Polarized Magnetic Hydrogel Microrobot Collectives for Efficient Cooperation and Self-Assembly

Microrobot collectives with good organizational manners provide a promising strategy to enable individual microrobots to tackle complex tasks. However, the current microrobot collectives are difficult to form robust connections among individuals. This paper proposes a novel design of the Polarized Magnetic Hydrogel Microrobot (PMHR) to strengthen the connections among individuals, thereby enhancing the efficiency of microrobot cooperation and self-assembly. The improved connections enable swift collective formation, dexterous manipulation, flexible locomotion for climbing obstacles, and resistance to harsh environmental disturbances. Experimental studies have been conducted on the PMHR for executing complex tasks such as swarm formation, resistance to fluid backflow, and object transportation, all controlled through external magnetic fields. The results show that PMHR can maintain stability and positioning under fluid flow, exert substantial forces to manipulate objects, and form dynamic and reconfigurable swarms. The results demonstrate the superior mobility and force exertion of PMHR compared to non-magnetized microspheres, emphasizing their potential for applications in micromanipulation, biomedical fields, and robotic systems.