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Rešetič A. Shape programming of liquid crystal elastomers. Commun Chem 2024; 7:56. [PMID: 38485773 PMCID: PMC10940691 DOI: 10.1038/s42004-024-01141-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 03/07/2024] [Indexed: 03/18/2024] Open
Abstract
Liquid crystal elastomers (LCEs) are shape-morphing materials that demonstrate reversible actuation when exposed to external stimuli, such as light or heat. The actuation's complexity depends heavily on the instilled liquid crystal alignment, programmed into the material using various shape-programming processes. As an unavoidable part of LCE synthesis, these also introduce geometrical and output restrictions that dictate the final applicability. Considering LCE's future implementation in real-life applications, it is reasonable to explore these limiting factors. This review offers a brief overview of current shape-programming methods in relation to the challenges of employing LCEs as soft, shape-memory components in future devices.
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Affiliation(s)
- Andraž Rešetič
- Jožef Stefan Institute, Solid State Physics Department, Jamova cesta 39, 1000, Ljubljana, Slovenia.
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2
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Pinchin NP, Guo H, Meteling H, Deng Z, Priimagi A, Shahsavan H. Liquid Crystal Networks Meet Water: It's Complicated! ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2303740. [PMID: 37392137 DOI: 10.1002/adma.202303740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/21/2023] [Accepted: 06/29/2023] [Indexed: 07/03/2023]
Abstract
Soft robots are composed of compliant materials that facilitate high degrees of freedom, shape-change adaptability, and safer interaction with humans. An attractive choice of material for soft robotics is crosslinked networks of liquid crystal polymers (LCNs), as they are responsive to a wide variety of external stimuli and capable of undergoing fast, programmable, complex shape morphing, which allows for their use in a wide range of soft robotic applications. However, unlike hydrogels, another popular material in soft robotics, LCNs have limited applicability in flooded or aquatic environments. This can be attributed not only to the poor efficiency of common LCN actuation methods underwater but also to the complicated relationship between LCNs and water. In this review, the relationship between water and LCNs is elaborated and the existing body of literature is surveyed where LCNs, both hygroscopic and non-hygroscopic, are utilized in aquatic soft robotic applications. Then the challenges LCNs face in widespread adaptation to aquatic soft robotic applications are discussed and, finally, possible paths forward for their successful use in aquatic environments are envisaged.
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Affiliation(s)
- Natalie P Pinchin
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Hongshuang Guo
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Henning Meteling
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Zixuan Deng
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Arri Priimagi
- Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, Tampere, FI-33101, Finland
| | - Hamed Shahsavan
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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3
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Li ZL, Lu Q, Honiball JR, Wan SHT, Yeung KWK, Cheung KMC. Mechanical characterization and design of biomaterials for nucleus pulposus replacement and regeneration. J Biomed Mater Res A 2023; 111:1888-1902. [PMID: 37555381 DOI: 10.1002/jbm.a.37593] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/23/2023] [Indexed: 08/10/2023]
Abstract
Biomaterials for nucleus pulposus (NP) replacement and regeneration have great potential to restore normal biomechanics in degenerated intervertebral discs following nucleotomy. Mechanical characterizations are essential for assessing the efficacy of biomaterial implants for clinical applications. While traditional compression tests are crucial to quantify various modulus values, relaxation behaviors and fatigue resistance, rheological measurements should also be conducted to investigate the viscoelastic properties, injectability, and overall stability upon deformation. To recapitulate the physiological in vivo environment, the use of spinal models is necessary to evaluate the risk of implant extrusion and the restoration of biomechanics under different loading conditions. When designing devices for NP replacement, injectable materials are ideal to fully fill the nucleus cavity and prevent implant migration. In addition to achieving biocompatibility and desirable mechanical characteristics, biomaterial implants should be optimized to avoid implant extrusion or re-herniation post-operatively. This review discusses the most commonly used testing protocols for assessing mechanical properties of biomaterial implants and serves as reference material for enabling researchers to characterize NP implants through a unified approach whereby newly developed biomaterials may be compared and contrasted to existing devices.
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Affiliation(s)
- Zhuoqi Lucas Li
- Department of Orthopaedics & Traumatology, The University of Hong Kong, Hong Kong, China
| | - Qiuji Lu
- Department of Orthopaedics & Traumatology, The University of Hong Kong, Hong Kong, China
| | - John Robert Honiball
- Department of Orthopaedics & Traumatology, The University of Hong Kong, Hong Kong, China
| | - Sandra Hiu-Tung Wan
- Department of Orthopaedics & Traumatology, The University of Hong Kong, Hong Kong, China
| | - Kelvin Wai-Kwok Yeung
- Department of Orthopaedics & Traumatology, The University of Hong Kong, Hong Kong, China
- Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong Shenzhen Hospital, Shenzhen, China
| | - Kenneth Man-Chee Cheung
- Department of Orthopaedics & Traumatology, The University of Hong Kong, Hong Kong, China
- Department of Orthopaedics and Traumatology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
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4
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Kantaros A, Ganetsos T. From Static to Dynamic: Smart Materials Pioneering Additive Manufacturing in Regenerative Medicine. Int J Mol Sci 2023; 24:15748. [PMID: 37958733 PMCID: PMC10647622 DOI: 10.3390/ijms242115748] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/26/2023] [Accepted: 10/28/2023] [Indexed: 11/15/2023] Open
Abstract
The emerging field of regenerative medicine holds immense promise for addressing complex tissue and organ regeneration challenges. Central to its advancement is the evolution of additive manufacturing techniques, which have transcended static constructs to embrace dynamic, biomimetic solutions. This manuscript explores the pivotal role of smart materials in this transformative journey, where materials are endowed with dynamic responsiveness to biological cues and environmental changes. By delving into the innovative integration of smart materials, such as shape memory polymers and stimulus-responsive hydrogels, into additive manufacturing processes, this research illuminates the potential to engineer tissue constructs with unparalleled biomimicry. From dynamically adapting scaffolds that mimic the mechanical behavior of native tissues to drug delivery systems that respond to physiological cues, the convergence of smart materials and additive manufacturing heralds a new era in regenerative medicine. This manuscript presents an insightful overview of recent advancements, challenges, and future prospects, underscoring the pivotal role of smart materials as pioneers in shaping the dynamic landscape of regenerative medicine and heralding a future where tissue engineering is propelled beyond static constructs towards biomimetic, responsive, and regenerative solutions.
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Affiliation(s)
- Antreas Kantaros
- Department of Industrial Design and Production Engineering, University of West Attica, 12244 Athens, Greece
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5
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Zhang Z, Yang X, Zhao Y, Ye F, Shang L. Liquid Crystal Materials for Biomedical Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2300220. [PMID: 37235719 DOI: 10.1002/adma.202300220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 04/04/2023] [Indexed: 05/28/2023]
Abstract
Liquid crystal is a state of matter being intermediate between solid and liquid. Liquid crystal materials exhibit both orientational order and fluidity. While liquid crystals have long been highly recognized in the display industry, in recent decades, liquid crystals provide new opportunities into the cross-field of material science and biomedicine due to their biocompatibility, multifunctionality, and responsiveness. In this review, the latest achievements of liquid crystal materials applied in biomedical fields are summarized. The start is made by introducing the basic concepts of liquid crystals, and then shifting to the components of liquid crystals as well as functional materials derived therefrom. After that, the ongoing and foreseeable applications of liquid crystal materials in the biomedical field with emphasis put on several cutting-edge aspects, including drug delivery, bioimaging, tissue engineering, implantable devices, biosensing, and wearable devices are discussed. It is hoped that this review will stimulate ingenious ideas for the future generation of liquid crystal-based drug development, artificial implants, disease diagnosis, health status monitoring, and beyond.
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Affiliation(s)
- Zhuohao Zhang
- Shanghai Xuhui Central Hospital, Zhongshan-Xuhui Hospital, and the Shanghai Key Laboratory of Medical Epigenetics, the International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
| | - Xinyuan Yang
- Shanghai Xuhui Central Hospital, Zhongshan-Xuhui Hospital, and the Shanghai Key Laboratory of Medical Epigenetics, the International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
| | - Yuanjin Zhao
- Shanghai Xuhui Central Hospital, Zhongshan-Xuhui Hospital, and the Shanghai Key Laboratory of Medical Epigenetics, the International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
- Department of Rheumatology and Immunology, Nanjing Drum Tower Hospital, School of Biological Science and Medical Engineering Southeast University, Nanjing, 210096, China
| | - Fangfu Ye
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, China
| | - Luoran Shang
- Shanghai Xuhui Central Hospital, Zhongshan-Xuhui Hospital, and the Shanghai Key Laboratory of Medical Epigenetics, the International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
- Department of Rheumatology and Immunology, Nanjing Drum Tower Hospital, School of Biological Science and Medical Engineering Southeast University, Nanjing, 210096, China
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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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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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8
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Stepulane A, Ahlgren K, Rodriguez-Palomo A, Rajasekharan AK, Andersson M. Lyotropic liquid crystal elastomers for drug delivery. Colloids Surf B Biointerfaces 2023; 226:113304. [PMID: 37062225 DOI: 10.1016/j.colsurfb.2023.113304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/30/2023] [Accepted: 04/08/2023] [Indexed: 04/18/2023]
Abstract
Silicone elastomers like polydimethylsiloxane (PDMS) possess a combination of attractive material and biological properties motivating their widespread use in biomedical applications. Development of elastomers with capacity to deliver active therapeutic substances in the form of drugs is of particular interest to produce medical devices with added functionality. In this work, silicone-based lyotropic liquid crystal elastomers with drug-eluting functionality were developed using PDMS and triblock copolymer (diacrylated Pluronic F127, DA-F127). Various ternary PDMS-DA-F127-H2O compositions were explored and evaluated. Three compositions were found to have specific properties of interest and were further investigated for their nanostructure, mechanical properties, water retention capacity, and morphology. The ability of the elastomers to encapsulate and release polar and nonpolar substances was demonstrated using vancomycin and ibuprofen as model drugs. It was shown that the materials could deliver both types of drugs with a sustained release profile for up to 6 and 5 days for vancomycin and ibuprofen, respectively. This works demonstrates a lyotropic liquid crystal, silicone-based elastomer with tailorable mechanical properties, water retention capacity and ability to host and release polar and nonpolar active substances.
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Affiliation(s)
- Annija Stepulane
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg SE-412 96, Sweden; Amferia AB, Astra Zeneca BioVentureHub c/o Astra Zeneca, Pepparedsleden 1, Mölndal SE-431 83, Sweden
| | - Kajsa Ahlgren
- Department of Physics, Chalmers University of Technology, Gothenburg SE-412 96, Sweden
| | | | - Anand Kumar Rajasekharan
- Amferia AB, Astra Zeneca BioVentureHub c/o Astra Zeneca, Pepparedsleden 1, Mölndal SE-431 83, Sweden
| | - Martin Andersson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg SE-412 96, Sweden; Amferia AB, Astra Zeneca BioVentureHub c/o Astra Zeneca, Pepparedsleden 1, Mölndal SE-431 83, Sweden.
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Jiang Y, Dong X, Zhu S, Dai S, Bai H, Li Q, Li L, Yuan N, Ding J. Skin-friendly and antibacterial monodomain liquid crystal elastomer actuator. Colloids Surf B Biointerfaces 2023; 222:113110. [PMID: 36586236 DOI: 10.1016/j.colsurfb.2022.113110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/13/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022]
Abstract
Monodomain liquid crystal elastomers (mLCEs) are flexible and biocompatible smart materials that show unique behaviors of soft elasticity, anisotropy, and reversible shape changes above the nematic-isotropic transition temperature. Therefore, it has great potential for application in wearable devices and biologically. However, most of the reported mLCEs have nematic-isotropic transition temperature (TNI) higher than 60 °C; and above this TNI, the tensile strength of the mLCEs decreases by orders of magnitude. These issues have received little attention, limiting their application in humans. Herein, the TNI of mLCEs was reduced from 78.4 °C to 23.5 °C by substituting part of the rigid LC mesogens with a flexible backbone. The physical entanglement of hydrogen bonds between molecular chains alleviated the molecular chain slip caused by the long flexible backbone. The tensile strength remained constant during the phase transformation. Furthermore, dynamic disulfide bonds were used to modify the LC polymer network, imparting it with excellent antimicrobial, programmable, and self-healing properties. To realize its application in the closure of skin wounds, a porous PHG-mLCE/hydrogel patch that was breathable and waterproof was designed to increase skin adhesion (262 N/m).
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Affiliation(s)
- Yaoyao Jiang
- Jiangsu Collaborative Innovation Centre for Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, PR China
| | - Xu Dong
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225009, PR China
| | - Shijie Zhu
- Jiangsu Collaborative Innovation Centre for Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, PR China
| | - Shengping Dai
- School of Chemistry and Chemical Engineering, Jinggangshan University, Ji'an 343009, PR China
| | - Hongyu Bai
- Jiangsu Collaborative Innovation Centre for Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, PR China
| | - Qingyue Li
- Jiangsu Collaborative Innovation Centre for Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, PR China
| | - Lvzhou Li
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225009, PR China.
| | - Ningyi Yuan
- Jiangsu Collaborative Innovation Centre for Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, PR China.
| | - Jianning Ding
- Jiangsu Collaborative Innovation Centre for Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, PR China; School of Mechanical Engineering, Yangzhou University, Yangzhou 225009, PR China.
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Zhang X, Yao L, Yan H, Zhang Y, Han D, He Y, Li C, Zhang J. Optical wavelength selective actuation of dye doped liquid crystalline elastomers by quasi-daylight. SOFT MATTER 2022; 18:9181-9196. [PMID: 36437786 DOI: 10.1039/d2sm01256a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We explore obtaining different photo responses of liquid crystalline elastomer (LCE) materials through modulating the optical wavelengths in order to promote the development of precise photocontrol on LCE actuators, and thus study the effect of light-absorbing dyes with different absorption bands on the selective actuation of LCE materials. The dye-doped LCEs were prepared by incorporating special visible absorber dyes into thiol-acrylate main chain LCE (MC-LCE) matrices. The dyes showed photo actuation performance to LCEs due to the photothermal effects. But, every dye-doped LCE could be effectively actuated by light irradiation whose wavelength was inside its absorption band, but could not be effectively actuated by the light whose wavelength was beyond its absorption band. Wavelength selective actuation effects, no matter actuating deformation or actuating force, could be remarkably demonstrated by these dye-doped LCEs through filtering the same quasi-daylight source to be different wavelength bands. Our work opens up a significant way for the precise and convenient photo actuation of LCE actuators, while expanding the utilization potential of quasi-daylight, and further natural sunlight.
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Affiliation(s)
- Xinyu Zhang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, P. R. China.
| | - Liru Yao
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, P. R. China.
| | - Huixuan Yan
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, P. R. China.
| | - Yuhe Zhang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, P. R. China.
| | - Dongxu Han
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, P. R. China.
| | - Yifan He
- Institute of Regulatory Science, Beijing Technology and Business University, Beijing 100048, P. R. China
| | - Chensha Li
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, P. R. China.
| | - Jianqi Zhang
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
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11
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Guan Z, Wang L, Bae J. Advances in 4D printing of liquid crystalline elastomers: materials, techniques, and applications. MATERIALS HORIZONS 2022; 9:1825-1849. [PMID: 35504034 DOI: 10.1039/d2mh00232a] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline elastomers (LCEs) are polymer networks exhibiting anisotropic liquid crystallinity while maintaining elastomeric properties. Owing to diverse polymeric forms and self-alignment molecular behaviors, LCEs have fascinated state-of-the-art efforts in various disciplines other than the traditional low-molar-mass display market. By patterning order to structures, LCEs demonstrate reversible high-speed and large-scale actuations in response to external stimuli, allowing for close integration with 4D printing and architectures of digital devices, which is scarcely observed in homogeneous soft polymer networks. In this review, we collect recent advances in 4D printing of LCEs, with emphases on synthesis and processing methods that enable microscopic changes in the molecular orientation and hence macroscopic changes in the properties of end-use objects. Promising potentials of printed complexes include fields of soft robotics, optics, and biomedical devices. Within this scope, we elucidate the relationships among external stimuli, tailorable morphologies in mesophases of liquid crystals, and programmable topological configurations of printed parts. Lastly, perspectives and potential challenges facing 4D printing of LCEs are discussed.
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Affiliation(s)
- Zhecun Guan
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
| | - Ling Wang
- School of Materials Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
| | - Jinhye Bae
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
- Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
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12
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Abadia AV, Herbert KM, White TJ, Schwartz DK, Kaar JL. Biocatalytic 3D Actuation in Liquid Crystal Elastomers via Enzyme Patterning. ACS APPLIED MATERIALS & INTERFACES 2022; 14:26480-26488. [PMID: 35652291 DOI: 10.1021/acsami.2c05802] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Liquid crystal elastomers (LCEs) are stimuli-responsive materials that undergo large shape transformations after undergoing an order-disorder transition. While shape reconfigurations in LCEs are predominantly triggered by heat, there is a considerable interest in developing highly specific triggers that work at room temperature. Herein, we report the fabrication of biocatalytic LCEs that respond to the presence of urea by covalently immobilizing urease within chemically responsive LCE networks. The hydrogen-bonded LCEs developed in this work exhibited contractile strains of up to 36% upon exposure to a base. Notably, the generation of ammonia by immobilized urease triggered a disruption in the supramolecular network and a large reduction of liquid crystalline order in the films when the LCEs were exposed to urea. This reduction in order was macroscopically translated into a strain response that could be modulated by changing the concentration of urea or exposure time to the substrate. Local control of the mechanical response of the LCE was realized by spatially patterning the enzyme on the surface of the films. Subsequent exposure of enzymatically patterned LCE to urea-triggered 3D shape transformations into a curl, arch, or accordion-like structure, depending on the motif patterned on the film surface. Furthermore, we showed that the presence of salt was critical to prevent bridging of the network by the presence of ammonium ions, thereby enabling such macroscopic 3D shape changes. The large actuation potential of LCEs and the ability to translate the biocatalytic activity of enzymes to macroscopic 3D shape transformations could enable use in applications ranging from cell culture, medicine, or antifouling.
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Affiliation(s)
- Albert Velasco Abadia
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Katie M Herbert
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Timothy J White
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
- Material Science and Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Joel L Kaar
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
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13
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Gurboga B, Tuncgovde EB, Kemiklioglu E. Liquid Crystal‐Based Elastomers in Tissue Engineering. Biotechnol Bioeng 2022; 119:1047-1052. [DOI: 10.1002/bit.28038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/03/2021] [Accepted: 11/16/2021] [Indexed: 11/08/2022]
Affiliation(s)
- Berfin Gurboga
- Engineering Faculty Manisa Celal Bayar University Manisa Turkey
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14
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Abstract
Smart soft materials are envisioned to be the building blocks of the next generation of advanced devices and digitally augmented technologies. In this context, liquid crystals (LCs) owing to their responsive and adaptive attributes could serve as promising smart soft materials. LCs played a critical role in revolutionizing the information display industry in the 20th century. However, in the turn of the 21st century, numerous beyond-display applications of LCs have been demonstrated, which elegantly exploit their controllable stimuli-responsive and adaptive characteristics. For these applications, new LC materials have been rationally designed and developed. In this Review, we present the recent developments in light driven chiral LCs, i.e., cholesteric and blue phases, LC based smart windows that control the entrance of heat and light from outdoor to the interior of buildings and built environments depending on the weather conditions, LC elastomers for bioinspired, biological, and actuator applications, LC based biosensors for detection of proteins, nucleic acids, and viruses, LC based porous membranes for the separation of ions, molecules, and microbes, living LCs, and LCs under macro- and nanoscopic confinement. The Review concludes with a summary and perspectives on the challenges and opportunities for LCs as smart soft materials. This Review is anticipated to stimulate eclectic ideas toward the implementation of the nature's delicate phase of matter in future generations of smart and augmented devices and beyond.
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Affiliation(s)
- Hari Krishna Bisoyi
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States
| | - Quan Li
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States.,Institute of Advanced Materials, School of Chemistry and Chemical Engineering, and Jiangsu Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing 211189, China
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15
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Saed MO, Elmadih W, Terentjev A, Chronopoulos D, Williamson D, Terentjev EM. Impact damping and vibration attenuation in nematic liquid crystal elastomers. Nat Commun 2021; 12:6676. [PMID: 34795251 PMCID: PMC8602409 DOI: 10.1038/s41467-021-27012-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/22/2021] [Indexed: 11/16/2022] Open
Abstract
Nematic liquid crystal elastomers (LCE) exhibit unique mechanical properties, placing them in a category distinct from other viscoelastic systems. One of their most celebrated properties is the 'soft elasticity', leading to a wide plateau of low, nearly-constant stress upon stretching, a characteristically slow stress relaxation, enhanced surface adhesion, and other remarkable effects. The dynamic soft response of LCE to shear deformations leads to the extremely large loss behaviour with the loss factor tanδ approaching unity over a wide temperature and frequency ranges, with clear implications for damping applications. Here we investigate this effect of anomalous damping, optimising the impact and vibration geometries to reach the greatest benefits in vibration isolation and impact damping by accessing internal shear deformation modes. We compare impact energy dissipation in shaped samples and projectiles, with elastic wave transmission and resonance, finding a good correlation between the results of such diverse tests. By comparing with ordinary elastomers used for industrial damping, we demonstrate that the nematic LCE is an exceptional damping material and propose directions that should be explored for further improvements in practical damping applications.
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Affiliation(s)
- Mohand O Saed
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
- Cambridge Smart Plastics Ltd, 18 Hurrell Rd, Cambridge, CB4 3RH, UK
| | - Waiel Elmadih
- Institute for Aerospace Technology, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Andrew Terentjev
- Cambridge Smart Plastics Ltd, 18 Hurrell Rd, Cambridge, CB4 3RH, UK
| | - Dimitrios Chronopoulos
- Department of Mechanical Engineering (LMSD), KU Leuven, Ghent Technology Campus, 9000, Gent, Belgium.
| | - David Williamson
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Eugene M Terentjev
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK.
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16
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Soft elasticity optimises dissipation in 3D-printed liquid crystal elastomers. Nat Commun 2021; 12:6677. [PMID: 34795228 PMCID: PMC8602646 DOI: 10.1038/s41467-021-27013-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/28/2021] [Indexed: 11/08/2022] Open
Abstract
Soft-elasticity in monodomain liquid crystal elastomers (LCEs) is promising for impact-absorbing applications where strain energy is ideally absorbed at constant stress. Conventionally, compressive and impact studies on LCEs have not been performed given the notorious difficulty synthesizing sufficiently large monodomain devices. Here, we use direct-ink writing 3D printing to fabricate bulk (>cm3) monodomain LCE devices and study their compressive soft-elasticity over 8 decades of strain rate. At quasi-static rates, the monodomain soft-elastic LCE dissipated 45% of strain energy while comparator materials dissipated less than 20%. At strain rates up to 3000 s-1, our soft-elastic monodomain LCE consistently performed closest to an ideal-impact absorber. Drop testing reveals soft-elasticity as a likely mechanism for effectively reducing the severity of impacts - with soft elastic LCEs offering a Gadd Severity Index 40% lower than a comparable isotropic elastomer. Lastly, we demonstrate tailoring deformation and buckling behavior in monodomain LCEs via the printed director orientation.
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17
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Bolshakov P, Kharin N, Kashapov R, Sachenkov O. Structural Design Method for Constructions: Simulation, Manufacturing and Experiment. MATERIALS 2021; 14:ma14206064. [PMID: 34683671 PMCID: PMC8540678 DOI: 10.3390/ma14206064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/05/2021] [Accepted: 10/12/2021] [Indexed: 11/16/2022]
Abstract
The development of additive manufacturing technology leads to new concepts for design implants and prostheses. The necessity of such approaches is fueled by patient-oriented medicine. Such a concept involves a new way of understanding material and includes complex structural geometry, lattice constructions, and metamaterials. This leads to new design concepts. In the article, the structural design method is presented. The general approach is based on the separation of the micro- and macro-mechanical parameters. For this purpose, the investigated region as a complex of the basic cells was considered. Each basic cell can be described by a parameters vector. An initializing vector was introduced to control the changes in the parameters vector. Changing the parameters vector according to the stress-strain state and the initializing vector leads to changes in the basic cells and consequently to changes in the microarchitecture. A medium with a spheroidal pore was considered as a basic cell. Porosity and ellipticity were used for the parameters vector. The initializing vector was initialized and depended on maximum von Mises stress. A sample was designed according to the proposed method. Then, solid and structurally designed samples were produced by additive manufacturing technology. The samples were scanned by computer tomography and then tested by structural loads. The results and analyses were presented.
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Affiliation(s)
- Pavel Bolshakov
- Department Machines Science and Engineering Graphics, Tupolev Kazan National Research Technical University, 420111 Kazan, Russia;
| | - Nikita Kharin
- Institute of Mathematics and Mechanics, Kazan Federal University, 420008 Kazan, Russia;
- Institute of Engineering, Kazan Federal University, 420008 Kazan, Russia;
| | - Ramil Kashapov
- Institute of Engineering, Kazan Federal University, 420008 Kazan, Russia;
| | - Oskar Sachenkov
- Department Machines Science and Engineering Graphics, Tupolev Kazan National Research Technical University, 420111 Kazan, Russia;
- Institute of Mathematics and Mechanics, Kazan Federal University, 420008 Kazan, Russia;
- Correspondence:
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18
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Zhu M, Tan J, Liu L, Tian J, Li L, Luo B, Zhou C, Lu L. Construction of biomimetic artificial intervertebral disc scaffold via 3D printing and electrospinning. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 128:112310. [PMID: 34474861 DOI: 10.1016/j.msec.2021.112310] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 12/16/2022]
Abstract
Intervertebral disc (IVD) degeneration is a clinically disease that seriously endangers people's health. Tissue engineering provides a promising method to repair and regenerate the damaged IVD physiological function. Successfully tissue-engineered IVD scaffold should mimic the native IVD histological and macro structures. Here, 3D printing and electrospinning were combined to construct an artificial IVD composite scaffold. Poly lactide (PLA) was used to print the IVD frame structure, the oriented porous poly(l-lactide)/octa-armed polyhedral oligomeric silsesquioxanes (PLLA/POSS-(PLLA)8) fiber bundles simulated the annulus fibrosus (AF), and the gellan gum/poly (ethylene glycol) diacrylate (GG/PEGDA) double network hydrogel loaded with bone marrow mesenchymal stem cells (BMSCs) simulated the nucleus pulposus (NP) structure. Morphological and mechanical tests showed that the structure and mechanical properties of the IVD scaffold were similar to that of the natural IVD. The compression modulus of the scaffold is about 10 MPa, which is comparable to natural IVD and provides good mechanical support for tissue repair and regeneration. At the same time, the porosity and mechanical properties of the scaffold can be regulated through the 3D model design. In the AF structure, the fiber bundles are oriented concentrically with each subsequent layer oriented 60° to the spinal column, and can withstand the tension generated during the deformation of the NP. In the NP structure, BMSCs were evenly distributed in the hydrogel and could maintain high cell viability. Animal experiment results demonstrated that the biomimetic artificial IVD scaffold could maintain the disc space and produce the new extracellular matrix. This engineered biomimetic IVD scaffold is a promising biomaterial for individualized IVD repair and regeneration.
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Affiliation(s)
- Meiling Zhu
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China
| | - Jianwang Tan
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China
| | - Lu Liu
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China
| | - Jinhuan Tian
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China
| | - Lihua Li
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China
| | - Binghong Luo
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China
| | - Changren Zhou
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China
| | - Lu Lu
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510632, China.
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19
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Kiyani S, Taheri-Behrooz F, Asadi A. Analytical and finite element analysis of shape memory polymer for use in lumbar total disc replacement. J Mech Behav Biomed Mater 2021; 122:104689. [PMID: 34298452 DOI: 10.1016/j.jmbbm.2021.104689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/27/2021] [Accepted: 07/02/2021] [Indexed: 11/30/2022]
Abstract
One-piece bearing is the latest type of total disc replacement (TDR) design that is used for the treatment of lumbar degenerative disc disease (DDD). Due to the unique properties of the shape memory polymers (SMPs), such as self-healing, shape-memory, adhesion control, and self-deployable ability, they may be a good candidate for the core of such a design. The purpose of the present study is to use an analytical method combined with a numerical analysis (finite element analysis (FEA)) to determine the mechanical responses of an SMP intervertebral disc (IVD) model, under pure torsion (axial rotation) and pure compression, two loading conditions to which natural intervertebral discs (IVDs) are subjected in vivo. We considered the SMP IVD model to be positioned at L4-L5 because most cases of lumbar DDD are reported at this segment. For the analytical method, an appropriate constitutive equation for an SMP was determined and, then, an analytical solution for the torsional response of a circular SMP IVD model, in a full cycle of stress-free strain recovery, was derived. The developed equations were implemented in finite element modeling to determine responses of the IVD disc model under pure torsion. Additionally, responses of the SMC IVD model, under a compressive load, and different conditions were determined. The analytical and FEA results were compared to experimental results give in the literature for intact lumbar spine segments as the core in a one-piece lumbar TDR. Based on this study, we suggest that SMPs can be used for TDR, as they are strong enough to bear the torsional and compressive loads that IVD is subjected through its life.
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Affiliation(s)
- Saeed Kiyani
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
| | | | - Amir Asadi
- Manufacturing and Mechanical Engineering Technology, Department of Engineering Technology and Industrial Distribution, Texas A&M University, College Station, TX, 77843, United States; Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, United States
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20
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Architecture-Promoted Biomechanical Performance-Tuning of Tissue-Engineered Constructs for Biological Intervertebral Disc Replacement. MATERIALS 2021; 14:ma14102692. [PMID: 34065565 PMCID: PMC8160686 DOI: 10.3390/ma14102692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/26/2022]
Abstract
Background: Biological approaches to intervertebral disc (IVD) restoration and/or regeneration have become of increasing interest. However, the IVD comprises a viscoelastic system whose biological replacement remains challenging. The present study sought to design load-sharing two-component model systems of circular, nested, concentric elements reflecting the nucleus pulposus and annulus fibrosus. Specifically, we wanted to investigate the effect of architectural design variations on (1) model system failure loads when testing the individual materials either separately or homogeneously mixed, and (2) also evaluate the potential of modulating other mechanical properties of the model systems. Methods: Two sets of softer and harder biomaterials, 0.5% and 5% agarose vs. 0.5% agarose and gelatin, were used for fabrication. Architectural design variations were realized by varying ring geometries and amounts while keeping the material composition across designs comparable. Results: Variations in the architectural design, such as lamellar width, number, and order, combined with choosing specific biomaterial properties, strongly influenced the biomechanical performance of IVD constructs. Biomechanical characterization revealed that the single most important parameter, in which the model systems vastly exceeded those of the individual materials, was failure load. The model system failure loads were 32.21- and 84.11-fold higher than those of the agarose materials and 55.03- and 2.14-fold higher than those of the agarose and gelatin materials used for system fabrication. The compressive strength, dynamic stiffness, and viscoelasticity of the model systems were always in the range of the individual materials. Conclusions: Relevant architecture-promoted biomechanical performance-tuning of tissue-engineered constructs for biological IVD replacement can be realized by slight modifications in the design of constructs while preserving the materials’ compositions. Minimal variations in the architectural design can be used to precisely control structure–function relations for IVD constructs rather than choosing different materials. These fundamental findings have important implications for efficient tissue-engineering of IVDs and other load-bearing tissues, as potential implants need to withstand high in situ loads.
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21
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Liquid Crystal Elastomers for Biological Applications. NANOMATERIALS 2021; 11:nano11030813. [PMID: 33810173 PMCID: PMC8005174 DOI: 10.3390/nano11030813] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 11/16/2022]
Abstract
The term liquid crystal elastomer (LCE) describes a class of materials that combine the elastic entropy behaviour associated with conventional elastomers with the stimuli responsive properties of anisotropic liquid crystals. LCEs consequently exhibit attributes of both elastomers and liquid crystals, but additionally have unique properties not found in either. Recent developments in LCE synthesis, as well as the understanding of the behaviour of liquid crystal elastomers—namely their mechanical, optical and responsive properties—is of significant relevance to biology and biomedicine. LCEs are abundant in nature, highlighting the potential use of LCEs in biomimetics. Their exceptional tensile properties and biocompatibility have led to research exploring their applications in artificial tissue, biological sensors and cell scaffolds by exploiting their actuation and shock absorption properties. There has also been significant recent interest in using LCEs as a model for morphogenesis. This review provides an overview of some aspects of LCEs which are of relevance in different branches of biology and biomedicine, as well as discussing how recent LCE advances could impact future applications.
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22
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Young CM, Chang CL, Chen YH, Chen CY, Chang YF, Chen HL. Dendrimer-mediated columnar mesophase of surfactants. SOFT MATTER 2021; 17:397-409. [PMID: 33174582 DOI: 10.1039/d0sm01506g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The columnar mesophase, in which the molecular or supramolecular building blocks with rod-like geometry pack into two-dimensional (2D) lattices, is an important class of mesomorphic structure having been found in various liquid crystalline materials for practical applications. The cylindrical micelles assembled by amphiphilic surfactants may also form columnar mesophases with the micelle packing symmetry being tunable by the molecular characteristics of the surfactants. In this study, we demonstrate that a positively charged tree-like polymer, poly(amidoamine) (PAMAM) G4 dendrimer, acted as an effective structure-directing agent for the columnar mesophase of a common anionic surfactant, sodium dodecyl sulfate (SDS), via their electrostatic interaction. By adjusting the dendrimer charge density and the nominal binding ratio (Xn) of SDS to dendrimer, the electrostatic complexes self-assembled to form a body-centered cubic (BCC) sphere phase, wherein the dendrimers were staggered between the interspaces of the SDS spherical micelles packed in the BCC lattice. Four types of 2D columnar mesophase composed of SDS cylindrical micelles and dendrimers were accommodated within the interstitial tunnels, including the hexagonal columnar phase (Colhex), simple rectangular columnar phase (Colsr), oblique columnar phase (Colob) and centered rectangular columnar phase (Colcr). A detailed analysis of the geometry of the dendrimer in the columnar mesophases revealed that the structural transition was governed by the interplay among the lateral and axial deformations of the dendrimer, and the deformation of the SDS micelle cross section for achieving effective charge matching and accommodation of the dendrimer. The present study demonstrated the power of the dendrimer in directing the long-range ordered packing of oppositely charged cylinders to yield a rich structural polymorphism of the columnar mesophase that may be exploited for the development of functional materials.
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Affiliation(s)
- Chih-Mei Young
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Chia Lun Chang
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Yu-Hsiang Chen
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan. and Material and Chemical Research Laboratories, Industrial Technology Research Institute, Chutung, Hsinchu 31057, Taiwan
| | - Chun-Yu Chen
- Experimental Facility Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yu-Fan Chang
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Hsin-Lung Chen
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
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23
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De Martino S, Netti PA. Dynamic azopolymeric interfaces for photoactive cell instruction. BIOPHYSICS REVIEWS 2020; 1:011302. [PMID: 38505629 PMCID: PMC10903377 DOI: 10.1063/5.0025175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/26/2020] [Indexed: 03/21/2024]
Abstract
The ability to affect a wide range of biophysical properties through the use of light has led to the development of dynamic cell instructive materials. Using photoresponsive materials such as azopolymers, smart systems that use external, minimally damaging, light irradiation can be used to trigger specific surface morpho-physical properties in the presence of living cells. The interaction of light with an azopolymer film induces a mass migration phenomenon, allowing a variety of topographic patterns to be embossed on the polymeric film. Photoisomerization induces conformational changes at the molecular and macroscopic scale, resulting in light-induced variations of substrate morphological, physical, and mechanical properties. In this review, we discuss the photoactuation of azopolymeric interfaces to provide guidelines for the engineering and design of azopolymer films. Laser micropatterning for the modulation of azopolymer surfaces is examined as a way to diversify the capabilities of these polymers in cellular systems. Mass migration effects induced by azopolymer switching provides a foundation for performing a broad range of cellular manipulation techniques. Applications of azopolymers are explored in the context of dynamic culture systems, gaining insight into the complex processes involved in dynamic cell-material interactions. The review highlights azopolymers as a candidate for various applications in cellular control, including cell alignment, migration, gene expression, and others. Recent advances have underlined the importance of these systems in applications regarding three-dimensional cell culture and stem cell morphology. Azopolymers can be used not only to manipulate cells but also to probe for mechanistic studies of cellular crosstalk in response to chemical and mechanical stimuli.
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24
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Shaha RK, Torbati AH, Frick CP. Body‐temperature
s
hape‐shifting
liquid crystal elastomers. J Appl Polym Sci 2020. [DOI: 10.1002/app.50136] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Rajib K. Shaha
- Department of Mechanical Engineering University of Wyoming Laramie WY USA
| | - Amir H. Torbati
- Department of Mechanical Engineering University of Colorado Denver Aurora CO USA
| | - Carl P. Frick
- Department of Mechanical Engineering University of Wyoming Laramie WY USA
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25
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Ambulo CP, Tasmim S, Wang S, Abdelrahman MK, Zimmern PE, Ware TH. Processing advances in liquid crystal elastomers provide a path to biomedical applications. JOURNAL OF APPLIED PHYSICS 2020; 128:140901. [PMID: 33060862 PMCID: PMC7546753 DOI: 10.1063/5.0021143] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/24/2020] [Indexed: 05/08/2023]
Abstract
Liquid crystal elastomers (LCEs) are a class of stimuli-responsive polymers that undergo reversible shape-change in response to environmental changes. The shape change of LCEs can be programmed during processing by orienting the liquid crystal phase prior to crosslinking. The suite of processing techniques that has been developed has resulted in a myriad of LCEs with different shape-changing behavior and mechanical properties. Aligning LCEs via mechanical straining yields large uniaxial actuators capable of a moderate force output. Magnetic fields are utilized to control the alignment within LCE microstructures. The generation of out-of-plane deformations such as bending, twisting, and coning is enabled by surface alignment techniques within thin films. 4D printing processes have emerged that enable the fabrication of centimeter-scale, 3D LCE structures with a complex alignment. The processing technique also determines, to a large extent, the potential applications of the LCE. For example, 4D printing enables the fabrication of LCE actuators capable of replicating the forces generated by human muscles. Employing surface alignment techniques, LCE films can be designed for use as coatings or as substrates for stretchable electronics. The growth of new processes and strategies opens and strengthens the path for LCEs to be applicable within biomedical device designs.
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Affiliation(s)
- Cedric P Ambulo
- Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas 75080, USA
| | | | | | | | - Philippe E Zimmern
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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26
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Traugutt NA, Mistry D, Luo C, Yu K, Ge Q, Yakacki CM. Liquid-Crystal-Elastomer-Based Dissipative Structures by Digital Light Processing 3D Printing. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2000797. [PMID: 32508011 DOI: 10.1002/adma.202000797] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/20/2020] [Indexed: 05/24/2023]
Abstract
Digital Light Processing (DLP) 3D printing enables the creation of hierarchical complex structures with specific micro- and macroscopic architectures that are impossible to achieve through traditional manufacturing methods. Here, this hierarchy is extended to the mesoscopic length scale for optimized devices that dissipate mechanical energy. A photocurable, thus DLP-printable main-chain liquid crystal elastomer (LCE) resin is reported and used to print a variety of complex, high-resolution energy-dissipative devices. Using compressive mechanical testing, the stress-strain responses of 3D-printed LCE lattice structures are shown to have 12 times greater rate-dependence and up to 27 times greater strain-energy dissipation compared to those printed from a commercially available photocurable elastomer resin. The reported behaviors of these structures provide further insight into the much-overlooked energy-dissipation properties of LCEs and can inspire the development of high-energy-absorbing device applications.
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Affiliation(s)
- Nicholas A Traugutt
- University of Colorado Denver, 1200 Larimer Street, Campus Box 112, Denver, CO, 80217, USA
| | - Devesh Mistry
- University of Colorado Denver, 1200 Larimer Street, Campus Box 112, Denver, CO, 80217, USA
| | - Chaoqian Luo
- University of Colorado Denver, 1200 Larimer Street, Campus Box 112, Denver, CO, 80217, USA
| | - Kai Yu
- University of Colorado Denver, 1200 Larimer Street, Campus Box 112, Denver, CO, 80217, USA
| | - Qi Ge
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen, 518055, P. R. China
| | - Christopher M Yakacki
- University of Colorado Denver, 1200 Larimer Street, Campus Box 112, Denver, CO, 80217, USA
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