Electrically activated artificial muscles made with liquid crystal elastomers

2000 ◽  
Author(s):  
Mohsen Shahinpoor
Keyword(s):  
Liquid Crystal ◽  
Artificial Muscles ◽  
Liquid Crystal Elastomers

scholarly journals Digital light processing of liquid crystal elastomers for self-sensing artificial muscles

2021 ◽  
Vol 7 (30) ◽  
pp. eabg3677
Author(s):  
Shuo Li ◽  
Hedan Bai ◽  
Zheng Liu ◽  
Xinyue Zhang ◽  
Chuqi Huang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Optical Transition ◽  
Orientational Order ◽  
Weight Ratio ◽  
Great Promise ◽  
Artificial Muscles ◽  
Specific Work ◽  
Digital Light Processing ◽  
Stimuli Responsive Polymers ◽  
Liquid Crystal Elastomers

Artificial muscles based on stimuli-responsive polymers usually exhibit mechanical compliance, versatility, and high power-to-weight ratio, showing great promise to potentially replace conventional rigid motors for next-generation soft robots, wearable electronics, and biomedical devices. In particular, thermomechanical liquid crystal elastomers (LCEs) constitute artificial muscle-like actuators that can be remotely triggered for large stroke, fast response, and highly repeatable actuations. Here, we introduce a digital light processing (DLP)–based additive manufacturing approach that automatically shear aligns mesogenic oligomers, layer-by-layer, to achieve high orientational order in the photocrosslinked structures; this ordering yields high specific work capacity (63 J kg−1) and energy density (0.18 MJ m−3). We demonstrate actuators composed of these DLP printed LCEs’ applications in soft robotics, such as reversible grasping, untethered crawling, and weightlifting. Furthermore, we present an LCE self-sensing system that exploits thermally induced optical transition as an intrinsic option toward feedback control.

Experimental Studies of Thermo-Induced Mechanical Effects in the Main-Chain Liquid Crystal Elastomers

2014 ◽  
Vol 896 ◽  
pp. 322-326 ◽  
Author(s):  
Supardi ◽  
Harsojo ◽  
Yusril Yusuf
Keyword(s):  
Liquid Crystal ◽  
Critical Temperature ◽  
Main Chain ◽  
Experimental Studies ◽  
Artificial Muscles ◽  
Direction Parallel ◽  
Mechanical Effects ◽  
Liquid Crystal Elastomers ◽  
Heating Up ◽  
Contraction And Expansion

Liquid crystal elastomers (LCEs), either side-chain LCEs (SCLCEs) or main-chain LCEs (MCLCEs), possess a combination of LC and elastic properties, and are expected to be used as artificial muscles. We experimentally investigated the thermo-induced mechanical effects showed by MCLCEs with four different crosslinker concentrations, i.e., 8%, 12%, 14% and 16%. The samples were heated up to the critical temperature and the images were recorded. The samples made the contraction in direction parallel to the director and the expansion in direction perpendicular to the director. Drastic changes occured when approaching the critical temperature, the greater the crosslinkers concentration the bigger the maximum contraction and expansion. The shape anisotropy expression showed that heating up to the critical temperature caused the system no longer in anisotropic state.

Artificial muscles based on liquid crystal elastomers

2006 ◽  
Vol 364 (1847) ◽  
pp. 2763-2777 ◽  
Author(s):  
Min-Hui Li ◽  
Patrick Keller
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Uv Light ◽  
Shape Change ◽  
Artificial Muscle ◽  
Isotropic Phase ◽  
Artificial Muscles ◽  
Stimuli Responsive ◽  
Liquid Crystal Elastomers ◽  
The Individual

This paper presents our results on liquid crystal (LC) elastomers as artificial muscle, based on the ideas proposed by de Gennes. In the theoretical model, the material consists of a repeated series of main-chain nematic LC polymer blocks, N, and conventional rubber blocks, R, based on the lamellar phase of a triblock copolymer RNR. The motor for the contraction is the reversible macromolecular shape change of the chain, from stretched to spherical, that occurs at the nematic-to-isotropic phase transition in the main-chain nematic LC polymers. We first developed a new kind of muscle-like material based on a network of side-on nematic LC homopolymers. Side-on LC polymers were used instead of main-chain LC polymers for synthetic reasons. The first example of these materials was thermo-responsive, with a typical contraction of around 35–45% and a generated force of around 210 kPa. Subsequently, a photo-responsive material was developed, with a fast photochemically induced contraction of around 20%, triggered by UV light. We then succeeded in preparing a thermo-responsive artificial muscle, RNR, with lamellar structure, using a side-on nematic LC polymer as N block. Micrometre-sized artificial muscles were also prepared. This paper illustrates the bottom-up design of stimuli-responsive materials, in which the overall material response reflects the individual macromolecular response, using LC polymer as building block.

scholarly journals Numerical Methods in Studies of Liquid Crystal Elastomers

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1650
Author(s):  
Madjid Soltani ◽  
Kaamran Raahemifar ◽  
Arman Nokhosteen ◽  
Farshad Moradi Kashkooli ◽  
Elham L. Zoudani
Keyword(s):  
Liquid Crystal ◽  
Numerical Models ◽  
Future Research ◽  
Artificial Muscles ◽  
Suitable Candidate ◽  
Numerical Studies ◽  
Wide Range ◽  
Electric And Magnetic Fields ◽  
Liquid Crystal Elastomers ◽  
External Stimuli

Liquid crystal elastomers (LCEs) are a type of material with specific features of polymers and of liquid crystals. They exhibit interesting behaviors, i.e., they are able to change their physical properties when met with external stimuli, including heat, light, electric, and magnetic fields. This behavior makes LCEs a suitable candidate for a variety of applications, including, but not limited to, artificial muscles, optical devices, microscopy and imaging systems, biosensor devices, and optimization of solar energy collectors. Due to the wide range of applicability, numerical models are needed not only to further our understanding of the underlining mechanics governing LCE behavior, but also to enable the predictive modeling of their behavior under different circumstances for different applications. Given that several mainstream methods are used for LCE modeling, viz. finite element method, Monte Carlo and molecular dynamics, and the growing interest and reliance on computer modeling for predicting the opto-mechanical behavior of complex structures in real world applications, there is a need to gain a better understanding regarding their strengths and weaknesses so that the best method can be utilized for the specific application at hand. Therefore, this investigation aims to not only to present a multitude of examples on numerical studies conducted on LCEs, but also attempts at offering a concise categorization of different methods based on the desired application to act as a guide for current and future research in this field.

Robust and Reprocessable Artificial Muscles Based on Liquid Crystal Elastomers with Dynamic Thiourea Bonds

2021 ◽  
pp. 2110360
Author(s):  
Jin‐Hyeong Lee ◽  
Jaehee Bae ◽  
Jae Hyuk Hwang ◽  
Moon‐Young Choi ◽  
Yong Seok Kim ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Artificial Muscles ◽  
Liquid Crystal Elastomers

Micro-Actuators:  When Artificial Muscles Made of Nematic Liquid Crystal Elastomers Meet Soft Lithography

2006 ◽  
Vol 128 (4) ◽  
pp. 1088-1089 ◽  
Author(s):  
Axel Buguin ◽  
Min-Hui Li ◽  
Pascal Silberzan ◽  
Benoit Ladoux ◽  
Patrick Keller
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Soft Lithography ◽  
Artificial Muscles ◽  
Micro Actuators ◽  
Liquid Crystal Elastomers

Mechano‐Optical Sensors Fabricated with Multilayered Liquid Crystal Elastomers Exhibiting Tunable Deformation Recovery

2021 ◽  
pp. 2104702
Author(s):  
Kyohei Hisano ◽  
Seiya Kimura ◽  
Kyosun Ku ◽  
Tomoki Shigeyama ◽  
Norihisa Akamatsu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Optical Sensors ◽  
Liquid Crystal Elastomers ◽  
Deformation Recovery

Thermomechanically active electrodes power work-dense soft actuators

Soft Matter ◽  
2021 ◽  
Author(s):  
Angel Martinez ◽  
Arul Clement ◽  
Junfeng Gao ◽  
Julia Kocherzat ◽  
Mohsen Tabrizi ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Metal ◽  
Chain Extender ◽  
Design Work ◽  
Liquid Crystal Elastomers ◽  
Soft Actuators ◽  
Dense Liquid

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.

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