Thickness mode high frequency MEMS piezoelectric micro ultrasound transducers

Issue Title: Special Issue on Piezoelectric for End Users II, Guest Editors: Robert Dorey and Sophie A. Rocks Thickness mode piezoelectric micro-electromechanical system (MEMS) ultrasound transducers, operating in the 50-75 MHz range, have been fabricated using a composite sol gel technique in combination with wet etching. The composite sol gel technique involves producing a PZT powder/sol composite slurry, which when spun down yields films a few micrometers thick. Repeated layering, and infiltration, has been used to produce PZT films between 20 and 40 μm thick. Due to the low firing temperature (