A Two-Layer Linear Piezoelectric Micromotor

A first bending (B-1) mode two-layer piezoelectric ultrasonic linear micromotor has been developed for micro-optics driving applications. The piezo-vibrator of the micromotor was composed of two small Pb(Zr, Ti)O-3 (PZT-5) plates, with overall dimensions and mass of only 2.0 x 2.0 x 5.0 mm(3) 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/mm(3), and a linear movement velocity of up to 230 mm/s were obtained under an applied voltage of 80 V-pp at the B-1 mode resonance frequency of 174 kHz.