A magnetic soft robot with multimodal sensing capability by multimaterial direct ink writing

The all-in-one integration of materials, structures and sensors for next-generation magnetic soft robots is a promising avenue to interact with external surroundings. However, few surroundings-perceiving magnetic soft robots have been reported due to the lack of effective material design and fabrication process. Herein, a multimaterial direct ink writing (M2DIW) process is utilized to accomplish the one-step fabrication of magnetic soft materials and flexible sensing materials, completing seamless integrations between magnetic soft robots and flexible electronics. The magnetic actuation mechanism is discussed theoretically and multi-dimensional deformations of the robot are demonstrated experimentally. The seamless integration design of the multimaterial system endows the robot with sensing abilities for temperature (a linearity of 3.383 kΩ/°C), tactile (i.e., material recognition) and electrochemical (a detection limit of 0.036 mM for NaOH solutions) stimuli. As a proof-of-concept example, the experiment of targeted drug delivery by the robot is performed and the integrated sensors detect the surrounding concentration changes induced by the drug dissolutions for a quantitative evaluation of drug delivery. As such, the proposed magnetic soft robot integrated with multimodal sensing functions will shed light on the development of next-generation magnetic soft robots.