Light‐Guided Dynamic Liquid Crystalline Elastomer Actuators enabled by Mussel Adhesive Protein Chemistry

Abstract Light‐guided soft actuators with dynamic polymer networks have drawn much attention in recent years. However, the application of such actuators is limited by their synthetic strategies, polymer structures, and shape‐morphing modes. This work reports a new class of liquid crystalline elastomer (LCE) actuators crosslinked by mussel‐inspired catechol‐Fe (III) complexes. The actuators are mechanically strong while being self‐healable, shape‐reprogrammable, and reprocessable. Importantly, the formation of catechol‐Fe (III) complexes enables the single‐component LCE network to exhibit outstanding photothermal effects without any light‐absorbing additives. Thus, actuators with designable structures and complex shape‐morphing capabilities can be readily programmed with mechanical force coupled with either environmental heating or NIR light irradiation. Furthermore, the material platform provides a robust and flexible way to fabricate actuators with different dimensional structures varying from 1D to 3D. The LCE shows great potential in robotic fields, and as a proof‐of‐concept, a crawling robot, C‐Bot, is specially designed. The robot is capable of moving untethered both on solid‐substrate and water surfaces under the guidance of light based on the mechanisms of shape‐morphing and Marangoni propulsion, respectively. Surprisingly, different from the vast majority of previously reported LCE‐based robots, the C‐Bot is strong enough to carry a heavy load while moving.