Chiral Liquid Crystalline Elastomer for Twisting Motion without Preset Alignment of Mesogens

A chiral liquid crystalline elastomer (CLCE) actuator is demonstrated. The solution-cast polydomain film of CLCE can twist upon order-disorder phase transition without any preset alignment of mesogens. The handedness of twisting is specific to the molecular chirality of the chiral dopant in the CLCE structure, while the degree of twisting, in terms of helical pitch and diameter, is sensitive to the aspect ratio and the thickness of the CLCE strip as well as the chiral dopant content. This phenomenon appears to stem from the local twisting forces and deformations of randomly oriented helical domains, which cannot cancel each other out due to the chirality and thus result in a macroscopic chiral force acting on the CLCE actuator. This finding reveals a materials design for preparing twisting LCE actuators.

Automated summary

A new type of chiral liquid crystalline elastomer (CLCE) actuator is demonstrated in this study, which can twist without any preset alignment. The direction and degree of twisting are influenced by various factors, including the molecular chirality of the chiral dopant, the aspect ratio and thickness of the CLCE strip, and the chiral dopant content.