DEVELOPMENT OF NOVEL TRANSDUCER MATERIALS

Conventional piezoelectric materials such as PZT-5H for transducer may not be suitable for VHF transducer and array fabrication. Moreover, better piezoelectric materials with higher coupling coefficient and variable dielectric constant allowing for wider bandwidth and more flexible transducer design are needed for the improvement of conventional linear array performance as well as the development of multidimensional arrays. In this project, fine grain PZT which has smaller grain size and single crystal relaxor materials such as PZN-PT which has a much higher coupling coefficient than PZT-5H will be prepared and improved for VHF linear array fabrication. In addition 1-3 fiber composites prepared via a sol-gel process will be developed for VHF single element transducers. The potential of these materials has been demonstrated by the better performance in bandwidth and sensitivity of ultrasonic transducers prepared from these materials in comparison to those prepared from PZT-5H under similar conditions.