Piezoelectric-driven miniature wheeled robot based on flexible transmission mechanisms

Abstract

A 935 mg weight coin-size piezoelectric-driven wheeled robot with a flexible body-actuator-transmission integrated structure is presented in this paper. The robot is monolithic designed and fabricated via planar graphic manufacturing and lamination methods. The flexible four-bar mechanism and the flexible pawl-ratchet mechanism based on film hinge convert the slight vibration of the dual-drive PZT actuator into a unidirectional rotation of wheels, thereby achieving straight or curved motion. The stress and response of the flexible pawl-ratchet mechanism are analyzed by mechanical model and FEM simulation. We experimentally characterized the resonant characteristics of the actuator, measured the velocity of the miniature wheeled robot when it is on or off the ground. Experiments suggest that the prototype of the robot can achieve a linear speed for 330 mm/s, a turning radius for about 200 mm, and a climbing angle for 7.5°.