Light-Actuated Liquid Crystal Elastomer Prepared by Projection Display

Soft materials with programmability have been widely used in drug delivery, tissue engineering, artificial muscles, biosensors, and related biomedical engineering applications. Liquid crystal elastomers (LCEs) can easily morph into three-dimensional (3D) shapes by external stimuli such as light, heat, and humidity. In order to program two-dimensional (2D) LCE sheets into desired 3D morphologies, it is critical to precisely control the molecular orientations in LCE. In this work, we propose a simple photopatterning method based on a maskless projection display system to create spatially varying molecular orientations in LCE films. By designing different synchronized rotations of the polarizer and projected images, diverse configurations ranging from individual to 2D lattice of topological defects are fabricated. The proposed technique significantly simplified the photopatterning procedure without using fabricated masks or waveplates. Shape transformations such as a cone and a truncated square pyramid, and functionality mimicking the responsive Mimosa Pudica are demonstrated in the fabricated LCE films. The programmable LCE morphing behaviors demonstrated in this work will open opportunities in soft robotics and smart functional devices.

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Toward Programmed Complex Stress-Induced Mechanical Deformations of Liquid Crystal Elastomers

Crystals ◽

10.3390/cryst10040315 ◽

2020 ◽

Vol 10 (4) ◽

pp. 315 ◽

Cited By ~ 1

Author(s):

Devesh Mistry ◽

Helen F. Gleeson

Keyword(s):

Liquid Crystal ◽

Complex Stress ◽

Stress Distributions ◽

Director Field ◽

Liquid Crystal Elastomer ◽

Mechanical Responses ◽

Mechanical Deformations ◽

Nonlinear Mechanical ◽

Liquid Crystal Elastomers ◽

Spatially Varying

We prepare a liquid crystal elastomer (LCE) with a spatially patterned liquid crystal director field from an all-acrylate LCE. Mechanical deformations of this material lead to a complex and spatially varying deformation with localised body rotations, shears and extensions. Together, these dictate the evolved shape of the deformed film. Using polarising microscopy, we map the local rotation of the liquid crystal director in Eulerian and Lagrangian frames and use these to determine rules for programming complex, stress-induced mechanical shape deformations of LCEs. Moreover, by applying a recently developed empirical model for the mechanical behaviour of our LCE, we predict the non-uniform stress distributions in our material. These results show the promise of empirical approaches to modelling the anisotropic and nonlinear mechanical responses of LCEs which will be important as the community moves toward realising real-world, LCE-based devices.

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Shape-programmable liquid crystal elastomer structures with arbitrary three-dimensional director fields and geometries

Nature Communications ◽

10.1038/s41467-021-26136-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yubing Guo ◽

Jiachen Zhang ◽

Wenqi Hu ◽

Muhammad Turab Ali Khan ◽

Metin Sitti

Keyword(s):

Liquid Crystal ◽

Three Dimensional ◽

Heterogeneous Material ◽

Two Dimensions ◽

Three Dimensions ◽

Field Orientation ◽

Liquid Crystal Elastomer ◽

Material Sample ◽

Liquid Crystal Elastomers ◽

Thermally Triggered

AbstractLiquid crystal elastomers exhibit large reversible strain and programmable shape transformations, enabling various applications in soft robotics, dynamic optics, and programmable origami and kirigami. The morphing modes of these materials depend on both their geometries and director fields. In two dimensions, a pixel-by-pixel design has been accomplished to attain more flexibility over the spatial resolution of the liquid crystal response. Here we generalize this idea in two steps. First, we create independent, cubic light-responsive voxels, each with a predefined director field orientation. Second, these voxels are in turn assembled to form lines, grids, or skeletal structures that would be rather difficult to obtain from an initially connected material sample. In this way, the orientation of the director fields can be made to vary at voxel resolution to allow for programmable optically- or thermally-triggered anisotropic or heterogeneous material responses and morphology changes in three dimensions that would be impossible or hard to implement otherwise.

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Effect of stretching angle on the stress plateau behavior of main-chain liquid crystal elastomers

Soft Matter ◽

10.1039/d0sm02244f ◽

2021 ◽

Vol 17 (11) ◽

pp. 3128-3136

Author(s):

Suzuka Okamoto ◽

Shinichi Sakurai ◽

Kenji Urayama

Keyword(s):

Liquid Crystal ◽

Main Chain ◽

Stress Plateau ◽

Liquid Crystal Elastomer ◽

Ultimate Elongation ◽

Liquid Crystal Elastomers

Stretching angle for a main-chain liquid crystal elastomer has pronounced effects on the width of the stress plateau as well as the ultimate elongation, while it has no effect on the plateau height.

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A new pathway for the formation of radial nematic droplets within a lipid-laden aqueous-liquid crystal interface

RSC Advances ◽

10.1039/c3ra48044e ◽

2014 ◽

Vol 4 (36) ◽

pp. 18889-18893 ◽

Cited By ~ 17

Author(s):

Sumyra Sidiq ◽

Dibyendu Das ◽

Santanu Kumar Pal

Keyword(s):

Liquid Crystal ◽

Topological Defects ◽

Soft Materials ◽

Stimuli Responsive ◽

First Time ◽

Crystal Interface

A new pathway for the formation of liquid crystal (LC) droplets with radial LC ordering is reported for the first time in the presence of surfactants and lipids. Interactions of an enzyme with the topological defects in the LC mediate the response of these droplets and thus provide new designs for stimuli-responsive soft materials.

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Quantification of internal strain in bent soft materials by a cholesteric liquid crystal elastomer

Liquid Crystals XXV ◽

10.1117/12.2595838 ◽

2021 ◽

Author(s):

Masayuki Kishino ◽

Norihisa Akamatsu ◽

Shoichi Kubo ◽

Kyohei Hisano ◽

Osamu Tsutsumi ◽

...

Keyword(s):

Liquid Crystal ◽

Cholesteric Liquid Crystal ◽

Soft Materials ◽

Internal Strain ◽

Liquid Crystal Elastomer

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Bio-inspired thermal-responsive inverse opal films with dual structural colors based on liquid crystal elastomer

Journal of Materials Chemistry C ◽

10.1039/c5tc00548e ◽

2015 ◽

Vol 3 (17) ◽

pp. 4424-4430 ◽

Cited By ~ 37

Author(s):

Huihui Xing ◽

Jun Li ◽

Jinbao Guo ◽

Jie Wei

Keyword(s):

Liquid Crystal ◽

Inverse Opal ◽

Liquid Crystal Elastomer ◽

Structural Colors ◽

Thermal Switching ◽

Liquid Crystal Elastomers

The fabrication of inverse opal micropatterns based on liquid crystal elastomers with dual structural colors and their thermal switching behaviors are described.

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Remote control of liquid crystal elastomer random laser using external stimuli

Applied Physics Letters ◽

10.1063/1.5038663 ◽

2018 ◽

Vol 113 (1) ◽

pp. 013701 ◽

Cited By ~ 9

Author(s):

Anjani Kumar Tiwari ◽

Lorenzo Pattelli ◽

Renato Torre ◽

Diederik S. Wiersma

Keyword(s):

Liquid Crystal ◽

Remote Control ◽

Random Laser ◽

Liquid Crystal Elastomer ◽

External Stimuli

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Topology control of human fibroblast cells monolayer by liquid crystal elastomer

Science Advances ◽

10.1126/sciadv.aaz6485 ◽

2020 ◽

Vol 6 (20) ◽

pp. eaaz6485 ◽

Cited By ~ 11

Author(s):

Taras Turiv ◽

Jess Krieger ◽

Greta Babakhanova ◽

Hao Yu ◽

Sergij V. Shiyanovskii ◽

...

Keyword(s):

Liquid Crystal ◽

Orientational Order ◽

Topological Defects ◽

Density Fluctuations ◽

Dermal Fibroblasts ◽

Produce Cell ◽

Surface Anchoring ◽

Liquid Crystal Elastomer ◽

Anisotropic Surface ◽

Living Tissues

Eukaryotic cells in living tissues form dynamic patterns with spatially varying orientational order that affects important physiological processes such as apoptosis and cell migration. The challenge is how to impart a predesigned map of orientational order onto a growing tissue. Here, we demonstrate an approach to produce cell monolayers of human dermal fibroblasts with predesigned orientational patterns and topological defects using a photoaligned liquid crystal elastomer (LCE) that swells anisotropically in an aqueous medium. The patterns inscribed into the LCE are replicated by the tissue monolayer and cause a strong spatial variation of cells phenotype, their surface density, and number density fluctuations. Unbinding dynamics of defect pairs intrinsic to active matter is suppressed by anisotropic surface anchoring allowing the estimation of the elastic characteristics of the tissues. The demonstrated patterned LCE approach has potential to control the collective behavior of cells in living tissues, cell differentiation, and tissue morphogenesis.

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Deuteron NMR investigation on orientational order parameter in polymer dispersed liquid crystal elastomers

Physical Chemistry Chemical Physics ◽

10.1039/d0cp04143b ◽

2020 ◽

Vol 22 (40) ◽

pp. 23064-23072

Author(s):

Andraž Rešetič ◽

Jerneja Milavec ◽

Valentina Domenici ◽

Blaž Zupančič ◽

Alexej Bubnov ◽

...

Keyword(s):

Liquid Crystal ◽

Order Parameter ◽

Orientational Order ◽

Orientational Order Parameter ◽

Liquid Crystal Elastomer ◽

H Nmr ◽

Polymer Dispersed Liquid Crystal ◽

Polymer Dispersed ◽

Liquid Crystal Elastomers ◽

Magnetically Aligned

Orientational order parameter of magnetically aligned liquid crystal elastomer particles suspended in a cured silicone matrix is assessed using 2H-NMR spectroscopy. Obtained results correspond well with the composite's thermomechanical response.

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