Simulation and experimental characterization of a 2-D capacitive micromachined ultrasonic transducer array element

In this letter, a 400-/spl mu/m/spl times/400-/spl mu/m 2-D capacitive micromachined ultrasonic transducer (cMUT) array element is experimentally characterised, and the results are found to be in good agreement with theoretical predictions. As a receiver, the transducer has a 1.8/spl times/10/sup -7/ nm//spl radic/(Hz) displacement sensitivity, and, as a transmitter, it produces 16.4 kPa/V of output pressure at the transducer surface at 3 MHz. The transducer also has more than 100% fractional bandwidth around 3 MHz, which makes it suitable for ultrasound imaging.