High Frequency PMN-PT 1-3 Composite Transducer for Ultrasonic Imaging Application

Development of PMN-PT single crystal/epoxy 1-3 composites for high-frequency ultrasonic transducers application is presented. The composite was fabricated by using a DRIE dry etching process with a 45% volume fraction of PMN-PT. A 35 MHz ultrasound flat transducer was fabricated with the composite, which was found to have an effective electromechanical coupling coefficient of 0.81, an insertion loss of 18 db, and a -6 dB bandwidth as high as 100%. Tungsten wire phantom image shows that the transducer had an axial resolution of 30 microm, which was in good agreement with the theoretical expectation. The initial results showed that the PMN-PT/epoxy 1-3 composite has many attractive properties over conventional piezoelectric materials for medical imaging applications.