Modeling and investigation of immersion based capacitive micromachined ultrasonic transducer

An immersion based Capacitive Micromachined Ultrasonic Transducer (CMUT) is modelled and investigated. Analysis on the displacement and output pressure is done using Finite Element Method (FEM) for different parameters of membrane thickness, gap thickness, width of the membrane, liquid material and bias voltage applied. With effectively optimizing the device parameters and the bias a satisfactory pulse shape has been achieved. From our observation it can be seen, bias potential applied must be kept high in order to get a better displacement on the membrane that will result in more output pressure in water immersion medium than air as the coupling medium. The coupling medium has profound effect on the propagation of acoustic pressure as is evident for different immersion environment analysed.