A Differential Friction Driving Piezoelectric Stepping Robot for 3-DOF Planar Micromanipulation

Miniature piezoelectric robots exhibit significant potential in high-precision actuation applications; however, their inherent structural complexity often limits their widespread adoption in the miniature robotics field. To address this limitation and develop a miniature robot characterized by high precision, 3-DOF, structural simplicity, and low driving requirements, this paper proposes a piezoelectric stepping robot based on a novel differential friction principle. This differential friction piezoelectric stepping robot effectively leverages the friction differential principle to achieve high-precision actuation while maintaining structural simplicity. Its 3-leg driving configuration provides excellent motion stability and enables 3-DOF planar motion (translational and rotational). Experimental results demonstrate that the robot (dimensions: 44.5 mm × 50.3 mm × 16 mm) achieved a translational resolution of 6.97 nm and a maximum speed of 339.35 μm/s, along with a rotational resolution of 2.82 μrad and a maximum speed of 4.31 mrad/s. The robot also demonstrated an excellent maximum payload-to-weight ratio of 64.52. Furthermore, the robot successfully performed precision alignment of a 200 μm diameter optical fiber. Its advantages such as simple structure and few driving units enhance its potential for practical applications and provide a promising approach for developing high-performance micro-robotic systems.