Large-Scale Swarm Control of Microrobots by a Hybrid-Style Magnetic Actuation System

Microrobot swarms have powerful functions and reconfigurable collective behaviors, which enable them to be a possible way to completely solve the low execution efficiency and poor practicability of a single microrobot. However, some general deficiencies hinder the advancement of research in the application of microrobot swarms. For example, the limited number of individuals and the tiny spatial size make the current microrobot swarms too insignificant to meet practical needs. To release these restrictions, we designed a hybrid-style magnetic actuation control system that integrates the electromagnetic coils and permanent magnet. This hybrid-style actuation system can generate customized magnetic fields spatiotemporally, including powerful rotating and gradient magnetic fields, which enables the emergence of a large-scale magnetic microrobot swarm (LMMS) under the coupling effect of the magnetic field and gradient. Besides, the LMMS based on ferrofluid droplets is studied to verify the actuation system's feasibility, with a series of control strategies being proposed accordingly and the performance of the actuation system being discussed theoretically by mathematical models. Finally, physical or simulation experiments were carried out on these bases, demonstrating that the aforementioned method can realize the controllable emergence, dispersion, and locomotion of the LMMS with excellent manipulation ability and maneuverability.