Ultrabroadband Single Crystal Composite Transducers for Underwater Ultrasound

Cochran, S. , Parker, M. and Marin-Franch, P. (2005) Ultrabroadband Single Crystal Composite Transducers for Underwater Ultrasound. In: 2005 IEEE International Ultrasonics Symposium, Rotterdam, The Netherlands, 18-21 Sep 2005, pp. 231-234. ISBN 9780780393820 (doi: 10.1109/ULTSYM.2005.1602838)

Abstract

Through the use of complex piezoelectric structures, it is possible to obtain resonant harmonics not observed in the usual oddharmonic response of a conventional structure. When combined with inherently broadband components, such as composites made with PMNPT single crystal material, this permits the realisation of ultrabroadband devices. In the work reported here, results from modelling indicate that a bandwidth improvement by a factor up to four is possible compared with standard piezoceramic transducers. Experimental validation of this theoretical finding has taken place. This validation required a three-stage development process. The first stage involved careful selection of material and full characterisation using the commercial PRAP code (TASI Technical, Ontario, Canada). The output data were then used in modelling to simulate the behaviour of the bulk PMN-PT and good correlation was established. The second stage involved the fabrication of several composites with different PMN-PT volume fractions and adjustment of the model parameters to reduce disagreements between experiment and theory. The new parameters were then utilised in the third stage which involved acoustic stack design and optimisation. Several single crystal composite multilayer transducers, designated PAT-UBB-SC, were subsequently made. Operating with centre frequencies around 600 kHz and apertures of 10 mm x 15 mm, pulse-echo tests have shown a -6 dB relative bandwidth up to 125%, very close to the predicted 135%.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cochran, Professor Sandy
• Authors: Cochran, S., Parker, M., and Marin-Franch, P.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• ISSN: 1051-0117
• ISBN: 9780780393820