51
|
Li Y, Liu Y, Li S, Zhou P, Zhan T, Chen Q, Su Y, Wu ST. Single-exposure fabrication of tunable Pancharatnam-Berry devices using a dye-doped liquid crystal. OPTICS EXPRESS 2019; 27:9054-9060. [PMID: 31052714 DOI: 10.1364/oe.27.009054] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
We report a non-interferometric single-exposure technique for fabricating Pancharatnam-Berry (PB) devices with arbitrary wavefronts, via photo-patterning an azo-dye doped LC with a two-dimensional linear polarization field, whose local polarization direction can be controlled by a spatial light modulator (SLM) on the pixel level. Upon one exposure, different local LC orientations are generated simultaneously. The non-interferometric approach is insensitive to environmental disturbance, and moreover, the dynamic phase mask on the SLM can be conveniently reconfigured by a computer. Our fabricated PB gratings, q-plates and hologram exhibit good optical performances. Such a simple yet reconfigurable fabrication method enables new PB devices to be developed, and it would open a new gateway towards widespread applications.
Collapse
|
52
|
Moon J, Kim B, Choi J, Cho M. Multiscale Study of the Relationship between Photoisomerization and Mechanical Behavior of Azo-Polymer Based on the Coarse-Grained Molecular Dynamics Simulation. Macromolecules 2019. [DOI: 10.1021/acs.macromol.8b02535] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
| | | | - Joonmyung Choi
- Department of Mechanical Engineering, Hanyang University, Ansan, Gyeonggi-do, Republic of Korea
| | | |
Collapse
|
53
|
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.
Collapse
Affiliation(s)
- Morgan Barnes
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
| | | |
Collapse
|
54
|
Donovan BR, Matavulj VM, Ahn SK, Guin T, White TJ. All-Optical Control of Shape. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805750. [PMID: 30417450 DOI: 10.1002/adma.201805750] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/12/2018] [Indexed: 06/09/2023]
Abstract
Photoresponsive liquid crystal elastomers (LCEs) are a unique class of anisotropic materials capable of undergoing large-scale, macroscopic deformations when exposed to light. Here, surface-aligned, azobenzene-functionalized LCEs are prepared via a radical-mediated, thiol-acrylate chain transfer reaction. A long-lived, macroscopic shape deformation is realized in an LCE composed with an o-fluorinated azobenzene (oF-azo) monomer. Under UV irradiation, the oF-azo LCE exhibits a persistent shape deformation for >72 h. By contrasting the photomechanical response of the oF-azo LCE to analogs prepared from classical and m-fluorinated azobenzene derivatives, the origin of the persistent deformation is clearly attributed to the underlying influence of positional functionalization on the kinetics of cis→trans isomerization. Informed by these studies and enabled by the salient features of light-induced deformations, oF-azo LCEs are demonstrated to undergo all-optical control of shape deformation and shape restoration.
Collapse
Affiliation(s)
- Brian R Donovan
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH, 45433-7750, USA
- Azimuth Corporation, 4027 Colonel Glenn Highway, Beavercreek, OH, 45431, USA
| | - Valentina M Matavulj
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH, 45433-7750, USA
- Azimuth Corporation, 4027 Colonel Glenn Highway, Beavercreek, OH, 45431, USA
| | - Suk-Kyun Ahn
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH, 45433-7750, USA
- Azimuth Corporation, 4027 Colonel Glenn Highway, Beavercreek, OH, 45431, USA
| | - Tyler Guin
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH, 45433-7750, USA
- Azimuth Corporation, 4027 Colonel Glenn Highway, Beavercreek, OH, 45431, USA
| | - Timothy J White
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Ave., Boulder, CO, 80303, USA
| |
Collapse
|
55
|
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
| |
Collapse
|
56
|
Karausta A, Bukusoglu E. Liquid Crystal-Templated Synthesis of Mesoporous Membranes with Predetermined Pore Alignment. ACS APPLIED MATERIALS & INTERFACES 2018; 10:33484-33492. [PMID: 30198253 DOI: 10.1021/acsami.8b14121] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We demonstrate that polymeric films templated from liquid crystals (LCs) provide basic design principles for the synthesis of mesoporous films with predetermined pore alignment. Specifically, we used LC mixtures of reactive [4-(3-acryloyoxypropyloxy) benzoic acid 2-methyl-1,4-phenylene ester (RM257)] and nonreactive [4-cyano-4'-pentylbiphenyl (5CB)] mesogens confined in film geometries. The LC alignment was maintained by functionalization of the surfaces contacting the films during polymerization. Through photopolymerization followed by extraction of the unreacted mesogens, films of area in the order of 10 cm2 were obtained. We found that, when restricted to an area either through a mechanical or a configurational constraint, open and accessible pores were incorporated into the films. The average direction of the pores could be determined by the LC director during polymerization, and the average diameter of the pores can be tuned in the range of 10-40 nm by varying the reactive monomer concentration. The polymeric films synthesized here can potentially be used for the ultrafiltration purposes. We demonstrated successful separations of proteins and nanoparticles from aqueous media using the polymeric films. The films exhibited 2 orders of magnitude higher flux when the pores were aligned parallel to the permeate direction compared to the perpendicular direction. Overall, the outcomes of this study provide basic tools for the synthesis of porous polymeric films with predetermined pore directions that can potentially be suitable for separations, drug delivery, catalysts, and so forth.
Collapse
Affiliation(s)
- Aslı Karausta
- Chemical Engineering Department , Middle East Technical University , Ankara 06800 , Turkey
| | - Emre Bukusoglu
- Chemical Engineering Department , Middle East Technical University , Ankara 06800 , Turkey
| |
Collapse
|
57
|
Kowalski BA, Mostajeran C, Godman NP, Warner M, White TJ. Curvature by design and on demand in liquid crystal elastomers. Phys Rev E 2018; 97:012504. [PMID: 29448377 DOI: 10.1103/physreve.97.012504] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Indexed: 12/27/2022]
Abstract
The shape of liquid crystalline elastomers (LCEs) with spatial variation in the director orientation can be transformed by exposure to a stimulus. Here, informed by previously reported analytical treatments, we prepare complex spiral patterns imprinted into LCEs and quantify the resulting shape transformation. Quantification of the stimuli-induced shapes reveals good agreement between predicted and experimentally observed curvatures. We conclude this communication by reporting a design strategy to allow LCE films to be anchored at their external boundaries onto rigid substrates without incurring internal, mechanical-mismatch stresses upon actuation, a critical advance to the realization of shape transformation of LCEs in practical device applications.
Collapse
Affiliation(s)
- B A Kowalski
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA.,Azimuth Corporation, Beavercreek, Ohio 45431, USA
| | - C Mostajeran
- Department of Engineering, University of Cambridge CB2 1PZ, United Kingdom
| | - N P Godman
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - M Warner
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | - T J White
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA
| |
Collapse
|
58
|
Guin T, Settle MJ, Kowalski BA, Auguste AD, Beblo RV, Reich GW, White TJ. Layered liquid crystal elastomer actuators. Nat Commun 2018; 9:2531. [PMID: 29955053 PMCID: PMC6023890 DOI: 10.1038/s41467-018-04911-4] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/29/2018] [Indexed: 11/25/2022] Open
Abstract
Liquid crystalline elastomers (LCEs) are soft, anisotropic materials that exhibit large shape transformations when subjected to various stimuli. Here we demonstrate a facile approach to enhance the out-of-plane work capacity of these materials by an order of magnitude, to nearly 20 J/kg. The enhancement in force output is enabled by the development of a room temperature polymerizable composition used both to prepare individual films, organized via directed self-assembly to retain arrays of topological defect profiles, as well as act as an adhesive to combine the LCE layers. The material actuator is shown to displace a load >2500× heavier than its own weight nearly 0.5 mm.
Collapse
Affiliation(s)
- Tyler Guin
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, 45433, USA
- Azimuth Corporation, 4027 Colonel Glenn Hwy, Beavercreek, OH, 45431, USA
| | - Michael J Settle
- Air Force Research Laboratory, Aerospace Systems Directorate, Wright-Patterson Air Force Base, OH, 45433, USA
- University of Dayton Research Institute, 1700 S Patterson Blvd, Dayton, OH, 45469, USA
| | - Benjamin A Kowalski
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, 45433, USA
- Azimuth Corporation, 4027 Colonel Glenn Hwy, Beavercreek, OH, 45431, USA
| | - Anesia D Auguste
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, 45433, USA
| | - Richard V Beblo
- Air Force Research Laboratory, Aerospace Systems Directorate, Wright-Patterson Air Force Base, OH, 45433, USA
- University of Dayton Research Institute, 1700 S Patterson Blvd, Dayton, OH, 45469, USA
| | - Gregory W Reich
- Air Force Research Laboratory, Aerospace Systems Directorate, Wright-Patterson Air Force Base, OH, 45433, USA
| | - Timothy J White
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, 45433, USA.
| |
Collapse
|
59
|
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.
Collapse
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.
| | | | | | | |
Collapse
|
60
|
Zeng H, Wasylczyk P, Wiersma DS, Priimagi A. Light Robots: Bridging the Gap between Microrobotics and Photomechanics in Soft Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1703554. [PMID: 29067734 DOI: 10.1002/adma.201703554] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/30/2017] [Indexed: 05/23/2023]
Abstract
For decades, roboticists have focused their efforts on rigid systems that enable programmable, automated action, and sophisticated control with maximal movement precision and speed. Meanwhile, material scientists have sought compounds and fabrication strategies to devise polymeric actuators that are small, soft, adaptive, and stimuli-responsive. Merging these two fields has given birth to a new class of devices-soft microrobots that, by combining concepts from microrobotics and stimuli-responsive materials research, provide several advantages in a miniature form: external, remotely controllable power supply, adaptive motion, and human-friendly interaction, with device design and action often inspired by biological systems. Herein, recent progress in soft microrobotics is highlighted based on light-responsive liquid-crystal elastomers and polymer networks, focusing on photomobile devices such as walkers, swimmers, and mechanical oscillators, which may ultimately lead to flying microrobots. Finally, self-regulated actuation is proposed as a new pathway toward fully autonomous, intelligent light robots of the future.
Collapse
Affiliation(s)
- Hao Zeng
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI, 33101, Tampere, Finland
| | - Piotr Wasylczyk
- Photonic Nanostructure Facility, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
| | - Diederik S Wiersma
- European Laboratory for Non Linear Spectroscopy (LENS), University of Florence and INRIM, via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - Arri Priimagi
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI, 33101, Tampere, Finland
| |
Collapse
|
61
|
Babakhanova G, Turiv T, Guo Y, Hendrikx M, Wei QH, Schenning APHJ, Broer DJ, Lavrentovich OD. Liquid crystal elastomer coatings with programmed response of surface profile. Nat Commun 2018; 9:456. [PMID: 29386512 PMCID: PMC5792610 DOI: 10.1038/s41467-018-02895-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/05/2018] [Indexed: 11/13/2022] Open
Abstract
Stimuli-responsive liquid crystal elastomers with molecular orientation coupled to rubber-like elasticity show a great potential as elements in soft robotics, sensing, and transport systems. The orientational order defines their mechanical response to external stimuli, such as thermally activated muscle-like contraction. Here we demonstrate a dynamic thermal control of the surface topography of an elastomer prepared as a coating with a pattern of in-plane molecular orientation. The inscribed pattern determines whether the coating develops elevations, depressions, or in-plane deformations when the temperature changes. The deterministic dependence of the out-of-plane dynamic profile on the in-plane orientation is explained by activation forces. These forces are caused by stretching-contraction of the polymer networks and by spatially varying molecular orientation. The activation force concept brings the responsive liquid crystal elastomers into the domain of active matter. The demonstrated relationship can be used to design coatings with functionalities that mimic biological tissues such as skin.
Collapse
Affiliation(s)
- Greta Babakhanova
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
- Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| | - Taras Turiv
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
- Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| | - Yubing Guo
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
- Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| | - Matthew Hendrikx
- Functional Organic Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5612 AZAE, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Qi-Huo Wei
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
- Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| | - Albert P H J Schenning
- Functional Organic Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5612 AZAE, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Dirk J Broer
- Functional Organic Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5612 AZAE, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Oleg D Lavrentovich
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA.
- Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA.
- Department of Physics, Kent State University, Kent, OH, 44242, USA.
| |
Collapse
|
62
|
White TJ. Photomechanical effects in liquid crystalline polymer networks and elastomers. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/polb.24576] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
63
|
Guin T, Kowalski BA, Rao R, Auguste AD, Grabowski CA, Lloyd PF, Tondiglia VP, Maruyama B, Vaia RA, White TJ. Electrical Control of Shape in Voxelated Liquid Crystalline Polymer Nanocomposites. ACS APPLIED MATERIALS & INTERFACES 2018; 10:1187-1194. [PMID: 29239172 DOI: 10.1021/acsami.7b13814] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Liquid crystal elastomers (LCEs) exhibit anisotropic mechanical, thermal, and optical properties. The director orientation within an LCE can be spatially localized into voxels [three-dimensional (3-D) volume elements] via photoalignment surfaces. Here, we prepare nanocomposites in which both the orientation of the LCE and single-walled carbon nanotube (SWNT) are locally and arbitrarily oriented in discrete voxels. The addition of SWNTs increases the stiffness of the LCE in the orientation direction, yielding a material with a 5:1 directional modulus contrast. The inclusion of SWNT modifies the thermomechanical response and, most notably, is shown to enable distinctive electromechanical deformation of the nanocomposite. Specifically, the incorporation of SWNTs sensitizes the LCE to a dc field, enabling uniaxial electrostriction along the orientation direction. We demonstrate that localized orientation of the LCE and SWNT allows complex 3-D shape transformations to be electrically triggered. Initial experiments indicate that the SWNT-polymer interfaces play a crucial role in enabling the electrostriction reported herein.
Collapse
Affiliation(s)
- Tyler Guin
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
- Azimuth Corporation , 4027 Colonel Glenn Highway, Beavercreek, Ohio 45431, United States
| | - Benjamin A Kowalski
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
- Azimuth Corporation , 4027 Colonel Glenn Highway, Beavercreek, Ohio 45431, United States
| | - Rahul Rao
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
| | - Anesia D Auguste
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
| | - Christopher A Grabowski
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
- UES, Inc. , 4401 Dayton Xenia Rd, Beavercreek, Ohio 45432, United States
| | - Pamela F Lloyd
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
- UES, Inc. , 4401 Dayton Xenia Rd, Beavercreek, Ohio 45432, United States
| | - Vincent P Tondiglia
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
- Azimuth Corporation , 4027 Colonel Glenn Highway, Beavercreek, Ohio 45431, United States
| | - Benji Maruyama
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
| | - Richard A Vaia
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
| | - Timothy J White
- Air Force Research Laboratory, Materials and Manufacturing Directorate , 3005 Hobson Way, Wright-Patterson AFB, Ohio 45433-7750, United States
| |
Collapse
|
64
|
Development of Coarse-Grained Liquid-Crystal Polymer Model with Efficient Electrostatic Interaction: Toward Molecular Dynamics Simulations of Electroactive Materials. MATERIALS 2018; 11:ma11010083. [PMID: 29316621 PMCID: PMC5793581 DOI: 10.3390/ma11010083] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/30/2017] [Accepted: 01/03/2018] [Indexed: 02/03/2023]
Abstract
Liquid-crystal polymers (LCPs) are well known materials for functional sensor and actuators, because of their high-responsiveness to an electric field. Owing to their complex physical nature, however, the prediction of the functions of LCPs is a challenge. To attack this problem from a molecular point of view, a simulation study is a promising approach. In this work, for future applications of molecular dynamics simulations to problems involving an electric field, we develop an LCP model which consists of coarse-grained mesogenic molecules and smeared charges. For the smearing function of the electrostatic force, the Gauss error function is introduced. This smearing is optimized to attain a reasonable accuracy for phase transition phenomena of liquid crystal while numerical instabilities arising from the singularity of the Coulomb potential are circumvented. For swelling systems, our LCP model exhibits the characteristics of both liquid crystals and unentangled polymer chains; orientational order of the mesogenic units and Rouse-like relaxation dynamics. Our coarse-grained LCP model successfully incorporates electric charges and dipoles and is therefore applicable to problems concerning an electric field.
Collapse
|
65
|
Kim M, Serra F. Tunable large-scale regular array of topological defects in nematic liquid crystals. RSC Adv 2018; 8:35640-35645. [PMID: 35547927 PMCID: PMC9088217 DOI: 10.1039/c8ra08251k] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 10/08/2018] [Indexed: 11/21/2022] Open
Abstract
We create regular and tunable large-scale array of topological defects in liquid crystals by alternating electrodes with different conductivity. We study the periodicity and the regularity of the network as a function of the electrodes size.
Collapse
Affiliation(s)
- MinSu Kim
- Department of Physics and Astronomy
- Johns Hopkins University
- Baltimore 21218
- USA
| | - Francesca Serra
- Department of Physics and Astronomy
- Johns Hopkins University
- Baltimore 21218
- USA
| |
Collapse
|
66
|
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).
Collapse
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
| |
Collapse
|
67
|
Liu Q, Zhan Y, Wei J, Ji W, Hu W, Yu Y. Dual-responsive deformation of a crosslinked liquid crystal polymer film with complex molecular alignment. SOFT MATTER 2017; 13:6145-6151. [PMID: 28795180 DOI: 10.1039/c7sm01291h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Crosslinked liquid crystal polymers (CLCPs) containing azobenzene mesogens have been developed as stimuli-responsive materials, which can undergo photodeformation and thus convert light energy into mechanical force. The deformation behavior of CLCPs is strongly influenced by the alignment of the mesogens; however, a precise control of the alignment domain at micro-scale is still a challenge. Here we report complex molecular alignment in the CLCP film by using photoalignment technology. First, azo dye SD1 is aligned in-plane by UV light with a discrete alternating striped director profile. The SD1 molecules in adjacent strips are aligned orthogonal, and the widths of the strips are controlled in several hundred micrometers by a photomask with grating patterns. Then the liquid crystal molecules in the CLCP film are aligned by SD1 through the anchoring effect on one side (SD1 side), and aligned perpendicular by the polyimide (PI) alignment layer on the other side (PI side). With these alignments, two kinds of splayed structures are formed through the depth of the film. When irradiated by UV light, the film bends toward the SD1 side with the bending direction along the diagonal of the film, determined by the resultant direction of molecular alignment on the SD1 side. When irradiated by blue light and heat, the bending direction is along the edge of the film. This dual-responsive deformable film with complex alignment is anticipated to be used in shape-changing biomedical devices, multiple controllable switches, and microactuators.
Collapse
Affiliation(s)
- Quan Liu
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai, 200433, China.
| | | | | | | | | | | |
Collapse
|
68
|
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.
Collapse
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
| |
Collapse
|
69
|
|
70
|
Kowalski BA, Tondiglia VP, Guin T, White TJ. Voxel resolution in the directed self-assembly of liquid crystal polymer networks and elastomers. SOFT MATTER 2017; 13:4335-4340. [PMID: 28540967 DOI: 10.1039/c7sm00663b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Monomeric mixtures formulated to prepare a liquid crystal polymer network (LCN) or elastomer (LCE) can be "programmed" by surface alignment to retain complex and arbitrary spatial distributions of the director orientation upon polymerization. The localized control of orientation in a given volume (voxel) within these materials is the subject of intense research, currently motivated by the prospect of distinctive mechanical responses (both active and passive). Here, we report on a rapid and scalable photopatterning method to prepare alignment surfaces with a throughput of 10 mm2 s-1, using a commercial spatial light modulator and projection optics. Enabled by this method, we detail that the resolution limit of the inscribed director profile is not dictated by the optical system but is determined by the elastic-mediated orientational relaxation of the liquid crystalline materials. A simple model is experimentally validated and the implications for device design are discussed.
Collapse
Affiliation(s)
- Benjamin A Kowalski
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, USA.
| | | | | | | |
Collapse
|
71
|
Boothby JM, Ware TH. Dual-responsive, shape-switching bilayers enabled by liquid crystal elastomers. SOFT MATTER 2017; 13:4349-4356. [PMID: 28466922 DOI: 10.1039/c7sm00541e] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Materials that change shape are attractive candidates to replace traditional actuators for applications with power or size restrictions. In this work, we design a polymeric bilayer that changes shape in response to both heat and water by the incorporation of a water-responsive hydrophilic polymer with a heat-responsive liquid crystal elastomer. The distinct shape changes based on stimulus are controlled by the molecular order, and consequently the anisotropic modulus, of a liquid crystal elastomer. In response to water, the hydrophilic polymer layer expands, bending the bilayer along the path dictated by the anisotropic modulus of the liquid crystal elastomer layer, which is approximately 5 times higher along the molecular orientation than in perpendicular directions. We demonstrate that by varying the direction of this stiffer axis in LCE films, helical pitch of the swollen bilayer can be controlled from 0.1 to 20 mm. By spatially patterning the stiffer axis with a resolution of 900 μm2, we demonstrate bilayers that fold and bend based on the pattern within the LCE. In response to heat, the liquid crystal elastomer contracts along the direction of molecular order, and when this actuation is constrained by the hydrophilic polymer, this contraction results in a 3D shape that is distinct from the shape seen in water. Furthermore, by using the vitrification of the dry hydrophilic polymer this 3D shape can be retained in the bilayer after cooling. By utilizing sequential exposure to heat and water, we can drive the initially flat bilayer to reversibly shift between 3D shapes.
Collapse
Affiliation(s)
- J M Boothby
- Bioengineering Department, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA.
| | | |
Collapse
|
72
|
Zeng H, Wani OM, Wasylczyk P, Priimagi A. Light‐Driven, Caterpillar‐Inspired Miniature Inching Robot. Macromol Rapid Commun 2017; 39. [DOI: 10.1002/marc.201700224] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 04/28/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Hao Zeng
- Laboratory of Chemistry and BioengineeringTampere University of Technology P.O. Box 541 FI‐33101 Tampere Finland
| | - Owies M. Wani
- Laboratory of Chemistry and BioengineeringTampere University of Technology P.O. Box 541 FI‐33101 Tampere Finland
| | - Piotr Wasylczyk
- Photonic Nanostructure FacilityInstitute of Experimental PhysicsFaculty of PhysicsUniversity of Warsaw ul. Pasteura 5 02‐093 Warsaw Poland
| | - Arri Priimagi
- Laboratory of Chemistry and BioengineeringTampere University of Technology P.O. Box 541 FI‐33101 Tampere Finland
| |
Collapse
|
73
|
Kowalski BA, Guin TC, Auguste AD, Godman NP, White TJ. Pixelated Polymers: Directed Self Assembly of Liquid Crystalline Polymer Networks. ACS Macro Lett 2017; 6:436-441. [PMID: 35610852 DOI: 10.1021/acsmacrolett.7b00116] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Polymeric materials are pervasive in modern society, in part attributable to the diverse range of properties that are accessible in these materials. Polymers can be stiff or soft, dissipative or elastic, adhesive or nonstick. Localizing the properties of polymeric materials can be achieved by a number of methods, including self-assembly, lithography, or 3-d printing. Here, we detail recent advances in the preparation of "pixelated" polymers prepared by the directed self-assembly of liquid crystalline monomers to yield cross-linked polymer networks (liquid crystalline polymer networks, LCN, or liquid crystalline elastomers, LCE). Through the local and arbitrary control of the orientation of the liquid crystalline units, monolithic elements can be realized with spatial variation in mechanical, thermal, electrical, optical, or acoustic properties. Stimuli-induced variation of these properties may enable paradigm-shifting end uses in a diverse set of applications.
Collapse
Affiliation(s)
- Benjamin A. Kowalski
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
- Azimuth Corporation, 4027 Colonel Glenn Highway, Beavercreek, Ohio 45431, United States
| | - Tyler C. Guin
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
- Azimuth Corporation, 4027 Colonel Glenn Highway, Beavercreek, Ohio 45431, United States
| | - Anesia D. Auguste
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| | - Nicholas P. Godman
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
- Azimuth Corporation, 4027 Colonel Glenn Highway, Beavercreek, Ohio 45431, United States
| | - Timothy J. White
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433-7750, United States
| |
Collapse
|
74
|
Zakharov AP, Pismen LM. Textures and shapes in nematic elastomers under the action of dopant concentration gradients. SOFT MATTER 2017; 13:2886-2892. [PMID: 28361142 DOI: 10.1039/c7sm00353f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We explore a novel strategy of patterning nematic elastomers that does not require inscribing the texture directly. It is based on varying the dopant concentration that, beside shifting the phase transition point, affects the nematic director field via coupling between the gradients of concentration and nematic order parameter. Rotation of the director around a point dopant source causes topological modification manifesting itself in a change of the number of defects. A variety of shapes, dependent on the dopant distribution, are obtained by anisotropic deformation following the nematic-isotropic transition.
Collapse
Affiliation(s)
- A P Zakharov
- Technion - Israel Institute of Technology, Haifa, 32000, Israel.
| | | |
Collapse
|
75
|
Silvestre NM, Telo da Gama MM, Tasinkevych M. Nematic films at chemically structured surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:074002. [PMID: 28035088 DOI: 10.1088/1361-648x/aa4fd6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigate theoretically the morphology of a thin nematic film adsorbed at flat substrate patterned by stripes with alternating aligning properties, normal and tangential respectively. We construct a simple 'exactly-solvable' effective interfacial model where the liquid crystal distortions are accounted for via an effective interface potential. We find that chemically patterned substrates can strongly deform the nematic-air interface. The amplitude of this substrate-induced undulations increases with decreasing average film thickness and with increasing surface pattern pitch. We find a regime where the interfacial deformation may be described in terms of a material-independent universal scaling function. Surprisingly, the predictions of the effective interfacial model agree semi-quantitatively with the results of the numerical solution of a full model based on the Landau-de Gennes theory coupled to a square-gradient phase field free energy functional for a two phase system.
Collapse
Affiliation(s)
- N M Silvestre
- Centro de Física Teórica e Computacional, Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Campo Grande P-1749-016 Lisboa, Portugal
| | | | | |
Collapse
|
76
|
Hidden topological constellations and polyvalent charges in chiral nematic droplets. Nat Commun 2017; 8:14594. [PMID: 28220770 PMCID: PMC5321799 DOI: 10.1038/ncomms14594] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/17/2017] [Indexed: 11/08/2022] Open
Abstract
Topology has an increasingly important role in the physics of condensed matter, quantum systems, material science, photonics and biology, with spectacular realizations of topological concepts in liquid crystals. Here we report on long-lived hidden topological states in thermally quenched, chiral nematic droplets, formed from string-like, triangular and polyhedral constellations of monovalent and polyvalent singular point defects. These topological defects are regularly packed into a spherical liquid volume and stabilized by the elastic energy barrier due to the helical structure and confinement of the liquid crystal in the micro-sphere. We observe, for the first time, topological three-dimensional point defects of the quantized hedgehog charge q=−2, −3. These higher-charge defects act as ideal polyvalent artificial atoms, binding the defects into polyhedral constellations representing topological molecules. Once a purely mathematical discipline, topology has become an essential tool to investigate physical phenomena such as topological states in liquid crystals. Posnjak et al. observe the existence of 3D point defects of higher than unit topological charge in thermally quenched chiral nematic droplets.
Collapse
|
77
|
Jeong J, Cho Y, Lee SY, Gong X, Kamien RD, Yang S, Yodh AG. Topography-guided buckling of swollen polymer bilayer films into three-dimensional structures. SOFT MATTER 2017; 13:956-962. [PMID: 28078333 DOI: 10.1039/c6sm02299e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Thin films that exhibit spatially heterogeneous swelling often buckle into the third dimension to minimize stress. These effects, in turn, offer a promising strategy to fabricate complex three-dimensional structures from two-dimensional sheets. Here we employ surface topography as a new means to guide buckling of swollen polymer bilayer films and thereby control the morphology of resulting three-dimensional objects. Topographic patterns are created on poly(dimethylsiloxane) (PDMS) films selectively coated with a thin layer of non-swelling parylene on different sides of the patterned films. After swelling in an organic solvent, various structures are formed, including half-pipes, helical tubules, and ribbons. We demonstrate these effects and introduce a simple geometric model that qualitatively captures the relationship between surface topography and the resulting swollen film morphologies. The model's limitations are also examined.
Collapse
Affiliation(s)
- Joonwoo Jeong
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
| | | | | | | | | | | | | |
Collapse
|
78
|
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.
Collapse
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
| |
Collapse
|
79
|
Liu L, Geng B, Sayed SM, Lin BP, Keller P, Zhang XQ, Sun Y, Yang H. Single-layer dual-phase nematic elastomer films with bending, accordion-folding, curling and buckling motions. Chem Commun (Camb) 2017; 53:1844-1847. [DOI: 10.1039/c6cc08976c] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we describe a two-stage temperature-varied photopatterning protocol to synthesize a series of single-layer dual-phase liquid crystalline elastomer films.
Collapse
Affiliation(s)
- Li Liu
- School of Chemistry and Chemical Engineering
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research
- Jiangsu Key Laboratory for Science and Application of Molecular Ferroelectrics
- Jiangsu Optoelectronic Functional Materials and Engineering Laboratory
- Southeast University
| | - Bin Geng
- School of Chemistry and Chemical Engineering
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research
- Jiangsu Key Laboratory for Science and Application of Molecular Ferroelectrics
- Jiangsu Optoelectronic Functional Materials and Engineering Laboratory
- Southeast University
| | - Sayed Mir Sayed
- School of Chemistry and Chemical Engineering
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research
- Jiangsu Key Laboratory for Science and Application of Molecular Ferroelectrics
- Jiangsu Optoelectronic Functional Materials and Engineering Laboratory
- Southeast University
| | - Bao-Ping Lin
- School of Chemistry and Chemical Engineering
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research
- Jiangsu Key Laboratory for Science and Application of Molecular Ferroelectrics
- Jiangsu Optoelectronic Functional Materials and Engineering Laboratory
- Southeast University
| | - Patrick Keller
- Institut Curie
- PSL Research University
- CNRS
- UMR 168
- F-75005 Paris
| | - Xue-Qin Zhang
- School of Chemistry and Chemical Engineering
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research
- Jiangsu Key Laboratory for Science and Application of Molecular Ferroelectrics
- Jiangsu Optoelectronic Functional Materials and Engineering Laboratory
- Southeast University
| | - Ying Sun
- School of Chemistry and Chemical Engineering
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research
- Jiangsu Key Laboratory for Science and Application of Molecular Ferroelectrics
- Jiangsu Optoelectronic Functional Materials and Engineering Laboratory
- Southeast University
| | - Hong Yang
- School of Chemistry and Chemical Engineering
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research
- Jiangsu Key Laboratory for Science and Application of Molecular Ferroelectrics
- Jiangsu Optoelectronic Functional Materials and Engineering Laboratory
- Southeast University
| |
Collapse
|
80
|
van der Asdonk P, Kouwer PHJ. Liquid crystal templating as an approach to spatially and temporally organise soft matter. Chem Soc Rev 2017; 46:5935-5949. [DOI: 10.1039/c7cs00029d] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Liquid crystal templating: an emerging technique to organise and control soft matter at multiple length scales.
Collapse
Affiliation(s)
- Pim van der Asdonk
- Radboud University
- Institute for Molecules and Materials
- 6525 AJ Nijmegen
- The Netherlands
| | - Paul H. J. Kouwer
- Radboud University
- Institute for Molecules and Materials
- 6525 AJ Nijmegen
- The Netherlands
| |
Collapse
|
81
|
Designs of Plasmonic Metamasks for Photopatterning Molecular Orientations in Liquid Crystals. CRYSTALS 2016. [DOI: 10.3390/cryst7010008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
82
|
Bisoyi HK, Li Q. Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications. Chem Rev 2016; 116:15089-15166. [PMID: 27936632 DOI: 10.1021/acs.chemrev.6b00415] [Citation(s) in RCA: 402] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Light-driven phenomena both in living systems and nonliving materials have enabled truly fascinating and incredible dynamic architectures with terrific forms and functions. Recently, liquid crystalline materials endowed with photoresponsive capability have emerged as enticing systems. In this Review, we focus on the developments of light-driven liquid crystalline materials containing photochromic components over the past decade. Design and synthesis of photochromic liquid crystals (LCs), photoinduced phase transitions in LC, and photoalignment and photoorientation of LCs have been covered. Photomodulation of pitch, polarization, lattice constant and handedness inversion of chiral LCs is discussed. Light-driven phenomena and properties of liquid crystalline polymers, elastomers, and networks have also been analyzed. The applications of photoinduced phase transitions, photoalignment, photomodulation of chiral LCs, and photomobile polymers have been highlighted wherever appropriate. The combination of photochromism, liquid crystallinity, and fabrication techniques has enabled some fascinating functional materials which can be driven by ultraviolet, visible, and infrared light irradiation. Nanoscale particles have been incorporated to widen and diversify the scope of the light-driven liquid crystalline materials. The developed materials possess huge potential for applications in optics, photonics, adaptive materials, nanotechnology, etc. The challenges and opportunities in this area are discussed at the end of the Review.
Collapse
Affiliation(s)
- Hari Krishna Bisoyi
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University , Kent, Ohio 44242, United States
| | - Quan Li
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University , Kent, Ohio 44242, United States
| |
Collapse
|
83
|
Noh J, Henx B, Lagerwall JPF. Taming Liquid Crystal Self-Assembly: The Multifaceted Response of Nematic and Smectic Shells to Polymerization. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:10170-10174. [PMID: 27689941 DOI: 10.1002/adma.201603158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/01/2016] [Indexed: 06/06/2023]
Abstract
By photopolymerizing liquid crystal shells, their rich variety of self-assembled structures can be rendered permanent and the lifetime extended from days to months, without removing the characteristic responsiveness. If polymerization is carried out close to either boundary of the nematic phase, the process triggers the transition into the adjacent phase, to higher or to lower degree of order.
Collapse
Affiliation(s)
- JungHyun Noh
- University of Luxembourg, Physics & Materials Science Research Unit, 162a Avenue de la Faiencerie, Luxembourg, L-1511, Luxembourg
| | - Benjamin Henx
- University of Luxembourg, Physics & Materials Science Research Unit, 162a Avenue de la Faiencerie, Luxembourg, L-1511, Luxembourg
| | - Jan P F Lagerwall
- University of Luxembourg, Physics & Materials Science Research Unit, 162a Avenue de la Faiencerie, Luxembourg, L-1511, Luxembourg
| |
Collapse
|
84
|
Large-scale self-organization of reconfigurable topological defect networks in nematic liquid crystals. Nat Commun 2016; 7:13238. [PMID: 27819290 PMCID: PMC5103064 DOI: 10.1038/ncomms13238] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 09/13/2016] [Indexed: 11/08/2022] Open
Abstract
Topological defects in nematic liquid crystals are ubiquitous. The defects are important in understanding the fundamental properties of the systems, as well as in practical applications, such as colloidal self-assembly, optical vortex generation and templates for molecular self-assembly. Usually, spatially and temporally stable defects require geometrical frustration imposed by surfaces; otherwise, the system relaxes because of the high cost of the elastic energy. So far, multiple defects are kept in bulk nematic liquid crystals by top-down lithographic techniques. In this work, we stabilize a large number of umbilical defects by doping with an ionic impurity. This method does not require pre-patterned surfaces. We demonstrate that molecular reorientation controlled by an AC voltage induces periodic density modulation of ions accumulated at an electrically insulating polymer interface, resulting in self-organization of a two-dimensional square array of umbilical defects that is reconfigurable and tunable. Patterning liquid crystals is essential for their applications in photonics, which is commonly achieved by top-down lithographic approaches. Here, Sasaki et al. show a template-free approach that enables fabricating a large number of ordered square microarrays with tunable lattice on millimetre scale.
Collapse
|
85
|
Liu X, Kim SK, Wang X. Thermomechanical liquid crystalline elastomer capillaries with biomimetic peristaltic crawling function. J Mater Chem B 2016; 4:7293-7302. [PMID: 32263731 DOI: 10.1039/c6tb02372j] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is highly desirable to fabricate liquid crystalline elastomer (LCE) devices with novel functions for applications in different areas. In this study, LCE capillaries with biomimetic peristaltic function are fabricated for the first time to mimic the peristaltic crawling locomotion of earthworms. A specifically designed LC cell was prepared for this purpose, which consisted of two coaxial glass capillaries coated with polyimide alignment layers on the inner cell surfaces. The side-on LCE capillaries were fabricated by photoinitiated polymerization/crosslinking of a monomer and a crosslinker in the LC cells. The results show that owing to the effect of the alignment layers on the LC cell walls, the mesogenic units in the network structures are predominantly oriented along the capillary axis. Reversible thermomechanical contraction and expansion are observed for the LCE capillaries, which show a relative contraction of 16% in the length and a relative expansion of 12% in the diameter upon the nematic to isotropic phase transition. When placed in a glass tube with an appropriate inner diameter, reversible peristaltic crawling locomotion of the LCE capillaries is realized by moving a heating source outside the tube along its axis. Under typical conditions, the peristaltic crawling motion shows a moving speed of 0.31 mm s-1. The mechanism of the peristaltic crawling of the LCE capillary is elucidated with the assistance of the finite elemental analysis (FEA) simulation. A five-stage motion model is established to rationalize these observations and correlate the observations with the crawling locomotion of earthworms. The LCE capillary with the peristaltic crawling locomotion function promises its potential applications in biomimetic miniature robots and actuators.
Collapse
Affiliation(s)
- Xiyang Liu
- Department of Chemical Engineering, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084, P. R. China.
| | | | | |
Collapse
|
86
|
Xia Y, Cedillo-Servin G, Kamien RD, Yang S. Guided Folding of Nematic Liquid Crystal Elastomer Sheets into 3D via Patterned 1D Microchannels. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:9637-9643. [PMID: 27717070 DOI: 10.1002/adma.201603751] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/05/2016] [Indexed: 05/23/2023]
Abstract
Two-dimensional liquid-crystal elastomer (LCE) sheets with preprogrammed topological defects are prepared by aligning liquid-crystal monomers within micropatterned epoxy channels, followed by photopolymerization. Upon heating, the LCE films form various three-dimensional structures in agreement with theoretical design. The miniaturized LCE actuators offer large-area work capacities (≈1.05 J m-2 ) to lift over 700 times their own weight.
Collapse
Affiliation(s)
- Yu Xia
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
| | - Gerardo Cedillo-Servin
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
| | - Randall D Kamien
- Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd St, Philadelphia, PA, 19104, USA
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
| |
Collapse
|
87
|
Photocontrol of fluid slugs in liquid crystal polymer microactuators. Nature 2016; 537:179-84. [DOI: 10.1038/nature19344] [Citation(s) in RCA: 631] [Impact Index Per Article: 78.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 07/20/2016] [Indexed: 12/13/2022]
|
88
|
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.
Collapse
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
| |
Collapse
|
89
|
Guo Y, Jiang M, Peng C, Sun K, Yaroshchuk O, Lavrentovich O, Wei QH. High-Resolution and High-Throughput Plasmonic Photopatterning of Complex Molecular Orientations in Liquid Crystals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:2353-2358. [PMID: 26800114 DOI: 10.1002/adma.201506002] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 12/19/2015] [Indexed: 06/05/2023]
Abstract
A plasmonic photopatterning technique is proposed and demonstrated for aligning the molecular orientation in liquid crystals (LCs) in patterns with designer complexity. Using plasmonic metamasks in which target molecular directors are encoded, LC alignments of arbitrary planar patterns can be achieved in a repeatable and scalable fashion withunprecedentedly high spatial resolution and high throughput.
Collapse
Affiliation(s)
- Yubing Guo
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| | - Miao Jiang
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| | - Chenhui Peng
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| | - Kai Sun
- Department of Material Science and Engineering, University of Michigan, Ann Harbor, MI, 48109, USA
| | - Oleg Yaroshchuk
- Institute of Physics, National Academy of Sciences of Ukraine, Kyiv, 03028, Ukraine
| | - Oleg Lavrentovich
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| | - Qi-Huo Wei
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| |
Collapse
|
90
|
Localized soft elasticity in liquid crystal elastomers. Nat Commun 2016; 7:10781. [PMID: 26902873 PMCID: PMC4766422 DOI: 10.1038/ncomms10781] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/21/2016] [Indexed: 12/11/2022] Open
Abstract
Synthetic approaches to prepare designer materials that localize deformation, by combining rigidity and compliance in a single material, have been widely sought. Bottom-up approaches, such as the self-organization of liquid crystals, offer potential advantages over top–down patterning methods such as photolithographic control of crosslink density, relating to the ease of preparation and fidelity of resolution. Here, we report on the directed self-assembly of materials with spatial and hierarchical variation in mechanical anisotropy. The highly nonlinear mechanical properties of the liquid crystalline elastomers examined here enables strain to be locally reduced >15-fold without introducing compositional variation or other heterogeneities. Each domain (⩾0.01 mm2) exhibits anisotropic nonlinear response to load based on the alignment of the molecular orientation with the loading axis. Accordingly, we design monoliths that localize deformation in uniaxial and biaxial tension, shear, bending and crack propagation, and subsequently demonstrate substrates for globally deformable yet locally stiff electronics. Ruggedized stretchable electronic devices motivate the development of globally stretchable yet locally stiff materials. Here, Ware et al. programme the self-organization of liquid crystal elastomers to yield stretchable materials of homogenous composition but with spatial variation in mechanical properties.
Collapse
|
91
|
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: 723] [Impact Index Per Article: 80.3] [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.
Collapse
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
| |
Collapse
|
92
|
Wrinkles and splay conspire to give positive disclinations negative curvature. Proc Natl Acad Sci U S A 2015; 112:12639-44. [PMID: 26420873 DOI: 10.1073/pnas.1514379112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recently, there has been renewed interest in the coupling between geometry and topological defects in crystalline and striped systems. Standard lore dictates that positive disclinations are associated with positive Gaussian curvature, whereas negative disclinations give rise to negative curvature. Here, we present a diblock copolymer system exhibiting a striped columnar phase that preferentially forms wrinkles perpendicular to the underlying stripes. In free-standing films this wrinkling behavior induces negative Gaussian curvature to form in the vicinity of positive disclinations.
Collapse
|
93
|
Torbati AH, Mather PT. A hydrogel-forming liquid crystalline elastomer exhibiting soft shape memory. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/polb.23892] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Amir H. Torbati
- Department of Biomedical and Chemical Engineering; Syracuse Biomaterials Institute, Syracuse University; Syracuse New York 13244
| | - Patrick T. Mather
- Department of Biomedical and Chemical Engineering; Syracuse Biomaterials Institute, Syracuse University; Syracuse New York 13244
| |
Collapse
|
94
|
Mostajeran C. Curvature generation in nematic surfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:062405. [PMID: 26172723 DOI: 10.1103/physreve.91.062405] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Indexed: 06/04/2023]
Abstract
In recent years there has been a growing interest in the study of shape formation using modern responsive materials that can be preprogrammed to undergo spatially inhomogeneous local deformations. In particular, nematic liquid crystalline solids offer exciting possibilities in this context. Considerable recent progress has been made in achieving a variety of shape transitions in thin sheets of nematic solids by engineering isolated points of concentrated Gaussian curvature using topological defects in the nematic director field across textured surfaces. In this paper, we consider ways of achieving shape transitions in thin sheets of nematic glass by generation of nonlocalized Gaussian curvature in the absence of topological defects in the director field. We show how one can blueprint any desired Gaussian curvature in a thin nematic sheet by controlling the nematic alignment angle across the surface and highlight specific patterns which present feasible initial targets for experimental verification of the theory.
Collapse
Affiliation(s)
- Cyrus Mostajeran
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom
| |
Collapse
|
95
|
Ware TH, McConney ME, Wie JJ, Tondiglia VP, White TJ. Actuating materials. Voxelated liquid crystal elastomers. Science 2015; 347:982-4. [PMID: 25722408 DOI: 10.1126/science.1261019] [Citation(s) in RCA: 509] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Dynamic control of shape can bring multifunctionality to devices. Soft materials capable of programmable shape change require localized control of the magnitude and directionality of a mechanical response. We report the preparation of soft, ordered materials referred to as liquid crystal elastomers. The direction of molecular order, known as the director, is written within local volume elements (voxels) as small as 0.0005 cubic millimeters. Locally, the director controls the inherent mechanical response (55% strain) within the material. In monoliths with spatially patterned director, thermal or chemical stimuli transform flat sheets into three-dimensional objects through controlled bending and stretching. The programmable mechanical response of these materials could yield monolithic multifunctional devices or serve as reconfigurable substrates for flexible devices in aerospace, medicine, or consumer goods.
Collapse
Affiliation(s)
- Taylor H Ware
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, USA. Azimuth Corporation, Dayton, OH, USA
| | - Michael E McConney
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, USA
| | - Jeong Jae Wie
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, USA. Azimuth Corporation, Dayton, OH, USA
| | - Vincent P Tondiglia
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, USA. Leidos, Dayton, OH, USA
| | - Timothy J White
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH, USA.
| |
Collapse
|
96
|
|
97
|
Martinez A, Smalyukh II. Light-driven dynamic Archimedes spirals and periodic oscillatory patterns of topological solitons in anisotropic soft matter. OPTICS EXPRESS 2015; 23:4591-4604. [PMID: 25836496 DOI: 10.1364/oe.23.004591] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Oscillatory and excitable systems commonly exhibit formation of dynamic non-equilibrium patterns. For example, rotating spiral patterns are observed in biological, chemical, and physical systems ranging from organization of slime mold cells to Belousov-Zhabotinsky reactions, and to crystal growth from nuclei with screw dislocations. Here we describe spontaneous formation of spiral waves and a large variety of other dynamic patterns in anisotropic soft matter driven by low-intensity light. The unstructured ambient or microscope light illumination of thin liquid crystal films in contact with a self-assembled azobenzene monolayer causes spontaneous formation, rich spatial organization, and dynamics of twisted domains and topological solitons accompanied by the dynamic patterning of azobenzene group orientations within the monolayer. Linearly polarized incident light interacts with the twisted liquid crystalline domains, mimicking their dynamics and yielding patterns in the polarization state of transmitted light, which can be transformed to similar dynamic patterns in its intensity and interference color. This shows that the delicate light-soft-matter interaction can yield complex self-patterning of both. We uncover underpinning physical mechanisms and discuss potential uses.
Collapse
|
98
|
Wie JJ, Lee KM, Ware TH, White TJ. Twists and Turns in Glassy, Liquid Crystalline Polymer Networks. Macromolecules 2015. [DOI: 10.1021/ma502563q] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jeong Jae Wie
- Air Force Research Laboratory, Materials
and Manufacturing Directorate, Wright-Patterson
Air Force Base, Ohio 45433-7750, United States
| | - Kyung Min Lee
- Air Force Research Laboratory, Materials
and Manufacturing Directorate, Wright-Patterson
Air Force Base, Ohio 45433-7750, United States
| | - Taylor H. Ware
- Air Force Research Laboratory, Materials
and Manufacturing Directorate, Wright-Patterson
Air Force Base, Ohio 45433-7750, United States
| | - Timothy J. White
- Air Force Research Laboratory, Materials
and Manufacturing Directorate, Wright-Patterson
Air Force Base, Ohio 45433-7750, United States
| |
Collapse
|
99
|
Abstract
Liquid crystal elastomers with tunable actuation strain are synthesized with simple techniques that enable complexly patterned actuation.
Collapse
Affiliation(s)
- T. H. Ware
- Materials and Manufacturing Directorate
- Air Force Research Laboratory
- Wright-Patterson Air Force Base
- USA
- Azimuth Corporation
| | - T. J. White
- Materials and Manufacturing Directorate
- Air Force Research Laboratory
- Wright-Patterson Air Force Base
- USA
| |
Collapse
|
100
|
Aharoni H, Sharon E, Kupferman R. Geometry of thin nematic elastomer sheets. PHYSICAL REVIEW LETTERS 2014; 113:257801. [PMID: 25554907 DOI: 10.1103/physrevlett.113.257801] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Indexed: 06/04/2023]
Abstract
A thin sheet of nematic elastomer attains 3D configurations depending on the nematic director field upon heating. In this Letter, we describe the intrinsic geometry of such a sheet and derive an expression for the metric induced by general nematic director fields. Furthermore, we investigate the reverse problem of constructing a director field that induces a specified 2D geometry. We provide an explicit recipe for how to construct any surface of revolution using this method. Finally, we show that by inscribing a director field gradient across the sheet's thickness, one can obtain a nontrivial hyperbolic reference curvature tensor, which together with the prescription of a reference metric allows dictation of actual configurations for a thin sheet of nematic elastomer.
Collapse
Affiliation(s)
- Hillel Aharoni
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Eran Sharon
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Raz Kupferman
- Institute of Mathematics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| |
Collapse
|