Investigation on Electro-acoustic Characteristics of a MEMS Microfluidic Ultrasonic Separator

MEMS Microfluidic Ultrasonic Separators are a novel type of micromachined silicon matching layered separation device that separates suspended micro-particles from within a liquid using a standing ultrasonic field. They are widely used in a variety of applications including chemical, bio-medical, and biological engineering. For example, in the biotechnology field, mammalian cells, bacteria, and yeasts need to be concentrated and separated from within a fluid. In the life sciences, monodispersed particles are used for diagnostic and treatment purposes. This paper focuses on investigating the electro-acoustic characteristics of a layered resonator for a microfluidic ultrasonic separator in terms of analysing the voltage across the transducer versus driving frequency. The electromechanical coupling with acoustic impedance transfer relationships is modelled and used to analyse the transducer and cavity resonance. In addition, the model is validated against experimental results by investigating the electrical impedance in the microfluidic ultrasonic separator. A comparison of the simulation results and experimental measurements indicates a good match. It shows that the model can effectively predict the electro-acoustic characteristics of the multilayered resonator in ultrasonic separator.