Parameters affecting performance of capacitive micro machined ultrasonic transducer (CMUT)

Ultrasonic waves (above 20 KHz) find many applications ranging from medical diagnostic to nondestructive testing. Capacitive Micro machined Ultrasonic Transducers are used to generate ultrasonic wave as they have number of advantages like impedance matching with surrounding, larger bandwidth, good capability to make high frequency arrays, ability to integrate with electronics, low cost for mass production, high pressure sensitivity rapid response to changing pressure, can withstand lot of vibrations and low temperature sensitivity. In this paper five parameters of CMUT viz. Collapse voltage, capacitive change, resonance frequency, spring softening effect and membrane geometry are studied.