A Piezoelectric Friction-Inertial Linear Motor Based on Piezoelectric Single-Crystal Cymbal Displacement Amplification Mechanism

Piezoelectric friction-inertial motor is known for its promise for a long-range and high-resolution motion. The movement of the slider/rotor of the motor is achieved by stick-slip effect. We report a relaxor-based-ferroelectric-single-crystal cymbal actuator and a miniature piezoelectric friction-inertial linear motor (abbreviated as PFILM) fabricated with the cymbal actuator. The cymbal actuator is fabricated with a 10 mm diameter disk of 0.70Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 single crystal. The displacement of the cymbal actuator increases almost proportionally from 0 to 23 μm with driving voltage up to 500 V, and the minimal hysteresis is observed. The cymbal-PFILM with 20 mm motion range works under driving voltage frequency of ca. 100 Hz to ca. 5 kHz, the fastest speed is obtained with 3.5 kHz and the no-load speed is 14 mm/s and the maximum thrust force is 98 mN. Compared with a PFILM based on multilayer piezoelectric ceramic, the proposed motor has a larger stroke under DC/quasistatic input voltage in fine motion mode, but a smaller driving force in long-travel mode due to lower resonance frequency.