Development of a Planar Piezoelectric Actuator Using Bending-Bending Hybrid Transducers

A planar piezoelectric actuator with large travel range is presented in this paper. The actuator is composed of four uniform piezoelectric transducers, and each transducer can bend along the horizontal direction or vertical direction independently. Trapezoidal-wave signals are used to excite the hybrid bending of the transducers and form rectangular movements on their driving feet. The actuator can move step by step by the static friction forces in nonresonant mode, and a long reliability life is obtained as there is no wear and tear problem. The operating principle is simulated by finite-element method, which reveals the generation of rectangular trajectory on each driving foot and the large structure stiffness of the actuator. A prototype is fabricated and its experiment system is established. A resolution of 16 nm is achieved at the quasi-static mode, a minimum step distance repeatability error rate of 1.06% is obtained at the stepper mode: the maximum output speed and carrying load of 300 mu m/s and 35 kg are achieved at voltage of 400 Vp-p and frequency of 40 Hz. The experiments also shows that the output speed is linearly related to the exciting voltage; the motion along any direction in the platform is achieved by controlling the voltage signals.