An accurate design to calculate and measure the capacitance of CMUT for pressure sensors

Capacitive Micromachined Ultrasonic Transducer (CMUT) is a type of micro-electro-mechanical system (MEMS) device which has the advantages such as ease of integration with front-end electronics and fabrication of uniform device arrays. The structure and fundamental working principle of a CMUT are similar to that of a parallel plate capacitor. When working in conventional mode, the deflection profiles can be described by analytical expressions and the capacitance can be calculated thereafter. A design was proposed to calculate the deflection profiles of the CMUT membrane accurately and eliminate the parasitic capacitance of the CMUT device. By appropriately selecting the dimensions of the device, the CMUT can be used as a pressure sensor.