Automatic Navigation Scheme for Micro-Robot Using Magnetic Potential Field Through Field Free Point

Abstract

Magnetic actuation is particularly useful due to its deep penetration and safety to control microrobots for biomedical purposes. This paper proposes an automatic navigation algorithm using a magnetic potential field in the form of a Field Free Point (FFP). The FFP is a powerful tool for magnetic actuation because of its efficiency and versatility, and it can also be used in Magnetic Particle Imaging (MPI). The FFP provides efficiency and versatility in imaging and actuation and the ability to perform both functions on a single device without additional hardware. We suggest a novel navigation scheme based on FFP and Magnetic Potential Field (MPF) to achieve automatic navigation. It consists of a modified attractive field with velocity-based disturbance cancellation and a repulsive field to avoid collision. The suggested algorithm, leveraging microrobot movements and effectively addressing disturbance as inertia, is characterized by its capability to reduce deviations. Thus, simulations were conducted to tune the parameters and evaluate the proposed actuation scheme's effectiveness. Also, the entire algorithm's performance was verified through experiments in a dynamic environment with moving fluid and obstacles. The results demonstrated the proposed navigation system's robustness in reaching the micro-robot to its destination even in an environment with a peak fluid velocity of 80 mm/s .