Selective Magnetic Field Generation Method for Effective Manipulation of Two-Dimensional Magnetic Microrobots Using a Triad of Electromagnetic Coils.

This study proposes a new method for effectively manipulating a magnetic microrobot in a two-dimensional manner using a triad of electromagnetic coils (TEC). A TEC is a system consisting of three circular coils of the same type arranged in the form of a triangle. It has a simple structure and exhibits magnetic symmetry. This study sought to develop a method to more accurately manipulate and reduce the energy consumption of microrobots using a TEC. This was accomplished by selectively using individual coils of a TEC with respect to the robot's position, moving direction, and other manipulating conditions based on the structural characteristics and magnetic field distribution pattern of the TEC. Effective calculation methods and operating procedures are also proposed. The proposed method was found to effectively generate the necessary actuation force to control microrobots by using either one or two of the coils of a TEC, depending on the given conditions. This type of process results in improved precision in magnetic field generation and a reduction in energy consumption while making it easier to control microrobots. Magnetic fields and actuation forces were generated using the proposed method under various experimental conditions, and these results were verified through simulations to confirm the validity of the proposed method. In addition, a TEC and a closed-loop control system were built and used to test the actuation of microrobots over various paths, and the results confirmed the superiority of the proposed method compared to existing methods.