A resonant quadruped piezoelectric robot inspired by human butterfly swimming patterns

Piezoelectric micro-robots have gained considerable attention in rescue and medical applications due to their rapid response times and high positioning accuracy. In this paper, inspired by the human butterfly locomotion pattern, we propose a novel resonant four-legged piezoelectric micro-robot designed to achieve fast and efficient movement in complex and confined spaces. The robot utilizes the parallel piezoelectric bimorph as the driving unit, and its leg structure mimics the butterfly motion. By employing asymmetric driving forces, the robot can achieve multi-directional movement. A dynamic model of the robot is developed, and the stress and motion characteristics are analyzed. The finite element method (FEM) is applied to optimize the structural parameters and determine the robot's optimal operating frequency. Finally, the prototype of the piezoelectric robot is constructed, and its performance is evaluated. The results show that, under an excitation voltage of 80 V, the robot achieves a maximum speed of 66.1 mm/s, can carry a load of up to 100 g, and withstand a maximum drag force of 15.3 mN. The robot demonstrates sub-micron resolution, excellent environmental adaptability, and precise rotational capabilities, making it suitable for tasks such as exploration, mapping, and sampling in constrained environments.