A Multimodal Magnetically Driven Soft Robot With Integrated Actuation-Sensing Based on Photothermal Reprogramming...

Conventional magnetic soft robots are fundamentally limited by static magnetization profiles and the absence of integrated perception, which restricts their adaptive functionality and environmental interactivity in dynamic settings. To address these challenges, we introduce a photothermal reprogramming strategy utilizing custom-designed PEG/SmFeN microspheres. Within these microspheres, the intrinsic photothermal effect of SmFeN particles enables selective rewriting of magnetic domains through near-infrared-induced solid-liquid phase transitions. This approach allows a single robot to achieve multiple locomotion modes and execute sophisticated shape transformations. The robot rolls substantially faster than it creeps, and the multi-legged configuration further enhances locomotion, achieving a maximum speed of 1.8 BL/s (27 mm/s) in the multi-legged rolling mode. Furthermore, a liquid-metal Archimedean spiral capacitive sensor is integrated via microelectronic printing to form an actuation-sensing system. This integrated sensor detects environmental changes and monitors self-motion through identifiable capacitance patterns while maintaining stable operation over 100 cycles. In a simulated gastric environment, the system successfully distinguishes between rolling and creeping gaits while tracking terrain interaction, demonstrating its potential for minimally invasive medical procedures and targeted therapy. Together, these capabilities set the stage for adaptive soft robots with spatially programmable actuation, integrated multimodal sensing, and a thermally safe reprogramming profile suitable for biomedical use.