Tuning the functionality of liquid crystal elastomer composites

Liquid crystal elastomers, or LCEs, are used in a wide variety of highly technical applications including soft robotics, photonic devices, displays, and tissue engineering. Wang et al. reviewed recent advances in composites made with these unique materials.

LCEs are more efficient and programmable than conventional isotropic materials. However, LCEs often have limitations to the range of their anisotropic properties including the need for heat to induce actuation.

Because of the large prevalence of research and literature centered on LCEs, the authors chose to review the increasingly popular research field of LCE composites. The composites offer higher degrees of responsiveness and tunability than LCEs.

“By putting nanofillers such as metallic and magnetic nanoparticles into the LCEs, you can go beyond heat to actuate the LCEs,” said co-author Yuchen Wang.

The resulting composites can be photo-responsive, electro-responsive, magnetic-responsive, or controlled remotely.

“LCE composites could achieve higher mechanical strength and faster response time, which are critical for soft robotic applications,” said co-author Jiaqi Liu.

“The ability to introduce different materials into LCE composites allows for responses to different cues,” said co-author Shu Yang. “Each response can be individually addressable or even work together with multiple responses.”

According to the authors, future work in LCE composites will center on embedding both chemical and physical intelligence with extra degrees of controllability via geometries. They also stress that research could be directed toward biocompatible and sustainable LCE composites using natural materials such as cellulose nanocrystals and silk fibers.

Source: “Multi-functional liquid crystal elastomer composites,” by Yuchen Wang, Jiaqi Liu, and Shu Yang. Applied Physics Reviews (2021). The article can be accessed at https://doi.org/10.1063/5.0075471 .