1
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Zhao J, Sun Y, Dai Y, Wu J, Li K. Dynamic response of a simply supported liquid-crystal elastomer beam under moving illumination. Phys Rev E 2024; 109:054704. [PMID: 38907412 DOI: 10.1103/physreve.109.054704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 04/03/2024] [Indexed: 06/24/2024]
Abstract
Optically responsive liquid crystal elastomer (LCE) devices have thriving potential to flourish in soft robots and microdrives, owing to their advantages of remote controllability, structural simplicity, and no power supply. In terms of illumination-driven modes, most research has focused on the dynamic response of LCE devices under continuous and periodic illumination, while the theoretical study of the dynamic response under moving illumination is limited. In this paper, based on the coupling of LCE and mechanical deformation under moving illumination, the dynamic model of a LCE simply supported beam is built to investigate its dynamic response under moving illumination. The analytical solution of the dynamic response of the LCE beam under moving illumination is derived through the modal superposition method and the Duhamel integration, and the solution is programed and analyzed with matlab software. By numerical calculations, the influence of the internal and driving parameters of the structure on the dynamic response of the LCE simply supported beam can be analyzed. The results show that when the moving speed of illumination reaches the first-order critical frequency, the maximum amplitude of the dynamic response at the beam mid-span will reach a peak. Meanwhile, the dynamic response of beam can be improved by increasing the illumination width, increasing the light intensity, increasing the shrinkage coefficient, and reducing the damping coefficient. This work provides theoretical guidance for applying the dynamic response of LCE devices under moving illumination in soft robots, microactuators, energy harvesters, sensors, etc.
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2
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Gruzdenko A, Mulder DJ, Schenning APHJ, den Toonder JMJ, Debije MG. Dual-Wavelength Volumetric Microlithography for Rapid Production of 4D Microstructures. ACS APPLIED MATERIALS & INTERFACES 2024; 16:22696-22703. [PMID: 38646711 PMCID: PMC11071039 DOI: 10.1021/acsami.4c01883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/11/2024] [Accepted: 04/11/2024] [Indexed: 04/23/2024]
Abstract
4D microstructured actuators are micro-objects made of stimuli-responsive materials capable of induced shape deformations, with applications ranging from microrobotics to smart micropatterned haptic surfaces. The novel technology dual-wavelength volumetric microlithography (DWVML) realizes rapid printing of high-resolution 3D microstructures and so has the potential to pave the way to feasible manufacturing of 4D microdevices. In this work, DWVML is applied for the first time to printing stimuli-responsive materials, namely, liquid crystal networks (LCNs). An LCN photoresist is developed and characterized, and large arrays of up to 5625 LCN micropillars with programmable shape changes are produced by means of DWVML in the time span of seconds, over areas as large as ∼5.4 mm2. The production rate of 0.24 mm3 h-1 is achieved, exceeding speeds previously reported for additive manufacturing of LCNs by 2 orders of magnitude. Finally, a membrane with tunable, micrometer-sized pores is fabricated to illustrate the potential DWVML holds for real-world applications.
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Affiliation(s)
- Alexandra Gruzdenko
- Stimuli-Responsive
Functional Materials and Devices, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Dirk J. Mulder
- Photosynthetic, De Boelelaan
1085, 1081HV Amsterdam, The Netherlands
| | - Albert P. H. J. Schenning
- Stimuli-Responsive
Functional Materials and Devices, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Jaap M. J. den Toonder
- Microsystems,
Department of Mechanical Engineering, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Michael G. Debije
- Stimuli-Responsive
Functional Materials and Devices, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Interactive
Polymer Materials (IPM), Eindhoven University
of Technology, Groene
Loper 3, 5612 AE Eindhoven, The Netherlands
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3
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Liu M, Fu J, Yang S. Synthesis of Microparticles with Diverse Thermally Responsive Shapes Originated from the Same Janus Liquid Crystalline Microdroplets. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303106. [PMID: 37495936 DOI: 10.1002/smll.202303106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/14/2023] [Indexed: 07/28/2023]
Abstract
Liquid crystalline elastomer (LCE)-based microparticles that can change shapes in response to external stimuli are of great interest for potential applications such as artificial cells, micro-actuators, micro-valves, and smart drug carriers. Here, the synthesis of LCE microparticles with diverse temperature-dependent anisotropic shapes originated from the same Janus microdroplets is reported. The Janus microdroplets, suspended in an aqueous solution of surfactants, are transformed from microdroplets consisting of a mixture of liquid crystal (LC) monomers, oligomers, silicone oil, and an organic solvent, after the removal of the organic solvent. The molecular alignment of the LC part at the interface, whether planar, homeotropic, or hybrid, is dependent on the choice of the surfactants but not affected by the silicone oil. After polymerization and solvent extraction of the unreacted components, LCE microparticles of various shapes are obtained depending on the concentration and composition of the surfactants, the weight ratio of the LC part to the silicone oil part, and the choice of the extraction solvent. The microparticles that undergo different synthetic pathways show distinct thermally responsive shapes, much like how stem cells differentiate in different environmental conditions.
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Affiliation(s)
- Mingzhu Liu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
- School of Chemistry, Beihang University, Beijing, 100191, P. R. China
| | - Jiemin Fu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
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4
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Lee YJ, Abdelrahman MK, Kalairaj MS, Ware TH. Self-Assembled Microactuators Using Chiral Liquid Crystal Elastomers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302774. [PMID: 37291979 DOI: 10.1002/smll.202302774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/18/2023] [Indexed: 06/10/2023]
Abstract
Materials that undergo reversible changes in form typically require top-down processing to program the microstructure of the material. As a result, it is difficult to program microscale, 3D shape-morphing materials that undergo non-uniaxial deformations. Here, a simple bottom-up fabrication approach to prepare bending microactuators is described. Spontaneous self-assembly of liquid crystal (LC) monomers with controlled chirality within 3D micromold results in a change in molecular orientation across thickness of the microstructure. As a result, heating induces bending in these microactuators. The concentration of chiral dopant is varied to adjust the chirality of the monomer mixture. Liquid crystal elastomer (LCE) microactuators doped with 0.05 wt% of chiral dopant produce needle-shaped actuators that bend from flat to an angle of 27.2 ± 11.3° at 180 °C. Higher concentrations of chiral dopant lead to actuators with reduced bending, and lower concentrations of chiral dopant lead to actuators with poorly controlled bending. Asymmetric molecular alignment inside 3D structure is confirmed by sectioning actuators. Arrays of microactuators that all bend in the same direction can be fabricated if symmetry of geometry of the microstructure is broken. It is envisioned that the new platform to synthesize microstructures can further be applied in soft robotics and biomedical devices.
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Affiliation(s)
- Yoo Jin Lee
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Mustafa K Abdelrahman
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA
| | | | - Taylor H Ware
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA
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5
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Concellón A. Liquid Crystal Emulsions: A Versatile Platform for Photonics, Sensing, and Active Matter. Angew Chem Int Ed Engl 2023:e202308857. [PMID: 37694542 DOI: 10.1002/anie.202308857] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/12/2023] [Accepted: 09/11/2023] [Indexed: 09/12/2023]
Abstract
The self-assembly of liquid crystals (LCs) is a fascinating method for controlling the organization of discrete molecules into nanostructured functional materials. Although LCs are traditionally processed in thin films, their confinement within micrometre-sized droplets has recently revealed new properties and functions, paving the way for next-generation soft responsive materials. These recent findings have unlocked a wealth of unprecedented applications in photonics (e.g. reflectors, lasing materials), sensing (e.g. biomolecule and pathogen detection), soft robotics (e.g. micropumps, artificial muscles), and beyond. This Minireview focuses on recent developments in LC emulsion designs and highlights a variety of novel potential applications. Perspectives on the opportunities and new directions for implementing LC emulsions in future innovative technologies are also provided.
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Affiliation(s)
- Alberto Concellón
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain
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6
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Li K, Lou J, Hu S, Dai Y, Wang F, Yu Y. Vibration of a Liquid Crystal Elastomer Spring Oscillator under Periodic Electrothermal Drive. Polymers (Basel) 2023; 15:2822. [PMID: 37447468 DOI: 10.3390/polym15132822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/25/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
The oscillations of electrically actuated thermally-responsive liquid crystal elastomer (LCE) microfibers under cyclic electric actuation have been discovered in recent experiments. Periodic electric actuation is a common method of active control with potential applications in the fields of micro-actuators. In this paper, the vibration behavior of LCE spring oscillator under periodic electrothermal drive is studied theoretically. Based on the dynamic LCE model, the dynamic governing equation of the LCE spring oscillator is established, and the time history curves of the vibration are obtained by numerical calculations. The results show that the periodic electrothermal drive can cause periodic vibration of the LCE spring oscillator. With the increase of time rate, the vibration amplitude increases first and then decreases. In a small damping system, there exist optimal sets of electrothermal drive period and electrothermal drive time rate to maximize the system amplitude. For the optimum periodic mode, the vibration amplitude of the spring oscillator is affected by the current heat, damping coefficient, gravital acceleration, spring constant and shrinkage coefficient, but not by the initial velocity. The application examples of LCE materials show that periodic electrothermally driven LCEs have promising applications. The results of this study are instructive for the design of soft robots and LCE-based electric locomotives.
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Affiliation(s)
- Kai Li
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Jiangfeng Lou
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Shaofei Hu
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Yuntong Dai
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Fei Wang
- Institute of Energy, Hefei Comprehensive National Science Center, Hefei 230039, China
- State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232002, China
| | - Yong Yu
- College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
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7
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Zhang Y, Wang X, Yang W, Yan H, Zhang X, Han D, He Y, Li C, Sun L. Programmable Complex Shape Changing of Polysiloxane Main-Chain Liquid Crystalline Elastomers. Molecules 2023; 28:4858. [PMID: 37375413 DOI: 10.3390/molecules28124858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/07/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Liquid crystal elastomers (LCEs) are shape-morphing materials whose large and reversible shape transformations are caused by the coupling between the mobile anisotropic properties of liquid crystal (LC) units and the rubber elastic of polymer networks. Their shape-changing behaviors under certain stimuli are largely directed by the LC orientation; therefore, various strategies have been developed to spatially modulate the LC alignments. However, most of these methods are limited as they require complex fabrication technologies or have intrinsic limitations in applicability. To address this issue, programmable complex shape changes in some LCE types, such as polysiloxane side-chain LCEs, thiol-acrylate main-chain LCEs, etc., were achieved by using a mechanical alignment programming process coupled with two-step crosslinking. Here, we report a polysiloxane main-chain LCE with programmable 2- and 3D shape-changing abilities that were created by mechanically programming the polydomain LCE with two crosslinking steps. The resulting LCEs exhibited a reversible thermal-induced shape transformation between the initial and programmed shapes due to the two-way memory between the first and second network structures. Our findings expand on the applications of LCE materials in actuators, soft robotics, and smart structures where arbitrary and easily programmed shape morphing is needed.
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Affiliation(s)
- Yuhe Zhang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Xiuxiu Wang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Wenlong Yang
- Department of Applied Science, Harbin University of Science and Technology, Harbin 150080, China
| | - Huixuan Yan
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Xinyu Zhang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Dongxu Han
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Yifan He
- Institute of Regulatory Science, Beijing Technology and Business University, Beijing 100048, China
| | - Chensha Li
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China
| | - Liguo Sun
- Key Laboratory of Chemical Engineering Process and Technology for High-Efficiency Conversion School of Chemistry and Material Science, Heilongjiang University, Harbin 150080, China
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8
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Patel M, Alvarez-Fernandez A, Fornerod MJ, Radhakrishnan ANP, Taylor A, Ten Chua S, Vignolini S, Schmidt-Hansberg B, Iles A, Guldin S. Liquid Crystal-Templated Porous Microparticles via Photopolymerization of Temperature-Induced Droplets in a Binary Liquid Mixture. ACS OMEGA 2023; 8:20404-20411. [PMID: 37323413 PMCID: PMC10268013 DOI: 10.1021/acsomega.3c00490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023]
Abstract
Porous polymeric microspheres are an emerging class of materials, offering stimuli-responsive cargo uptake and release. Herein, we describe a new approach to fabricate porous microspheres based on temperature-induced droplet formation and light-induced polymerization. Microparticles were prepared by exploiting the partial miscibility of a thermotropic liquid crystal (LC) mixture composed of 4-cyano-4'-pentylbiphenyl (5CB, unreactive mesogens) with 2-methyl-1,4-phenylene bis4-[3-(acryloyloxy)propoxy] benzoate (RM257, reactive mesogens) in methanol (MeOH). Isotropic 5CB/RM257-rich droplets were generated by cooling below the binodal curve (20 °C), and the isotropic-to-nematic transition occurred after cooling below 0 °C. The resulting 5CB/RM257-rich droplets with radial configuration were subsequently polymerized under UV light, resulting in nematic microparticles. Upon heating the mixture, the 5CB mesogens underwent a nematic-isotropic transition and eventually became homogeneous with MeOH, while the polymerized RM257 preserved its radial configuration. Repeated cycles of cooling and heating resulted in swelling and shrinking of the porous microparticles. The use of a reversible materials templating approach to obtain porous microparticles provides new insights into binary liquid manipulation and potential for microparticle production.
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Affiliation(s)
- Mehzabin Patel
- Department
of Chemical Engineering, University College
London, London, WC1E 7JE, United
Kingdom
| | | | | | | | - Alaric Taylor
- Department
of Chemical Engineering, University College
London, London, WC1E 7JE, United
Kingdom
| | - Singg Ten Chua
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge, CB2 1EW, United
Kingdom
| | - Silvia Vignolini
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge, CB2 1EW, United
Kingdom
| | - Benjamin Schmidt-Hansberg
- Chemical
& Process Engineering, Coating & Film Processing, BASF SE, 67056 Ludwigshafen am Rhein, Germany
| | - Alexander Iles
- Lab-on-a-Chip
Research Group, Department of Chemistry and Biochemistry, University of Hull, Hull, HU6 7RX, United Kingdom
| | - Stefan Guldin
- Department
of Chemical Engineering, University College
London, London, WC1E 7JE, United
Kingdom
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9
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Chen M, Gao M, Bai L, Zheng H, Qi HJ, Zhou K. Recent Advances in 4D Printing of Liquid Crystal Elastomers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209566. [PMID: 36461147 DOI: 10.1002/adma.202209566] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/22/2022] [Indexed: 06/09/2023]
Abstract
Liquid crystal elastomers (LCEs) are renowned for their large, reversible, and anisotropic shape change in response to various external stimuli due to their lightly cross-linked polymer networks with an oriented mesogen direction, thus showing great potential for applications in robotics, bio-medics, electronics, optics, and energy. To fully take advantage of the anisotropic stimuli-responsive behaviors of LCEs, it is preferable to achieve a locally controlled mesogen alignment into monodomain orientations. In recent years, the application of 4D printing to LCEs opens new doors for simultaneously programming the mesogen alignment and the 3D geometry, offering more opportunities and higher feasibility for the fabrication of 4D-printed LCE objects with desirable stimuli-responsive properties. Here, the state-of-the-art advances in 4D printing of LCEs are reviewed, with emphasis on both the mechanisms and potential applications. First, the fundamental properties of LCEs and the working principles of the representative 4D printing techniques are briefly introduced. Then, the fabrication of LCEs by 4D printing techniques and the advantages over conventional manufacturing methods are demonstrated. Finally, perspectives on the current challenges and potential development trends toward the 4D printing of LCEs are discussed, which may shed light on future research directions in this new field.
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Affiliation(s)
- Mei Chen
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- HP-NTU Digital Manufacturing Corporate Lab, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Ming Gao
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- HP-NTU Digital Manufacturing Corporate Lab, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Lichun Bai
- School of Traffic and Transportation Engineering, Central South University, Changsha, 410075, China
| | - Han Zheng
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - H Jerry Qi
- School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Kun Zhou
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- HP-NTU Digital Manufacturing Corporate Lab, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore
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10
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Zhao L, Tian H, Liu H, Zhang W, Zhao F, Song X, Shao J. Bio-Inspired Soft-Rigid Hybrid Smart Artificial Muscle Based on Liquid Crystal Elastomer and Helical Metal Wire. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206342. [PMID: 36653937 DOI: 10.1002/smll.202206342] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 01/01/2023] [Indexed: 06/17/2023]
Abstract
Artificial muscles are of significant value in robotic applications. Rigid artificial muscles possess a strong load-bearing capacity, while their deformation is small; soft artificial muscles can be shifted to a large degree; however, their load-bearing capacity is weak. Furthermore, artificial muscles are generally controlled in an open loop due to a lack of deformation-related feedback. Human arms include muscles, bones, and nerves, which ingeniously coordinate the actuation, load-bearing, and sensory systems. Inspired by this, a soft-rigid hybrid smart artificial muscle (SRH-SAM) based on liquid crystal elastomer (LCE) and helical metal wire is proposed. The thermotropic responsiveness of the LCE is adopted for large reversible deformation, and the helical metal wire is used to fulfill high bearing capacity and electric heating function requirements. During actuation, the helical metal wire's resistance changes with the LCE's electrothermal deformation, thereby achieving deformation-sensing characteristics. Based on the proposed SRH-SAM, a reconfigurable blazed grating plane and the effective switch between attachment and detachment in bionic dry adhesion are accomplished. The SRH-SAM opens a new avenue for designing smart artificial muscles and can promote the development of artificial muscle-based devices.
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Affiliation(s)
- Limeng Zhao
- Micro-/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Hongmiao Tian
- Micro-/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Haoran Liu
- Micro-/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Weitian Zhang
- Micro-/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Fabo Zhao
- Micro-/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Xiaowen Song
- Micro-/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Jinyou Shao
- Micro-/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
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11
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Ishizu M, Hisano K, Aizawa M, Barrett CJ, Shishido A. Alignment Control of Smectic Layer Structures in Liquid-Crystalline Polymers by Photopolymerization with Scanned Slit Light. ACS APPLIED MATERIALS & INTERFACES 2022; 14:48143-48149. [PMID: 36197073 PMCID: PMC9615981 DOI: 10.1021/acsami.2c13299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Photoalignment control of hierarchical structures is a key process to enhance the properties of optical and mechanical materials. We developed an in situ molecular alignment method, where photopolymerization with the scanned slit light causes molecular flow, leading to two-dimensional precise alignment of molecules over large areas; however, the alignment control has been explored only on a molecular scale. In this study, we demonstrate this photopolymerization-induced molecular flow, enabling mesoscopic alignment of smectic layer structures composed of anisotropic molecules. Side-chain liquid-crystalline polymers were obtained from two different monomers with or without alkyl spacers by photopolymerization with one-dimensionally scanned slit light. The polymer with an alkyl spacer displayed mesogens aligned parallel to the scanning direction, while the polymer with no alkyl spacer resulted in perpendicular alignment of mesogens to the scanning direction, regulated by the alignment of the polymer main chain along the light scanning direction. Moreover, the polymerization with the scanned light aligned not only the mesogens but also mesoscopic smectic layer structures over large areas, depending on the structure and scanning pattern of light. We envision that such a simple polymerization technique could become a powerful and versatile alignment platform of anisotropic materials in a wide range of scales.
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Affiliation(s)
- Masaki Ishizu
- Laboratory
for Chemistry and Life Science, Institute
of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, Japan
- Department
of Chemical Science and Engineering, Tokyo
Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Kyohei Hisano
- Laboratory
for Chemistry and Life Science, Institute
of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, Japan
- Department
of Chemical Science and Engineering, Tokyo
Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Miho Aizawa
- Laboratory
for Chemistry and Life Science, Institute
of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, Japan
- Department
of Chemical Science and Engineering, Tokyo
Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Christopher J. Barrett
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Québec QC H3A 0B8, Canada
| | - Atsushi Shishido
- Laboratory
for Chemistry and Life Science, Institute
of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, Japan
- Department
of Chemical Science and Engineering, Tokyo
Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
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12
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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: 8] [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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13
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Arisawa M, Yoshida M, Fukumoto K, Sawato T, Yamaguchi M, Matsubara M, Kanie K. Three‐state Structural Switching and Selective Molecular Interactions of Cylindrical Concentric Monodomain Liquid Crystal Elastomer. ChemistrySelect 2021. [DOI: 10.1002/slct.202103490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mieko Arisawa
- Department of Organic Chemistry Graduate School of Pharmaceutical Sciences Tohoku University, Aoba Sendai 980-8578 Japan
- Department of Bioscience and Biotechnology Graduate School of Bioresource and Bioenviromental Sciences Kyushu University Fukuoka 819-0395 Japan
| | - Miyu Yoshida
- Department of Organic Chemistry Graduate School of Pharmaceutical Sciences Tohoku University, Aoba Sendai 980-8578 Japan
| | - Kohei Fukumoto
- Department of Organic Chemistry Graduate School of Pharmaceutical Sciences Tohoku University, Aoba Sendai 980-8578 Japan
| | - Tsukasa Sawato
- Department of Organic Chemistry Graduate School of Pharmaceutical Sciences Tohoku University, Aoba Sendai 980-8578 Japan
| | - Masahiko Yamaguchi
- Department of Organic Chemistry Graduate School of Pharmaceutical Sciences Tohoku University, Aoba Sendai 980-8578 Japan
| | - Masaki Matsubara
- Institute of Multidisciplinary Research for Advanced Materials Tohoku University, Aoba Sendai 980-8577 Japan
| | - Kiyoshi Kanie
- Institute of Multidisciplinary Research for Advanced Materials Tohoku University, Aoba Sendai 980-8577 Japan
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14
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Ni B, Liu G, Zhang M, Tatoulian M, Keller P, Li MH. Customizable Sophisticated Three-Dimensional Shape Changes of Large-Size Liquid Crystal Elastomer Actuators. ACS APPLIED MATERIALS & INTERFACES 2021; 13:54439-54446. [PMID: 34738782 DOI: 10.1021/acsami.1c18424] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Stimuli-responsive liquid crystal elastomers (LCEs), which exhibit sophisticated and versatile shape variations and functions upon stimulations, have constantly interested material science researchers. To date, many challenges still exist in scaling up orientated LCEs with sophisticated physical shapes and multi-functions. Herein, LCEs with various customizable conventional and exotic three-dimensional (3D) shapes and with sizes larger than those previously reported have been prepared by combining magnetic field alignment and soft lithography technology. These LCEs have film, cylinder, ellipsoid, hemispheroid, tube, pyramid, triangle and rectangle frame, grid pattern, cubic frame, and spring shapes. Meanwhile, diversified deformation behaviors such as contraction, expansion, bending, and twisting have been achieved by effectively controlling the alignment directions. Finally, the LCE actuator with hemispheroid shape has been explored for its possible applications in dynamic Braille displays or lenses with adjustable focal length. The simple strategy reported here provides a convenient way to customize multimorphological large-size 3D LCE actuators and their stimuli-responsive deformations. These systems will considerably enlarge the potential applications of LCEs and benefit the development of LCE soft robots and the future special bionic systems.
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Affiliation(s)
- Bin Ni
- CNRS, Institut de Recherche de Chimie Paris, UMR8247, Chimie ParisTech, Université Paris Sciences & Lettres, 75005 Paris, France
| | - Gaoyu Liu
- CNRS, Institut de Recherche de Chimie Paris, UMR8247, Chimie ParisTech, Université Paris Sciences & Lettres, 75005 Paris, France
| | - Mengxue Zhang
- CNRS, Institut de Recherche de Chimie Paris, UMR8247, Chimie ParisTech, Université Paris Sciences & Lettres, 75005 Paris, France
| | - Michael Tatoulian
- CNRS, Institut de Recherche de Chimie Paris, UMR8247, Chimie ParisTech, Université Paris Sciences & Lettres, 75005 Paris, France
| | - Patrick Keller
- Institut Curie, Université Paris Sciences & Lettres, CNRS, Sorbonne Université, Laboratoire Physico-Chimie Curie, UMR168, 75005 Paris, France
| | - Min-Hui Li
- CNRS, Institut de Recherche de Chimie Paris, UMR8247, Chimie ParisTech, Université Paris Sciences & Lettres, 75005 Paris, France
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15
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Liu X, Debije MG, Heuts JPA, Schenning APHJ. Liquid-Crystalline Polymer Particles Prepared by Classical Polymerization Techniques. Chemistry 2021; 27:14168-14178. [PMID: 34320258 PMCID: PMC8596811 DOI: 10.1002/chem.202102224] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Indexed: 11/06/2022]
Abstract
Liquid-crystalline polymer particles prepared by classical polymerization techniques are receiving increased attention as promising candidates for use in a variety of applications including micro-actuators, structurally colored objects, and absorbents. These particles have anisotropic molecular order and liquid-crystalline phases that distinguish them from conventional polymer particles. In this minireview, the preparation of liquid-crystalline polymer particles from classical suspension, (mini-)emulsion, dispersion, and precipitation polymerization reactions are discussed. The particle sizes, molecular orientations, and liquid-crystalline phases produced by each technique are summarized and compared. We conclude with a discussion of the challenges and prospects of the preparation of liquid-crystalline polymer particles by classical polymerization techniques.
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Affiliation(s)
- Xiaohong Liu
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
| | - Michael G. Debije
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
| | - Johan P. A. Heuts
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
| | - Albert P. H. J. Schenning
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
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16
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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: 7.0] [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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17
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Kim K, Guo Y, Bae J, Choi S, Song HY, Park S, Hyun K, Ahn SK. 4D Printing of Hygroscopic Liquid Crystal Elastomer Actuators. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2100910. [PMID: 33938152 DOI: 10.1002/smll.202100910] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Liquid crystal elastomers (LCEs) are broadly recognized as programmable actuating materials that are responsive to external stimuli, typically heat or light. Yet, soft LCEs that respond to changes in environmental humidity are not reported, except a few examples based on rigid liquid crystal networks with limited processing. Herein, a new class of highly deformable hygroscopic LCE actuators that can be prepared by versatile processing methods, including surface alignment as well as 3D printing is presented. The dimethylamino-functionalized LCE is prepared by the aza-Michael addition reaction between a reactive LC monomer and N,N'-dimethylethylenediamine as a chain extender, followed by photopolymerization. The humidity-responsive properties are introduced by activating one of the LCE surfaces with an acidic solution, which generates cations on the surface and provides asymmetric hydrophilicity to the LCE. The resulting humidity-responsive LCE undergoes programmed and reversible hygroscopic actuation, and its shape transformation can be directed by the cut angle with respect to a nematic director or by localizing activation regions in the LCE. Most importantly, various hygroscopic LCE actuators, including (porous) bilayers, a flower, a concentric square array, and a soft gripper, are successfully fabricated by using LC inks in UV-assisted direct-ink-writing-based 3D printing.
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Affiliation(s)
- Keumbee Kim
- Department of Polymer Science and Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Yuanhang Guo
- Department of Polymer Science and Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Jaehee Bae
- Department of Polymer Science and Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Subi Choi
- Department of Polymer Science and Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Hyeong Yong Song
- Institute for Environment and Energy, Pusan National University, Busan, 46241, Republic of Korea
- School of Chemical Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Sungmin Park
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejeon, 34114, Republic of Korea
| | - Kyu Hyun
- School of Chemical Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Suk-Kyun Ahn
- Department of Polymer Science and Engineering, Pusan National University, Busan, 46241, Republic of Korea
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18
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Martinez AM, Cox LM, Killgore JP, Bongiardina NJ, Riley RD, Bowman CN. Permanent and reversibly programmable shapes in liquid crystal elastomer microparticles capable of shape switching. SOFT MATTER 2021; 17:467-474. [PMID: 33346289 DOI: 10.1039/d0sm01836h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Reversibly programmable liquid crystal elastomer microparticles (LCEMPs), formed as a covalent adaptable network (CAN), with an average diameter of 7 μm ± 2 μm, were synthesized via a thiol-Michael dispersion polymerization. The particles were programmed to a prolate shape via a photoinitiated addition-fragmentation chain-transfer (AFT) exchange reaction by activating the AFT after undergoing compression. Due to the thermotropic nature of the AFT-LCEMPs, shape switching was driven by heating the particles above their nematic-isotropic phase transition temperature (TNI). The programmed particles subsequently displayed cyclable two-way shape switching from prolate to spherical when at low or high temperatures, respectively. Furthermore, the shape programming is reversible, and a second programming step was done to erase the prolate shape by initiating AFT at high temperature while the particles were in their spherical shape. Upon cooling, the particles remained spherical until additional programming steps were taken. Particles were also programmed to maintain a permanent oblate shape. Additionally, the particle surface was programmed with a diffraction grating, demonstrating programmable complex surface topography via AFT activation.
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Affiliation(s)
- Alina M Martinez
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA.
| | - Lewis M Cox
- Department of Mechanical Engineering, Montana State University, Culbertson Hall, 100, Bozeman, MT 59717, USA
| | - Jason P Killgore
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
| | - Nicholas J Bongiardina
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA.
| | - Russell D Riley
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA
| | - Christopher N Bowman
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA. and Department of Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA
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19
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Ni B, Zhang M, Guyon C, Keller P, Tatoulian M, Li MH. Plasma-Induced Polymerizations: A New Synthetic Entry in Liquid Crystal Elastomer Actuators. Macromol Rapid Commun 2020; 41:e2000385. [PMID: 32812328 DOI: 10.1002/marc.202000385] [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] [Received: 07/17/2020] [Revised: 08/05/2020] [Indexed: 12/25/2022]
Abstract
The research on soft actuators including liquid crystal elastomers (LCEs) becomes more and more appealing at a time when the expansion of artificial systems is blooming. Among the various LCE actuators, the bending deformation is often in the origin of many actuation modes. Here, a new strategy with plasma technology is developed to prepare single-layer main-chain LCEs with thermally actuated bending and contraction deformations. Two distinct reactions, plasma polymerization and plasma-induced photopolymerization, are used to polymerize in one step the nematic monomer mixture aligned by magnetic field. The plasma polymerization forms cross-linked but disoriented structures at the surface of the LCE film, while the plasma-induced photopolymerization produces aligned LCE structure in the bulk. The actuation behaviors (bending and/or contraction) of LCE films can be adjusted by plasma power, reaction time, and sample thickness. Soft robots like crawling walker and flower mimic are built by LCE films with bending actuation.
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Affiliation(s)
- Bin Ni
- Chimie ParisTech, PSL University Paris, CNRS, Institut de Recherche de Chimie Paris, UMR8247, 11 rue Pierre et Marie Curie, Paris, 75005, France
| | - Mengxue Zhang
- Chimie ParisTech, PSL University Paris, CNRS, Institut de Recherche de Chimie Paris, UMR8247, 11 rue Pierre et Marie Curie, Paris, 75005, France
| | - Cédric Guyon
- Chimie ParisTech, PSL University Paris, CNRS, Institut de Recherche de Chimie Paris, UMR8247, 11 rue Pierre et Marie Curie, Paris, 75005, France
| | - Patrick Keller
- Institut Curie, Laboratoire Physico-Chimie Curie, UMR168, 11 rue Pierre et Marie Curie, Paris, 75005, France
| | - Michael Tatoulian
- Chimie ParisTech, PSL University Paris, CNRS, Institut de Recherche de Chimie Paris, UMR8247, 11 rue Pierre et Marie Curie, Paris, 75005, France
| | - Min-Hui Li
- Chimie ParisTech, PSL University Paris, CNRS, Institut de Recherche de Chimie Paris, UMR8247, 11 rue Pierre et Marie Curie, Paris, 75005, France
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20
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Zaquen N, Rubens M, Corrigan N, Xu J, Zetterlund PB, Boyer C, Junkers T. Polymer Synthesis in Continuous Flow Reactors. Prog Polym Sci 2020. [DOI: 10.1016/j.progpolymsci.2020.101256] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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21
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Lyu X, Xiao A, Shi D, Li Y, Shen Z, Chen EQ, Zheng S, Fan XH, Zhou QF. Liquid crystalline polymers: Discovery, development, and the future. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122740] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Liu X, Pan X, Debije MG, Heuts JPA, Mulder DJ, Schenning APHJ. Programmable liquid crystal elastomer microactuators prepared via thiol-ene dispersion polymerization. SOFT MATTER 2020; 16:4908-4911. [PMID: 32452499 DOI: 10.1039/d0sm00817f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Narrowly dispersed, 10 micron-sized, liquid crystalline elastomer polymer actuators were first prepared via thiol-ene dispersion polymerization and then embedded and stretched in a polyvinyl alcohol film, followed by photopolymerization of the residual acrylate groups. Prolate micro spheroids in which the mesogens are aligned parallel to the long axis were obtained and showed reversible thermally driven actuation owing to nematic to isotropic transition of the liquid crystal molecules. The particles were also compressed to form disk-shaped oblate microactuators in which the mesogens are aligned perpendicular to the short axis, demonstrating that the reported method is a versatile method to fabricate liquid crystal elastomer microactuators with programmable properties.
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Affiliation(s)
- Xiaohong Liu
- Stimuli-Responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven, The Netherlands.
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23
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A Review on Liquid Crystal Polymers in Free-Standing Reversible Shape Memory Materials. Molecules 2020; 25:molecules25051241. [PMID: 32164147 PMCID: PMC7179413 DOI: 10.3390/molecules25051241] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/29/2020] [Accepted: 03/03/2020] [Indexed: 01/25/2023] Open
Abstract
Liquid crystal polymers have attracted massive attention as stimuli-responsive shape memory materials due to their unique reversible large-scale and high-speed actuations. These materials can be utilized to fabricate artificial muscles, sensors, and actuators driven by thermal order–disorder phase transition or trans–cis photoisomerization. This review collects most commonly used liquid crystal monomers and techniques to macroscopically order and align liquid crystal materials (monodomain), highlighting the unique materials on the thermal and photo responsive reversible shape memory effects. Challenges and potential future applications are also discussed.
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24
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Zhao Q, Cui H, Wang Y, Du X. Microfluidic Platforms toward Rational Material Fabrication for Biomedical Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1903798. [PMID: 31650698 DOI: 10.1002/smll.201903798] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/03/2019] [Indexed: 05/16/2023]
Abstract
The emergence of micro/nanomaterials in recent decades has brought promising alternative approaches in various biomedicine-related fields such as pharmaceutics, diagnostics, and therapeutics. These micro/nanomaterials for specific biomedical applications shall possess tailored properties and functionalities that are closely correlated to their geometries, structures, and compositions, therefore placing extremely high demands for manufacturing techniques. Owing to the superior capabilities in manipulating fluids and droplets at microscale, microfluidics has offered robust and versatile platform technologies enabling rational design and fabrication of micro/nanomaterials with precisely controlled geometries, structures and compositions in high throughput manners, making them excellent candidates for a variety of biomedical applications. This review briefly summarizes the progress of microfluidics in the fabrication of various micro/nanomaterials ranging from 0D (particles), 1D (fibers) to 2D/3D (film and bulk materials) materials with controllable geometries, structures, and compositions. The applications of these microfluidic-based materials in the fields of diagnostics, drug delivery, organs-on-chips, tissue engineering, and stimuli-responsive biodevices are introduced. Finally, an outlook is discussed on the future direction of microfluidic platforms for generating materials with superior properties and on-demand functionalities. The integration of new materials and techniques with microfluidics will pave new avenues for preparing advanced micro/nanomaterials with enhanced performance for biomedical applications.
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Affiliation(s)
- Qilong Zhao
- Institute of Biomedical & Health Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen, 518035, China
| | - Huanqing Cui
- Institute of Biomedical & Health Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen, 518035, China
| | - Yunlong Wang
- Institute of Biomedical & Health Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen, 518035, China
| | - Xuemin Du
- Institute of Biomedical & Health Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen, 518035, China
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25
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Davidson EC, Kotikian A, Li S, Aizenberg J, Lewis JA. 3D Printable and Reconfigurable Liquid Crystal Elastomers with Light-Induced Shape Memory via Dynamic Bond Exchange. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1905682. [PMID: 31664754 DOI: 10.1002/adma.201905682] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/06/2019] [Indexed: 05/19/2023]
Abstract
3D printable and reconfigurable liquid crystal elastomers (LCEs) that reversibly shape-morph when cycled above and below their nematic-to-isotropic transition temperature (TNI ) are created, whose actuated shape can be locked-in via high-temperature UV exposure. By synthesizing LCE-based inks with light-triggerable dynamic bonds, printing can be harnessed to locally program their director alignment and UV light can be used to enable controlled network reconfiguration without requiring an imposed mechanical field. Using this integrated approach, 3D LCEs are constructed in both monolithic and heterogenous layouts that exhibit complex shape changes, and whose transformed shapes could be locked-in on demand.
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Affiliation(s)
- Emily C Davidson
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - Arda Kotikian
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - Shucong Li
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Joanna Aizenberg
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jennifer A Lewis
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
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26
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Belmonte A, Ussembayev YY, Bus T, Nys I, Neyts K, Schenning APHJ. Dual Light and Temperature Responsive Micrometer-Sized Structural Color Actuators. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1905219. [PMID: 31793728 DOI: 10.1002/smll.201905219] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/28/2019] [Indexed: 05/15/2023]
Abstract
Externally induced color- and shape-changes in micrometer-sized objects are of great interest in novel application fields such as optofluidics and microrobotics. In this work, light and temperature responsive micrometer-sized structural color actuators based on cholesteric liquid-crystalline (CLC) polymer particles are presented. The particles are synthesized by suspension polymerization using a reactive CLC monomer mixture having a light responsive azobenzene dye. The particles exhibit anisotropic spot-like and arc-like reflective colored domains ranging from red to blue. Electron microscopy reveals a multidirectional asymmetric arrangement of the cholesteric layers in the particles and numerical simulations elucidate the anisotropic optical properties. Upon light exposure, the particles show reversible asymmetric shape deformations combined with structural color changes. When the temperature is increased above the liquid crystal-isotropic phase transition temperature of the particles, the deformation is followed by a reduction or disappearance of the reflection. Such dual light and temperature responsive structural color actuators are interesting for a variety of micrometer-sized devices.
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Affiliation(s)
- Alberto Belmonte
- Stimuli-Responsive Functional Materials and Devices, Department of Chemical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
- SCNU-TUE Joint Laboratory of Device Integrated Responsive Materials (DIRM), South China Normal University, Guangzhou Higher Education Mega Center, 510006, Guangzhou, China
| | - Yera Ye Ussembayev
- Liquid Crystals and Photonics Group, Department of Electronics and Information Systems, Ghent University, Tech Lane Ghent Science Park - Campus A 126, 9052, Ghent, Belgium
| | - Tom Bus
- Stimuli-Responsive Functional Materials and Devices, Department of Chemical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
- SCNU-TUE Joint Laboratory of Device Integrated Responsive Materials (DIRM), South China Normal University, Guangzhou Higher Education Mega Center, 510006, Guangzhou, China
| | - Inge Nys
- Liquid Crystals and Photonics Group, Department of Electronics and Information Systems, Ghent University, Tech Lane Ghent Science Park - Campus A 126, 9052, Ghent, Belgium
| | - Kristiaan Neyts
- Liquid Crystals and Photonics Group, Department of Electronics and Information Systems, Ghent University, Tech Lane Ghent Science Park - Campus A 126, 9052, Ghent, Belgium
| | - Albertus P H J Schenning
- Stimuli-Responsive Functional Materials and Devices, Department of Chemical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
- SCNU-TUE Joint Laboratory of Device Integrated Responsive Materials (DIRM), South China Normal University, Guangzhou Higher Education Mega Center, 510006, Guangzhou, China
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Den Dolech 2, 5600 MB, Eindhoven, The Netherlands
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27
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Hu J, Kuang ZY, Tao L, Huang YF, Wang Q, Xie HL, Yin JR, Chen EQ. Programmable 3D Shape-Change Liquid Crystalline Elastomer Based on a Vertically Aligned Monodomain with Cross-link Gradient. ACS APPLIED MATERIALS & INTERFACES 2019; 11:48393-48401. [PMID: 31786930 DOI: 10.1021/acsami.9b17393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A liquid crystalline elastomer (LCE) as a kind of stimuli-responsive materials, which can be fabricated to present the three-dimensional (3D) change in shape, shows a wide range of applications. Herein, we propose a simple and robust way to prepare a 3D shape-change actuator based on gradient cross-linking of the vertically aligned monodomain of liquid crystals (LCs). First, gold nanoparticles grafted by liquid crystalline polymers (LCPs) are used to induce the homeotropic orientation of the LC monomer and cross-linkers. Then, photopolymerization under UV irradiation is carried out, which can result in the LCE film with a cross-link gradient. Different from the typical LCEs with homogenous alignment that usually show the shape change of extension/contraction, the obtained vertically aligned LCE film exhibits excellent bendability under a thermal stimulus. The nanoindentation experiment demonstrates that the deformation of LCE films comes from the difference in Young's modulus on two sides of the thin film. Simply scissoring the thin film can prepare the samples with different bending angles under the fixed length. Moreover, using a photomask to pattern the film during photopolymerization can realize the complex 3D deformation, such as bend, fold, and buckling. Further, the patterned LCE film doped with multiwalled carbon nanotubes modified by LCPs (CNT-PDB) can act as a light-fueled microwalker with fast crawl behavior.
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Affiliation(s)
- Jun Hu
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, and Key Laboratory of Advanced Functional Polymer Materials of Colleges, Universities of Hunan Province and College of Chemistry , Xiangtan University , Xiangtan , Hunan 411105 , China
| | - Ze-Yang Kuang
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, and Key Laboratory of Advanced Functional Polymer Materials of Colleges, Universities of Hunan Province and College of Chemistry , Xiangtan University , Xiangtan , Hunan 411105 , China
| | - Lei Tao
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, and Key Laboratory of Advanced Functional Polymer Materials of Colleges, Universities of Hunan Province and College of Chemistry , Xiangtan University , Xiangtan , Hunan 411105 , China
| | - Yi-Fei Huang
- College of Civil Engineering & Mechanics , Xiangtan University , Xiangtan 411105 , Hunan Province, China
| | - Qing Wang
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, and Key Laboratory of Advanced Functional Polymer Materials of Colleges, Universities of Hunan Province and College of Chemistry , Xiangtan University , Xiangtan , Hunan 411105 , China
| | - He-Lou Xie
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, and Key Laboratory of Advanced Functional Polymer Materials of Colleges, Universities of Hunan Province and College of Chemistry , Xiangtan University , Xiangtan , Hunan 411105 , China
| | - Jiu-Ren Yin
- College of Civil Engineering & Mechanics , Xiangtan University , Xiangtan 411105 , Hunan Province, China
| | - Er-Qiang Chen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
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28
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Yang Y, Terentjev EM, Zhang Y, Chen Q, Zhao Y, Wei Y, Ji Y. Reprocessable Thermoset Soft Actuators. Angew Chem Int Ed Engl 2019; 58:17474-17479. [DOI: 10.1002/anie.201911612] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Yang Yang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | | | - Yubai Zhang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Qiaomei Chen
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Yuan Zhao
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Yen Wei
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Yan Ji
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
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29
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Yang Y, Terentjev EM, Zhang Y, Chen Q, Zhao Y, Wei Y, Ji Y. Reprocessable Thermoset Soft Actuators. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201911612] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Yang Yang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | | | - Yubai Zhang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Qiaomei Chen
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Yuan Zhao
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Yen Wei
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
| | - Yan Ji
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education)Department of ChemistryTsinghua University Beijing 100084 China
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30
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Zentel R. From LC‐polymers to Nanomedicines: Different Aspects of Polymer Science from a Materials Viewpoint. MACROMOL CHEM PHYS 2019. [DOI: 10.1002/macp.201900448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rudolf Zentel
- Chemistry University of Mainz Duesbergweg 10‐14 D‐55128 Mainz Germany
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31
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Liu X, Xu Y, Heuts JPA, Debije MG, Schenning APHJ. Monodisperse Liquid Crystal Network Particles Synthesized via Precipitation Polymerization. Macromolecules 2019; 52:8339-8345. [PMID: 31736513 PMCID: PMC6854653 DOI: 10.1021/acs.macromol.9b01852] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/18/2019] [Indexed: 01/29/2023]
Abstract
![]()
The production of
liquid crystalline (LC) polymer particles with
a narrow size distribution on a large scale remains a challenge. Here,
we report the preparation of monodisperse, cross-linked liquid crystalline
particles via precipitation polymerization. This versatile and scalable
method yields polymer particles with a smectic liquid crystal order.
Although the LC monomers are randomly dissolved in solution, the oligomers
self-align and LC order is induced. For the polymerization, a smectic
LC monomer mixture consisting of cross-linkers and benzoic acid hydrogen-bonded
dimers is used. The average diameter of the particles increases at
higher polymerization temperatures and in better solvents, whereas
the monomer and initiator concentration have only minor impact on
the particle size. After deprotonating of the benzoic acid groups,
the particles show rapid absorption of a common cationic dye, methylene
blue. The methylene blue in the particles can be subsequently released
with the addition of Ca2+, while monovalent ions fail to
trigger the release. These results reveal that precipitation polymerization
is an attractive method to prepare functional LC polymer particles
of a narrow size distribution and on a large scale.
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Affiliation(s)
- Xiaohong Liu
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Yifei Xu
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Johan P A Heuts
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Michael G Debije
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Albert P H J Schenning
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
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32
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Concellón A, Zentner CA, Swager TM. Dynamic Complex Liquid Crystal Emulsions. J Am Chem Soc 2019; 141:18246-18255. [DOI: 10.1021/jacs.9b09216] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Alberto Concellón
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Cassandra A. Zentner
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Timothy M. Swager
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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33
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Fischer L, Menzel AM. Magnetostriction in magnetic gels and elastomers as a function of the internal structure and particle distribution. J Chem Phys 2019; 151:114906. [DOI: 10.1063/1.5118875] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Lukas Fischer
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Andreas M. Menzel
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
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34
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Guo Y, Lee J, Son J, Ahn SK, Carrillo JMY, Sumpter BG. Decoding Liquid Crystal Oligomer Phase Transitions: Toward Molecularly Engineered Shape Changing Materials. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01218] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Yuanhang Guo
- Department of Polymer Science and Engineering, Pusan National University, Busan 46241, Korea
| | - Jieun Lee
- Department of Polymer Science and Engineering, Pusan National University, Busan 46241, Korea
| | - Jinha Son
- Department of Polymer Science and Engineering, Pusan National University, Busan 46241, Korea
| | - Suk-kyun Ahn
- Department of Polymer Science and Engineering, Pusan National University, Busan 46241, Korea
| | - Jan-Michael Y. Carrillo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Bobby G. Sumpter
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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35
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Ditter D, Braun LB, Zentel R. Influences of Ortho‐Fluoroazobenzenes on Liquid Crystalline Phase Stability and 2D (Planar) Actuation Properties of Liquid Crystalline Elastomers. MACROMOL CHEM PHYS 2019. [DOI: 10.1002/macp.201900265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- David Ditter
- Institut für Organische Chemie Johannes Gutenberg‐Universität Mainz Duesbergweg 10–14 55128 Mainz Germany
| | - Lukas B. Braun
- Institut für Organische Chemie Johannes Gutenberg‐Universität Mainz Duesbergweg 10–14 55128 Mainz Germany
| | - Rudolf Zentel
- Institut für Organische Chemie Johannes Gutenberg‐Universität Mainz Duesbergweg 10–14 55128 Mainz Germany
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36
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Akdeniz B, Bukusoglu E. Liquid Crystal Templates Combined with Photolithography Enable Synthesis of Chiral Twisted Polymeric Microparticles. Macromol Rapid Commun 2019; 40:e1900160. [PMID: 31183928 DOI: 10.1002/marc.201900160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/28/2019] [Indexed: 12/25/2022]
Abstract
Liquid crystals (LC), when combined with photolithography, enable synthesis of microparticles with 2D and 3D shapes and internal complexities. Films of nematic LCs are prepared using mixtures of reactive (RM257) and non-reactive mesogens with controlled alignment of LCs at the confining surfaces, photo-polymerized the RM257 using a photomask, and then extracted the unreacted mesogens to yield the polymeric microparticles. The extraction results in a controlled anisotropic shrinkage amount dependent on the RM257 content and the direction dependent on LC alignment. Control over the aspect ratio, size, and thickness of the microparticles are obtained with a coefficient of variance less than 2%. In addition, non-parallel LC anchoring at the two surfaces results in a controllable right- or left-handed twisting of microparticles. These methods may find substantial use in applications including drug delivery, emulsions, separations, and sensors, besides their potential in revealing new fundamental concepts in self-assembly and colloidal interactions.
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Affiliation(s)
- Burak Akdeniz
- Chemical Engineering Department, Middle East Technical University, Dumlupınar Bulvarı No: 1, Çankaya, Ankara, 06800, Turkey
| | - Emre Bukusoglu
- Chemical Engineering Department, Middle East Technical University, Dumlupınar Bulvarı No: 1, Çankaya, Ankara, 06800, Turkey
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37
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Wang J, Le-The H, Wang Z, Li H, Jin M, van den Berg A, Zhou G, Segerink LI, Shui L, Eijkel JCT. Microfluidics Assisted Fabrication of Three-Tier Hierarchical Microparticles for Constructing Bioinspired Surfaces. ACS NANO 2019; 13:3638-3648. [PMID: 30856322 DOI: 10.1021/acsnano.9b00245] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Construction of textured bioinspired surfaces with refined structures that exhibit superior wetting properties is of great importance for many applications ranging from self-cleaning, antibiofouling, anti-icing, oil/water separation, smart membrane, and microfluidic devices. Previously, the preparation of artificial surfaces generally relies on the combination of different approaches together, which is a lack of flexibility to control over the individual architecture unit, the surface topology, as well as the complex procedure needed. In this work, we report a method for rapid fabrication of three-tier hierarchical microunits (structures consisting of multiple levels) using a facile droplet microfluidics approach. These units include the first-tier microspheres consisting of the second-tier close-packed polystyrene (PS) nanoparticles decorated with the third-tier elegant polymer nanowrinkles. These nanowrinkles on the PS nanoparticles are formed according to the interfacial instability induced by gradient photopolymerization of N-isopropylacrylamide (NIPAM) monomers. The formation process and topologies of nanowrinkles can be regulated by the photopolymerization process and the fraction of carboxylic groups on the PS nanoparticle surface. Such a hierarchical microsphere mimics individual units of bioinspired surfaces. Therefore, the surfaces from self-assembly of these fabricated two-tier and three-tier hierarchical microunits collectively exhibit "gecko" and "rose petal" wetting states, with the micro- and nanoscale structures amplifying the initial hydrophobicity but still being highly adhesive to water. This approach offers promising advantages of high-yield fabrication, precise control over the size and component of the microspheres, and integration of microfluidic droplet generation, colloidal nanoparticle self-assembly, and interfacial polymerization-induced nanowrinkles in a straightforward manner.
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Affiliation(s)
- Juan Wang
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Hai Le-The
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Zuankai Wang
- Department of Mechanical and Biomedical Engineering , City University of Hong Kong , Hong Kong 999077 , China
| | - Hao Li
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Mingliang Jin
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Albert van den Berg
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Guofu Zhou
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Loes I Segerink
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Lingling Shui
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
- School of Information and Optoelectronic Science and Engineering , South China Normal University , Guangzhou 510006 , China
| | - Jan C T Eijkel
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
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38
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Karausta A, Bukusoglu E. Liquid Crystal-Templated Synthesis of Mesoporous Membranes with Predetermined Pore Alignment. ACS APPLIED MATERIALS & INTERFACES 2018; 10:33484-33492. [PMID: 30198253 DOI: 10.1021/acsami.8b14121] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We demonstrate that polymeric films templated from liquid crystals (LCs) provide basic design principles for the synthesis of mesoporous films with predetermined pore alignment. Specifically, we used LC mixtures of reactive [4-(3-acryloyoxypropyloxy) benzoic acid 2-methyl-1,4-phenylene ester (RM257)] and nonreactive [4-cyano-4'-pentylbiphenyl (5CB)] mesogens confined in film geometries. The LC alignment was maintained by functionalization of the surfaces contacting the films during polymerization. Through photopolymerization followed by extraction of the unreacted mesogens, films of area in the order of 10 cm2 were obtained. We found that, when restricted to an area either through a mechanical or a configurational constraint, open and accessible pores were incorporated into the films. The average direction of the pores could be determined by the LC director during polymerization, and the average diameter of the pores can be tuned in the range of 10-40 nm by varying the reactive monomer concentration. The polymeric films synthesized here can potentially be used for the ultrafiltration purposes. We demonstrated successful separations of proteins and nanoparticles from aqueous media using the polymeric films. The films exhibited 2 orders of magnitude higher flux when the pores were aligned parallel to the permeate direction compared to the perpendicular direction. Overall, the outcomes of this study provide basic tools for the synthesis of porous polymeric films with predetermined pore directions that can potentially be suitable for separations, drug delivery, catalysts, and so forth.
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Affiliation(s)
- Aslı Karausta
- Chemical Engineering Department , Middle East Technical University , Ankara 06800 , Turkey
| | - Emre Bukusoglu
- Chemical Engineering Department , Middle East Technical University , Ankara 06800 , Turkey
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39
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Hessberger T, Braun LB, Serra CA, Zentel R. Microfluidic Preparation of Liquid Crystalline Elastomer Actuators. J Vis Exp 2018:57715. [PMID: 29863684 PMCID: PMC6101297 DOI: 10.3791/57715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This paper focuses on the microfluidic process (and its parameters) to prepare actuating particles from liquid crystalline elastomers. The preparation usually consists in the formation of droplets containing low molar mass liquid crystals at elevated temperatures. Subsequently, these particle precursors are oriented in the flow field of the capillary and solidified by a crosslinking polymerization, which produces the final actuating particles. The optimization of the process is necessary to obtain the actuating particles and the proper variation of the process parameters (temperature and flow rate) and allows variations of size and shape (from oblate to strongly prolate morphologies) as well as the magnitude of actuation. In addition, it is possible to vary the type of actuation from elongation to contraction depending on the director profile induced to the droplets during the flow in the capillary, which again depends on the microfluidic process and its parameters. Furthermore, particles of more complex shapes, like core-shell structures or Janus particles, can be prepared by adjusting the setup. By the variation of the chemical structure and the mode of crosslinking (solidification) of the liquid crystalline elastomer, it is also possible to prepare actuating particles triggered by heat or UV-vis irradiation.
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Affiliation(s)
| | - Lukas B Braun
- Department of Organic Chemistry, Johannes Gutenberg University
| | | | - Rudolf Zentel
- Department of Organic Chemistry, Johannes Gutenberg University;
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40
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Caggioni M, Traini D, Young PM, Spicer PT. Microfluidic production of endoskeleton droplets with controlled size and shape. POWDER TECHNOL 2018. [DOI: 10.1016/j.powtec.2018.01.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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41
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Prévôt ME, Ustunel S, Hegmann E. Liquid Crystal Elastomers-A Path to Biocompatible and Biodegradable 3D-LCE Scaffolds for Tissue Regeneration. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E377. [PMID: 29510523 PMCID: PMC5872956 DOI: 10.3390/ma11030377] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 02/21/2018] [Accepted: 02/23/2018] [Indexed: 11/25/2022]
Abstract
The development of appropriate materials that can make breakthroughs in tissue engineering has long been pursued by the scientific community. Several types of material have been long tested and re-designed for this purpose. At the same time, liquid crystals (LCs) have captivated the scientific community since their discovery in 1888 and soon after were thought to be, in combination with polymers, artificial muscles. Within the past decade liquid crystal elastomers (LCE) have been attracting increasing interest for their use as smart advanced materials for biological applications. Here, we examine how LCEs can potentially be used as dynamic substrates for culturing cells, moving away from the classical two-dimensional cell-culture nature. We also briefly discuss the integration of a few technologies for the preparation of more sophisticated LCE-composite scaffolds for more dynamic biomaterials. The anisotropic properties of LCEs can be used not only to promote cell attachment and the proliferation of cells, but also to promote cell alignment under LCE-stimulated deformation. 3D LCEs are ideal materials for new insights to simulate and study the development of tissues and the complex interplay between cells.
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Affiliation(s)
- Marianne E Prévôt
- Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
| | - Senay Ustunel
- Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
- Chemical Physics Interdisciplinary Program (CPIP), Kent State University, Kent, OH 44242, USA.
| | - Elda Hegmann
- Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
- Chemical Physics Interdisciplinary Program (CPIP), Kent State University, Kent, OH 44242, USA.
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA.
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42
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Wang H, Zetterlund PB, Boyer C, Boyd BJ, Prescott SW, Spicer PT. Soft polyhedral particles based on cubic liquid crystalline emulsion droplets. SOFT MATTER 2017; 13:8492-8501. [PMID: 29091103 DOI: 10.1039/c7sm01521f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Soft polyhedral particles based on variations of the cubic symmetry group are produced from a precursor emulsion by extracting solvent to grow facets on the droplets. The droplets transform into liquid crystals with solid-like rheology and controlled size and shape. Small-angle X-ray scattering confirms a bicontinuous cubic liquid crystalline phase forms from aqueous glycerol monoolein and is responsible for the particle faceting observed. Different polyhedra are produced by varying face growth rates through control of precursor droplet size, system temperature, and solubilization and adsorption of guest molecules. More exotic faceted shapes can be formed by the soft particles by applying asymmetric solvent removal gradients and by deforming the precursor droplets into, for example, ellipsoids before crystallization. The method is a powerful means to produce soft polyhedra, using continuous microfluidic or other approaches, or to act as templates for hard polyhedral particle synthesis.
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Affiliation(s)
- Haiqiao Wang
- Complex Fluids Group, School of Chemical Engineering, UNSW Sydney, Australia.
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Shahsavan H, Yu L, Jákli A, Zhao B. Smart biomimetic micro/nanostructures based on liquid crystal elastomers and networks. SOFT MATTER 2017; 13:8006-8022. [PMID: 29090297 DOI: 10.1039/c7sm01466j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A plethora of living organisms are equipped with smart functionalities that are usually rooted in their surface micro/nanostructures or underlying muscle tissues. Inspired by nature, extensive research efforts have been devoted to the development of novel biomimetic functional micro/nanostructured systems. Despite all the accomplishments, the emulation of biological adaptation and stimuli responsive actuation has been a longstanding challenge. The use of liquid crystal elastomers (LCEs) and networks (LCNs) for the fabrication of smart biomimetic micro/nanostructures has recently drawn extensive scientific attention and has become a growing field of research with promising prospects for emerging technologies. In this study, we review the recent progress in this field and portray the current challenges as well as the outlook of this field of research.
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Affiliation(s)
- Hamed Shahsavan
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Institute for Polymer Research, Centre for Bioengineering and Biotechnology, 200 University Avenue West Waterloo, ON N2L 3G1, Canada.
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Chen Q, Wei Y, Ji Y. Photo-responsive liquid crystalline vitrimer containing oligoanilines. CHINESE CHEM LETT 2017. [DOI: 10.1016/j.cclet.2017.09.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ambulo CP, Burroughs JJ, Boothby JM, Kim H, Shankar MR, Ware TH. Four-dimensional Printing of Liquid Crystal Elastomers. ACS APPLIED MATERIALS & INTERFACES 2017; 9:37332-37339. [PMID: 28967260 DOI: 10.1021/acsami.7b11851] [Citation(s) in RCA: 190] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Three-dimensional structures capable of reversible changes in shape, i.e., four-dimensional-printed structures, may enable new generations of soft robotics, implantable medical devices, and consumer products. Here, thermally responsive liquid crystal elastomers (LCEs) are direct-write printed into 3D structures with a controlled molecular order. Molecular order is locally programmed by controlling the print path used to build the 3D object, and this order controls the stimulus response. Each aligned LCE filament undergoes 40% reversible contraction along the print direction on heating. By printing objects with controlled geometry and stimulus response, magnified shape transformations, for example, volumetric contractions or rapid, repetitive snap-through transitions, are realized.
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Affiliation(s)
- Cedric P Ambulo
- Department of Bioengineering, The University of Texas at Dallas , Richardson, Texas 75080, United States
| | - Julia J Burroughs
- Department of Bioengineering, The University of Texas at Dallas , Richardson, Texas 75080, United States
| | - Jennifer M Boothby
- Department of Bioengineering, The University of Texas at Dallas , Richardson, Texas 75080, United States
| | - Hyun Kim
- Department of Bioengineering, The University of Texas at Dallas , Richardson, Texas 75080, United States
| | - M Ravi Shankar
- Department of Industrial Engineering, The University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Taylor H Ware
- Department of Bioengineering, The University of Texas at Dallas , Richardson, Texas 75080, United States
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Wang X, Zhou Y, Kim YK, Miller DS, Zhang R, Martinez-Gonzalez JA, Bukusoglu E, Zhang B, Brown TM, de Pablo JJ, Abbott NL. Patterned surface anchoring of nematic droplets at miscible liquid-liquid interfaces. SOFT MATTER 2017; 13:5714-5723. [PMID: 28752888 DOI: 10.1039/c7sm00975e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on the internal configurations of droplets of nematic liquid crystals (LCs; 10-50 μm-in-diameter; comprised of 4-cyano-4'-pentylbiphenyl and 4-(3-acryloyloxypropyloxy)benzoic acid 2-methyl-1,4-phenylene ester) sedimented from aqueous solutions of sodium dodecyl sulfate (SDS) onto interfaces formed with pure glycerol. We observed a family of internal LC droplet configurations and topological defects consistent with a remarkably abrupt transition from homeotropic (perpendicular) to tangential anchoring on the surface of the LC droplets in the interfacial environment. Calculations of the interdiffusion of water and glycerol at the aqueous-glycerol interface revealed the thickness of the diffuse interfacial region of the two miscible liquids to be small (0.2-0.5 μm) compared to the diameters of the LC droplets on the experimental time-scale (15-120 minutes), leading us to hypothesize that the patterned surface anchoring was induced by gradients in concentration of SDS and glycerol across the diameter of the LC droplets in the interfacial region. This hypothesis received additional support from experiments in which the time of sedimentation of the LC droplets onto the interface was systematically increased and the droplets were photo-polymerized to preserve their configurations: the configurations of the LC droplets were consistent with a time-dependent decrease in the fraction of the surface area of each droplet exhibiting homeotropic anchoring. Specifically, LC droplets with <10% surface area with tangential anchoring exhibited a bulk point defect within the LC droplet, whereas droplets with >10% surface area with tangential anchoring exhibited a boojum defect within the tangential region and a disclination loop separated the regions with tangential and homeotropic anchoring. The topological charge of these LC droplet configurations was found to be consistent with the geometrical theorems of Poincaré and Gauss and also well-described by computer simulations performed by minimization of a Landau-de Gennes free energy. Additional experimental observations (e.g., formation of "Janus-like" particles with one hemisphere exhibiting tangential anchoring and the other perpendicular anchoring) and simulations (e.g., a size-dependent set of LC droplet configurations with <10% surface area exhibiting tangential anchoring) support our general conclusion that placement of LC droplets into miscible liquid-liquid interfacial environments with compositional gradients can lead to a rich set of LC droplet configurations with symmetries and optical characteristics that are not encountered in LC droplet systems in homogeneous, bulk environments. Our results also reveal that translocation of LC droplets across liquid-liquid interfaces can define new transition pathways that connect distinct configurations of LC droplets.
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Affiliation(s)
- Xiaoguang Wang
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
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Yuan C, Roach DJ, Dunn CK, Mu Q, Kuang X, Yakacki CM, Wang TJ, Yu K, Qi HJ. 3D printed reversible shape changing soft actuators assisted by liquid crystal elastomers. SOFT MATTER 2017; 13:5558-5568. [PMID: 28721407 DOI: 10.1039/c7sm00759k] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this work, we advance printed active composites by combining 3D printing, printed electronics, and liquid crystal elastomers (LCEs) to achieve soft actuators with free-standing two-way shape changing behaviors. Incorporated LCE strips are activated by Joule heating produced by printed conductive wires, while uniaxial deformation of the LCE strip is utilized as a driving force to achieve bending in the printed composite. The bending behavior of laminated hinges is first characterized in order to obtain a precise control of actuation, which is then exploited to actuate four demonstrative designs: a morphing airplane, a miura-ori structure, a cubic box, and a soft crawler. The soft morphing airplane and miura-ori structure are designed and fabricated with multiple laminated hinges to demonstrate the synergistic actions during actuation. The cubic box is constructed to show the capability of sequential folding by implementing multiple groups of conductive wires to achieve accurately addressable heating with temporal control. Finally, the two-way transformation is utilized as a driving force for the locomotion of a soft crawler stimulated by a periodic rectangular wave current. These examples show the great potential of using the hybrid 3D printing and pick-and-place method and using LCEs to achieve controllable shape change structures for a variety of potential practical applications.
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Affiliation(s)
- Chao Yuan
- G.W.W. School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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Abstract
Droplet microfluidics generates and manipulates discrete droplets through immiscible multiphase flows inside microchannels. Due to its remarkable advantages, droplet microfluidics bears significant value in an extremely wide range of area. In this review, we provide a comprehensive and in-depth insight into droplet microfluidics, covering fundamental research from microfluidic chip fabrication and droplet generation to the applications of droplets in bio(chemical) analysis and materials generation. The purpose of this review is to convey the fundamentals of droplet microfluidics, a critical analysis on its current status and challenges, and opinions on its future development. We believe this review will promote communications among biology, chemistry, physics, and materials science.
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Affiliation(s)
- Luoran Shang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yao Cheng
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yuanjin Zhao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
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Urbanski M, Reyes CG, Noh J, Sharma A, Geng Y, Subba Rao Jampani V, Lagerwall JPF. Liquid crystals in micron-scale droplets, shells and fibers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:133003. [PMID: 28199222 DOI: 10.1088/1361-648x/aa5706] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The extraordinary responsiveness and large diversity of self-assembled structures of liquid crystals are well documented and they have been extensively used in devices like displays. For long, this application route strongly influenced academic research, which frequently focused on the performance of liquid crystals in display-like geometries, typically between flat, rigid substrates of glass or similar solids. Today a new trend is clearly visible, where liquid crystals confined within curved, often soft and flexible, interfaces are in focus. Innovation in microfluidic technology has opened for high-throughput production of liquid crystal droplets or shells with exquisite monodispersity, and modern characterization methods allow detailed analysis of complex director arrangements. The introduction of electrospinning in liquid crystal research has enabled encapsulation in optically transparent polymeric cylinders with very small radius, allowing studies of confinement effects that were not easily accessible before. It also opened the prospect of functionalizing textile fibers with liquid crystals in the core, triggering activities that target wearable devices with true textile form factor for seamless integration in clothing. Together, these developments have brought issues center stage that might previously have been considered esoteric, like the interaction of topological defects on spherical surfaces, saddle-splay curvature-induced spontaneous chiral symmetry breaking, or the non-trivial shape changes of curved liquid crystal elastomers with non-uniform director fields that undergo a phase transition to an isotropic state. The new research thrusts are motivated equally by the intriguing soft matter physics showcased by liquid crystals in these unconventional geometries, and by the many novel application opportunities that arise when we can reproducibly manufacture these systems on a commercial scale. This review attempts to summarize the current understanding of liquid crystals in spherical and cylindrical geometry, the state of the art of producing such samples, as well as the perspectives for innovative applications that have been put forward.
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Hines L, Petersen K, Lum GZ, Sitti M. Soft Actuators for Small-Scale Robotics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1603483. [PMID: 28032926 DOI: 10.1002/adma.201603483] [Citation(s) in RCA: 492] [Impact Index Per Article: 70.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/05/2016] [Indexed: 05/17/2023]
Abstract
This review comprises a detailed survey of ongoing methodologies for soft actuators, highlighting approaches suitable for nanometer- to centimeter-scale robotic applications. Soft robots present a special design challenge in that their actuation and sensing mechanisms are often highly integrated with the robot body and overall functionality. When less than a centimeter, they belong to an even more special subcategory of robots or devices, in that they often lack on-board power, sensing, computation, and control. Soft, active materials are particularly well suited for this task, with a wide range of stimulants and a number of impressive examples, demonstrating large deformations, high motion complexities, and varied multifunctionality. Recent research includes both the development of new materials and composites, as well as novel implementations leveraging the unique properties of soft materials.
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Affiliation(s)
- Lindsey Hines
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569, Stuttgart, Germany
| | | | - Guo Zhan Lum
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569, Stuttgart, Germany
| | - Metin Sitti
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569, Stuttgart, Germany
- Max Planck ETH Center for Learning Systems, Heisenbergstraße 3, 70569, Stuttgart, Germany
- Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA, 15213, USA
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