A novel high-speed bi-directional piezoelectric inchworm actuator based on flexible supported baffles

Typical bionic piezoelectric inchworm actuators utilize at least two clamping piezo-stacks (PZTs) and one driving PZT to achieve bi-directional actuation, resulting in complex structures, complicated electronic systems, and high cost. Actuators with lesser PZTs (1 or 2) can effectively alleviate these problems; however, existing designs are limited to unidirectional or bidirectional low-speed motion. This study proposes a high-speed bi-directional inchworm actuator with two PZTs, where the clamping switching is achieved by only one PZT through innovative use of flexible supported baffles and enhanced clamping mechanisms. The design also reduces the six sub-steps of the driving principle (alternate elongation and shortening of three PZTs) required for each step of typical designs to four, thus effectively increasing the maximum speed of the actuation. Experimental results show that the proposed design facilitates bi-directional motions in a stable manner with a maximum speed of 5.1 mm s⁻¹, which is approximately 23 times faster than the existing design with two PZTs. The proposed design can effectively expand the application range of dual-piezoelectric inchworm actuators and can find a promising application in the field of high-speed precision positioning.