Clawed Miniature Inchworm Robot Driven by Electromagnetic Oscillatory Actuator

In this research we propose a novel inchworm robot, which is composed of an Electromagnetic Oscillatory Actuator (EOA) and claws. The EOA consists of a yoke, a magnet, and a coil. The overall robot size is 12.2 mm × 11 mm × 9 mm (length × height × width). The locomotion of the robot is achieved by different amounts of slips when the robot stretches and contracts its front leg. To realize locomotion, the working conditions were calculated theoretically and the calculated input signal was applied to the robot. The performance of the inchworm robot was evaluated experimentally with varying input voltages and frequencies. A simple op-amps based driving circuit was used to provide a square-wave input. Travel speed, average distance per step of the robot, and moving distance of the leg and body at each step were measured. The maximum travel speed was 36 mm·s−1 at 30 Hz, which validates our simple locomotion strategy experimentally.