3A-5 A Novel Back Scattering Ultrasound Transducer for Nondestructive Material Evaluation

This research proposes a new type of focusing ultrasound transducer called Analytical Back Scattering Arrayed Ultrasound Transducer (ABSAUT). It is designed for detecting and characterizing internal defects of a sample in an analytic and quantitative way via collecting multiple back scattering ultrasound signals. Different from conventional focusing ultrasound transducers, a PVDF film with patterned electrodes is attached to the concave spherical surface for collecting back scattered ultrasounds. Standard testing including pulse-echo testing, transducer defocusing testing, tone burst source testing, and sound field scanning are carried out and all the information is recorded for performance verification. Furthermore, the angular spectrum analysis is adopted in predicting the time-domain waveforms measured by the PVDF sensing elements. In this work, we have proved that ABSAUT can collect the reflected or back scattering sound wave information from the sample under testing. And the time-domain waveforms predicted by angular spectrum algorithm also show good agreements with the data measured by PVDF sensing elements. Finally, future improvements and applications of the ABSAUT will be addressed