Development and experiment evaluation of a compact inchworm piezoelectric actuator using three-jaw type clamping mechanism

A compact inchworm piezoelectric actuator using three-jaw type clamping mechanism is developed in this study. Different from the previous inchworm piezoelectric actuators constructed with guiding structures, the proposed actuator can drive an output shaft to realize linear motion without other auxiliary structures based on the automatic centering and guidance functions of the designed three-jaw type clamping mechanism, and a compact structure is obtained. The configuration of the actuator is presented to describe the operating principle in detail. Then the structures of the clamping and actuating units are designed by the assistance of finite element simulations. A prototype is fabricated and a compact structure is achieved with outer diameter of 34 mm and length of 40 mm. The experiments are performed to investigate the characteristics, a maximum speed of 155.5 μm s⁻¹ and a thrust force of 12.3 N are achieved. The experimental results confirm that the proposed inchworm actuator can achieve a compact structure by adopting the designed three-jaw type clamping mechanisms, it has great potential in integration with precision equipment, which is conductive to apply in the fields of biological manipulation robots and aerospace devices.