A miniature standing wave linear ultrasonic motor

Abstract

A miniature linear ultrasonic motor that utilizes the principle of coupling the first-order longitudinal vibration mode with the second-order bending vibration mode is proposed, which is currently the smallest linear ultrasonic actuator that uses this principle in the known literature. The dimensions of the prototype stator with two piezoelectric elements are approximately 3.93×1.12×1.63 mm3, and the mass is 80 mg. In this paper, we introduced the design process in detail and evaluated the performance of the miniature motor. The proposed miniature motor has a simple and compact structure and can drive the runner bidirectionally at a fixed frequency. At a voltage of 20 Vp-p and an optimal frequency of 583.5 kHz, the motor can generate a linear velocity of 81.1 mm/s and a driving force of above 5.7 gf, the output performance is relatively satisfactory. The piezoelectric miniature motor has a wide range of applications due to its small size, simple structure, and relative superior driving capability, such as micro-lens drivers in imaging devices.