title: Use of sputtered zinc oxide film on aluminium foil substrate to produce a flexible and low profile ultrasonic transducer.
abstract: A flexible and low profile ultrasonic transducer was fabricated for non-destructive testing (NDT) applications by DC sputtering of 3 μm thick, c-axis oriented, ZnO film on 50 μm aluminium foil. Due to the thin foil-based construction, the transducer can be applied to curved objects and used in sites of restricted accessibility. The device has been used to demonstrate detection of simulated defects in a 45 mm diameter steel pipe, and for thickness measurement on a 3.1 mm thick flat carbon steel plate. Centre frequency measured on the flat plate was 24-29 MHz, with -6 dB bandwidth 4-7 MHz. The pulse duration depended on the couplant, at best 3 cycles or 0.12 μs using SONO Ultragel or epoxy couplant. Transducer performance was found to be comparable to a commercial 10 MHz piezoelectric ultrasonic transducer.
authors.affiliation: School of Engineering and Computing, University of the West of Scotland, Paisley PA1 2BE, UK.
authors.forename: Ruozhou
authors.initials: R
authors.lastname: Hou
authors.affiliation: School of Engineering and Computing, University of the West of Scotland, Paisley PA1 2BE, UK.
authors.forename: Yong Qing
authors.initials: YQ
authors.lastname: Fu
authors.affiliation: School of Engineering and Computing, University of the West of Scotland, Paisley PA1 2BE, UK.
authors.forename: David
authors.initials: D
authors.lastname: Hutson
authors.affiliation: School of Engineering and Computing, University of the West of Scotland, Paisley PA1 2BE, UK.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhao
authors.affiliation: School of Engineering and Computing, University of the West of Scotland, Paisley PA1 2BE, UK.
authors.forename: Esteban
authors.initials: E
authors.lastname: Gimenez
authors.affiliation: School of Engineering and Computing, University of the West of Scotland, Paisley PA1 2BE, UK. Electronic address: katherine.kirk@uws.ac.uk.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Kirk
keywords: DC sputtering; Flexible ultrasonic transducer; Non-destructive testing; Thin film; Zinc oxide