A two degrees-of-freedom piezoelectric single-crystal micromotor

A two degrees-of-freedom (DOF) ultrasonic micromotor made of piezoelectric Pb(In1/2Nb1/2) O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PIN-PMN-PT) single crystal square-bar (dimensions 2 x 2 x 9 mm(3)) was developed. The PIN-PMN-PT square-bar stator can generate standing wave elliptical motions in two orthogonal vertical planes by combining the first longitudinal and second bending vibration modes, enabling it to drive a slider in two orthogonal directions. The relatively large driving forces of 0.25 N and motion speed of 35 mm/s were obtained under a voltage of 80 V-pp at its resonance frequency of 87.5 kHz. The proposed micromotor has potential for applications in micro robots, cell manipulators, and digital cameras as a two-DOF actuator. (C) 2014 AIP Publishing LLC.