A Folding Magnetic Soft Sheet Robot With Real‐Time Reconfigurable Magnetization for Targeted Drug Delivery

ABSTRACT Magnetic soft robots have the characteristics of small size, noncable drive, and motion agility, which are suitable for medical operations in the gastrointestinal tract. However, multiangle folding and reconfigurable magnetization have yet to be fully investigated, and thus, the study of magnetic soft robots with morphological changes and medical functions is still challenging. To this end, we propose a magnetic soft sheet robot based on the magnetorheological fluids, which presents a remarkable capability for reversible folding motion, rapid real‐time reconfigurable magnetization, and targeted drug delivery functions. Furthermore, the robot has a fully soft sheet structure that is not magnetized in a zero magnetic field. After folding, the surface area of the soft sheet robot can be reduced to one third of its original area to cope with the complex gastrointestinal cavities. Five kinds of soft sheet robot prototypes with different magnetic driving abilities are fabricated, and the movement experiments of these robots are carried out on a smooth surface, a flexible fluff surface, a slope surface, underwater, and under load, respectively. The influence mechanisms of different magnetic field strengths and frequencies on robot movement are analyzed. The effectiveness of the proposed scheme is verified by ex vivo porcine stomach experiments and ultrasonic detection.