Liquid Crystal Elastomers as Actuators for Soft Robotics: A Review

Soft robotics relies on materials that are lightweight, flexible, and capable of large, reversible shape changes. Liquid crystal elastomers (LCEs) have become a leading candidate because they couple the orientational order of liquid crystals with the elasticity of polymer networks, enabling programmable deformation under thermal, optical, magnetic, or chemical stimuli. Over the past decade, advances in synthesis and processing have transformed LCEs from laboratory curiosities into increasingly practical actuator materials. This review surveys key developments from 2015 to 2025, highlighting progress in fabrication methods, actuation strategies, and emerging robotic applications. Techniques such as controlled crosslinking, additive manufacturing, fiber-based architectures, and field‑guided alignment now allow precise control over molecular orientation and actuator geometry. Recent innovations have improved mechanical robustness, responsiveness, and integration with multifunctional components, though challenges remain in achieving rapid actuation and scalable manufacturing. Overall, LCEs are evolving into a versatile platform for adaptive, high‑performance soft robotic systems, with continued advances in materials design and system‑level integration poised to expand their capabilities further.