A novel back scattering ultrasound transducer for non-destructive material evaluation and defect inspection

This research proposes a new type of focusing ultrasound transducer called Analytical Back Scattering Arrayed Ultrasound Transducer (ABSAUT). Different to the conventional focusing ultrasound transducer, an additional PVDF film with patterned electrodes is attached to the concave spherical surface for collecting back scattered ultrasound. It is designed for detecting and characterizing internal defects of a sample in an analytic and quantitative way via multiple back scattering ultrasound signals collection. Standard testing including pulse echo, transducer defocusing testing and sound field scanning are carried out and all the information is recorded for performance verification. Furthermore, a powerful angular spectrum algorithm is involved in the study for time-domain waveform prediction 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 waveform predicted by angular spectrum algorithm also shows good agreement with the data measured by PVDF sensing elements. Finally, future improvements and applications of the ABSAUT will be addressed.