Design and fabrication of novel sensor for high pressure measurement of acoustic wave

Previous studies have shown that focused ultrasound produces very high acoustic pressure in the focusing area. In traditional measurement system, piezoelectric hydrophone is one of the mostly used sensor. However, both the piezoelectric ceramic hydrophones and PVDF (polyvinylidene fluoride) hydrophones are easily destroyed due to the high acoustic pressure in the focal area. In this study, a novel sensor based on spherical scattering was designed for high pressure measurement of acoustic wave. First, the scattering theory was studied. The acoustic field of the focusing transducer was simulated, and the relationship of the input acoustic pressure and the output acoustic pressure was analyzed and certificated by an scattering experiment system. Second, a novel sensor was design and fabricated by using a steel scattering sphere, PVDF receiving element and acoustic absorbing cavity. Finally, the sensor was applied for acoustic pressure measurement of a focusing transducer. The obtained results were similar with the results which were measured by a PVDF needle-type hydrophone. The result showed that the novel sensor was feasible and the sensitivity of the sensor was -236.7dB. And it shows a potential for HIFU measurement application.