A two-layer linear piezoelectric micromotor

A first bending (B1) mode two-layer piezoelectric ultrasonic linear micromotor has been developed for microoptics driving applications. The piezo-vibrator of the micromotor was composed of two small Pb(Zr,Ti)O₃ (PZT-5) plates, with overall dimensions and mass of only 2.0 × 2.0 × 5.0 mm³ and 0.2 g, respectively. The proposed micromotor could operate either in single-phase voltage (standing wave) mode or two-phase voltage (traveling wave) mode to drive a slider via friction force to provide bidirectional linear motion. A large thrust of up to 0.30 N, which corresponds to a high unit volume direct driving force of 15 mN/mm³, and a linear movement velocity of up to 230 mm/s were obtained under an applied voltage of 80 Vpp at the B1 mode resonance frequency of 174 kHz.