We investigate the spectral response of capacitive sensors with 28 μm thick Polyvinylidene Fluoride (PVDF) films operating in the piezoelectric mode. We present spectra of signals obtained from laser-induced photoacoustic emissions in several materials. We examine the sensor response to direct laser pulses and to ultrasonic signals generated by laser pulses interacting with polyvinyl alcohol (PVA) phantoms, neoprene slabs and a composite of PVA phantom with a hidden slab of neoprene. We exhibit the sensor's sensitivity to the phantom thickness, affecting the amplitude and bandwidth of the ultrasonic output signal. The sensors fabricated and tested under water achieved an operational frequency bandwidth ranging from 1 to 50 MHz.

Date Published: 20 March 2014
PDF: 8 pages
Proc. SPIE 9040, Medical Imaging 2014: Ultrasonic Imaging and Tomography, 90401J (20 March 2014); doi: 10.1117/12.2043789

Published in SPIE Proceedings Vol. 9040:
Medical Imaging 2014: Ultrasonic Imaging and Tomography
Johan G. Bosch; Marvin M. Doyley, Editor(s)