Two-dimensional locomotion of a microrobot with a novel stationary electromagnetic actuation system

In this paper, we study the locomotion of a microrobot for intravascular therapy. As an intravascular microrobot has to be small, a conventional actuator, such as a micro-motor, and a battery cannot be integrated. To solve this integration problem, we analyze a microrobot with an electromagnetic actuation (EMA) system. Previously, an EMA system using two stationary coil pairs was proposed for the 2-dimensional (D) planar locomotion of a microrobot. The EMA system used two stationary pairs of Helmholtz coils and two stationary pairs of Maxwell coils in the x- and y-direction, respectively. This paper proposes a novel stationary EMA system using two pairs of Helmholtz coils and one pair of Maxwell coils. The 2D locomotion of the microrobot using the proposed EMA system is analyzed and verified by various experiments. The microrobot actuated by the proposed EMA system was able to move in the desired direction on the desired path. The comparison between the proposed EMA system and the previous EMA system showed that the proposed system had an 18% smaller volume and used 91% less coil current for the same actuation force than the previous EMA system. The proposed EMA system produced 2D locomotion of the microrobot, while having a small volume and a lower power consumption than the previous EMA system.