Laser-induced microtextured stators coupling with flexible rotors for low-voltage driving rotational piezoelectric motors

Traveling-wave ultrasonic motors promise widespread applications in precision engineering, medical, and aerospace field due to their high-power density, but suffer from low efficiency and stress gradient. In this case, the synergy effect of surface-functionalized friction regulation and interface coupling interference of wear loss/debris could effectively eliminate these deficiencies. Herein, we report a low-voltage driving rotational piezoelectric motor (PM30) that proceeds through laser-induced microtextured stators coupling with flexible rotors, which enables working at a rotational speed of 158 rpm and torque of 73 N·mm, respectively, under the condition of low-voltage (80Vp) and low-preload (40 N). Such operation parameters are far beyond the current reported results. Furthermore, FEM simulation and SEM observation demonstrated that the low-voltage driving and high-performance output are resulting from the combination of surface microtextured stators for friction enhancement and flexible rotors for displacement amplification with contact expansion, which regulates tangential friction and reshares the stresses distribution during the dynamic contact along with the rotary motion of rotors. This work provides a promising strategy to construct friction-stress regulation and energy-transformation enhancement toward energy-saving and high-efficient friction drive for piezoelectric devices.