A novel design of capacitive micromachined ultrasonic transducers for therpaeutic ultrasound

Performance (i.e., resonant frequency and pressure output) of a capacitive micromachined ultrasonic transducer (CMUT) was improved by adding a thin layer of aluminum nitride (AlN) to the capacitive parallel plate as proposed in this paper. A finite element model was built to simulate the newly proposed AlN-CMUT. The simulation results show that the resonant frequency of CMUT can be tuned with increased output pressure because of the higher tension applied to the CMUT membrane by the thin layer of AlN.