Recently, various types of mobile micro-robots have been proposed for medical and industrial applications. Especially in medical applications, a motor system for propulsion cannot easily be used in a micro-robot due to their small size. Therefore, micro-robots are usually actuated by controlling the magnitude and direction of an external magnetic field. However, for micro-robots, these methods in general are only applicable for moving and drilling operations, but not for the undertaking of various missions.
In this paper, two types of micro-robot which is based on wireless power transfer system which can generate propulsion force and torque as well as electrical energy to perform complex missions. The magnetic field and the induced current from the wireless power transfer coils can be utilized into propulsion force, and the Lorentz force for implement rotational movement. The mechanism of Lorentz force generation and the coil design methodologies are explained, and validation of the proposed propulsion system for a micro-robot is discussed thorough a simulation and with actual measurements with up-scaled test vehicles.