A Compact Three-DOF Inertial Piezoelectric Robot for High-Precision Cross-Scale Operations

Precision engineering applications demand actuators possessing high precision, high velocity, and substantial payload capacity to execute precise operations effectively. Therefore, a novel three-degrees of freedom (DOF) inertial piezoelectric robot is proposed in this study to improve the performance of traditional inertial piezoelectric actuation systems in terms of velocity, resolution, and payload capacity. Experimental validation on a 90-mm-diameter prototype demonstrates critical performance achievements: 1) integrated three-DOF actuation mechanism utilizing a common inertial mass and piezoelectric drive assembly, enabling enhanced structural compactness and integration; 2) achieving both 51.07 mm/s high-velocity and 11 nm ultrahigh resolution without altering the fundamental driving principle; and 3) the large-mass inertial block combined with multiple piezoelectric sheets is used to achieve a 70 N payload capacity (26 times its own weight). As a practical demonstration, an alignment experiment on two 190-μm-diameter optical fibers achieved submicron positioning accuracy. The proposed robot improves traditional inertial structures speed-resolution-payload performance and achieves cross-scale motion capability. These advances show significant potential for applications scenarios requiring high-velocity, high-precision, and heavy-payload performance, including precision microassembly and biological micromanipulation.