1
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van Hazendonk L, Khalil ZJ, van Grondelle W, Wijkhuijs LEA, Schreur-Piet I, Debije MG, Friedrich H. Hot Fingers: Individually Addressable Graphene-Heater Actuated Liquid Crystal Grippers. ACS APPLIED MATERIALS & INTERFACES 2024; 16:32739-32747. [PMID: 38869014 PMCID: PMC11212024 DOI: 10.1021/acsami.4c06130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/23/2024] [Accepted: 06/03/2024] [Indexed: 06/14/2024]
Abstract
Liquid crystal-based actuators are receiving increased attention for their applications in wearables and biomedical or surgical devices, with selective actuation of individual parts/fingers still being in its infancy. This work presents the design and realization of two gripper devices with four individually addressable liquid-crystal network (LCN) actuators thermally driven via printed graphene-based heating elements. The resistive heat causes the all-organic actuator to bend due to anisotropic volume expansions of the splay-aligned sample. A heat transfer model that includes all relevant interfaces is presented and verified via thermal imaging, which provides good estimates of dimensions, power production, and resistance required to reach the desired temperature for actuation while maintaining safe electrical potentials. The LCN films displace up to 11 mm with a bending force of 1.10 mN upon application of 0-15 V potentials. The robustness of the LCN finger is confirmed by repetitive on/off switching for 500 cycles. Actuators are assembled into two prototypes able to grip and lift objects of small weights (70-100 mg) and perform complex actions by individually controlling one of the device's fingers to grip an additional object. Selective actuation of parts in soft robotic devices will enable more complex motions and actions to be performed.
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Affiliation(s)
- Laura
S. van Hazendonk
- Laboratory
of Physical Chemistry, Department of Chemical
Engineering and Chemistry Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
| | - Zafeiris J. Khalil
- Laboratory
of Physical Chemistry, Department of Chemical
Engineering and Chemistry Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
| | - Wilko van Grondelle
- Laboratory
of Physical Chemistry, Department of Chemical
Engineering and Chemistry Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
| | - Levina E. A. Wijkhuijs
- Laboratory
of Physical Chemistry, Department of Chemical
Engineering and Chemistry Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
| | - Ingeborg Schreur-Piet
- Laboratory
of Physical Chemistry, Department of Chemical
Engineering and Chemistry Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
- Center
for Multiscale Electron Microscopy, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
| | - Michael G. Debije
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
- Stimuli-responsive
Functional Materials and Devices (SFD), Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
| | - Heiner Friedrich
- Laboratory
of Physical Chemistry, Department of Chemical
Engineering and Chemistry Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
- Center
for Multiscale Electron Microscopy, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. box 513, Eindhoven 5600 MB, The Netherlands
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2
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Tholen HM, Ambulo CP, Lee KM, Buskohl PR, Harne RL. Optomechanical computing in liquid crystal elastomers. SOFT MATTER 2023; 19:6978-6986. [PMID: 37665593 DOI: 10.1039/d3sm00819c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Embodied decision-making in soft, engineered matter has sparked recent interest towards the development of intelligent materials. Such decision-making capabilities can be realized in soft materials via digital information processing with combinational logic operations. Although previous research has explored soft material actuators and embedded logic in soft materials, achieving a high degree of autonomy in these material systems remains a challenge. Light is an ideal stimulus to trigger information processing in soft materials due to its low thermal effect and remote use. Thus, one approach for developing soft, autonomous materials is to integrate optomechanical computing capabilities in photoresponsive materials. Here, we establish a methodology to embed combinational logic circuitry in a photoresponsive liquid crystal elastomer (LCE) film. These LCEs are designed with embedded switches and integrated circuitry using liquid metal-based conductive traces. The resulting optomechanical computing LCEs can effectively process optical information via light, thermal, and mechanical energy conversion. The methods introduced in this work to fabricate a material capable of optical information processing can facilitate the implementation of a sense of sight in soft robotic systems and other compliant devices.
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Affiliation(s)
- Haley M Tholen
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, USA.
| | - Cedric P Ambulo
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH, USA
- Azimuth Corporation, Fairborn, OH, USA
| | - Kyung Min Lee
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH, USA
- Azimuth Corporation, Fairborn, OH, USA
| | - Philip R Buskohl
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH, USA
| | - Ryan L Harne
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, USA.
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3
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Liao W, Yang Z. 3D printing programmable liquid crystal elastomer soft pneumatic actuators. MATERIALS HORIZONS 2023; 10:576-584. [PMID: 36468657 DOI: 10.1039/d2mh01001a] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Soft pneumatic actuators (SPAs) rely on anisotropic mechanical properties to generate specific motions after inflation. To achieve mechanical anisotropy, additional stiff materials or heterogeneous structures are typically introduced in isotropic base materials. However, the inherent limitations of these strategies may lead to potential interfacial problems or inefficient material usage. Herein, we develop a new strategy for fabricating SPAs based on an aligned liquid crystal elastomer (LCE) by a modified 3D printing technology. A rotating substrate enables the one-step fabrication of tubular LCE-SPAs with designed alignments in three dimensions. The alignment can be precisely programmed through printing, resulting in intrinsic mechanical anisotropy of the LCE. With a specially designed alignment, LCE-SPAs can achieve basic motions-contraction, elongation, bending, and twisting-and accomplish diverse tasks, e.g., grabbing objects and mixing water. This study provides a new perspective for the design and fabrication of SPAs.
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Affiliation(s)
- Wei Liao
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, China.
| | - Zhongqiang Yang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, China.
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, China
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4
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Wang DH, Lee KM, Lee DH, Baczkowski M, Park H, McConney ME, Tan LS. Role of Alicyclic Conformation-Isomerization in the Photomechanical Performance of Azobenzene-Functionalized Cross-Linked Polyimides Containing Tetra-Substituted Cyclohexane Moieties. ACS Macro Lett 2021; 10:278-283. [PMID: 35570785 DOI: 10.1021/acsmacrolett.0c00903] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The classical "chair-twist boat-boat" conformational dynamics (CD) of cyclohexane is thermally activated. Here we report on the photoinduced/azobenzene-assisted CD of bilaterally fused cyclohexane moieties contributing to large photomechanical response of cross-linked azobenzene-functionalized polyimides (X-azoPI), based on 1,2,4,5-cyclohexane-tetracarboxylic-dianhydride (CHDA), exhibiting a photobending angle and photogenerated stress, up to ∼90° and 370 kPa, respectively. In contrast, X-azoPI containing planar pyromellitimide (PMDI) or cage-like bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic-diimide (BCDI) show smaller photomechanical responses. The superior photomechanical performance of X-azoPI with constrained cyclohexane-diimide (CHDI) units is attributed to an increased mobility of segments comprising "hinged" p-phenylene rings, azobenzene, and CHDI units in the cross-link sites. Blue light irradiation initiates the motions driven by photoisomerization/reorientation of azobenzenes connected to CHDI units, whose CD is then amplified, leading to longer-range segmental mobility, more local free volume, and culminating in large photoinduced bending. The trapping of redistributed CHDI's stereoisomers in X-azoPI backbone at Troom is implicated for the observed photothermal memory.
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Affiliation(s)
- David H. Wang
- Air Force Research Laboratory, Functional Materials Division (AFRL/RXA), Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| | - Kyung Min Lee
- Air Force Research Laboratory, Functional Materials Division (AFRL/RXA), Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| | - Deborah H. Lee
- Air Force Research Laboratory, Functional Materials Division (AFRL/RXA), Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| | - Matthew Baczkowski
- Air Force Research Laboratory, Functional Materials Division (AFRL/RXA), Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| | - Hajin Park
- Air Force Research Laboratory, Functional Materials Division (AFRL/RXA), Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| | - Michael E. McConney
- Air Force Research Laboratory, Functional Materials Division (AFRL/RXA), Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| | - Loon-Seng Tan
- Air Force Research Laboratory, Functional Materials Division (AFRL/RXA), Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
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5
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Lutz-Bueno V, Bolisetty S, Azzari P, Handschin S, Mezzenga R. Self-Winding Gelatin-Amyloid Wires for Soft Actuators and Sensors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2004941. [PMID: 33103302 DOI: 10.1002/adma.202004941] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/21/2020] [Indexed: 05/20/2023]
Abstract
The origin of self-winding mechanisms in plants' tendrils has fascinated scientists for centuries and continues to inspire developments in material science and nanotechnology. Here, bioinspired water-responsive wires that replicate these mechanisms, including the formation of coils and chiral perversions, are presented. A right-handed gelatin matrix is loaded with rigid left-handed amyloid fibrils and roll-dry-spun into wires in which self-winding activation emerges from simultaneous bending and twisting deformations. Wire bending is a consequence of amyloid fibrils' concentration and distribution within the wire, whereas twisting is controlled by amyloid fibrils' orientation. The resultant wires can be functionalized by organic molecules and inorganic nanoparticles, and potential applications in magnetic actuators and sensors are demonstrated. The simple fabrication method and the remarkable spontaneous self-winding response of these gelatin-amyloid wires exemplify how biomaterials based on mixed proteins have striking potential to develop advanced and tunable properties that can serve robotics, soft machines, and engineering systems.
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Affiliation(s)
- Viviane Lutz-Bueno
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Sreenath Bolisetty
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Paride Azzari
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Stephan Handschin
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Raffaele Mezzenga
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
- Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
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6
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Verpaalen RC, Engels T, Schenning APHJ, Debije MG. Stimuli-Responsive Shape Changing Commodity Polymer Composites and Bilayers. ACS APPLIED MATERIALS & INTERFACES 2020; 12:38829-38844. [PMID: 32805900 PMCID: PMC7472435 DOI: 10.1021/acsami.0c10802] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Commodity polymers are produced in large volumes, providing robust mechanical properties at relatively low costs. The products made from these commodity polymers typically offer only static functionalities. Over the past decade, however, in the scientific literature, stimuli-responsive additives and/or polymer coatings have been introduced to commodity polymers, yielding composites and bilayers that change shape in response to light, temperature, and/or humidity. These stimuli responsive commodity polymers allow the marketing and sales of these otherwise bulk products as "high-end" smart materials for applications spanning from soft actuators to adaptive textiles. This Spotlight on Applications presents an overview of recent intriguing works on how shape changing commodity polymer composite and bilayer actuators based on polyamide 6, poly(ethylene terephthalate), polyethylene, and polypropylene have been fabricated that respond to environmental stimuli and discusses their potential applications.
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Affiliation(s)
- Rob C.
P. Verpaalen
- Laboratory
of 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
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Tom Engels
- DSM
Material Science Center, Urmonderbaan 22, 6167 RD Geleen, The Netherlands
- Department
of Mechanical Engineering, Materials Technology Institute, Polymer
Technology Group, Eindhoven University of
Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Albert P. H. J. Schenning
- Laboratory
of 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
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB, Eindhoven, The Netherlands
| | - Michael G. Debije
- Laboratory
of 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
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
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7
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Verpaalen RCP, Souren AEJ, Debije MG, Engels TAP, Bastiaansen CWM, Schenning APHJ. Unravelling humidity-gated, temperature responsive bilayer actuators. SOFT MATTER 2020; 16:2753-2759. [PMID: 32083272 DOI: 10.1039/d0sm00030b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
By spraying liquid crystal mixtures onto stretched polyamide 6 (PA6) substrates, dual-responsive heat/humidity bilayer actuators are generated. The oriented PA6 guides the self-organization of the liquid crystal monomers into well-aligned, anisotropic liquid crystal networks. The bilayer responds to changes in the environmental relative humidity, resulting in bending of the actuator with the liquid crystal network inside the curvature. In contrast, in conditions of constant high humidity (80%RH), increasing the temperature triggers the liquid crystal network coating to bend the bilayer in the opposing direction. The dual-responsivity to changes in environmental humidity and temperature is examined in detail and discussed theoretically to elucidate the humidity-gated, temperature responsive properties revealing guidelines for fabricating anisotropic bilayer actuators.
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Affiliation(s)
- Rob C P Verpaalen
- Laboratory of 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. and Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Anne E J Souren
- Laboratory of 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.
| | - Michael G Debije
- Laboratory of 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.
| | - Tom A P Engels
- Department of Mechanical Engineering, Materials Technology Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands and Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Cees W M Bastiaansen
- Laboratory of 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. and Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands and School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Albertus P H J Schenning
- Laboratory of 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. and Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
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8
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Waters JT, Li S, Yao Y, Lerch MM, Aizenberg M, Aizenberg J, Balazs AC. Twist again: Dynamically and reversibly controllable chirality in liquid crystalline elastomer microposts. SCIENCE ADVANCES 2020; 6:eaay5349. [PMID: 32258400 PMCID: PMC7101207 DOI: 10.1126/sciadv.aay5349] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 01/02/2020] [Indexed: 05/23/2023]
Abstract
Photoresponsive liquid crystalline elastomers (LCEs) constitute ideal actuators for soft robots because their light-induced macroscopic shape changes can be harnessed to perform specific articulated motions. Conventional LCEs, however, do not typically exhibit complex modes of bending and twisting necessary to perform sophisticated maneuvers. Here, we model LCE microposts encompassing side-chain mesogens oriented along a magnetically programmed nematic director, and azobenzene cross-linkers, which determine the deformations of illuminated posts. On altering the nematic director orientation from vertical to horizontal, the post's bending respectively changes from light-seeking to light-avoiding. Moreover, both modeling and subsequent experiments show that with the director tilted at 45°, the initially achiral post reversibly twists into a right- or left-handed chiral structure, controlled by the angle of incident light. We exploit this photoinduced chirality to design "chimera" posts (encompassing two regions with distinct director orientations) that exhibit simultaneous bending and twisting, mimicking motions exhibited by the human musculoskeletal system.
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Affiliation(s)
- James T. Waters
- Chemical Engineering Department, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Shucong Li
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Yuxing Yao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Michael M. Lerch
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Michael Aizenberg
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
| | - Joanna Aizenberg
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Anna C. Balazs
- Chemical Engineering Department, University of Pittsburgh, Pittsburgh, PA 15261, USA
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9
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Barnes M, Verduzco R. Direct shape programming of liquid crystal elastomers. SOFT MATTER 2019; 15:870-879. [PMID: 30628627 DOI: 10.1039/c8sm02174k] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Liquid crystal elastomers (LCEs) are shape morphing materials promising for many applications including soft robotics, actuators, and biomedical devices, but current LCE synthesis techniques lack a simple method to program new and arbitrary shape changes. Here, we demonstrate a straightforward method to directly program complex, reversible, non-planar shape changes in nematic LCEs. We utilize a double network synthesis process that results in a competitive double network LCE. By optimizing the crosslink densities of the first and second network we can mechanically program non-planar shapes with strains between 4-100%. This enables us to directly program LCEs using mechanical deformations that impart low or high strains in the LCE including stamping, curling, stretching and embossing methods. The resulting LCEs reversibly shape-shift between the initial and programmed shape. This work widens the potential application of LCEs in biomedical devices, soft-robotics and micro-fluidics where arbitrary and easily programmed shapes are needed.
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Affiliation(s)
- Morgan Barnes
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
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10
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Dzhardimalieva GI, Uflyand IE. Synthetic Methodologies for Chelating Polymer Ligands: Recent Advances and Future Development. ChemistrySelect 2018. [DOI: 10.1002/slct.201802516] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Gulzhian I. Dzhardimalieva
- Laboratory of MetallopolymersThe Institute of Problems of Chemical Physics RAS Academician Semenov avenue 1, Chernogolovka, Moscow Region 142432 Russian Federation
| | - Igor E. Uflyand
- Department of ChemistrySouthern Federal University B. Sadovaya str. 105/42, Rostov-on-Don 344006 Russian Federation
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11
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Wan G, Jin C, Trase I, Zhao S, Chen Z. Helical Structures Mimicking Chiral Seedpod Opening and Tendril Coiling. SENSORS (BASEL, SWITZERLAND) 2018; 18:E2973. [PMID: 30200611 PMCID: PMC6164363 DOI: 10.3390/s18092973] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/24/2018] [Accepted: 09/03/2018] [Indexed: 12/30/2022]
Abstract
Helical structures are ubiquitous in natural and engineered systems across multiple length scales. Examples include DNA molecules, plants' tendrils, sea snails' shells, and spiral nanoribbons. Although this symmetry-breaking shape has shown excellent performance in elastic springs or propulsion generation in a low-Reynolds-number environment, a general principle to produce a helical structure with programmable geometry regardless of length scales is still in demand. In recent years, inspired by the chiral opening of Bauhinia variegata's seedpod and the coiling of plant's tendril, researchers have made significant breakthroughs in synthesizing state-of-the-art 3D helical structures through creating intrinsic curvatures in 2D rod-like or ribbon-like precursors. The intrinsic curvature results from the differential response to a variety of external stimuli of functional materials, such as hydrogels, liquid crystal elastomers, and shape memory polymers. In this review, we give a brief overview of the shape transformation mechanisms of these two plant's structures and then review recent progress in the fabrication of biomimetic helical structures that are categorized by the stimuli-responsive materials involved. By providing this survey on important recent advances along with our perspectives, we hope to solicit new inspirations and insights on the development and fabrication of helical structures, as well as the future development of interdisciplinary research at the interface of physics, engineering, and biology.
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Affiliation(s)
- Guangchao Wan
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
| | - Congran Jin
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
| | - Ian Trase
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
| | - Shan Zhao
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
| | - Zi Chen
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
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12
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Visschers FLL, Hendrikx M, Zhan Y, Liu D. Liquid crystal polymers with motile surfaces. SOFT MATTER 2018; 14:4898-4912. [PMID: 29892763 DOI: 10.1039/c8sm00524a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In analogy with developments in soft robotics it is anticipated that soft robotic functions at surfaces of objects may have a large impact on human life with respect to comfort, health, medical care and energy. In this review, we demonstrate the possibilities and versatilities of liquid crystal networks and elastomers being explored for soft robotics, with an emphasis on motile surface properties, such as topographical dynamics. Typically the surfaces reversibly transfer from a flat state to a pre-designed corrugated state under various stimuli. But also reversible conversion between different corrugated states is feasible. Generally, the driving triggers are heat, light, electricity or contact with pH changing media. Also, the macroscopic effects of those dynamic topographies, such as altering the friction, wettability and/or performing work are illustrated. The review concludes with the existing challenges as well as outlook opportunities.
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Affiliation(s)
- Fabian L L Visschers
- Laboratory of Functional Organic Materials & Devices, Department of Chemical Engineering & Chemistry, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands.
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13
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Baczkowski ML, Wang DH, Lee DH, Lee KM, Smith ML, White TJ, Tan LS. Photomechanical Deformation of Azobenzene-Functionalized Polyimides Synthesized with Bulky Substituents. ACS Macro Lett 2017; 6:1432-1437. [PMID: 35650807 DOI: 10.1021/acsmacrolett.7b00854] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photomechanical effects realized in azobenzene-functionalized polyimides have shown large deformation and an exceptional increase in photogenerated force output. Here, we synthesize and characterize the photomechanical output of a series of linear polyimide materials prepared with a bulky substituent, incorporated via the development of a new bis(azobenzene-diamine) monomer containing a 9,9-diphenylfluorene cardo structure (azoCBODA). All six azoCBODA-containing polyimides are amorphous and exhibit high glass transition temperatures (Tg) ranging from 298 to 358 °C, storage moduli ranging from 2.27 to 3.81 GPa (at 30 °C), and good thermal stability. The magnitude of the photoinduced mechanical response of the azobenzene-functionalized polyimide is correlated to the rotational freedom of the polyimide chains (resulting in extensive segmental mobility) and fractional free volume (FFV > 0.1).
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Affiliation(s)
- Matthew L. Baczkowski
- Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, United States
| | - David H. Wang
- Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, United States
| | - Deborah H. Lee
- Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, United States
| | - Kyung Min Lee
- Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, United States
| | - Matthew L. Smith
- Department
of Engineering, Hope College, Holland, Michigan 49423, United States
| | - Timothy J. White
- Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, United States
| | - Loon-Seng Tan
- Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, United States
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14
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Skandani A, Clement JA, Tristram-Nagle S, Shankar MR. Aliphatic flexible spacer length controls photomechanical response in compact, ordered liquid crystalline polymer networks. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.10.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Nocentini S, Martella D, Wiersma DS, Parmeggiani C. Beam steering by liquid crystal elastomer fibres. SOFT MATTER 2017; 13:8590-8596. [PMID: 29105720 DOI: 10.1039/c7sm02063e] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The problem of utilizing a laser beam as an information vehicle and dividing it into different channels is an open problem in the telecommunication field. The switching of a signal into different ports has been demonstrated, to date, by employing complex devices and mechanisms such as the electro optic effect, microelectromechanical system (MEMS) mirrors, or liquid crystal-based spatial light modulators (SLMs). We present here a simple device, namely a mirror held by a liquid crystal elastomer (LCE) fibre, as an optically and remotely driven beam steerer. In fact, a considered signal (laser beam) can be addressed in every in-plane direction by controlling the fibre and mirror rotation, i.e., the deflected probe beam angle. Such movement is possible due to the preparation of LCE fibres able to rotate and contract under a selective light stimulus. By adjusting the irradiation stimulus power, elastic fibres are able to rotate with a specific angle, performing more than one complete revolution around their axis. The described movement is perfectly reversible as soon as the stimulus is removed.
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Affiliation(s)
- S Nocentini
- European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino, Italy.
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16
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Influence of external loads on structure and photoactuation in densely crosslinked azo-incorporated liquid crystalline polymers. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.09.061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Zeng H, Wani OM, Wasylczyk P, Kaczmarek R, Priimagi A. Self-Regulating Iris Based on Light-Actuated Liquid Crystal Elastomer. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1701814. [PMID: 28589679 DOI: 10.1002/adma.201701814] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 04/20/2017] [Indexed: 05/23/2023]
Abstract
The iris, found in many animal species, is a biological tissue that can change the aperture (pupil) size to regulate light transmission into the eye in response to varying illumination conditions. The self-regulation of the eye lies behind its autofocusing ability and large dynamic range, rendering it the ultimate "imaging device" and a continuous source of inspiration in science. In optical imaging devices, adjustable apertures play a vital role as they control the light exposure, the depth of field, and optical aberrations of the systems. Tunable irises demonstrated to date require external control through mechanical actuation, and are not capable of autonomous action in response to changing light intensity without control circuitry. A self-regulating artificial iris would offer new opportunities for device automation and stabilization. Here, this paper reports the first iris-like, liquid crystal elastomer device that can perform automatic shape-adjustment by reacting to the incident light power density. Similar to natural iris, the device closes under increasing light intensity, and upon reaching the minimum pupil size, reduces the light transmission by a factor of seven. The light-responsive materials design, together with photoalignment-based control over the molecular orientation, provides a new approach to automatic, self-regulating optical systems based on soft smart materials.
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Affiliation(s)
- Hao Zeng
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P. O. Box 541, Tampere, FI 33101, Finland
| | - Owies M Wani
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P. O. Box 541, Tampere, FI 33101, Finland
| | - Piotr Wasylczyk
- Photonic Nanostructure Facility, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, Warsaw, 02-093, Poland
| | - Radosław Kaczmarek
- Department and Clinic of Ophthalmology, Wrocław Medical University, ul. Borowska 213, Wrocław, 50-556, Poland
| | - Arri Priimagi
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P. O. Box 541, Tampere, FI 33101, Finland
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18
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Aßhoff SJ, Lancia F, Iamsaard S, Matt B, Kudernac T, Fletcher SP, Katsonis N. High-Power Actuation from Molecular Photoswitches in Enantiomerically Paired Soft Springs. Angew Chem Int Ed Engl 2017; 56:3261-3265. [PMID: 28181400 PMCID: PMC5363340 DOI: 10.1002/anie.201611325] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Indexed: 11/08/2022]
Abstract
Motion in plants often relies on dynamic helical systems as seen in coiling tendrils, spasmoneme springs, and the opening of chiral seedpods. Developing nanotechnology that would allow molecular-level phenomena to drive such movements in artificial systems remains a scientific challenge. Herein, we describe a soft device that uses nanoscale information to mimic seedpod opening. The system exploits a fundamental mechanism of stimuli-responsive deformation in plants, namely that inflexible elements with specific orientations are integrated into a stimuli-responsive matrix. The device is operated by isomerization of a light-responsive molecular switch that drives the twisting of strips of liquid-crystal elastomers. The strips twist in opposite directions and work against each other until the pod pops open from stress. This mechanism allows the photoisomerization of molecular switches to stimulate rapid shape changes at the macroscale and thus to maximize actuation power.
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Affiliation(s)
- Sarah J. Aßhoff
- Bio-inspired and Smart MaterialsUniversity of TwenteP.O. Box 2077500AEEnschedeThe Netherlands
| | - Federico Lancia
- Bio-inspired and Smart MaterialsUniversity of TwenteP.O. Box 2077500AEEnschedeThe Netherlands
| | - Supitchaya Iamsaard
- Bio-inspired and Smart MaterialsUniversity of TwenteP.O. Box 2077500AEEnschedeThe Netherlands
| | - Benjamin Matt
- Bio-inspired and Smart MaterialsUniversity of TwenteP.O. Box 2077500AEEnschedeThe Netherlands
| | - Tibor Kudernac
- Molecular Nanofabrication GroupUniversity of TwenteP.O. Box 2077500AEEnschedeThe Netherlands
| | - Stephen P. Fletcher
- Department of Chemistry, Chemistry Research LaboratoryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Nathalie Katsonis
- Bio-inspired and Smart MaterialsUniversity of TwenteP.O. Box 2077500AEEnschedeThe Netherlands
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19
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Aßhoff SJ, Lancia F, Iamsaard S, Matt B, Kudernac T, Fletcher SP, Katsonis N. High-Power Actuation from Molecular Photoswitches in Enantiomerically Paired Soft Springs. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611325] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sarah J. Aßhoff
- Bio-inspired and Smart Materials; University of Twente; P.O. Box 207 7500 AE Enschede The Netherlands
| | - Federico Lancia
- Bio-inspired and Smart Materials; University of Twente; P.O. Box 207 7500 AE Enschede The Netherlands
| | - Supitchaya Iamsaard
- Bio-inspired and Smart Materials; University of Twente; P.O. Box 207 7500 AE Enschede The Netherlands
| | - Benjamin Matt
- Bio-inspired and Smart Materials; University of Twente; P.O. Box 207 7500 AE Enschede The Netherlands
| | - Tibor Kudernac
- Molecular Nanofabrication Group; University of Twente; P.O. Box 207 7500 AE Enschede The Netherlands
| | - Stephen P. Fletcher
- Department of Chemistry, Chemistry Research Laboratory; University of Oxford; 12 Mansfield Road Oxford OX1 3TA UK
| | - Nathalie Katsonis
- Bio-inspired and Smart Materials; University of Twente; P.O. Box 207 7500 AE Enschede The Netherlands
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20
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Kularatne RS, Kim H, Boothby JM, Ware TH. Liquid crystal elastomer actuators: Synthesis, alignment, and applications. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/polb.24287] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Ruvini S. Kularatne
- Department of Bioengineering; University of Texas at Dallas; 800 W. Campbell Rd. Richardson Texas 75080 USA
| | - Hyun Kim
- Department of Bioengineering; University of Texas at Dallas; 800 W. Campbell Rd. Richardson Texas 75080 USA
| | - Jennifer M. Boothby
- Department of Bioengineering; University of Texas at Dallas; 800 W. Campbell Rd. Richardson Texas 75080 USA
| | - Taylor H. Ware
- Department of Bioengineering; University of Texas at Dallas; 800 W. Campbell Rd. Richardson Texas 75080 USA
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21
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Lee DW, Phadikar J, Shankar MR. Multiplicity of shape selection in functionally graded liquid crystalline polymers. RSC Adv 2017. [DOI: 10.1039/c7ra03465b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The synergy of through-thickness gradation in the orientation of the molecular director and the extent of polymerization is shown to offer a framework for controlling shape selection in integral polymer films.
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Affiliation(s)
- Da-Wei Lee
- Department of Industrial Engineering
- Swanson School of Engineering
- University of Pittsburgh
- Pittsburgh
- USA
| | - Jayanta Phadikar
- Department of Industrial Engineering
- Swanson School of Engineering
- University of Pittsburgh
- Pittsburgh
- USA
| | - M. Ravi Shankar
- Department of Industrial Engineering
- Swanson School of Engineering
- University of Pittsburgh
- Pittsburgh
- USA
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22
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Li Y, Zhang Y, Rios O, Keum JK, Kessler MR. Photo-responsive liquid crystalline epoxy networks with exchangeable disulfide bonds. RSC Adv 2017. [DOI: 10.1039/c7ra06343a] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Disulfide exchange and thiol–disulfide interchange reactions allow for reprocessing and recycling of azobenzene-based liquid crystalline networks.
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Affiliation(s)
- Yuzhan Li
- School of Mechanical and Materials Engineering
- Washington State University
- Pullman
- USA
| | - Yuehong Zhang
- School of Mechanical and Materials Engineering
- Washington State University
- Pullman
- USA
| | - Orlando Rios
- Deposition Sciences Group
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Jong K. Keum
- Center for Nanophase Materials Sciences
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Michael R. Kessler
- School of Mechanical and Materials Engineering
- Washington State University
- Pullman
- USA
- Department of Mechanical Engineering
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23
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Abstract
Light is distinguished as a contactless energy source for microscale devices as it can be directed from remote distances, rapidly turned on or off, spatially modulated across length scales, polarized, or varied in intensity. Motivated in part by these nascent properties of light, transducing photonic stimuli into macroscopic deformation of materials systems has been examined in the last half-century. Here we report photoinduced motion (photomotility) in monolithic polymer films prepared from azobenzene-functionalized liquid crystalline polymer networks (azo-LCNs). Leveraging the twisted-nematic orientation, irradiation with broad spectrum ultraviolet–visible light (320–500 nm) transforms the films from flat sheets to spiral ribbons, which subsequently translate large distances with continuous irradiation on an arbitrary surface. The motion results from a complex interplay of photochemistry and mechanics. We demonstrate directional control, as well as climbing. The demand for soft robots urges the development of new light-responsive materials for remotely powered actuation. Here, Wie et al. show directional motion over centimeter scales using azobenzene-functionalized liquid crystalline polymer films upon continuous radiation from ultraviolet to visible light.
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24
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Li C, Yun JH, Kim H, Cho M. Light Propagation and Photoactuation in Densely Cross-Linked Azobenzene-Functionalized Liquid-Crystalline Polymers: Contribution of Host and Concerted Isomerism. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Chenzhe Li
- Department
of Mechanical
and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Jung-Hoon Yun
- Department
of Mechanical
and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Hyunsu Kim
- Department
of Mechanical
and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Maenghyo Cho
- Department
of Mechanical
and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea
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25
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Li Y, Rios O, Keum JK, Chen J, Kessler MR. Photoresponsive Liquid Crystalline Epoxy Networks with Shape Memory Behavior and Dynamic Ester Bonds. ACS APPLIED MATERIALS & INTERFACES 2016; 8:15750-15757. [PMID: 27245744 DOI: 10.1021/acsami.6b04374] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Functional polymers are intelligent materials that can respond to a variety of external stimuli. However, these materials have not yet found widespread real world applications because of the difficulties in fabrication and the limited number of functional building blocks that can be incorporated into a material. Here, we demonstrate a simple route to incorporate three functional building blocks (azobenzene chromophores, liquid crystals, and dynamic covalent bonds) into an epoxy-based liquid crystalline network (LCN), in which an azobenzene-based epoxy monomer is polymerized with an aliphatic dicarboxylic acid to create exchangeable ester bonds that can be thermally activated. All three functional building blocks exhibited good compatibility, and the resulting materials exhibits various photomechanical, shape memory, and self-healing properties because of the azobenzene molecules, liquid crystals, and dynamic ester bonds, respectively.
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Affiliation(s)
- Yuzhan Li
- School of Mechanical and Materials Engineering, Washington State University , PO Box 642920, Pullman, Washington 99164-2920, United States
| | - Orlando Rios
- Deposition Sciences Group, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Jong K Keum
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Jihua Chen
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Michael R Kessler
- School of Mechanical and Materials Engineering, Washington State University , PO Box 642920, Pullman, Washington 99164-2920, United States
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26
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Mostajeran C, Warner M, Ware TH, White TJ. Encoding Gaussian curvature in glassy and elastomeric liquid crystal solids. Proc Math Phys Eng Sci 2016; 472:20160112. [PMID: 27279777 PMCID: PMC4893188 DOI: 10.1098/rspa.2016.0112] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/05/2016] [Indexed: 11/22/2022] Open
Abstract
We describe shape transitions of thin, solid nematic sheets with smooth, preprogrammed, in-plane director fields patterned across the surface causing spatially inhomogeneous local deformations. A metric description of the local deformations is used to study the intrinsic geometry of the resulting surfaces upon exposure to stimuli such as light and heat. We highlight specific patterns that encode constant Gaussian curvature of prescribed sign and magnitude. We present the first experimental results for such programmed solids, and they qualitatively support theory for both positive and negative Gaussian curvature morphing from flat sheets on stimulation by light or heat. We review logarithmic spiral patterns that generate cone/anti-cone surfaces, and introduce spiral director fields that encode non-localized positive and negative Gaussian curvature on punctured discs, including spherical caps and spherical spindles. Conditions are derived where these cap-like, photomechanically responsive regions can be anchored in inert substrates by designing solutions that ensure compatibility with the geometric constraints imposed by the surrounding media. This integration of such materials is a precondition for their exploitation in new devices. Finally, we consider the radial extension of such director fields to larger sheets using nematic textures defined on annular domains.
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Affiliation(s)
- Cyrus Mostajeran
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK
| | - Mark Warner
- Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - Taylor H. Ware
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433, USA
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
| | - Timothy J. White
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433, USA
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27
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Zhao H, Wie JJ, Copic D, Oliver CR, Orbaek White A, Kim S, Hart AJ. High-Fidelity Replica Molding of Glassy Liquid Crystalline Polymer Microstructures. ACS APPLIED MATERIALS & INTERFACES 2016; 8:8110-7. [PMID: 26943057 DOI: 10.1021/acsami.6b00785] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Liquid crystalline polymers have recently been engineered to exhibit complex macroscopic shape adaptivity, including optically- and thermally driven bending, self-sustaining oscillation, torsional motion, and three-dimensional folding. Miniaturization of these novel materials is of great interest for both fundamental study of processing conditions and for the development of shape-changing microdevices. Here, we present a scalable method for high-fidelity replica molding of glassy liquid crystalline polymer networks (LCNs), by vacuum-assisted replica molding, along with magnetic field-induced control of the molecular alignment. We find that an oxygen-free environment is essential to establish high-fidelity molding with low surface roughness. Identical arrays of homeotropic and polydomain LCN microstructures are fabricated to assess the influence of molecular alignment on the elastic modulus (E = 1.48 GPa compared to E = 0.54 GPa), and side-view imaging is used to quantify the reversible thermal actuation of individual LCN micropillars by high-resolution tracking of edge motion. The methods and results from this study will be synergistic with future advances in liquid crystalline polymer chemistry, and could enable the scalable manufacturing of stimuli-responsive surfaces for applications including microfluidics, tunable optics, and surfaces with switchable wetting and adhesion.
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Affiliation(s)
- Hangbo Zhao
- Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jeong Jae Wie
- Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department of Polymer Science and Engineering, Inha University , 100 Inha-ro, Nam-gu, Incheon 402-751, Republic of Korea
| | - Davor Copic
- Department of Mechanical Engineering, University of Michigan , 2350 Hayward Street, Ann Arbor, Michigan 48109, United States
| | - C Ryan Oliver
- Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Alvin Orbaek White
- Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Sanha Kim
- Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - A John Hart
- Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department of Mechanical Engineering, University of Michigan , 2350 Hayward Street, Ann Arbor, Michigan 48109, United States
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28
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Abstract
Thermo- and pH-responsive poly(ionic liquid) membranes with tunable shape and transparency were synthesized.
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Affiliation(s)
- Fei Chen
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- Department of Polymer Science and Engineering
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Jiangna Guo
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- Department of Polymer Science and Engineering
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Dan Xu
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- Department of Polymer Science and Engineering
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Feng Yan
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- Department of Polymer Science and Engineering
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
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29
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White TJ, Broer DJ. Programmable and adaptive mechanics with liquid crystal polymer networks and elastomers. NATURE MATERIALS 2015; 14:1087-98. [PMID: 26490216 DOI: 10.1038/nmat4433] [Citation(s) in RCA: 729] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 08/26/2015] [Indexed: 05/22/2023]
Abstract
Liquid crystals are the basis of a pervasive technology of the modern era. Yet, as the display market becomes commoditized, researchers in industry, government and academia are increasingly examining liquid crystalline materials in a variety of polymeric forms and discovering their fascinating and useful properties. In this Review, we detail the historical development of liquid crystalline polymeric materials, with emphasis on the thermally and photogenerated macroscale mechanical responses--such as bending, twisting and buckling--and on local-feature development (primarily related to topographical control). Within this framework, we elucidate the benefits of liquid crystallinity and contrast them with other stimuli-induced mechanical responses reported for other materials. We end with an outlook of existing challenges and near-term application opportunities.
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Affiliation(s)
- Timothy J White
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Dirk J Broer
- Eindhoven University of Technology, Institute for Complex Molecular Systems, Department of Chemical Engineering and Chemistry, Helix Building STO 0.34, PO Box 513, 5600 MB Eindhoven, The Netherlands
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30
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Yun JH, Li C, Chung H, Choi J, Cho M. Photo deformation in azobenzene liquid-crystal network: Multiscale model prediction and its validation. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.08.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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