Acoustic levitation effect on ultrasonic piezoactuators

Abstract

The development of applications of piezoelectric material has grown widely ranging from those for daily use products to more specialized devices. Some typical applications include sensors in automotive industry, ultrasonic imaging in medical industry, disc drive in computing industry and many more. Recently, the application of piezoelectric material as an acoustic levitation device is being studied.

This paper is focused on the design of the piezoelectric actuator which performs squeeze film or near field levitation. The utilization of the concept of resonant frequency between the piezoelectric actuator and the piezoelectric stack will be discussed. Few actuators were designed according to some design pre-requirements and the most suitable one was selected, it was then fabricated for the experiment use. In addition, hammer test was done to compare the predicted natural frequency and the actual natural frequency of the flexure beam of piezoelectric actuator. In latter part, acoustic levitation experiment was also done to check the acoustic levitation force exerted by the actuator.

The predicted natural frequency from ANSYS simulation shows a good agreement with the experimental results. In addition, the acoustic levitation experiment shows a positive outcome as well. Moreover, further development to improve the acoustic levitation force was discussed and the method to better quantify the acoustic levitation force was suggested.