Ultrasound Transducers for High Pressure Environments Up to 1000 Bar

Abstract

This paper studies the influence of high ambient pressure on ultrasound transducers where the piezoelectric layer is bonded to the acoustic matching layer by two different methods: Au-Sn solid-liquid interdiffusion and standard polymer adhesives. The transducers were fabricated by bonding 6 MHz piezoelectric elements to silicon matching layers. Electrical impedance was measured on the transducers during exposure to 1000 bar pressure at 15 °C in a silicone oil filled pressure vessel. The bondlines of the transducers were characterized before and after pressure exposure by scanning acoustic microscopy and optical microscopy. The exposure to high pressure was found to have noticeable effects on the piezoelectric material of the transducers, whereas no degradation was observed in the bondlines.

Measurement Stability of Oil-Filled Flexural Ultrasonic Transducers Across Sequential In Situ Pressurization Cycles

“…There is industrial need and academic interest in engineering ultrasound transducers for environments of elevated pressure. For example, a recent study has demonstrated the operation of 6 MHz piezoelectric composites bonded to matching layers towards at 1000 bar in silicone oil [28], though this study along with others, do not consider a configuration like the FUT.…”