Analysis of Piezoelectric Transducers for Generating Acoustic Fields in Ultrasonic Cell Manipulation

We present a comprehensive theoretical and experimental investigation on the various parameters influencing piezoelectric actuation in acoustophoretic devices used for cell manipulation and trapping. Our study focuses on glass chips with cavities and fluidic channels, on which a piezoelectric actuator is mounted to generate the necessary acoustic radiation and drag forces on cells or particles. This setup is suitable for 3D imaging. Although the impact of various design parameters on acoustofluidic operation has been investigated, to the best of our knowledge, systematic optimization efforts covering the impact of the actuator have not yet been undertaken. To this end, we developed a multi-energy domain-coupled finite element model, calibrated with impedance measurements, to examine the effects of positioning, fixation, impedance, displacement, and energy transfer of the piezo element. Additionally, it allows to vary substrate parameters as well. From this, we identify measures to achieve optimal acoustofluidic performance.