Preliminary Study of a Legged Capsule Robot Actuated Wirelessly by Magnetic Torque

This paper describes a novel legged capsule robot, which is actuated by magnetic torque, that can move through the intestinal lumen, especially in the small intestine. The proposed capsule robot has four legs and is actuated by magnetic torque without the need for an embedded power supply such as a battery. The principle of magnetic actuation is based on a magnet configuration of an internal permanent magnet (IPM) embedded in the robot and two external permanent magnets (EPMs). When the two EPMs are actuated, the IPM will rotate relative to the body of the proposed robot. Through internal mechanisms, the magnetic torque is transmitted to actuate a set of legs. These legs propel the proposed robot forward or backward while distending the intestinal lumen. The magnetic torque exerted on the IPM by the EPMs has been calculated. Sufficient force can be generated at the tips of the legs. An in vitro experiment has demonstrated that the proposed robot offers a good walking performance.