Design, modeling and experiment of a novel ultrasonic elliptical vibration generator

This paper presents the design, optimization, and characteristic analysis of a novel ultrasonic elliptical vibration generator with adjustable phase difference and amplitude ratio. The elliptical vibration generator is composed of two sandwich piezoelectric transducers in orthogonal arrangement. Initial structural parameters of transducers are determined by an analytical model based on the electromechanical equivalent method. The transducers are investigated and optimized using finite element method to acquire the designed resonance frequency. Dynamic performances of the transducers after optimization and the developed elliptical vibration generator are then analyzed through modal analysis and frequency response analysis. A prototyped elliptical vibration generator is fabricated and experimental investigations are conducted to further test its characteristics. The results show that the resonant frequencies of two transducers are 95.8 kHz and 96.4 kHz, respectively, and 96 kHz is selected as the operating frequency of the generator. The generator is proven to vibrate along an elliptical trajectory in the vertical plane, and the phase difference, size and amplitude ratio of the vibration ellipse can be adjusted. A probe-type acoustic tweezer system is established based on the generator, and it is proven that it can successfully capture, translate and release silver nanowires.