A Double-Mode Piezoelectric Single-Crystal Ultrasonic Micro-Actuator

Ternary Pb(In1/2Nb1/2) O-3-Pb(Mg1/3Nb2/3) O-3-PbTiO3 (PIN-PMN-PT) single crystals with higher coercive field (EC similar to 9 kV/cm) and higher ferroelectric-transition temperature (TR-T = 108 degrees C) were grown, and correspondingly, a double-mode piezoelectric ultrasonic micro-actuator made of PIN-PMN-PT crystal brick (5 x 1.5 x 1.32 mm) and operated in the first longitudinal and the second bending modes was developed. The ferroelectric, dielectric, electromechanical, and resonance displacement properties of the micro-actuator were characterized for miniature linear piezo-motor applications. The longitudinal displacement of the actuator is similar to 0.11 mu m (with an applied voltage of 5 V), which is comparable to that of a multilayer piezoelectric-ceramic actuator of the same size. This crystal micro-actuator was successfully used to drive a slider moving linearly.