Piezoelectric Micro-Machined Ultrasonic Transducers for Medical Ultrasound


Authors: Katie Smyth, Charles Sodini, Sang-Gook Kim

Medical ultrasound imaging is becoming increasingly widespread because it is relatively inexpensive, portable, compact, and non-invasive compared to other diagnostic scanning techniques. However, commercial realization of advanced imaging trends will require cost effective, large scale arrays of miniaturized elements, which are expensive to fabricate using traditional bulk piezoelectric materials. At high volume, micro-fabricated transducers are an array compatible and low cost alternative. By leveraging a 31-mode actuation and sensing mechanism, a vibrating plate-based piezoelectric micro-machined ultrasonic transducer (pMUT) cell design is developed using lead zirconate titanate thin film. Based on previously validated analytical and finite element models, pMUT cells are incorporated into elements and a 1D array optimized for power efficiency, acoustic pressure output and bandwidth. Current work focuses on array micro-fabrication with the ultimate goal of demonstrating preliminary beamforming and imaging with the completed 1D array.