A Compact Cantilever-Type Ultrasonic Motor With Nanometer Resolution: Design and Performance Evaluation

A cantilever ultrasonic motor with nanometer resolution is designed, fabricated, and tested in this article. Two orthogonal first bending vibration modes are used to form elliptical movements on driving tip to move slider. The structure of this motor is depicted, and its geometric dimensions are determined by modal analysis. The total size of this motor is 30 × 30 × 34.2 mm along the X-, Y-, and Z-direction. The working principle of the proposed motor is illustrated, and the motion characteristics of the driving tip are studied by transient analysis. A prototype of this motor is manufactured to investigate its vibration performances and mechanical characteristics. The tested results denote that this motor generates an output speed of 344.35 mm/s when the frequency and voltage are 22.7 kHz and 200 Vp-p, respectively. The maximum output force is tested as about 8 N under the voltage and preload of 100 V_p-p and 50 N, respectively. Furthermore, the proposed ultrasonic motor obtains a high displacement resolution of 48 nm under the resonant working state.