Acoustic radiation force on a particle in ultrasonic standing wave fields driven by a piezoelectric plate

Acoustic radiation forces on a particle or droplet in a liquid have been studied mostly for relative simple acoustic fields such as plane traveling waves, or planar standing waves. In this study, a more complicated acoustic field is considered, namely, the acoustic standing wave field generated by a rectangular piezoelectric plate with finite size. The piezo-electric plate is excited in its thickness mode. A three dimensional model of the vibration of the piezo-electric plate has been developed. The plate is loaded by an acoustic standing wave field in a fluid on one side, and is air backed on the other side. The three-dimensional acoustic standing wave field generated by the piezo-electric plate is calculated. The acoustic radiation force on a particle or droplet can then be calculated using a framework such as developed by Gor’kov or Ilinskii and Zabolotskaya. The theoretical calculations are compared with numerical predictions using a two-dimensional model of the piezo-electric plate and resonator. Fin...