scholarly journals Liquid Crystal Elastomers for Biological Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 813
Author(s):  
Mariam Hussain ◽  
Ethan I. L. Jull ◽  
Richard J. Mandle ◽  
Thomas Raistrick ◽  
Peter J. Hine ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Stimuli Responsive ◽  
Absorption Properties ◽  
Liquid Crystal Elastomer ◽  
Cell Scaffolds ◽  
Artificial Tissue ◽  
Recent Developments ◽  
Liquid Crystal Elastomers ◽  
Potential Use

The term liquid crystal elastomer (LCE) describes a class of materials that combine the elastic entropy behaviour associated with conventional elastomers with the stimuli responsive properties of anisotropic liquid crystals. LCEs consequently exhibit attributes of both elastomers and liquid crystals, but additionally have unique properties not found in either. Recent developments in LCE synthesis, as well as the understanding of the behaviour of liquid crystal elastomers—namely their mechanical, optical and responsive properties—is of significant relevance to biology and biomedicine. LCEs are abundant in nature, highlighting the potential use of LCEs in biomimetics. Their exceptional tensile properties and biocompatibility have led to research exploring their applications in artificial tissue, biological sensors and cell scaffolds by exploiting their actuation and shock absorption properties. There has also been significant recent interest in using LCEs as a model for morphogenesis. This review provides an overview of some aspects of LCEs which are of relevance in different branches of biology and biomedicine, as well as discussing how recent LCE advances could impact future applications.

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

Soft Matter ◽  
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.

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

2015 ◽  
Vol 3 (17) ◽  
pp. 4424-4430 ◽  
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.

scholarly journals Effect of Crosslinkers on Optical and Mechanical Behavior of Chiral Nematic Liquid Crystal Elastomers

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6193
Author(s):  
Kyosun Ku ◽  
Kyohei Hisano ◽  
Kyoko Yuasa ◽  
Tomoki Shigeyama ◽  
Norihisa Akamatsu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Polymer Network ◽  
Molar Ratio ◽  
Stimuli Responsive ◽  
Breaking Strain ◽  
Responsive Materials ◽  
Sensor Applications ◽  
Color Changes ◽  
Chiral Nematic ◽  
Liquid Crystal Elastomers

Chiral nematic (N*) liquid crystal elastomers (LCEs) are suitable for fabricating stimuli-responsive materials. As crosslinkers considerably affect the N*LCE network, we investigated the effects of crosslinking units on the physical properties of N*LCEs. The N*LCEs were synthesized with different types of crosslinkers, and the relationship between the N*LC polymeric system and the crosslinking unit was investigated. The N*LCEs emit color by selective reflection, in which the color changes in response to mechanical deformation. The LC-type crosslinker decreases the helical twisting power of the N*LCE by increasing the total molar ratio of the mesogenic compound. The N*LCE exhibits mechano-responsive color changes by coupling the N*LC orientation and the polymer network, where the N*LCEs exhibit different degrees of pitch variation depending on the crosslinker. Moreover, the LC-type crosslinker increases the Young’s modulus of N*LCEs, and the long methylene chains increase the breaking strain. An analysis of experimental results verified the effect of the crosslinkers, providing a design rationale for N*LCE materials in mechano-optical sensor applications.

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

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.

Swelling dynamics of liquid crystal elastomers swollen with low molecular weight liquid crystals

2004 ◽  
Vol 69 (2) ◽  
Author(s):  
Yusril Yusuf ◽  
Yukitada Ono ◽  
Yusuke Sumisaki ◽  
P. E. Cladis ◽  
Helmut R. Brand ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Low Molecular Weight ◽  
Liquid Crystal Elastomers

Force Characterization of Hygroscopic Liquid Crystal Elastomers

2010 ◽  
Author(s):  
Michael R. Hays ◽  
Hongbo Wang ◽  
William S. Oates
Keyword(s):  
Liquid Crystal ◽  
Water Vapor ◽  
Water Source ◽  
Vapor Source ◽  
Measuring Device ◽  
Liquid Crystal Elastomer ◽  
Liquid Crystal Elastomers ◽  
Response To Water ◽  
Water Vapor Source

The actuation forces of a hydrophilic liquid crystal elastomer (LCE) in response to water vapor was tested and modeled. These materials exhibit asymmetric swelling as water vapor is absorbed into one side of the elastomer film. This gives rise to deflection away from the water source. Deformation due to water vapor has shown to be on the order of seconds and is reversible which provides unique sensing and actuation characteristics for elastomer films. The constitutive behavior is modeled by using nonlinear continuum mechanics to predict internal changes in density of the liquid crystal elastomer and subsequent deformation by correlating moisture exposure with changes in the elastomer’s density. In order to compare the model and obtain a set material parameters, a micro-Newton measuring device was designed and tested to quantify the forces generated in the liquid crystal elastomer under bending. Forces ranging between 1 to 8 μN were measured as a function of the location of the water vapor source. The results provide important insight into chemical force response and sensing for a number of biomedical and microfluidic applications.

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

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 315 ◽  
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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