Micromachined Transducers

Capacitative micromachined Ultrasonic transducers, manufactured using standard semiconductor fabrication techniques have received a lot of interest over recent years. Working in collaboration with Qinetiq we have a number projects in this area, working with devices using standard CMOS processes. These devices vary in dimension from 0.100-5mm area, somewhat larger than those reported elsewhere, with membrane thickness from 0.5-2µm.

Schematic of transducer.
Schematic of Transducer construction


SEM image of Transducer
SEM image of Micromachined Transducer

Current research is concerned characterising arrays of devices machined on the same substrate for use as as passive 2-D arrays for imaging, active 1-D phased arrays and as apodised imersion transducers..

Photograph of micromachined array
Photograph of Micromachined array
Scanned image of 20p coin
Image of a 20 pence coin obtained by scanning with an unfocussed passive array

Related Paper
R.A. Noble, A.R.D. Jones, T.J. Robertson, D.A. Hutchins and D.R. Billson, "Novel wide bandwidth micromachined ultrasonic transducers", IEEE Trans. Ultras. Ferr. Freq. Contr. 48, 1495-1507 (2001)