A single-mode Mn-doped 0.27PIN-0.46PMN-0.27PT single-crystal ultrasonic motor

Mn-modified rhombohedral phase yPb(In_1/2Nb_1/2)O₃-(1-x-y)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PIN-PMN-PT:Mn) single crystal has attracted considerable attention for its outstanding piezoelectric properties and high mechanical quality factor. Here, we report a device innovation using Mn doped 0.27PIN-0.46PMN-0.27PT single crystal in a single-mode piezoelectric ultrasonic motor. Based on the analyses of actuator characteristics with finite element method, the PIN-PMN-PT:Mn crystal actuator predicts lower excitation frequency, lower driving voltage, and less power loss comparing with the PZT ceramic actuator. A prototype motor (size: 12 × 6 × 1.5 mm³) was fabricated and tested. The typical output of this PIN-PMN-PT:Mn motor is a speed up to 42.3 cm/s, a driving torque of 0.42 N cm, and an output power density of 0.45 W/cm³, under the driving voltage of 21 V_0−P. This work presents that PIN-PMN-PT:Mn single crystal is quite advantageous in making miniaturized and high-power piezoelectric ultrasonic motors.