Development of a Starfish‐Inspired Piezoelectric Micro‐Mobile Robot Based on the Foot‐Leg‐Torso Integration and Built‐In‐Ceramic Strategy

ABSTRACT Piezoelectric micro‐mobile robots can perform micro‐nano manipulation tasks due to their high precision, fast response, and flexible structure. However, existing piezoelectric robots typically adopt a modular structure to achieve flexible motions with multiple degrees of freedom (MDOF), resulting in a complex structure. A piezoelectric micro‐mobile robot is proposed inspired by the radially symmetric structure of starfish, in which a compact quadrupedal radially symmetrical structure is designed based on the foot‐leg‐torso integration and built‐in‐ceramic strategy, and 3‐DOF motions are achieved by the cooperation among the four legs. The structure is optimized by modal and harmonic analyses, in which the modal degeneracy of the actuating units and the generation of the elliptical trajectories of the driving feet have been completed. A prototype with dimensions of 53.6 × 53.6 × 8 mm 3 is fabricated, and its performance is characterized. The robot achieves a maximum linear speed of 142 mm/s and a rotational speed of 135°/s. The linear displacement resolution is measured as 0.33 µm, corresponding to a rotational resolution of 12.3 µrad. These results indicate that the proposed robot possesses high precision, rapid motion, compact structure, and agile mobility, exhibiting promising application potential in fields such as micro‐manipulation and confined‐space exploration.