Design, Modeling, and Experiment of a 3-DoF Miniature Plate Piezoelectric Robot

The piezoelectric plate robot driven by traveling waves (TWs) boasts a compact structure and excellent load-bearing capacity. However, vibration coupling across the plate restricts its freedom of movement, along with issues such as poor straight-line motion and a large turning radius. Inspired by octopus locomotion, we designed a three-degree-of-freedom (3-DoF) piezoelectric plate robot using a 0.7 mm metal plate. Through drive region division and dynamic modeling, our design achieves fully controllable motion in any planar direction, providing the highest DoF among TW driven plate robots. Weighing just 14.2g, it is lighter and easier to fabricate compared to other 3-DoF piezoelectric robots. The robot demonstrated 3-DoF movement capabilities, climbing (16.5°), dragging (20 g), and carrying (180 g), and can bear over 5,000 times its own body weight. A wireless drive prototype with closed-loop control reduced trajectory errors by more than 80% compared to open-loop control. Experiments involving high-curvature path movement, confined-space “search and rescue” and light focusing highlight its potential in extreme environments and high-precision tasks.