A Mechano-Electromagnetic Hybrid Actuation System for Multimodal Control of Magnetic Microrobots

The motion of magnetic microrobots relies on an external magnetic field. Current electromagnetic propulsion systems are often complex in structural design, challenging in control strategies, and associated with high energy consumption. In this study, we introduce a mechano-electromagnetic hybrid actuation system that employs only a pair of Helmholtz coils to generate an oscillating uniform magnetic field, combined with a rotating platform to modify the field’s direction, thereby enabling the control of microrobot speed and direction. The properties of this hybrid actuation system were modeled and validated to analyze the magnetic field distribution within the workspace. The design and actuation of two microrobots are described in detail. Furthermore, a visual feedback closed-loop control strategy for the system was developed. A series of navigation control experiments were conducted, demonstrating that the proposed hybrid actuation system achieves effective microrobot actuation and precise control while reducing manufacturing costs and simplifying control strategies. The proposed novel mechano-electromagnetic hybrid structure contributes to the field of electromagnetically driven systems and magnetically controlled microrobots. Note to Practitioners—This paper was motivated by the importance of electromagnetic field in the actuation and control of magnetic microrobots which have shown significant potential in medical and bioengineering applications. In this paper, we propose a mechano-electromagnetic hybrid actuation system that utilizes only a pair of Helmholtz coils to generate an oscillating uniform magnetic field, with a rotating platform to alter the magnetic field’s direction, thereby controlling the motion speed and direction of microrobots. The results demonstrate that the proposed system achieves effective microrobot actuation and precise control with reduced manufacturing costs and simpler control strategies.