Electromechanical modeling, characterization, and optimization design of the postcomplementary metal-oxide-semiconductor capacitive microarrayed ultrasonic transducer

Abstract

In this study, an electromechanical modeling technique for characterization and optimization design of the postcomplementary-metal-oxide-semiconductor (pCMOS) capacitive microarrayed ultrasonic transducer (CMUT) is presented. A two-dimensional, axisymmetric finite element model is developed using the ANSYS parametric design language. Electromechanical simulations are performed to investigate the fundamental characteristics of the CMUT, such as collapse voltage, resonant frequency, capacitance, and electromechanical coupling coefficient. Both the numerical and analytical (experimental) results agree well to show the validity of the proposed approach. The study of the influence of each defined parameter on the collapse voltage and resonant frequency is also presented. An integrated design approach that couples the genetic algorithm (GA) with the commercial finite element method (FEM) software ANSYS is developed to obtain the best design parameters. The optimal results show that the design objective with the equality constraint, which are to minimize the collapse voltage while simultaneously achieving the customized resonant frequency, are satisfied. From the presented results, it is concluded that the GA/FEM coupling approach provides another useful numerical tool for multiobjective design of the pCMOS-CMUT.