Shape-Switchable Liquid-Crystal Polymer Actuators with Light-Induced Shape Memory Effect

The initial shape of a soft actuator plays a vital role in its functional performance as it dictates the internal stress distribution and deformation pathway during the actuation process. Photodeformable liquid-crystal polymers (LCPs) have demonstrated significant potential in soft actuators due to their fast, localized, precise, and reversible deformation under light irradiation. However, the initial shape of LCP actuators is generally nonswitchable once fabricated, limiting them to a single deformation mode and monofunctionality. Herein, we present a strategy for fabricating shape-switchable LCP actuators by integrating an athermal light-induced shape memory effect (SME) into photodeformable LCP systems. The reversible photodimerization of coumarins introduces an additional crosslinking network that regulates the mobility of molecular chains, enabling LCPs to exhibit a light-induced SME for shape-switching. Moreover, the photothermal effect of disperse red 1 acrylate induces mesogen alignment changes under 470 nm light irradiation, allowing for the independent actuation of each switched shape. Leveraging this unique shape-switching mechanism, we fabricated a soft actuator capable of transforming among multiple motion modes, including rolling, crawling, and gripping, for the first time. This study establishes a novel design paradigm for developing multimorphology and multifunctional soft actuators, advancing the complexity and versatility of LCP-based intelligent systems.