Design and experimental study of a planar piezoelectric actuator with resonant actuation

Planar piezoelectric actuators, which can achieve high-precision motions over a wide range, have been widely applied in high-end equipment fields. However, the existing planar piezoelectric actuators can no longer meet the high actuation characteristics required for the rapidly development of these fields, which include large travel, high resolution, fast speed, planar three degrees of freedom (3-DOF) and a compact structure. A planar piezoelectric actuator with resonant actuation is proposed and tested in this work. The actuator consists of four symmetrically configured uniform bending-bending hybrid piezoelectric units, which coordinate to achieve large travel and planar 3-DOF characteristics. A vibration isolation mechanism adopting thin beam structure with low stiffness in coupling directions is designed to achieve vibration isolation among the units. The actuator can operate in high frequency resonance mode and low frequency stepping mode, allowing for the achievement of high-speed and high-resolution characteristics. A prototype is fabricated and tested. A compact structure measuring 53 mm x 53 mm x 13 mm and weighing only 30.2 g has been achieved. The maximum linear and rotary speeds have been tested to be over 400 mm/s and 13 rad/s, respectively. The linear and rotary resolutions are 0.42 mu m and 12.9 mu rad, respectively. The proposed actuator achieves characteristics of large travel, high resolution, fast speed, 3-DOF and a compact structure.