Capacitive micromachined ultrasonic transducers with asymmetric membranes for microfluidic applications

Abstract

A 2D finite element model for capacitive micromachined ultrasonic transducer (cMUT) arrays is developed. The model is verified by comparing the results to experimental data obtained on 1D cMUT arrays. The model accurately predicts the phenomenon involved in crosstalk in cMUT arrays, namely Lamb and Stoneley waves. Using normal mode theory in conjunction with finite element analysis, the acoustic power coupled to the Stoneley waves is found to be significant and its use for fluidic sensing and actuation is proposed. The effect of cMUT geometry on the efficiency and mode selectivity of Stoneley wave generation is also studied and the results are presented.