Biped Walking of Magnetic Microrobot in Oscillating Field for Indirect Manipulation of Non-Magnetic Objects

Magnetic microrobots have been developed for various biomedical applications, such as microswimmers for indirect manipulation and assembly of objects. When non-magnetic targets fall or adhere to the substrate by gravity, the indirect manipulation is required tomove objects on substrate surface. Inspired by human walking, a novel magnetic microrobot with two pseudopods was designed. Driven by a periodic magnetic field, the structure can subtly lift and move two feet alternately to walk forward. The amplitude and frequency of oscillation were optimized and the controllability of the system was evaluated through performing the motion along planned paths with a velocity of 3.5 mm/s. Finally, microbeads and cell aggregates were pushed and arranged together by the microrobot, which shows potential application in flexible microassembly on substrate surface.