Influence of piezoelectric materials on the performance of thin film hydrophones

Piezoelectric materials have been implemented in hydrophones in the early 20th century, mostly as cut bulk sensors or in cylindrical or spherical form made of piezoelectric materials [1]. Beginning with quartz soon other materials have been used, especially lead zirconate titanate with its high piezoelectric coefficients has been a large improvement in acoustic measurements. Nowadays miniaturization of the hydrophones is of interest, for example, in high resolution arrays for noise monitoring. Thus hydrophones materials are needed which have with less volume a similar performance as the state of the art bulk materials. Therefore, this work investigates hydrophones based on different piezoelectric thin films. These are mostly MEMS-production compatible and show good properties for the detection of acoustic signals. Therefore, sensors with different materials have been produced and the performance has been evaluated under laboratory conditions. [1] C. H. Sherman, J. L. Butler, Transducers and Arrays for Underwater Sound, Spring Sciences + Business Media, New York, 2007.