Nature-Inspired Liquid Crystal Polymer Actuators: From Alignment Regulation to Nano-composition

Liquid crystal polymers (LCPs) that possess crosslinked networks and ordered alignment of mesogens are renowned for their large and reversible anisotropic deformation in response to external stimuli, which holds great potential in the burgeoning field of nature-inspired actuators and robots. Continuous efforts have been made in revealing the interplay between materials chemistry, processing, and alignment of LCPs, to broaden the actuation modes and enhance the actuation performance toward practical utilization. In this review, the advances in nature-inspired LCP actuators is focused with special attentions devoted in their mesogen alignment and the macroscopic geometry. Since the mesogen alignment is vital for the attainable actuation modes, the methods for alignment regulating are detailly combed, including surface-enforced alignment, field-assisted alignment, mechanical alignment, rheological alignment, and self-assembly. Subsequently, the composition of nanomaterials is futher surveyed in LCP actuators with a focus on enhancing the actuation performance. Finally, perspectives on the current challenges and potential development trends are discussed, which may shed light on future investigations.