Cableless Magnetic Actuator Capable of Locomotion in a Thin Pipe by Means of a New Motion Principle

This paper proposes a novel cableless magnetic actuator with a new propulsion module that exhibits a very high thrusting force and is capable of locomotion in a thin pipe by means of a new motion principle. The magnetic actuator is moved according to the vibration amplitude and elastic energy of a mass-spring system due to mechanical resonance energy. The proposed actuator contains an electrical inverter that directly transforms dc from button batteries into ac. The electrical dc-ac inverter incorporates a mass-spring system, a reed switch, and a curved permanent magnet that switches under electromagnetic force. Experimental results reveal that the actuator is able to move upward at a speed of 52 mm/s when powered by 10-button batteries and pulling a load mass of 10 g.