Liquid Crystal Elastomers with Mechanical Properties of a Muscle

2001 ◽  
Vol 34 (17) ◽  
pp. 5868-5875 ◽  
Author(s):  
Donald L. Thomsen ◽  
Patrick Keller ◽  
Jawad Naciri ◽  
Roger Pink ◽  
Hong Jeon ◽  
...  
Soft Matter ◽  
2018 ◽  
Vol 14 (31) ◽  
pp. 6449-6462 ◽  
Author(s):  
D. Rogez ◽  
S. Krause ◽  
P. Martinoty

The shear and Young moduli, the poly-domain to mono-domain transition, the Poisson ratio and the supercritical or subcritical nature of main-chain and side-chain liquid-crystal elastomers are characterized with various mechanical experiments.


2016 ◽  
Vol 17 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Santosh A. Mani ◽  
Sameer U. Hadkar ◽  
P. J. Jessy ◽  
Suman Lal ◽  
Patrick Keller ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3094
Author(s):  
Yoojin Lee ◽  
Subi Choi ◽  
Beom-Goo Kang ◽  
Suk-kyun Ahn

Among the various types of shape changing materials, liquid crystal elastomers (LCEs) have received significant attention as they can undergo programmed and reversible shape transformations. The molecular engineering of LCEs is the key to manipulating their phase transition, mechanical properties, and actuation performance. In this work, LCEs containing three different types of butyl groups (n-, iso-, and sec-butyl) in the side chain were synthesized, and the effect of isomeric amine chain extenders on the thermal, mechanical, and actuation properties of the resulting LCEs was investigated. Because of the considerably low reactivity of the sec-butyl group toward the diacrylate in the LC monomer, only a densely crosslinked LCE was synthesized. Most interestingly, the mechanical properties, actuation temperature, and blocking stress of the LCEs comprising isobutyl groups were higher than those of the LCEs comprising n-butyl groups. This difference was attributed to the presence of branches in the LCEs with isobutyl groups, which resulted in a tighter molecular packing and reduced the free volume. Our results suggest a facile and effective method for synthesizing LCEs with tailored mechanical and actuation properties by the choice of chain extenders, which may advance the development of soft actuators for a variety of applications in aerospace, medicine, and optics.


2021 ◽  
pp. 2104702
Author(s):  
Kyohei Hisano ◽  
Seiya Kimura ◽  
Kyosun Ku ◽  
Tomoki Shigeyama ◽  
Norihisa Akamatsu ◽  
...  

Soft Matter ◽  
2021 ◽  
Author(s):  
Angel Martinez ◽  
Arul Clement ◽  
Junfeng Gao ◽  
Julia Kocherzat ◽  
Mohsen Tabrizi ◽  
...  

The effect of chain extender structure and composition on the properties of liquid crystal elastomers (LCE) is presented. Compositions are optimized to design work-dense liquid metal LCE composites that are operated with 100 mW power.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Takuya Ohzono ◽  
Kaoru Katoh ◽  
Hiroyuki Minamikawa ◽  
Mohand O. Saed ◽  
Eugene M. Terentjev

AbstractNematic liquid crystal elastomers (N-LCE) exhibit intriguing mechanical properties, such as reversible actuation and soft elasticity, which manifests as a wide plateau of low nearly-constant stress upon stretching. N-LCE also have a characteristically slow stress relaxation, which sometimes prevents their shape recovery. To understand how the inherent nematic order retards and arrests the equilibration, here we examine hysteretic stress-strain characteristics in a series of specifically designed main-chain N-LCE, investigating both macroscopic mechanical properties and the microscopic nematic director distribution under applied strains. The hysteretic features are attributed to the dynamics of thermodynamically unfavoured hairpins, the sharp folds on anisotropic polymer strands, the creation and transition of which are restricted by the nematic order. These findings provide a new avenue for tuning the hysteretic nature of N-LCE at both macro- and microscopic levels via different designs of polymer networks, toward materials with highly nonlinear mechanical properties and shape-memory applications.


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