Magnetically Switchable Adhesive Millirobots for Universal Manipulation in both Air and Water.

Magnetic soft robots with multimodal locomotion have demonstrated significant potential for target manipulation tasks in hard-to-reach spaces in recent years. Achieving universal manipulation between robots and their targets requires a nondestructive and easily switchable interaction with broad applicability across diverse targets. However, establishing versatile and dynamic interactions between diverse targets and robotic systems remains a significant challenge. Herein, a series of magnetic millirobots capable of universal target manipulation with magnetically switchable adhesion is reported. Through two-photon lithography-assisted molding, magnetic soft double-reentrant micropillar arrays with liquid repellency are fabricated on the robots. These micropillar arrays can serve as switchable adhesion units for the millirobots to effectively manipulate targets of various geometries (0D, 1D, 2D, and 3D) in both air and water. As proof-of-concept demonstrations, these adhesive robots can perform various complex tasks, including circuit repair, mini-turbine assembly, and high-speed underwater rotation of the turbine machine. This work may offer a versatile approach to magnetic manipulation of non-magnetic objects through amphibious adhesion, emerging as a new paradigm in robotic manipulation.