Magnetic soft actuator with self-sensing capability

Abstract

Magnetic soft robots have shown great potential in biomedical engineering due to their non-contact actuation and rapid response. For intelligent control of magnetic soft robots, the integration of driving and sensing capability is crucial but still remains challenging. Previous studies on self-sensing magnetic actuators have always utilized multi-layer structures, which introduce issues of interfacial adhesion and complex fabrication. Here, we have developed a single-layer magnetic soft actuator with self-sensing capability. The actuator is fabricated using a functional composite with graphene and magnetic particles embedded in an elastomer matrix. Magnetic particles enable actuation, while graphene enables electrical sensing. We have quantified the sensing performance of the functional composite and demonstrated its capability to monitor motions of a human joint and robotic arm. Utilizing the photothermal conversion of graphene, we further designed self-feedback systems with integration of driving and sensing capabilities. The self-feedback system can be used as an electronic switch responding to environmental changes and used as a protection system similar to the reflex of human fingers. This work may provide a facile strategy for intelligent and autonomous control of magnetic soft robots.