A Crab Claw-Inspired Stick-Slip Piezoelectric Actuator with Low-Frequency, High-Speed Operation and Autonomous Backward Motion Suppression

At present, piezoelectric actuators featuring both multi-directional output capability and autonomous backward motion suppression are scarce, which limits the application of piezoelectric actuation technology. To address this issue, inspired by the rapid opening-closing switching of crab claws during movement, a novel bionic crab-claw stick-slip piezoelectric actuator is designed based on the stick-slip actuation principle. The actuator adopts a symmetric structure and exhibits bi-directional motion characteristics and is equipped with a flexible hinge amplification mechanism for autonomous backward motion suppression. In this paper, the structural reliability is first verified through mechanical theoretical analysis and the finite element method. Then, an experimental platform is built, and a prototype is fabricated for experimental testing. The results show that the proposed actuator not only has high symmetry in bi-directional output performance but also demonstrates the effectiveness of the backward motion suppression mechanism in the designed comparative experiments. The mechanism can achieve high-speed motion at low frequencies, with a maximum speed of 4.58 mm/s, which exhibits a high speed under comparable dimensions and a lower driving frequency, and the maximum load capacity reaches 0.9 N.