Manufacturing and applications in soft robotics of liquid crystal elastomer actuators

Soft robotics is driving a paradigm shift in conventional rigid robotics by fostering adaptable and safe interactions within dynamic environments. At the forefront of this advancement are liquid crystal elastomer (LCE) actuators, which offer programmable, reversible deformations triggered by various external stimuli. This review provides a comprehensive analysis of LCE actuators, focusing on their alignment strategies, actuation mechanisms, and diverse application potential. Various alignment methods, such as mechanical, external-field (including electric and magnetic), and surface-based techniques, are introduced as effective approaches to tailor mesogen orientation for optimized actuation. Furthermore, we analyze different actuation mechanisms, including heat-, external field-, and light-driven methods, and their distinct advantages for specific applications. The versatility of LCE actuators is showcased through their applications in artificial muscle systems, soft robotic manipulators and grippers, adaptive locomotion, and complex shape-morphing structures. Additionally, this review critically examines the challenges that must be addressed for LCE commercialization, such as manufacturing scalability, mechanical durability, performance optimization, and material safety. Finally, we outline future research directions aimed at overcoming these limitations and unlocking the full potential of LCE technology in next-generation soft robotics. By highlighting the transformative capabilities of LCE actuators, this review underscores their pivotal role in advancing intelligent and reconfigurable robotic l.