Piezoelectric circular microdiaphragm based pressure sensors

Pressure influences on the vibration characteristics of piezoelectric circular microdiaphragm based pressure sensors are investigated theoretically and experimentally. It was demonstrated that only Bessel function of zero order, m = 0, participates in the vibration modes of the microdiaphragm symmetrically loaded by pressure. The piezoelectric circular microdiaphragm was fabricated by combining sol–gel PZT thin film and MEMS technology. A high value of pressure sensitivity, as high as 280 Hz/mbar, has been achieved; this value is 2.43 times higher than the currently reported sensitivity (i.e., 115 Hz/mbar) in the literature.