Propulsion of a Magnetic Material-Applied Microrobot in a Tube Based on a Wireless Power Transfer System

Abstract

Microrobots can be utilized in various applications, but their ability to move and perform tasks in various environments is especially important. In this paper, we introduce a 3-mm microrobot that can move in a liquid-filled tube, such as a vein, against gravity using an external wireless power transfer-based microrobot propulsion system. The force required to move against gravity was determined by calculating the effects of buoyance and gravity on the microrobot. Based on this information, the current required for the transmitting coil to induce sufficient propulsion was derived using the relation between the incident magnetic field and the magnetic force on a magnetic material. The propulsion system was experimentally tested, and the microrobot successfully moved upward against gravity. In addition, the level of human exposure to the applied electromagnetic field was determined to be within recommended guidelines using the electromagnetic simulation software Sim4Life.