101
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Bauman GE, Koch JA, White TJ. Rheology of liquid crystalline oligomers for 3-D printing of liquid crystalline elastomers. SOFT MATTER 2022; 18:3168-3176. [PMID: 35380153 DOI: 10.1039/d2sm00166g] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline monomers can be oligomerized and subsequently 3-D printed to prepare liquid crystalline elastomers (LCEs) with spatial variation of the nematic director to create soft materials that undergo complex shape change when subject to stimulus. Here, we detail the correlation of alignment in 3-D printed LCE on the shear history of the oligomeric ink. This coupling is evident both in the polymerization of sheared LCE samples as well as steady-state rheological experiments that quantify the time-dependent flow behaviors of these complex fluids. Under a steady shear flow, oligomeric LC inks transition from a nematic state with unaligned (polydomain) orientation to a uniaxially aligned (monodomain) nematic phase over a large range of applied strain. After cessation of shear flow, the oligomeric LC inks return the polydomain orientation over approximately 30 minutes. The alignment of liquid crystalline segments in the LCE (and the associated stimuli-response of the materials) is ultimately correlated to the degree of strain applied to the ink.
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Affiliation(s)
- Grant E Bauman
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado, 80309, USA.
| | - Jeremy A Koch
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado, 80309, USA.
| | - Timothy J White
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado, 80309, USA.
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102
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Li Y, Liu T, Ambrogi V, Rios O, Xia M, He W, Yang Z. Liquid Crystalline Elastomers Based on Click Chemistry. ACS APPLIED MATERIALS & INTERFACES 2022; 14:14842-14858. [PMID: 35319184 DOI: 10.1021/acsami.1c21096] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline elastomers (LCEs) have emerged as an important class of functional materials that are suitable for a wide range of applications, such as sensors, actuators, and soft robotics. The unique properties of LCEs originate from the combination between liquid crystal and elastomeric network. The control of macroscopic liquid crystalline orientation and network structure is crucial to realizing the useful functionalities of LCEs. A variety of chemistries have been developed to fabricate LCEs, including hydrosilylation, free radical polymerization of acrylate, and polyaddition of epoxy and carboxylic acid. Over the past few years, the use of click chemistry has become a more robust and energy-efficient way to construct LCEs with desired structures. This article provides an overview of emerging LCEs based on click chemistries, including aza-Michael addition between amine and acrylate, radical-mediated thiol-ene and thiol-yne reactions, base-catalyzed thiol-acrylate and thiol-epoxy reactions, copper-catalyzed azide-alkyne cycloaddition, and Diels-Alder cycloaddition. The similarities and differences of these reactions are discussed, with particular attention focused on the strengths and limitations of each reaction for the preparation of LCEs with controlled structures and orientations. The compatibility of these reactions with the traditional and emerging processing techniques, such as surface alignment and additive manufacturing, are surveyed. Finally, the challenges and opportunities of using click chemistry for the design of LCEs with advanced functionalities and applications are discussed.
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Affiliation(s)
- Yuzhan Li
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Tuan Liu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Veronica Ambrogi
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II, Napoli 80125, Italy
| | - Orlando Rios
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Min Xia
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Wanli He
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhou Yang
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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103
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Taylor JM, Luan H, Lewis JA, Rogers JA, Nuzzo RG, Braun PV. Biomimetic and Biologically Compliant Soft Architectures via 3D and 4D Assembly Methods: A Perspective. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2108391. [PMID: 35233865 DOI: 10.1002/adma.202108391] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/08/2022] [Indexed: 06/14/2023]
Abstract
Recent progress in soft material chemistry and enabling methods of 3D and 4D fabrication-emerging programmable material designs and associated assembly methods for the construction of complex functional structures-is highlighted. The underlying advances in this science allow the creation of soft material architectures with properties and shapes that programmably vary with time. The ability to control composition from the molecular to the macroscale is highlighted-most notably through examples that focus on biomimetic and biologically compliant soft materials. Such advances, when coupled with the ability to program material structure and properties across multiple scales via microfabrication, 3D printing, or other assembly techniques, give rise to responsive (4D) architectures. The challenges and prospects for progress in this emerging field in terms of its capacities for integrating chemistry, form, and function are described in the context of exemplary soft material systems demonstrating important but heretofore difficult-to-realize biomimetic and biologically compliant behaviors.
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Affiliation(s)
- Jay M Taylor
- Department of Materials Science and Engineering, Materials Research Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, 104 South Goodwin Ave., Urbana, IL, 61801, USA
| | - Haiwen Luan
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, 60208, USA
| | - Jennifer A Lewis
- John A. Paulson School of Engineering and Applied Sciences Wyss Institute for Biologically Inspired Engineering, Harvard University, 29 Oxford Street, Cambridge, MA, 02138, USA
| | - John A Rogers
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, 60208, USA
- Departments of Materials Science and Engineering, Biomedical Engineering, Neurological Surgery, Chemistry, Mechanical Engineering, Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Ralph G Nuzzo
- Department of Chemistry, University of Illinois Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA
- Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Drottning Kristinasväg 51, Stockholm, 10044, Sweden
| | - Paul V Braun
- Department of Materials Science and Engineering, Materials Research Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, 104 South Goodwin Ave., Urbana, IL, 61801, USA
- Department of Chemistry, University of Illinois Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA
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104
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Sun Y, Li D, Wu M, Yang Y, Su J, Wong T, Xu K, Li Y, Li L, Yu X, Yu J. Origami-inspired folding assembly of dielectric elastomers for programmable soft robots. MICROSYSTEMS & NANOENGINEERING 2022; 8:37. [PMID: 35450326 PMCID: PMC8971403 DOI: 10.1038/s41378-022-00363-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/24/2022] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
Origami has become an optimal methodological choice for creating complex three-dimensional (3D) structures and soft robots. The simple and low-cost origami-inspired folding assembly provides a new method for developing 3D soft robots, which is ideal for future intelligent robotic systems. Here, we present a series of materials, structural designs, and fabrication methods for developing independent, electrically controlled origami 3D soft robots for walking and soft manipulators. The 3D soft robots are based on soft actuators, which are multilayer structures with a dielectric elastomer (DE) film as the deformation layer and a laser-cut PET film as the supporting flexible frame. The triangular and rectangular design of the soft actuators allows them to be easily assembled into crawling soft robots and pyramidal- and square-shaped 3D structures. The crawling robot exhibits very stable crawling behaviors and can carry loads while walking. Inspired by origami folding, the pyramidal and square-shaped 3D soft robots exhibit programmable out-of-plane deformations and easy switching between two-dimensional (2D) and 3D structures. The electrically controllable origami deformation allows the 3D soft robots to be used as soft manipulators for grasping and precisely locking 3D objects. This work proves that origami-inspired fold-based assembly of DE actuators is a good reference for the development of soft actuators and future intelligent multifunctional soft robots.
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Affiliation(s)
- Yanhua Sun
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054 People’s Republic of China
- Chongqing Key Laboratory of Materials Surface & Interface Science, Chongqing Co-Innovation Center for Micro/Nano Optoelectronic Materials and Devices, Micro/Nano Optoelectronic Materials and Devices International Science and Technology Cooperation Base of China, School of Materials Science and Engineering, Chongqing University of Arts and Sciences, Chongqing, 402160 People’s Republic of China
| | - Dengfeng Li
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong SAR, 999077 People’s Republic of China
| | - Mengge Wu
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054 People’s Republic of China
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong SAR, 999077 People’s Republic of China
| | - Yale Yang
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054 People’s Republic of China
- Chongqing Key Laboratory of Materials Surface & Interface Science, Chongqing Co-Innovation Center for Micro/Nano Optoelectronic Materials and Devices, Micro/Nano Optoelectronic Materials and Devices International Science and Technology Cooperation Base of China, School of Materials Science and Engineering, Chongqing University of Arts and Sciences, Chongqing, 402160 People’s Republic of China
| | - Jingyou Su
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong SAR, 999077 People’s Republic of China
| | - Tszhung Wong
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong SAR, 999077 People’s Republic of China
| | - Kangming Xu
- Chongqing Key Laboratory of Materials Surface & Interface Science, Chongqing Co-Innovation Center for Micro/Nano Optoelectronic Materials and Devices, Micro/Nano Optoelectronic Materials and Devices International Science and Technology Cooperation Base of China, School of Materials Science and Engineering, Chongqing University of Arts and Sciences, Chongqing, 402160 People’s Republic of China
| | - Ying Li
- Chongqing Key Laboratory of Materials Surface & Interface Science, Chongqing Co-Innovation Center for Micro/Nano Optoelectronic Materials and Devices, Micro/Nano Optoelectronic Materials and Devices International Science and Technology Cooperation Base of China, School of Materials Science and Engineering, Chongqing University of Arts and Sciences, Chongqing, 402160 People’s Republic of China
| | - Lu Li
- Chongqing Key Laboratory of Materials Surface & Interface Science, Chongqing Co-Innovation Center for Micro/Nano Optoelectronic Materials and Devices, Micro/Nano Optoelectronic Materials and Devices International Science and Technology Cooperation Base of China, School of Materials Science and Engineering, Chongqing University of Arts and Sciences, Chongqing, 402160 People’s Republic of China
| | - Xinge Yu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong SAR, 999077 People’s Republic of China
| | - Junsheng Yu
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054 People’s Republic of China
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105
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Saed M, Gablier A, Terentjev EM. Exchangeable Liquid Crystalline Elastomers and Their Applications. Chem Rev 2022; 122:4927-4945. [PMID: 33596647 PMCID: PMC8915166 DOI: 10.1021/acs.chemrev.0c01057] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Indexed: 12/30/2022]
Abstract
This Review presents and discusses the current state of the art in "exchangeable liquid crystalline elastomers", that is, LCE materials utilizing dynamically cross-linked networks capable of reprocessing, reprogramming, and recycling. The focus here is on the chemistry and the specific reaction mechanisms that enable the dynamic bond exchange, of which there is a variety. We compare and contrast these different chemical mechanisms and the key properties of their resulting elastomers. In the conclusion, we discuss the most promising applications that are enabled by dynamic cross-linking and present a summary table: a library of currently available materials and their main characteristics.
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Affiliation(s)
- Mohand
O. Saed
- Cavendish Laboratory, University
of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, U.K.
| | - Alexandra Gablier
- Cavendish Laboratory, University
of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, U.K.
| | - Eugene M. Terentjev
- Cavendish Laboratory, University
of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, U.K.
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106
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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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107
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Towards enduring autonomous robots via embodied energy. Nature 2022; 602:393-402. [PMID: 35173338 DOI: 10.1038/s41586-021-04138-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 10/14/2021] [Indexed: 11/08/2022]
Abstract
Autonomous robots comprise actuation, energy, sensory and control systems built from materials and structures that are not necessarily designed and integrated for multifunctionality. Yet, animals and other organisms that robots strive to emulate contain highly sophisticated and interconnected systems at all organizational levels, which allow multiple functions to be performed simultaneously. Herein, we examine how system integration and multifunctionality in nature inspires a new paradigm for autonomous robots that we call Embodied Energy. Whereas most untethered robots use batteries to store energy and power their operation, recent advancements in energy-storage techniques enable chemical or electrical energy sources to be embodied directly within the structures and materials used to create robots, rather than requiring separate battery packs. This perspective highlights emerging examples of Embodied Energy in the context of developing autonomous robots.
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108
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Ge Q, Jian B, Li H. Shaping soft materials via digital light processing-based 3D printing: A review. FORCES IN MECHANICS 2022. [DOI: 10.1016/j.finmec.2022.100074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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109
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Patterned crystal growth and heat wave generation in hydrogels. Nat Commun 2022; 13:259. [PMID: 35017471 PMCID: PMC8752664 DOI: 10.1038/s41467-021-27505-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/19/2021] [Indexed: 11/24/2022] Open
Abstract
The crystallization of metastable liquid phase change materials releases stored energy as latent heat upon nucleation and may therefore provide a triggerable means of activating downstream processes that respond to changes in temperature. In this work, we describe a strategy for controlling the fast, exothermic crystallization of sodium acetate from a metastable aqueous solution into trihydrate crystals within a polyacrylamide hydrogel whose polymerization state has been patterned using photomasks. A comprehensive experimental study of crystal shapes, crystal growth front velocities and evolving thermal profiles showed that rapid growth of long needle-like crystals through unpolymerized solutions produced peak temperatures of up to 45˚C, while slower-crystallizing polymerized solutions produced polycrystalline composites and peaked at 30˚C due to lower rates of heat release relative to dissipation in these regions. This temperature difference in the propagating heat waves, which we describe using a proposed analytical model, enables the use of this strategy to selectively activate thermoresponsive processes in predefined areas. The crystallization of metastable liquid phase change materials releases stored energy upon nucleation. Here, the authors demonstrate area-selective activation of thermoresponsive processes by exothermic crystallization of sodium acetate into trihydrate crystals within a patterned polyacrylamide hydrogel.
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110
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Tanjeem N, Minnis MB, Hayward RC, Shields CW. Shape-Changing Particles: From Materials Design and Mechanisms to Implementation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2105758. [PMID: 34741359 PMCID: PMC9579005 DOI: 10.1002/adma.202105758] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 09/06/2021] [Indexed: 05/05/2023]
Abstract
Demands for next-generation soft and responsive materials have sparked recent interest in the development of shape-changing particles and particle assemblies. Over the last two decades, a variety of mechanisms that drive shape change have been explored and integrated into particulate systems. Through a combination of top-down fabrication and bottom-up synthesis techniques, shape-morphing capabilities extend from the microscale to the nanoscale. Consequently, shape-morphing particles are rapidly emerging in a variety of contexts, including photonics, microfluidics, microrobotics, and biomedicine. Herein, the key mechanisms and materials that facilitate shape changes of microscale and nanoscale particles are discussed. Recent progress in the applications made possible by these particles is summarized, and perspectives on their promise and key open challenges in the field are discussed.
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Affiliation(s)
- Nabila Tanjeem
- Department of Chemical & Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA
| | - Montana B Minnis
- Department of Chemical & Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA
| | - Ryan C Hayward
- Department of Chemical & Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA
| | - Charles Wyatt Shields
- Department of Chemical & Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA
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111
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Xia X, Spadaccini CM, Greer JR. Responsive materials architected in space and time. NATURE REVIEWS. MATERIALS 2022; 7:683-701. [PMID: 35757102 PMCID: PMC9208549 DOI: 10.1038/s41578-022-00450-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/10/2022] [Indexed: 05/03/2023]
Abstract
Rationally designed architected materials have attained previously untapped territories in materials property space. The properties and behaviours of architected materials need not be stagnant after fabrication; they can be encoded with a temporal degree of freedom such that they evolve over time. In this Review, we describe the variety of materials architected in both space and time, and their responses to various stimuli, including mechanical actuation, changes in temperature and chemical environment, and variations in electromagnetic fields. We highlight the additive manufacturing methods that can precisely prescribe complex geometries and local inhomogeneities to make such responsiveness possible. We discuss the emergent physics phenomena observed in architected materials that are analogous to those in classical materials, such as the formation and behaviour of defects, phase transformations and topologically protected properties. Finally, we offer a perspective on the future of architected materials that have a degree of intelligence through mechanical logic and artificial neural networks.
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Affiliation(s)
- Xiaoxing Xia
- Center for Engineered Materials and Manufacturing, Lawrence Livermore National Laboratory, Livermore, CA USA
- Materials Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Christopher M. Spadaccini
- Center for Engineered Materials and Manufacturing, Lawrence Livermore National Laboratory, Livermore, CA USA
- Materials Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Julia R. Greer
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA USA
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112
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Del Pozo M, Sol JAHP, Schenning APHJ, Debije MG. 4D Printing of Liquid Crystals: What's Right for Me? ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2104390. [PMID: 34716625 DOI: 10.1002/adma.202104390] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/20/2021] [Indexed: 05/24/2023]
Abstract
Recent years have seen major advances in the developments of both additive manufacturing concepts and responsive materials. When combined as 4D printing, the process can lead to functional materials and devices for use in health, energy generation, sensing, and soft robots. Among responsive materials, liquid crystals, which can deliver programmed, reversible, rapid responses in both air and underwater, are a prime contender for additive manufacturing, given their ease of use and adaptability to many different applications. In this paper, selected works are compared and analyzed to come to a didactical overview of the liquid crystal-additive manufacturing junction. Reading from front to back gives the reader a comprehensive understanding of the options and challenges in the field, while researchers already experienced in either liquid crystals or additive manufacturing are encouraged to scan through the text to see how they can incorporate additive manufacturing or liquid crystals into their own work. The educational text is closed with proposals for future research in this crossover field.
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Affiliation(s)
- Marc Del Pozo
- Laboratory for Stimuli-Responsive Functional Materials & Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TU/e), Groene Loper 3, Eindhoven, 5612 AE, The Netherlands
| | - Jeroen A H P Sol
- Laboratory for Stimuli-Responsive Functional Materials & Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TU/e), Groene Loper 3, Eindhoven, 5612 AE, The Netherlands
| | - Albert P H J Schenning
- Laboratory for Stimuli-Responsive Functional Materials & Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TU/e), Groene Loper 3, Eindhoven, 5612 AE, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Groene Loper 3, Eindhoven, 5612 AE, The Netherlands
| | - Michael G Debije
- Laboratory for Stimuli-Responsive Functional Materials & Devices (SFD), Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TU/e), Groene Loper 3, Eindhoven, 5612 AE, The Netherlands
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113
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Cheng M, Zeng H, Li Y, Liu J, Luo D, Priimagi A, Liu YJ. Light-Fueled Polymer Film Capable of Directional Crawling, Friction-Controlled Climbing, and Self-Sustained Motion on a Human Hair. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103090. [PMID: 34713627 PMCID: PMC8728837 DOI: 10.1002/advs.202103090] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/11/2021] [Indexed: 05/21/2023]
Abstract
Recent efforts in stimuli-responsive soft materials have enabled wirelessly controlled actuation with increasing degrees of freedom, yielding miniature robots capable of various locomotion in open environments such as on a plane or inside fluids. However, grand challenges remain in harnessing photomechanical deformation to induce locomotion and control of friction during the movement, especially for robotic actuations within constrained spaces. Here, the authors report a centimeter-long polymer strip made of a liquid crystal network that is capable of versatile light-fueled motions along a human hair. The soft polymer robot can translocate directionally upon temporally modulated excitation and climb vertically through friction control with light. A self-oscillating strip is demonstrated to continuously translocate along the hair upon a constant light stimulus, and its gaiting is associated to the smoothness of the hair surface. The results offer new insights to small-scale photo-actuator, mechanical control, and automation in soft micro robotics.
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Affiliation(s)
- Ming Cheng
- Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen518055China
| | - Hao Zeng
- Smart Photonic MaterialsFaculty of Engineering and Natural SciencesTampere UniversityP.O. Box 541TampereFI‐33101Finland
| | - Yifei Li
- Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen518055China
| | - Jianxun Liu
- Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen518055China
| | - Dan Luo
- Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen518055China
| | - Arri Priimagi
- Smart Photonic MaterialsFaculty of Engineering and Natural SciencesTampere UniversityP.O. Box 541TampereFI‐33101Finland
| | - Yan Jun Liu
- Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen518055China
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114
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Zhang C, Lu X, Wang Z, Xia H. Progress in Utilizing Dynamic Bonds to Fabricate Structurally Adaptive Self-Healing, Shape Memory, and Liquid Crystal Polymers. Macromol Rapid Commun 2021; 43:e2100768. [PMID: 34964192 DOI: 10.1002/marc.202100768] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/15/2021] [Indexed: 11/09/2022]
Abstract
Stimuli-responsive structurally dynamic polymers are capable of mimicking the biological systems to adapt themselves to the surrounding environmental changes and subsequently exhibiting a wide range of responses ranging from self-healing to complex shape-morphing. Dynamic self-healing polymers (SHPs), shape-memory polymers (SMPs) and liquid crystal elastomers (LCEs), which are three representative examples of stimuli-responsive structurally dynamic polymers, have been attracting broad and growing interest in recent years because of their potential applications in the fields of electronic skin, sensors, soft robots, artificial muscles, and so on. We review recent advances and challenges in the developments towards dynamic SHPs, SMPs and LCEs, focusing on the chemistry strategies and the dynamic reaction mechanisms that enhance the performances of the materials including self-healing, reprocessing and reprogramming. We compare and discuss the different dynamic chemistries and their mechanisms on the enhanced functions of the materials, where three summary tables are presented: a library of dynamic bonds and the resulting characteristics of the materials. Finally, we provide a critical outline of the unresolved issues and future perspectives on the emerging developments. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- 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
| | - Zhanhua Wang
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu, 610065, China
| | - Hesheng Xia
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu, 610065, China
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115
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Feng R, Zhang Y, Liu J, Zhang Y, Li J, Baoyin H. Soft Robotic Perspective and Concept for Planetary Small Body Exploration. Soft Robot 2021; 9:889-899. [PMID: 34939854 DOI: 10.1089/soro.2021.0054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Tens of thousands of planetary small bodies (asteroids, comets, and small moons) are flying beside our Earth with little understanding. Explorers on the surfaces of these bodies, unlike the Lunar or Mars rovers, have only few attempts and no sophisticated solution. Current concerns mainly focus on landing uncertainties and mobility limitations, which soft robots may suitably aid utilizing their compliance and adaptivity. In this study, we present a perspective of designating soft robots for the surface exploration. Based on the lessons from recent space missions and an astronomy survey, we summarize the surface features of typical small bodies and the associated challenges for possible soft robotic design. Different kinds of soft mobile robots are reviewed, whose morphology and locomotion are analyzed for the microgravity, rugged environment. We also propose an alternative to current asteroid hoppers, as a case of applying progress in soft material. Specifically, the structure is a deployable cube whose outer shell is made of shape memory polymer, so that it can achieve morphing and variable stiffness between liftoff and landing phases. Dynamic simulations of the free-fall landing are carried out with a rigid counterpart for comparison. The results show that the soft deployed shell can effectively contribute to dissipating the kinetic energy and attenuating the excessive rebounds.
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Affiliation(s)
- Ruoyu Feng
- School of Aerospace Engineering, Tsinghua University, Beijing, China
| | - Yu Zhang
- School of Aerospace Engineering, Tsinghua University, Beijing, China
| | - Jinyu Liu
- School of Aerospace Engineering, Tsinghua University, Beijing, China
| | - Yonglong Zhang
- School of Aerospace Engineering, Tsinghua University, Beijing, China
| | - Junfeng Li
- School of Aerospace Engineering, Tsinghua University, Beijing, China
| | - Hexi Baoyin
- School of Aerospace Engineering, Tsinghua University, Beijing, China
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116
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Pozo MD, Sol JAHP, van Uden SHP, Peeketi AR, Lugger SJD, Annabattula RK, Schenning APHJ, Debije MG. Patterned Actuators via Direct Ink Writing of Liquid Crystals. ACS APPLIED MATERIALS & INTERFACES 2021; 13:59381-59391. [PMID: 34870984 PMCID: PMC8678986 DOI: 10.1021/acsami.1c20348] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/19/2021] [Indexed: 05/24/2023]
Abstract
Soft actuators allowing multifunctional, multishape deformations based on single polymer films or bilayers remain challenging to produce. In this contribution, direct ink writing is used for generating patterned actuators, which are in between single- and bilayer films, with multifunctionality and a plurality of possible shape changes in a single object. The key is to use the controlled deposition of a light-responsive liquid crystal ink with direct ink writing to partially cover a foil at strategic locations. We found patterned films with 40% coverage of the passive substrate by an active material outperformed "standard" fully covered bilayers. By patterning the film as two stripes, a range of motions, including left- and right-handed twisting and bending in orthogonal directions, could be controllably induced in the same actuator. The partial coverage also left space for applying liquid crystal inks with other functionalities, exemplified by fabricating a light-responsive green reflective actuator whose reflection can be switched "on" and "off". The results presented here serve as a toolbox for the design and fabrication of patterned actuators with dramatically expanded shape deformation and functionality capabilities.
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Affiliation(s)
- Marc del Pozo
- Laboratory
for Stimuli-responsive Functional Materials & Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology (TU/e), Groene Loper 3, 5600 MB Eindhoven, The Netherlands
| | - Jeroen A. H. P. Sol
- Laboratory
for Stimuli-responsive Functional Materials & Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology (TU/e), Groene Loper 3, 5600 MB Eindhoven, The Netherlands
| | - Stefan H. P. van Uden
- Laboratory
for Stimuli-responsive Functional Materials & Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology (TU/e), Groene Loper 3, 5600 MB Eindhoven, The Netherlands
| | - Akhil R. Peeketi
- Center
for Responsive Soft Matter, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sean J. D. Lugger
- Laboratory
for Stimuli-responsive Functional Materials & Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology (TU/e), Groene Loper 3, 5600 MB Eindhoven, The Netherlands
| | - Ratna K. Annabattula
- Center
for Responsive Soft Matter, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Albert P. H. J. Schenning
- Laboratory
for Stimuli-responsive Functional Materials & Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology (TU/e), Groene Loper 3, 5600 MB Eindhoven, The Netherlands
| | - Michael G. Debije
- Laboratory
for Stimuli-responsive Functional Materials & Devices (SFD), Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology (TU/e), Groene Loper 3, 5600 MB Eindhoven, The Netherlands
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117
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Li Y, Avis SJ, Zhang T, Kusumaatmaja H, Wang X. Tailoring the multistability of origami-inspired, buckled magnetic structures via compression and creasing. MATERIALS HORIZONS 2021; 8:3324-3333. [PMID: 34528049 DOI: 10.1039/d1mh01152a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Origami-inspired multistable structures are gaining increasing interest because of their potential applications in fields ranging from deployable structures to reconfigurable microelectronics. The multistability of such structures is critical for their applications but is challenging to manipulate due to the highly nonlinear deformations and complex configurations of the structures. Here, a comprehensive experimental and computational study is reported to tailor the multistable states of origami-inspired, buckled ferromagnetic structures and their reconfiguration paths. Using ribbon structures as an example, a design phase diagram is constructed as a function of the crease number and compressive strain. As the crease number increases from 0 to 7, the number of distinct stable states first increases and then decreases. The multistability is also shown to be actively tuned by varying the strain from 0% to 40%. Furthermore, analyzing energy barriers for reconfiguration among the stable states reveals dynamic changes in reconfiguration paths with increasing strains. Guided by studies above, diverse examples are designed and demonstrated, from programmable structure arrays to a soft robot. These studies lay out the foundation for the rational design of functional, multistable structures.
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Affiliation(s)
- Yi Li
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, 06269, USA.
| | - Samuel J Avis
- Department of Physics, Durham University, Durham, DH1 3LE, UK.
| | - Teng Zhang
- Department of Mechanical and Aerospace Engineering, BioInspired Syracuse, Syracuse University, Syracuse, NY, 13244, USA.
| | | | - Xueju Wang
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, 06269, USA.
- Polymer program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
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118
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Xin C, Jin D, Hu Y, Yang L, Li R, Wang L, Ren Z, Wang D, Ji S, Hu K, Pan D, Wu H, Zhu W, Shen Z, Wang Y, Li J, Zhang L, Wu D, Chu J. Environmentally Adaptive Shape-Morphing Microrobots for Localized Cancer Cell Treatment. ACS NANO 2021; 15:18048-18059. [PMID: 34664936 DOI: 10.1021/acsnano.1c06651] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Microrobots have attracted considerable attention due to their extensive applications in microobject manipulation and targeted drug delivery. To realize more complex micro-/nanocargo manipulation (e.g., encapsulation and release) in biological applications, it is highly desirable to endow microrobots with a shape-morphing adaptation to dynamic environments. Here, environmentally adaptive shape-morphing microrobots (SMMRs) have been developed by programmatically encoding different expansion rates in a pH-responsive hydrogel. Due to a combination with magnetic propulsion, a shape-morphing microcrab (SMMC) is able to perform targeted microparticle delivery, including gripping, transporting, and releasing by "opening-closing" of a claw. As a proof-of-concept demonstration, a shape-morphing microfish (SMMF) is designed to encapsulate a drug (doxorubicin (DOX)) by closing its mouth in phosphate-buffered saline (PBS, pH ∼ 7.4) and release the drug by opening its mouth in a slightly acidic solution (pH < 7). Furthermore, localized HeLa cell treatment in an artificial vascular network is realized by "opening-closing" of the SMMF mouth. With the continuous optimization of size, motion control, and imaging technology, these magnetic SMMRs will provide ideal platforms for complex microcargo operations and on-demand drug release.
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Affiliation(s)
- Chen Xin
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Dongdong Jin
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong 999077, China
| | - Yanlei Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Liang Yang
- Institute of Nanotechnology Karlsruhe Institute of Technology (KIT), Karlsruhe 76128, Germany
| | - Rui Li
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Li Wang
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine and Division of Molecular Medicine, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Zhongguo Ren
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Dawei Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Shengyun Ji
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Kai Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Deng Pan
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Hao Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Wulin Zhu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Zuojun Shen
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine and Division of Molecular Medicine, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Yucai Wang
- Intelligent Nanomedicine Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine and Division of Molecular Medicine, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Jiawen Li
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Li Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin NT, Hong Kong 999077, China
| | - Dong Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Jiaru Chu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
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119
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Yan W, Mehta A. A Cut-and-Fold Self-Sustained Compliant Oscillator for Autonomous Actuation of Origami-Inspired Robots. Soft Robot 2021; 9:871-881. [PMID: 34813378 DOI: 10.1089/soro.2021.0018] [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: 11/13/2022] Open
Abstract
Origami-inspired robots are of particular interest due to their potential for rapid and accessible design and fabrication of elegant designs and complex functionalities through cutting and folding of flexible two-dimensional sheets or even strings, that is, printable manufacturing. Yet, origami robots still require bulky rigid components or electronics for actuation and control to accomplish tasks with reliability, programmability, ability to output substantial force, and durability, restricting their full potential. In this study, we present a printable self-sustained compliant oscillator that generates periodic actuation using only constant electrical power, without discrete components or electronic control hardware. This oscillator is robust (9 out of 10 prototypes worked successfully on the first try), configurable (with tunable periods from 3 to 12 s), powerful (can overcome hydrodynamic resistance to consistently propel a swimmer at ∼1.6 body lengths/min or 3.66 mm/s), and long lasting (∼103 cycles); it enables driving macroscale devices with prescribed autonomous behaviors, for example, locomotion and sequencing. This oscillator is also fully functional underwater and in high magnetic fields. Our analytical model characterizes essential parameters of the oscillation period, enabling programmable design of the oscillator. The printable oscillator can be integrated into origami-inspired systems seamlessly and monolithically, allowing rapid design and prototyping; the resulting integrated devices are lightweight, low cost, compliant, electronic free, and nonmagnetic, enabling practical applications in extreme areas. We demonstrate the functionalities of the oscillator with: (1) autonomous gliding of a printable swimmer, (2) LED flashing, and (3) fluid stirring. This work paves the way for realizing fully printable autonomous robots with high integration of actuation and control.
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Affiliation(s)
- Wenzhong Yan
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California, USA
| | - Ankur Mehta
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California, USA
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120
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Patdiya J, Kandasubramanian B. Progress in 4D printing of stimuli responsive materials. POLYM-PLAST TECH MAT 2021. [DOI: 10.1080/25740881.2021.1934016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Affiliation(s)
- Jigar Patdiya
- Rapid Prototyping Laboratory, Department of Metallurgical and Materials Engineering,Defence Institute of Advanced Technology (DU), Ministry of Defence, Girinagar, Pune India
| | - Balasubramanian Kandasubramanian
- Rapid Prototyping Laboratory, Department of Metallurgical and Materials Engineering,Defence Institute of Advanced Technology (DU), Ministry of Defence, Girinagar, Pune India
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121
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Soft elasticity optimises dissipation in 3D-printed liquid crystal elastomers. Nat Commun 2021; 12:6677. [PMID: 34795228 PMCID: PMC8602646 DOI: 10.1038/s41467-021-27013-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/28/2021] [Indexed: 11/08/2022] Open
Abstract
Soft-elasticity in monodomain liquid crystal elastomers (LCEs) is promising for impact-absorbing applications where strain energy is ideally absorbed at constant stress. Conventionally, compressive and impact studies on LCEs have not been performed given the notorious difficulty synthesizing sufficiently large monodomain devices. Here, we use direct-ink writing 3D printing to fabricate bulk (>cm3) monodomain LCE devices and study their compressive soft-elasticity over 8 decades of strain rate. At quasi-static rates, the monodomain soft-elastic LCE dissipated 45% of strain energy while comparator materials dissipated less than 20%. At strain rates up to 3000 s-1, our soft-elastic monodomain LCE consistently performed closest to an ideal-impact absorber. Drop testing reveals soft-elasticity as a likely mechanism for effectively reducing the severity of impacts - with soft elastic LCEs offering a Gadd Severity Index 40% lower than a comparable isotropic elastomer. Lastly, we demonstrate tailoring deformation and buckling behavior in monodomain LCEs via the printed director orientation.
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122
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Chen Q, Feng F, Lv P, Duan H. Origami Spring-Inspired Shape Morphing for Flexible Robotics. Soft Robot 2021; 9:798-806. [PMID: 34747664 DOI: 10.1089/soro.2021.0030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Flexible robotics are capable of achieving various functionalities by shape morphing, benefiting from their compliant bodies and reconfigurable structures. In this study, we construct and study a class of origami springs generalized from the known interleaved origami spring, as promising candidates for shape morphing in flexible robotics. These springs are found to exhibit nonlinear stretch-twist coupling and linear/nonlinear mechanical response in the compression/tension region, analyzed by the demonstrated continuum mechanics models, experiments, and finite element simulations. To improve the mechanical performance such as the damage resistance, we establish an origami rigidization method by adding additional creases to the spring system. Guided by the theoretical framework, we experimentally realize three types of flexible robotics-origami spring ejectors, crawlers, and transformers. These robots show the desired functionality and outstanding mechanical performance. The proposed concept of origami-aided design is expected to pave the way to facilitate the diverse shape morphing of flexible robotics.
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Affiliation(s)
- Qianying Chen
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing, China.,CAPT, HEDPS and IFSA Collaborative Innovation Center of MoE, Peking University, Beijing, China
| | - Fan Feng
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing, China
| | - Pengyu Lv
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing, China
| | - Huiling Duan
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing, China.,CAPT, HEDPS and IFSA Collaborative Innovation Center of MoE, Peking University, Beijing, China
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123
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Ren L, Li B, Wei G, Wang K, Song Z, Wei Y, Ren L, Qingping Liu. Biology and bioinspiration of soft robotics: Actuation, sensing, and system integration. iScience 2021; 24:103075. [PMID: 34568796 PMCID: PMC8449090 DOI: 10.1016/j.isci.2021.103075] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Organisms in nature grow with senses, nervous, and actuation systems coordinated in ingenious ways to sustain metabolism and other essential life activities. The understanding of biological structures and functions guide the construction of soft robotics with unprecedented performances. However, despite the progress in soft robotics, there still remains a big gap between man-made soft robotics and natural lives in terms of autonomy, adaptability, self-repair, durability, energy efficiency, etc. Here, the actuation and sensing strategies in the natural biological world are summarized along with their man-made counterparts applied in soft robotics. The development trends of bioinspired soft robotics toward closed loop and embodiment are proposed. Challenges for obtaining autonomous soft robotics similar to natural organisms are outlined to provide a perspective in this field.
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Affiliation(s)
- Luquan Ren
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China
| | - Bingqian Li
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China
| | - Guowu Wei
- School of Science, Engineering and Environment, University of Salford, M5 4WT Salford, UK
| | - Kunyang Wang
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China
| | - Zhengyi Song
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China
| | - Yuyang Wei
- School of Mechanical, Aerospace and Civil Engineering, University of Manchester, M13 9PL Manchester, UK
| | - Lei Ren
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China.,School of Mechanical, Aerospace and Civil Engineering, University of Manchester, M13 9PL Manchester, UK
| | - Qingping Liu
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China
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124
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Xiao K, Zhou X, Ju J. Effect of disconnection of deformable units on the mobility and stiffness of 3D prismatic modular origami structures using angular kinematics. Sci Rep 2021; 11:18259. [PMID: 34521915 PMCID: PMC8440563 DOI: 10.1038/s41598-021-97609-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/27/2021] [Indexed: 12/11/2022] Open
Abstract
Architected modular origami structures show potential for future robotic matter owing to their reconfigurability with multiple mobilities. Similar to modular robots, the units of modular origami structures do not need to be assembled in a fully packed fashion; in fact, disconnection can provide more freedom for the design of mobility and functionality. Despite the potential of expanded design freedom, the effect of the disconnection of units on the mobility and physical properties has not yet been explored in modular origami structures. Determining the mobility and weak spots of modular origami structures is significant to enable transformation with minimum energy. Herein, we investigate the effect of the disconnection of units on the mobility and stiffness of architected modular origami structures with deformable units using angular kinematics of geometry and topology of units and closed loops. Angular kinematics provides a valuable tool for investigating the complex mobility of architected modular origami structures with the disconnection of loops. The mobility of the network structure is a function not only of the number of disconnections but also of the topology of the loop. In contrast to the conventional negative perception of defects or disconnection in these materials, the disconnection can potentially be used to expand the design space of mobility for future robotic matter. Our findings can be used to develop powerful design guidelines for topologically reconfigurable structures for soft modular robots, active architected materials, implanted modular devices, deployable structures, thermal metamaterials, and active acoustic metamaterials.
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Affiliation(s)
- Kai Xiao
- UM-SJTU Joint Institute, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China
| | - Xiang Zhou
- School of Aeronautic and Astronautic Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China
| | - Jaehyung Ju
- UM-SJTU Joint Institute, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China.
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125
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Zhang YF, Li Z, Li H, Li H, Xiong Y, Zhu X, Lan H, Ge Q. Fractal-Based Stretchable Circuits via Electric-Field-Driven Microscale 3D Printing for Localized Heating of Shape Memory Polymers in 4D Printing. ACS APPLIED MATERIALS & INTERFACES 2021; 13:41414-41423. [PMID: 33779155 DOI: 10.1021/acsami.1c03572] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Thermally responsive shape memory polymers (SMPs) used in 4D printing are often reported to be activated by external heat sources or embedded stiff heaters. However, such heating strategies impede the practical application of 4D printing due to the lack of precise control over heating or the limited ability to accommodate the stretching during shape programming. Herein, we propose a novel 4D printing paradigm by fabricating stretchable heating circuits with fractal motifs via electric-field-driven microscale 3D printing of conductive paste for seamless integration into 3D printed structures with SMP components. By regulating the fractal order and printing/processing parameters, the overall electrical resistance and areal coverage of the circuits can be tuned to produce an efficient and uniform heating performance. Compared with serpentine structures, the resistance of fractal-based circuits remains relatively stable under both uniaxial and biaxial stretching. In practice, steady-state and transient heating modes can be respectively used during the shape programming and actuation phases. We demonstrate that this approach is suitable for 4D printed structures with shape programming by either uniaxial or biaxial stretching. Notably, the biaxial stretchability of fractal-based heating circuits enables the shape change between a planar structure and a 3D one with double curvature. The proposed strategy would offer more freedom in designing 4D printed structures and enable the manipulation of the latter in a controlled and selective manner.
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Affiliation(s)
- Yuan-Fang Zhang
- Digital Manufacturing and Design Centre, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Zhenghao Li
- Shandong Engineering Research Center for Additive Manufacturing, Qingdao University of Technology, Qingdao 266520, China
| | - Hongke Li
- Shandong Engineering Research Center for Additive Manufacturing, Qingdao University of Technology, Qingdao 266520, China
| | - Honggeng Li
- Digital Manufacturing and Design Centre, Singapore University of Technology and Design, Singapore 487372, Singapore
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055 P. R. China
| | - Yi Xiong
- School of System Design and Intelligent Manufacturing, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, PR China
| | - Xiaoyang Zhu
- Shandong Engineering Research Center for Additive Manufacturing, Qingdao University of Technology, Qingdao 266520, China
| | - Hongbo Lan
- Shandong Engineering Research Center for Additive Manufacturing, Qingdao University of Technology, Qingdao 266520, China
| | - Qi Ge
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055 P. R. China
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Abstract
Inspired by the embodied intelligence observed in octopus arms, we introduce magnetically controlled origami robotic arms based on Kresling patterns for multimodal deformations, including stretching, folding, omnidirectional bending, and twisting. The highly integrated motion of the robotic arms is attributed to inherent features of the reconfigurable Kresling unit, whose controllable bistable deploying/folding and omnidirectional bending are achieved through precise magnetic actuation. We investigate single- and multiple-unit robotic systems, the latter exhibiting higher biomimetic resemblance to octopus' arms. We start from the single Kresling unit to delineate the working mechanism of the magnetic actuation for deploying/folding and bending. The two-unit Kresling assembly demonstrates the basic integrated motion that combines omnidirectional bending with deploying. The four-unit Kresling assembly constitutes a robotic arm with a larger omnidirectional bending angle and stretchability. With the foundation of the basic integrated motion, scalability of Kresling assemblies is demonstrated through distributed magnetic actuation of double-digit number of units, which enables robotic arms with sophisticated motions, such as continuous stretching and contracting, reconfigurable bending, and multiaxis twisting. Such complex motions allow for functions mimicking octopus arms that grasp and manipulate objects. The Kresling robotic arm with noncontact actuation provides a distinctive mechanism for applications that require synergistic robotic motions for navigation, sensing, and interaction with objects in environments with limited or constrained access. Based on small-scale Kresling robotic arms, miniaturized medical devices, such as tubes and catheters, can be developed in conjunction with endoscopy, intubation, and catheterization procedures using functionalities of object manipulation and motion under remote control.
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127
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Abstract
Smart materials are a kind of functional materials which can sense and response to environmental conditions or stimuli from optical, electrical, magnetic mechanical, thermal, and chemical signals, etc. Patterning of smart materials is the key to achieving large-scale arrays of functional devices. Over the last decades, printing methods including inkjet printing, template-assisted printing, and 3D printing are extensively investigated and utilized in fabricating intelligent micro/nano devices, as printing strategies allow for constructing multidimensional and multimaterial architectures. Great strides in printable smart materials are opening new possibilities for functional devices to better serve human beings, such as wearable sensors, integrated optoelectronics, artificial neurons, and so on. However, there are still many challenges and drawbacks that need to be overcome in order to achieve the controllable modulation between smart materials and device performance. In this review, we give an overview on printable smart materials, printing strategies, and applications of printed functional devices. In addition, the advantages in actual practices of printing smart materials-based devices are discussed, and the current limitations and future opportunities are proposed. This review aims to summarize the recent progress and provide reference for novel smart materials and printing strategies as well as applications of intelligent devices.
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Affiliation(s)
- Meng Su
- Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing Engineering Research Center of Nanomaterials for Green Printing Technology, Beijing National Laboratory for Molecular Sciences (BNLMS), Zhongguancun North First Street 2, 100190 Beijing, P. R. China.,University of Chinese Academy of Sciences, Yuquan Road no.19A, 100049 Beijing, P. R. China
| | - Yanlin Song
- Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing Engineering Research Center of Nanomaterials for Green Printing Technology, Beijing National Laboratory for Molecular Sciences (BNLMS), Zhongguancun North First Street 2, 100190 Beijing, P. R. China.,University of Chinese Academy of Sciences, Yuquan Road no.19A, 100049 Beijing, P. R. China
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128
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Korpas LM, Yin R, Yasuda H, Raney JR. Temperature-Responsive Multistable Metamaterials. ACS APPLIED MATERIALS & INTERFACES 2021; 13:31163-31170. [PMID: 34164975 DOI: 10.1021/acsami.1c07327] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The ability for materials to adapt their shape and mechanical properties to the local environment is useful in a variety of applications, from soft robots to deployable structures. In this work, we integrate liquid crystal elastomers (LCEs) with multistable structures to allow autonomous reconfiguration in response to local changes in temperature. LCEs are incorporated in a kirigami-inspired system in which squares are connected at their vertices by small hinges composed of LCE-silicone bilayers. These bend and soften as the temperature increases above room temperature. By choosing geometric parameters for the hinges such that bifurcation points in the stability exist, a transition from mono- or tristability to bistability can be triggered by a sufficient increase in temperature, forcing rearrangements of the structure as minima in the energy landscape are removed. We demonstrate temperature-induced propagation of transition waves, enabling local structural changes to autonomously propagate and affect other parts of the structure. These effects could be harnessed in applications in interface control, reconfigurable structures, and soft robotics.
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Affiliation(s)
- Lucia M Korpas
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Rui Yin
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Hiromi Yasuda
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jordan R Raney
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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129
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Kotikian A, Morales JM, Lu A, Mueller J, Davidson ZS, Boley JW, Lewis JA. Innervated, Self-Sensing Liquid Crystal Elastomer Actuators with Closed Loop Control. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2101814. [PMID: 34057260 DOI: 10.1002/adma.202101814] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/01/2021] [Indexed: 06/12/2023]
Abstract
The programmable assembly of innervated LCE actuators (iLCEs) with prescribed contractile actuation, self-sensing, and closed loop control via core-shell 3D printing is reported. This extrusion-based direct ink writing method enables coaxial filamentary features composed of pure LM core surrounded by an LCE shell, whose director is aligned along the print path. Specifically, the thermal response of the iLCE fiber-type actuators is programmed, measured, and modeled during Joule heating, including quantifying the concomitant changes in fiber length and resistance that arise during simultaneous heating and self-sensing. Due to their reversible, high-energy actuation and their resistive feedback, it is also demonstrated that iLCEs can be regulated with closed loop control even when perturbed with large bias loads. Finally, iLCE architectures capable of programmed, self-sensing 3D shape change with closed loop control are fabricated.
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Affiliation(s)
- Arda Kotikian
- John A. Paulson School of Engineering and Applied Sciences and Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - Javier M Morales
- Mechanical Engineering Department, Boston University, Boston, MA, 02215, USA
| | - Aric Lu
- John A. Paulson School of Engineering and Applied Sciences and Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
- Biological Engineering Division, Draper Laboratory, Cambridge, MA, 02139, USA
| | - Jochen Mueller
- John A. Paulson School of Engineering and Applied Sciences and Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - Zoey S Davidson
- John A. Paulson School of Engineering and Applied Sciences and Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - J William Boley
- Mechanical Engineering Department, Boston University, Boston, MA, 02215, USA
| | - Jennifer A Lewis
- John A. Paulson School of Engineering and Applied Sciences and Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
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130
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Li S, Bai H, Liu Z, Zhang X, Huang C, Wiesner LW, Silberstein M, Shepherd RF. Digital light processing of liquid crystal elastomers for self-sensing artificial muscles. SCIENCE ADVANCES 2021; 7:7/30/eabg3677. [PMID: 34301600 PMCID: PMC8302124 DOI: 10.1126/sciadv.abg3677] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 06/04/2021] [Indexed: 05/04/2023]
Abstract
Artificial muscles based on stimuli-responsive polymers usually exhibit mechanical compliance, versatility, and high power-to-weight ratio, showing great promise to potentially replace conventional rigid motors for next-generation soft robots, wearable electronics, and biomedical devices. In particular, thermomechanical liquid crystal elastomers (LCEs) constitute artificial muscle-like actuators that can be remotely triggered for large stroke, fast response, and highly repeatable actuations. Here, we introduce a digital light processing (DLP)-based additive manufacturing approach that automatically shear aligns mesogenic oligomers, layer-by-layer, to achieve high orientational order in the photocrosslinked structures; this ordering yields high specific work capacity (63 J kg-1) and energy density (0.18 MJ m-3). We demonstrate actuators composed of these DLP printed LCEs' applications in soft robotics, such as reversible grasping, untethered crawling, and weightlifting. Furthermore, we present an LCE self-sensing system that exploits thermally induced optical transition as an intrinsic option toward feedback control.
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Affiliation(s)
- Shuo Li
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Hedan Bai
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Zheng Liu
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Xinyue Zhang
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Chuqi Huang
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Lennard W Wiesner
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Meredith Silberstein
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Robert F Shepherd
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA.
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
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131
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Xu Y, Dupont RL, Yao Y, Zhang M, Fang JC, Wang X. Random Liquid Crystalline Copolymers Consisting of Prolate and Oblate Liquid Crystal Monomers. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Yang Xu
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Robert L. Dupont
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Yuxing Yao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Meng Zhang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jen-Chun Fang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Xiaoguang Wang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
- Sustainability Institute, The Ohio State University, Columbus, Ohio 43210, United States
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132
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Park JE, Won S, Cho W, Kim JG, Jhang S, Lee JG, Wie JJ. Fabrication and applications of stimuli‐responsive micro/nanopillar arrays. JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1002/pol.20210311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Jeong Eun Park
- Department of Polymer Science and Engineering Inha University Incheon 22212 Republic of Korea
- Program in Environmental and Polymer Engineering Inha University Incheon 22212 Republic of Korea
| | - Sukyoung Won
- Department of Polymer Science and Engineering Inha University Incheon 22212 Republic of Korea
- Program in Environmental and Polymer Engineering Inha University Incheon 22212 Republic of Korea
| | - Woongbi Cho
- Department of Polymer Science and Engineering Inha University Incheon 22212 Republic of Korea
- Program in Environmental and Polymer Engineering Inha University Incheon 22212 Republic of Korea
| | - Jae Gwang Kim
- Department of Polymer Science and Engineering Inha University Incheon 22212 Republic of Korea
- Program in Environmental and Polymer Engineering Inha University Incheon 22212 Republic of Korea
| | - Saebohm Jhang
- Department of Polymer Science and Engineering Inha University Incheon 22212 Republic of Korea
- Program in Environmental and Polymer Engineering Inha University Incheon 22212 Republic of Korea
| | - Jae Gyeong Lee
- Department of Polymer Science and Engineering Inha University Incheon 22212 Republic of Korea
- Program in Environmental and Polymer Engineering Inha University Incheon 22212 Republic of Korea
| | - Jeong Jae Wie
- Department of Polymer Science and Engineering Inha University Incheon 22212 Republic of Korea
- Program in Environmental and Polymer Engineering Inha University Incheon 22212 Republic of Korea
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133
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Sun D, Zhang J, Li H, Shi Z, Meng Q, Liu S, Chen J, Liu X. Toward Application of Liquid Crystalline Elastomer for Smart Robotics: State of the Art and Challenges. Polymers (Basel) 2021; 13:1889. [PMID: 34204168 PMCID: PMC8201031 DOI: 10.3390/polym13111889] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 11/17/2022] Open
Abstract
Liquid crystalline elastomers (LCEs) are lightly crosslinked polymers that combine liquid crystalline order and rubber elasticity. Owing to their unique anisotropic behavior and reversible shape responses to external stimulation (temperature, light, etc.), LCEs have emerged as preferred candidates for actuators, artificial muscles, sensors, smart robots, or other intelligent devices. Herein, we discuss the basic action, control mechanisms, phase transitions, and the structure-property correlation of LCEs; this review provides a comprehensive overview of LCEs for applications in actuators and other smart devices. Furthermore, the synthesis and processing of liquid crystal elastomer are briefly discussed, and the current challenges and future opportunities are prospected. With all recent progress pertaining to material design, sophisticated manipulation, and advanced applications presented, a vision for the application of LCEs in the next generation smart robots or automatic action systems is outlined.
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Affiliation(s)
- Dandan Sun
- School of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China; (D.S.); (Z.S.); (Q.M.); (J.C.); (X.L.)
| | - Juzhong Zhang
- School of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China; (D.S.); (Z.S.); (Q.M.); (J.C.); (X.L.)
| | - Hongpeng Li
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China;
| | - Zhengya Shi
- School of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China; (D.S.); (Z.S.); (Q.M.); (J.C.); (X.L.)
| | - Qi Meng
- School of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China; (D.S.); (Z.S.); (Q.M.); (J.C.); (X.L.)
| | - Shuiren Liu
- School of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China; (D.S.); (Z.S.); (Q.M.); (J.C.); (X.L.)
| | - Jinzhou Chen
- School of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China; (D.S.); (Z.S.); (Q.M.); (J.C.); (X.L.)
| | - Xuying Liu
- School of Materials Science and Engineering, The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China; (D.S.); (Z.S.); (Q.M.); (J.C.); (X.L.)
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134
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Lin X, Saed MO, Terentjev EM. Continuous spinning aligned liquid crystal elastomer fibers with a 3D printer setup. SOFT MATTER 2021; 17:5436-5443. [PMID: 33970980 PMCID: PMC8170681 DOI: 10.1039/d1sm00432h] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Fibrous liquid crystalline elastomers (LCE) are an attractive variant of LCE-based actuators due to their small thickness, leading to faster response times to stimuli, as well as the increased mechanical strength. Fabrication of LCE fibers has been attempted by various research groups using electro-spinning or micro-fluidic techniques, without much success. Here we propose an alternative way to achieve single-step continuous spinning LCE fibers in a more scalable and robust way, based on a liquid-ink 3D printer. We demonstrate this technique in our home-made device by dynamically extruding/stretching liquid crystalline oligomer mixed with photo-reactive cross-linker, to fix the aligned network under UV light after extrusion. The report also describes a protocol for material synthesis and identifies optimal conditions for the stable fiber spinning process. Microns-thick LCE fibers with two different compositions have been successfully spun, and demonstrated enhanced mechanical properties with the inherited thermal-actuation capability. This technique also demonstrates the potential to fine-tune the mechanical properties of fibers to enable further development in fiber-based LCE applications.
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Affiliation(s)
- Xueyan Lin
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK.
| | - Mohand O Saed
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK.
| | - Eugene M Terentjev
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK.
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135
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Soltani M, Raahemifar K, Nokhosteen A, Kashkooli FM, Zoudani EL. Numerical Methods in Studies of Liquid Crystal Elastomers. Polymers (Basel) 2021; 13:1650. [PMID: 34069440 PMCID: PMC8159147 DOI: 10.3390/polym13101650] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 01/24/2023] Open
Abstract
Liquid crystal elastomers (LCEs) are a type of material with specific features of polymers and of liquid crystals. They exhibit interesting behaviors, i.e., they are able to change their physical properties when met with external stimuli, including heat, light, electric, and magnetic fields. This behavior makes LCEs a suitable candidate for a variety of applications, including, but not limited to, artificial muscles, optical devices, microscopy and imaging systems, biosensor devices, and optimization of solar energy collectors. Due to the wide range of applicability, numerical models are needed not only to further our understanding of the underlining mechanics governing LCE behavior, but also to enable the predictive modeling of their behavior under different circumstances for different applications. Given that several mainstream methods are used for LCE modeling, viz. finite element method, Monte Carlo and molecular dynamics, and the growing interest and reliance on computer modeling for predicting the opto-mechanical behavior of complex structures in real world applications, there is a need to gain a better understanding regarding their strengths and weaknesses so that the best method can be utilized for the specific application at hand. Therefore, this investigation aims to not only to present a multitude of examples on numerical studies conducted on LCEs, but also attempts at offering a concise categorization of different methods based on the desired application to act as a guide for current and future research in this field.
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Affiliation(s)
- Madjid Soltani
- Department of Mechanical Engineering, K.N. Toosi University of Technology, Tehran 19991-43344, Iran; (F.M.K.); (E.L.Z.)
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Centre for Biotechnology and Bioengineering (CBB), University of Waterloo, Waterloo, ON N2L 3G1, Canada
- School of Optometry and Vision Science, Faculty of Science, University of Waterloo, 200 University Ave. W, Waterloo, ON N2L 3G1, Canada;
- Advanced Bioengineering Initiative Center, Computational Medicine Center, K.N. Toosi University of Technology, Tehran 19991-43344, Iran
| | - Kaamran Raahemifar
- School of Optometry and Vision Science, Faculty of Science, University of Waterloo, 200 University Ave. W, Waterloo, ON N2L 3G1, Canada;
- College of Information Sciences and Technology (IST), Data Science and Artificial Intelligence Program, Penn State University, State College, Pennsylvania, PA 16801, USA
- Department of Chemical Engineering, Faculty of Engineering, University of Waterloo, 200 University Ave. W, Waterloo, ON N2L 3G1, Canada
| | - Arman Nokhosteen
- Department of Civil and Mechanical Engineering, University of Missouri-Kansas City, Kansas City, MO 64110, USA;
| | - Farshad Moradi Kashkooli
- Department of Mechanical Engineering, K.N. Toosi University of Technology, Tehran 19991-43344, Iran; (F.M.K.); (E.L.Z.)
| | - Elham L. Zoudani
- Department of Mechanical Engineering, K.N. Toosi University of Technology, Tehran 19991-43344, Iran; (F.M.K.); (E.L.Z.)
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136
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Dolinski ND, Callaway EB, Sample CS, Gockowski LF, Chavez R, Page ZA, Eisenreich F, Hecht S, Valentine MT, Zok FW, Hawker CJ. Tough Multimaterial Interfaces through Wavelength-Selective 3D Printing. ACS APPLIED MATERIALS & INTERFACES 2021; 13:22065-22072. [PMID: 33929835 DOI: 10.1021/acsami.1c06062] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Strong and well-engineered interfaces between dissimilar materials are a hallmark of natural systems but have proven difficult to emulate in synthetic materials, where interfaces often act as points of failure. In this work, curing reactions that are triggered by exposure to different wavelengths of visible light are used to produce multimaterial objects with tough, well-defined interfaces between chemically distinct domains. Longer-wavelength (green) light selectively initiates acrylate-based radical polymerization, while shorter-wavelength (blue) light results in the simultaneous formation of epoxy and acrylate networks through orthogonal cationic and radical processes. The improved mechanical strength of these interfaces is hypothesized to arise from a continuous acrylate network that bridges domains. Using printed test structures, interfaces were characterized through spatial resolution of their chemical composition, localized mechanical properties, and bulk fracture strength. This wavelength-selective photocuring of interpenetrating polymer networks is a promising strategy for increasing the mechanical performance of 3D-printed objects and expanding light-based additive manufacturing technologies.
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Affiliation(s)
- Neil D Dolinski
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - E Benjamin Callaway
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Caitlin S Sample
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Luke F Gockowski
- Mechanical Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Roberto Chavez
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Zachariah A Page
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Fabian Eisenreich
- Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Stefan Hecht
- Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Megan T Valentine
- Mechanical Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Frank W Zok
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Craig J Hawker
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
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137
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Chen Q, Lv P, Huang J, Huang TY, Duan H. Intelligent Shape-Morphing Micromachines. RESEARCH (WASHINGTON, D.C.) 2021; 2021:9806463. [PMID: 34056618 PMCID: PMC8139332 DOI: 10.34133/2021/9806463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/11/2021] [Indexed: 11/06/2022]
Abstract
Intelligent machines are capable of switching shape configurations to adapt to changes in dynamic environments and thus have offered the potentials in many applications such as precision medicine, lab on a chip, and bioengineering. Even though the developments of smart materials and advanced micro/nanomanufacturing are flouring, how to achieve intelligent shape-morphing machines at micro/nanoscales is still significantly challenging due to the lack of design methods and strategies especially for small-scale shape transformations. This review is aimed at summarizing the principles and methods for the construction of intelligent shape-morphing micromachines by introducing the dimensions, modes, realization methods, and applications of shape-morphing micromachines. Meanwhile, this review highlights the advantages and challenges in shape transformations by comparing micromachines with the macroscale counterparts and presents the future outlines for the next generation of intelligent shape-morphing micromachines.
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Affiliation(s)
- Qianying Chen
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
- CAPT, HEDPS, Peking University, Beijing 100871, China
| | - Pengyu Lv
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Jianyong Huang
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Tian-Yun Huang
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Huiling Duan
- State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
- CAPT, HEDPS, Peking University, Beijing 100871, China
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138
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Abstract
In the last century, robots have been revolutionizing our lives, augmenting human actions with greater precision and repeatability. Unfortunately, most robotic systems can only operate in controlled environments. While increasing the complexity of the centralized controller is an instinctive direction to enable robots that are capable of autonomously adapting to their environment, there are ample examples in nature where adaptivity emerges from simpler decentralized processes. Here we perform experiments and simulations on a modular and scalable robotic platform in which each unit is stochastically updating its own behavior to explore requirements needed for a decentralized learning strategy capable of achieving locomotion in a continuously changing environment or when undergoing damage. One of the main challenges in robotics is the development of systems that can adapt to their environment and achieve autonomous behavior. Current approaches typically aim to achieve this by increasing the complexity of the centralized controller by, e.g., direct modeling of their behavior, or implementing machine learning. In contrast, we simplify the controller using a decentralized and modular approach, with the aim of finding specific requirements needed for a robust and scalable learning strategy in robots. To achieve this, we conducted experiments and simulations on a specific robotic platform assembled from identical autonomous units that continuously sense their environment and react to it. By letting each unit adapt its behavior independently using a basic Monte Carlo scheme, the assembled system is able to learn and maintain optimal behavior in a dynamic environment as long as its memory is representative of the current environment, even when incurring damage. We show that the physical connection between the units is enough to achieve learning, and no additional communication or centralized information is required. As a result, such a distributed learning approach can be easily scaled to larger assemblies, blurring the boundaries between materials and robots, paving the way for a new class of modular “robotic matter” that can autonomously learn to thrive in dynamic or unfamiliar situations, for example, encountered by soft robots or self-assembled (micro)robots in various environments spanning from the medical realm to space explorations.
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139
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Khajehtourian R, Kochmann DM. Soft Adaptive Mechanical Metamaterials. Front Robot AI 2021; 8:673478. [PMID: 34012982 PMCID: PMC8126663 DOI: 10.3389/frobt.2021.673478] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/16/2021] [Indexed: 12/12/2022] Open
Abstract
Soft materials are inherently flexible and make suitable candidates for soft robots intended for specific tasks that would otherwise not be achievable (e.g., smart grips capable of picking up objects without prior knowledge of their stiffness). Moreover, soft robots exploit the mechanics of their fundamental building blocks and aim to provide targeted functionality without the use of electronics or wiring. Despite recent progress, locomotion in soft robotics applications has remained a relatively young field with open challenges yet to overcome. Justly, harnessing structural instabilities and utilizing bistable actuators have gained importance as a solution. This report focuses on substrate-free reconfigurable structures composed of multistable unit cells with a nonconvex strain energy potential, which can exhibit structural transitions and produce strongly nonlinear transition waves. The energy released during the transition, if sufficient, balances the dissipation and kinetic energy of the system and forms a wave front that travels through the structure to effect its permanent or reversible reconfiguration. We exploit a triangular unit cell’s design space and provide general guidelines for unit cell selection. Using a continuum description, we predict and map the resulting structure’s behavior for various geometric and material properties. The structural motion created by these strongly nonlinear metamaterials has potential applications in propulsion in soft robotics, morphing surfaces, reconfigurable devices, mechanical logic, and controlled energy absorption.
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Affiliation(s)
- Romik Khajehtourian
- Mechanics and Materials Lab, Department of Mechanical and Process Engineering, ETH Zürich, Zürich, Switzerland
| | - Dennis M Kochmann
- Mechanics and Materials Lab, Department of Mechanical and Process Engineering, ETH Zürich, Zürich, Switzerland
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140
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Sachyani Keneth E, Kamyshny A, Totaro M, Beccai L, Magdassi S. 3D Printing Materials for Soft Robotics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2003387. [PMID: 33164255 DOI: 10.1002/adma.202003387] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/09/2020] [Indexed: 05/23/2023]
Abstract
Soft robotics is a growing field of research, focusing on constructing motor-less robots from highly compliant materials, some are similar to those found in living organisms. Soft robotics has a high potential for applications in various fields such as soft grippers, actuators, and biomedical devices. 3D printing of soft robotics presents a novel and promising approach to form objects with complex structures, directly from a digital design. Here, recent developments in the field of materials for 3D printing of soft robotics are summarized, including high-performance flexible and stretchable materials, hydrogels, self-healing materials, and shape memory polymers, as well as fabrication of all-printed robots (multi-material printing, embedded electronics, untethered and autonomous robotics). The current challenges in the fabrication of 3D printed soft robotics, including the materials available and printing abilities, are presented and the recent activities addressing these challenges are also surveyed.
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Affiliation(s)
- Ela Sachyani Keneth
- Casali Center of Applied Chemistry, Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Alexander Kamyshny
- Casali Center of Applied Chemistry, Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Massimo Totaro
- Istituto Italiano di Tecnologia (IIT) Soft BioRobotics Perception lab, Viale Rinaldo Piaggio 34, Pontedera, Pisa, 56025, Italy
| | - Lucia Beccai
- Istituto Italiano di Tecnologia (IIT) Soft BioRobotics Perception lab, Viale Rinaldo Piaggio 34, Pontedera, Pisa, 56025, Italy
| | - Shlomo Magdassi
- Casali Center of Applied Chemistry, Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
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141
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Pal A, Restrepo V, Goswami D, Martinez RV. Exploiting Mechanical Instabilities in Soft Robotics: Control, Sensing, and Actuation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006939. [PMID: 33792085 DOI: 10.1002/adma.202006939] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/13/2020] [Indexed: 06/12/2023]
Abstract
The rapidly expanding field of soft robotics has provided multiple examples of how entirely soft machines and actuators can outperform conventional rigid robots in terms of adaptability, maneuverability, and safety. Unfortunately, the soft and flexible materials used in their construction impose intrinsic limitations on soft robots, such as low actuation speeds and low output forces. Nature offers multiple examples where highly flexible organisms exploit mechanical instabilities to store and rapidly release energy. Guided by these examples, researchers have recently developed a variety of strategies to overcome speed and power limitations in soft robotics using mechanical instabilities. These mechanical instabilities provide, through rapid transitions from structurally stable states, a new route to achieve high output power amplification and attain impressive actuation speeds. Here, an overview of the literature related to the development of soft robots and actuators that exploit mechanical instabilities to expand their actuation speed, output power, and functionality is presented. Additionally, strategies using structural phase transitions to address current challenges in the area of soft robotic control, sensing, and actuation are discussed. Approaches using instabilities to create entirely soft logic modules to imbue soft robots with material intelligence and distributed computational capabilities are also reviewed.
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Affiliation(s)
- Aniket Pal
- School of Industrial Engineering, Purdue University, 315 N. Grant Street, West Lafayette, IN, 47907, USA
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569, Stuttgart, Germany
| | - Vanessa Restrepo
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN, 47907, USA
| | - Debkalpa Goswami
- School of Industrial Engineering, Purdue University, 315 N. Grant Street, West Lafayette, IN, 47907, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, 45 Carleton Street, Cambridge, MA, 02142, USA
| | - Ramses V Martinez
- School of Industrial Engineering, Purdue University, 315 N. Grant Street, West Lafayette, IN, 47907, USA
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN, 47907, USA
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142
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Liu K, Hacker F, Daraio C. Robotic surfaces with reversible, spatiotemporal control for shape morphing and object manipulation. Sci Robot 2021; 6:6/53/eabf5116. [PMID: 34043570 DOI: 10.1126/scirobotics.abf5116] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 03/16/2021] [Indexed: 12/13/2022]
Abstract
Continuous and controlled shape morphing is essential for soft machines to conform, grasp, and move while interacting safely with their surroundings. Shape morphing can be achieved with two-dimensional (2D) sheets that reconfigure into target 3D geometries, for example, using stimuli-responsive materials. However, most existing solutions lack the ability to reprogram their shape, face limitations on attainable geometries, or have insufficient mechanical stiffness to manipulate objects. Here, we develop a soft, robotic surface that allows for large, reprogrammable, and pliable shape morphing into smooth 3D geometries. The robotic surface consists of a layered design composed of two active networks serving as artificial muscles, one passive network serving as a skeleton, and cover scales serving as an artificial skin. The active network consists of a grid of strips made of heat-responsive liquid crystal elastomers (LCEs) containing stretchable heating coils. The magnitude and speed of contraction of the LCEs can be controlled by varying the input electric currents. The 1D contraction of the LCE strips activates in-plane and out-of-plane deformations; these deformations are both necessary to transform a flat surface into arbitrary 3D geometries. We characterize the fundamental deformation response of the layers and derive a control scheme for actuation. We demonstrate that the robotic surface provides sufficient mechanical stiffness and stability to manipulate other objects. This approach has potential to address the needs of a range of applications beyond shape changes, such as human-robot interactions and reconfigurable electronics.
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Affiliation(s)
- Ke Liu
- Division of Engineering and Applied Science, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91105, USA
| | - Felix Hacker
- Division of Engineering and Applied Science, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91105, USA.,Department of Mechanical and Process Engineering, ETH-Zürich, Rämistrasse 101, 8092 Zürich, Switzerland
| | - Chiara Daraio
- Division of Engineering and Applied Science, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91105, USA.
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143
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Wang Z, Cai S. Recent progress in dynamic covalent chemistries for liquid crystal elastomers. J Mater Chem B 2021; 8:6610-6623. [PMID: 32555841 DOI: 10.1039/d0tb00754d] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Liquid crystal elastomers (LCEs) have recently shown great potential in the applications of soft robotics, biomedical devices, active morphing structures, self-regulating systems and biomimetic demonstrations. Physical properties of LCEs highly depend on their crosslinking and the alignment of mesogens in the polymer network. Different strategies have been adopted to control and program the alignment of mesogens in LCEs over the recent decades, including stretching a loosely crosslinked LCE during its second-step crosslinking reaction, application of a strong magnetic or electrical field onto an LCE during its crosslinking process, and crosslinking a LCE thin film on the top of a surface with predesigned molecular texture. In the most recent decade, dynamic covalent bonds, which can undergo exchange reactions with or without external stimuli, have been introduced into LCEs to enable facile programing of mesogen orientation in the elastomer. In addition to the programmability, the LCEs with dynamic covalent bonds have also shown great recyclability, self-healing abilities and reprogrammability. In this article, we will review the recent progress in the synthesis, programming and application of LCEs with dynamic covalent bonds. We will also discuss the challenges and research opportunities in the field.
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Affiliation(s)
- Zhijian Wang
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA.
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144
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Zhang F, Li S, Shen Z, Cheng X, Xue Z, Zhang H, Song H, Bai K, Yan D, Wang H, Zhang Y, Huang Y. Rapidly deployable and morphable 3D mesostructures with applications in multimodal biomedical devices. Proc Natl Acad Sci U S A 2021; 118:e2026414118. [PMID: 33836614 PMCID: PMC7980465 DOI: 10.1073/pnas.2026414118] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Structures that significantly and rapidly change their shapes and sizes upon external stimuli have widespread applications in a diversity of areas. The ability to miniaturize these deployable and morphable structures is essential for applications in fields that require high-spatial resolution or minimal invasiveness, such as biomechanics sensing, surgery, and biopsy. Despite intensive studies on the actuation mechanisms and material/structure strategies, it remains challenging to realize deployable and morphable structures in high-performance inorganic materials at small scales (e.g., several millimeters, comparable to the feature size of many biological tissues). The difficulty in integrating actuation materials increases as the size scales down, and many types of actuation forces become too small compared to the structure rigidity at millimeter scales. Here, we present schemes of electromagnetic actuation and design strategies to overcome this challenge, by exploiting the mechanics-guided three-dimensional (3D) assembly to enable integration of current-carrying metallic or magnetic films into millimeter-scale structures that generate controlled Lorentz forces or magnetic forces under an external magnetic field. Tailored designs guided by quantitative modeling and developed scaling laws allow formation of low-rigidity 3D architectures that deform significantly, reversibly, and rapidly by remotely controlled electromagnetic actuation. Reconfigurable mesostructures with multiple stable states can be also achieved, in which distinct 3D configurations are maintained after removal of the magnetic field. Demonstration of a functional device that combines the deep and shallow sensing for simultaneous measurements of thermal conductivities in bilayer films suggests the promising potential of the proposed strategy toward multimodal sensing of biomedical signals.
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Affiliation(s)
- Fan Zhang
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Shupeng Li
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60201
| | - Zhangming Shen
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Xu Cheng
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Zhaoguo Xue
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Hang Zhang
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Honglie Song
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Ke Bai
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Dongjia Yan
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Heling Wang
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208;
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60201
| | - Yihui Zhang
- Key Laboratory of Applied Mechanics of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China;
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Yonggang Huang
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208;
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60201
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145
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Chen Y, Yang J, Zhang X, Feng Y, Zeng H, Wang L, Feng W. Light-driven bimorph soft actuators: design, fabrication, and properties. MATERIALS HORIZONS 2021; 8:728-757. [PMID: 34821314 DOI: 10.1039/d0mh01406k] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Soft robots that can move like living organisms and adapt to their surroundings are currently in the limelight from fundamental studies to technological applications, due to their advances in material flexibility, human-friendly interaction, and biological adaptation that surpass conventional rigid machines. Light-fueled smart actuators based on responsive soft materials are considered to be one of the most promising candidates to promote the field of untethered soft robotics, thereby attracting considerable attention amongst materials scientists and microroboticists to investigate photomechanics, photoswitch, bioinspired design, and actuation realization. In this review, we discuss the recent state-of-the-art advances in light-driven bimorph soft actuators, with the focus on bilayer strategy, i.e., integration between photoactive and passive layers within a single material system. Bilayer structures can endow soft actuators with unprecedented features such as ultrasensitivity, programmability, superior compatibility, robustness, and sophistication in controllability. We begin with an explanation about the working principle of bimorph soft actuators and introduction of a synthesis pathway toward light-responsive materials for soft robotics. Then, photothermal and photochemical bimorph soft actuators are sequentially introduced, with an emphasis on the design strategy, actuation performance, underlying mechanism, and emerging applications. Finally, this review is concluded with a perspective on the existing challenges and future opportunities in this nascent research Frontier.
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Affiliation(s)
- Yuanhao Chen
- School of Materials Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
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146
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Zhang J, Guo Y, Hu W, Soon RH, Davidson ZS, Sitti M. Liquid Crystal Elastomer-Based Magnetic Composite Films for Reconfigurable Shape-Morphing Soft Miniature Machines. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006191. [PMID: 33448077 PMCID: PMC7610459 DOI: 10.1002/adma.202006191] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/30/2020] [Indexed: 05/08/2023]
Abstract
Stimuli-responsive and active materials promise radical advances for many applications. In particular, soft magnetic materials offer precise, fast, and wireless actuation together with versatile functionality, while liquid crystal elastomers (LCEs) are capable of large reversible and programmable shape-morphing with high work densities in response to various environmental stimuli, e.g., temperature, light, and chemical solutions. Integrating the orthogonal stimuli-responsiveness of these two kinds of active materials could potentially enable new functionalities and future applications. Here, magnetic microparticles (MMPs) are embedded into an LCE film to take the respective advantages of both materials without compromising their independent stimuli-responsiveness. This composite material enables reconfigurable magnetic soft miniature machines that can self-adapt to a changing environment. In particular, a miniature soft robot that can autonomously alter its locomotion mode when it moves from air to hot liquid, a vine-like filament that can sense and twine around a support, and a light-switchable magnetic spring are demonstrated. The integration of LCEs and MMPs into monolithic structures introduces a new dimension in the design of soft machines and thus greatly enhances their use in applications in complex environments, especially for miniature soft robots, which are self-adaptable to environmental changes while being remotely controllable.
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Affiliation(s)
- Jiachen Zhang
- Physical Intelligence DepartmentMax Planck Institute for Intelligent SystemsStuttgart70569Germany
| | - Yubing Guo
- Physical Intelligence DepartmentMax Planck Institute for Intelligent SystemsStuttgart70569Germany
| | - Wenqi Hu
- Physical Intelligence DepartmentMax Planck Institute for Intelligent SystemsStuttgart70569Germany
| | - Ren Hao Soon
- Physical Intelligence DepartmentMax Planck Institute for Intelligent SystemsStuttgart70569Germany
| | - Zoey S. Davidson
- Physical Intelligence DepartmentMax Planck Institute for Intelligent SystemsStuttgart70569Germany
| | - Metin Sitti
- Physical Intelligence DepartmentMax Planck Institute for Intelligent SystemsStuttgart70569Germany
- Department of Information Technology and Electrical EngineeringETH ZürichZürich8092Switzerland
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147
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Programmable Stimuli-Responsive Actuators for Complex Motions in Soft Robotics: Concept, Design and Challenges. ACTUATORS 2020. [DOI: 10.3390/act9040131] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
During the last years, great progress was made in material science in terms of concept, design and fabrication of new composite materials with conferred properties and desired functionalities. The scientific community paid particular interest to active soft materials, such as soft actuators, for their potential as transducers responding to various stimuli aiming to produce mechanical work. Inspired by this, materials engineers today are developing multidisciplinary approaches to produce new active matters, focusing on the kinematics allowed by the material itself more than on the possibilities offered by its design. Traditionally, more complex motions beyond pure elongation and bending are addressed by the robotics community. The present review targets encompassing and rationalizing a framework which will help a wider scientific audience to understand, sort and design future soft actuators and methods enabling complex motions. Special attention is devoted to recent progress in developing innovative stimulus-responsive materials and approaches for complex motion programming for soft robotics. In this context, a challenging overview of the new materials as well as their classification and comparison (performances and characteristics) are proposed. In addition, the great potential of soft transducers are outlined in terms of kinematic capabilities, illustrated by the related application. Guidelines are provided to design actuators and to integrate asymmetry enabling motions along any of the six basic degrees of freedom (translations and rotations), and strategies towards the programming of more complex motions are discussed. As a final note, a series of manufacturing methods are described and compared, from molding to 3D and 4D printing. The review ends with a Perspectives section, from material science and microrobotic points of view, on the soft materials’ future and close future challenges to be overcome.
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148
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Ambulo CP, Tasmim S, Wang S, Abdelrahman MK, Zimmern PE, Ware TH. Processing advances in liquid crystal elastomers provide a path to biomedical applications. JOURNAL OF APPLIED PHYSICS 2020; 128:140901. [PMID: 33060862 PMCID: PMC7546753 DOI: 10.1063/5.0021143] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/24/2020] [Indexed: 05/08/2023]
Abstract
Liquid crystal elastomers (LCEs) are a class of stimuli-responsive polymers that undergo reversible shape-change in response to environmental changes. The shape change of LCEs can be programmed during processing by orienting the liquid crystal phase prior to crosslinking. The suite of processing techniques that has been developed has resulted in a myriad of LCEs with different shape-changing behavior and mechanical properties. Aligning LCEs via mechanical straining yields large uniaxial actuators capable of a moderate force output. Magnetic fields are utilized to control the alignment within LCE microstructures. The generation of out-of-plane deformations such as bending, twisting, and coning is enabled by surface alignment techniques within thin films. 4D printing processes have emerged that enable the fabrication of centimeter-scale, 3D LCE structures with a complex alignment. The processing technique also determines, to a large extent, the potential applications of the LCE. For example, 4D printing enables the fabrication of LCE actuators capable of replicating the forces generated by human muscles. Employing surface alignment techniques, LCE films can be designed for use as coatings or as substrates for stretchable electronics. The growth of new processes and strategies opens and strengthens the path for LCEs to be applicable within biomedical device designs.
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Affiliation(s)
- Cedric P Ambulo
- Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas 75080, USA
| | | | | | | | - Philippe E Zimmern
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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149
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Ceamanos L, Kahveci Z, López-Valdeolivas M, Liu D, Broer DJ, Sánchez-Somolinos C. Four-Dimensional Printed Liquid Crystalline Elastomer Actuators with Fast Photoinduced Mechanical Response toward Light-Driven Robotic Functions. ACS APPLIED MATERIALS & INTERFACES 2020; 12:44195-44204. [PMID: 32885661 DOI: 10.1021/acsami.0c13341] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Remote light exposure of photoresponsive liquid crystalline polymers has drawn great attention over the last years as an attractive strategy to generate mechanical work with high spatial resolution. To tailor these materials into practical engineering devices, it is of key importance to gain control over their morphology and thus precisely program their mechanical response, which must also be fast and relevant in magnitude. In this communication, we report the four-dimensional (4D) printing of azobenzene-containing liquid crystalline elastomers (LCEs) that respond to light. During extrusion of the LCE precursor, mesogen orientation is defined by the needle's moving direction enabling a precise definition of the director, which is later fixed by photopolymerization. Fast mechanical responses have been observed in these 4D printed LCE elements when excited with ultraviolet (UV) light. These 4D printed elements lift objects many times heavier than their own weight, demonstrating a capacity to produce effective work. Photochemical and photothermal contributions to the deformation and force have been identified. Advantageously, the use of blue and UV light excitation enables adjustment of generated forces that can be maintained even in the dark and can be released by light excitation or temperature. The demonstrated ability to generate light-responsive elements quickly delivering sufficient work paves the way for implementing remotely addressed mechanical functions to future soft robotics and engineering.
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Affiliation(s)
- Lorena Ceamanos
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Departamento de Fı́sica de la Materia Condensada, Zaragoza 50009, Spain
| | - Zehra Kahveci
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Departamento de Fı́sica de la Materia Condensada, Zaragoza 50009, Spain
| | - María López-Valdeolivas
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Departamento de Fı́sica de la Materia Condensada, Zaragoza 50009, Spain
| | - Danqing Liu
- Stimuli-Responsive Functional Materials and Devices Group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Institute of Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Dirk Jan Broer
- Stimuli-Responsive Functional Materials and Devices Group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Institute of Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Carlos Sánchez-Somolinos
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Departamento de Fı́sica de la Materia Condensada, Zaragoza 50009, Spain
- CIBER in Bioengineering, Biomaterials and Nanomedicine (CIBERBBN), 28029 Madrid, Spain
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150
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Gablier A, Saed MO, Terentjev EM. Transesterification in Epoxy–Thiol Exchangeable Liquid Crystalline Elastomers. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01757] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Alexandra Gablier
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K
| | - Mohand O. Saed
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K
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