Manoharan
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
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40
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Mistry D. The richness of liquid crystal elastomer mechanics keeps growing. LIQUID CRYSTALS TODAY 2022. [DOI: 10.1080/1358314x.2022.2048974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Devesh Mistry
- School of Physics and Astronomy, University of Leeds, Leeds, UK
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41
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Yu Z, Shang J, Shi Q, Xia Y, Zhai DH, Wang H, Huang Q, Fukuda T. Electrically Controlled Aquatic Soft Actuators with Desynchronized Actuation and Light-Mediated Reciprocal Locomotion. ACS APPLIED MATERIALS & INTERFACES 2022; 14:12936-12948. [PMID: 35244389 DOI: 10.1021/acsami.2c01838] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Soft-bodied aquatic invertebrates can overcome hydrodynamic resistance and display diverse locomotion modes in response to environmental cues. Exploring the dynamics of locomotion from bioinspired aquatic actuators will broaden the perspective of underwater manipulation of artificial systems in fluidic environments. Here, we report a multilayer soft actuator design based on a light-driven hydrogel and a laser-induced graphene (LIG) actuator, minimizing the effect of the time delay by a monolithic hydrogel-based system while maintaining shape-morphing functionality. Moreover, different time scales in the response of actuator materials enable a real-time desynchronization of energy inputs, holding great potential for applications requiring desynchronized stimulation. This hybrid design principle is ultimately demonstrated with a high-performance aquatic soft actuator possessing an underwater walking speed of 0.81 body length per minute at a relatively low power consumption of 3 W. When integrated with an optical sensor, the soft actuator can sense the variation in light intensity and achieve mediated reciprocal motion. Our proposed locomotion mechanism could inspire other multilayer soft actuators to achieve underwater functionalities at the same spatiotemporal scale. The underwater actuation platform could be used to study locomotion kinematics and control mechanisms that mimic the motion of soft-bodied aquatic organisms.
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Affiliation(s)
- Zhiqiang Yu
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
- Key Laboratory of Biomimetic Robots and Systems, Beijing Institute of Technology, Ministry of Education, Beijing 100081, China
| | - Junyi Shang
- School of Automation, Beijing Institute of Technology, Beijing 100081, China
| | - Qing Shi
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
- Key Laboratory of Biomimetic Robots and Systems, Beijing Institute of Technology, Ministry of Education, Beijing 100081, China
| | - Yuanqing Xia
- School of Automation, Beijing Institute of Technology, Beijing 100081, China
| | - Di-Hua Zhai
- School of Automation, Beijing Institute of Technology, Beijing 100081, China
| | - Huaping Wang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
- Key Laboratory of Biomimetic Robots and Systems, Beijing Institute of Technology, Ministry of Education, Beijing 100081, China
| | - Qiang Huang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
- Key Laboratory of Biomimetic Robots and Systems, Beijing Institute of Technology, Ministry of Education, Beijing 100081, China
| | - Toshio Fukuda
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
- Key Laboratory of Biomimetic Robots and Systems, Beijing Institute of Technology, Ministry of Education, Beijing 100081, China
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42
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Pu J, Meng Y, Xie Z, Peng Z, Wu J, Shi Y, Plamthottam R, Yang W, Pei Q. A unimorph nanocomposite dielectric elastomer for large out-of-plane actuation. SCIENCE ADVANCES 2022; 8:eabm6200. [PMID: 35245109 PMCID: PMC8896788 DOI: 10.1126/sciadv.abm6200] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/12/2022] [Indexed: 05/28/2023]
Abstract
Dielectric elastomer actuators (DEAs) feature large, reversible in-plane deformation, and stacked DEA layers are used to produce large strokes in the thickness dimension. We introduce an electrophoretic process to concentrate boron nitride nanosheet dispersion in a dielectric elastomer precursor solution onto a designated electrode surface. The resulting unimorph nanocomposite dielectric elastomer (UNDE) has a seamless bilayer structure with 13 times of modulus difference. The UNDE can be actuated to large bending curvatures, with enhanced breakdown field strength and durability as compared to conventional nanocomposite dielectric elastomer. Multiple UNDE units can be formed in a simple electrophoretic concentration process using patterned electrode areas. A disc-shaped actuator comprising six UNDE units outputs large bidirectional stroke up to 10 Hz. This actuator is used to demonstrate a high-speed lens motor capable of varying the focal length of a two-lens system by 40 times.
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Affiliation(s)
- Junhong Pu
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Yuan Meng
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Zhixin Xie
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Zihang Peng
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jianghan Wu
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ye Shi
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Roshan Plamthottam
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Wei Yang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Qibing Pei
- Soft Materials Research Laboratory Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
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43
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Fernandes Minori A, Jadhav S, Chen H, Fong S, Tolley MT. Power Amplification for Jumping Soft Robots Actuated by Artificial Muscles. Front Robot AI 2022; 9:844282. [PMID: 35308461 PMCID: PMC8927657 DOI: 10.3389/frobt.2022.844282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/01/2022] [Indexed: 12/04/2022] Open
Abstract
Robots composed of soft materials can passively adapt to constrained environments and mitigate damage due to impact. Given these features, jumping has been explored as a mode of locomotion for soft robots. However, for mesoscale jumping robots, lightweight and compact actuation are required. Previous work focused on systems powered by fluids, combustion, smart materials, electromagnetic, or electrostatic motors, which require one or more of the following: large rigid components, external power supplies, components of specific, pre-defined sizes, or fast actuation. In this work, we propose an approach to design and fabricate an electrically powered soft amplification mechanism to enable untethered mesoscale systems with continuously tunable performance. We used the tunable geometry of a liquid crystal elastomer actuator, an elastic hemispherical shell, and a pouch motor for active latching to achieve rapid motions for jumping despite the slow contraction rate of the actuator. Our system amplified the power output of the LCE actuator by a factor of 8.12 × 103 with a specific power of 26.4 W/kg and jumped to a height of 55.6 mm (with a 20 g payload). This work enables future explorations for electrically untethered soft systems capable of rapid motions (e.g., jumping).
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Affiliation(s)
- Adriane Fernandes Minori
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA, United States
- School of Computer Science, Human and Computer Interaction Institute, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Saurabh Jadhav
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA, United States
| | - Haojin Chen
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA, United States
| | - Samantha Fong
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA, United States
| | - Michael T. Tolley
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA, United States
- *Correspondence: Michael T. Tolley,
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44
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Li M, Pal A, Aghakhani A, Pena-Francesch A, Sitti M. Soft actuators for real-world applications. NATURE REVIEWS. MATERIALS 2022; 7:235-249. [PMID: 35474944 PMCID: PMC7612659 DOI: 10.1038/s41578-021-00389-7] [Citation(s) in RCA: 243] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/21/2021] [Indexed: 05/22/2023]
Abstract
Inspired by physically adaptive, agile, reconfigurable and multifunctional soft-bodied animals and human muscles, soft actuators have been developed for a variety of applications, including soft grippers, artificial muscles, wearables, haptic devices and medical devices. However, the complex performance of biological systems cannot yet be fully replicated in synthetic designs. In this Review, we discuss new materials and structural designs for the engineering of soft actuators with physical intelligence and advanced properties, such as adaptability, multimodal locomotion, self-healing and multi-responsiveness. We examine how performance can be improved and multifunctionality implemented by using programmable soft materials, and highlight important real-world applications of soft actuators. Finally, we discuss the challenges and opportunities for next-generation soft actuators, including physical intelligence, adaptability, manufacturing scalability and reproducibility, extended lifetime and end-of-life strategies.
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Affiliation(s)
- Meng Li
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | - Aniket Pal
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | - Amirreza Aghakhani
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | - Abdon Pena-Francesch
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart, Germany
- Department of Materials Science and Engineering, Macromolecular Science and Engineering, Robotics Institute, University of Michigan, Ann Arbor, MI, USA
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
- School of Medicine and College of Engineering, Koç University, Istanbul, Turkey
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45
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46
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Hwang D, Barron EJ, Haque ABMT, Bartlett MD. Shape morphing mechanical metamaterials through reversible plasticity. Sci Robot 2022; 7:eabg2171. [PMID: 35138882 DOI: 10.1126/scirobotics.abg2171] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Biological organisms such as the octopus can reconfigure their shape and properties to perform diverse tasks. However, soft machines struggle to achieve complex configurations, morph into shape to support loads, and go between multiple states reversibly. Here, we introduce a multifunctional shape-morphing material with reversible and rapid polymorphic reconfigurability. We couple elastomeric kirigami with an unconventional reversible plasticity mechanism in metal alloys to rapidly (<0.1 seconds) morph flat sheets into complex, load-bearing shapes, with reversibility and self-healing through phase change. This kirigami composite overcomes trade-offs in deformability and load-bearing capacity and eliminates power requirements to sustain reconfigured shapes. We demonstrate this material through integration with onboard control, motors, and power to create a soft robotic morphing drone, which autonomously transforms from a ground to air vehicle and an underwater morphing machine, which can be reversibly deployed to collect cargo.
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Affiliation(s)
- Dohgyu Hwang
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA.,Department of Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
| | - Edward J Barron
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA.,Department of Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
| | - A B M Tahidul Haque
- Department of Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
| | - Michael D Bartlett
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA.,Department of Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
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47
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Wang J, Suo J, Chortos A. Design of Fully Controllable and Continuous Programmable Surface Based on Machine Learning. IEEE Robot Autom Lett 2022. [DOI: 10.1109/lra.2021.3129542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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48
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Hebner TS, Fowler HE, Herbert KM, Skillin NP, Bowman CN, White TJ. Polymer Network Structure, Properties, and Formation of Liquid Crystalline Elastomers Prepared via Thiol–Acrylate Chain Transfer Reactions. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01919] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Tayler S. Hebner
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Hayden E. Fowler
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Katie M. Herbert
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Nathaniel P. Skillin
- 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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49
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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: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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50
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Fowler HE, Rothemund P, Keplinger C, White TJ. Liquid Crystal Elastomers with Enhanced Directional Actuation to Electric Fields. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2103806. [PMID: 34510561 DOI: 10.1002/adma.202103806] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 08/04/2021] [Indexed: 06/13/2023]
Abstract
The integration of soft, stimuli-responsive materials in robotic systems is a promising approach to introduce dexterous and delicate manipulation of objects. Electrical control of mechanical response offers many benefits in robotic systems including the availability of this energy input, the associated response time, magnitude of actuation, and opportunity for self-regulation. Here, a materials chemistry is detailed to prepare liquid crystal elastomers (LCEs) with a 14:1 modulus contrast and increase in dielectric constant to enhance electromechanical deformation. The inherent modulus contrast of these LCEs (when coated with compliant electrodes) directly convert an electric field to a directional expansion of 20%. The electromechanical response of LCE actuators is observed upon application of voltage ranging from 0.5 to 6 kV. The deformation of these materials is rapid, reaching strain rates of 18% s-1 . Upon removal of the electric field, little hysteresis is observed. Patterning the spatial orientation of the nematic director of the LCEs results in a 2D-3D shape transformation to a cone 8 mm in height. Individual and sequential addressing of an array of LCE actuators is demonstrated as a haptic surface.
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Affiliation(s)
- Hayden E Fowler
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Boulder, CO, 80309, USA
| | - Philipp Rothemund
- Department of Mechanical Engineering, University of Colorado, Boulder, Boulder, CO, 80309, USA
- Robotic Materials Department, Max Planck Institute for Intelligent Systems, Stuttgart, 70569, Germany
| | - Christoph Keplinger
- Department of Mechanical Engineering, University of Colorado, Boulder, Boulder, CO, 80309, USA
- Robotic Materials Department, Max Planck Institute for Intelligent Systems, Stuttgart, 70569, Germany
- Materials Science and Engineering Program, University of Colorado, Boulder, Boulder, CO, 80309, USA
| | - Timothy J White
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Boulder, CO, 80309, USA
- Materials Science and Engineering Program, University of Colorado, Boulder, Boulder, CO, 80309, USA
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