Thermo-magnetic soft robot for adaptive locomotion and delivery

Abstract

Soft robots based on stimuli-responsive materials, such as those responsive to thermal, magnetic, or light stimuli, hold great potential for adaptive locomotion and multifunctionality in complex environments. Among these, liquid crystal elastomers (LCEs) and magnetic microparticles have emerged as particularly promising candidates, leveraging their thermal responsiveness and magnetic controllability, respectively. However, integrating these modes to achieve synergistic multimodal actuation remains a significant challenge. Here, we present the thermo-magnetic petal morphing robot, which combines LCEs with embedded magnetic microparticles to enable reversible shape morphing via remote light-to-thermal actuation and high-speed rolling locomotion under external magnetic fields. The robot can achieve rapid deformation under near-infrared light, transitioning from a closed spherical to an open cross-like configuration with consistent shape recovery across multiple cycles, and demonstrates a maximum locomotion speed of 30 body lengths per second, outperforming many state-of-the-art soft robots. Moreover, the robot's performance remains robust across dry, wet, and underwater conditions, with adjustable magnetic particle concentrations allowing tunable actuation performance. Our work addresses the need for soft robots with enhanced versatility and adaptability in complex environments, paving the way for applications in areas such as targeted drug delivery and industrial material handling.