A dual-layer micromachined PMN-PT 1-3 composite transducer for broadband ultrasound imaging

Broadband ultrasound imaging including tissue harmonic imaging usually captures acoustic information from the frequency higher than that of transmission waves, and has been widely studied in imaging for cardiology, bladder and other fluid-filled or cyst structures. Compared to the conventional pulse-echo method, the broadband imaging possesses the advantages including contrast resolution enhancement, artifacts reduction, and improved signal-to-noise ratio. However, those benefits require broadband ultrasound transducers. In this paper, a micromachined PMN-PT 1-3 composite based dual frequency transducer was designed, fabricated and characterized. The transmitting sensitivity at 17.5 MHz reached 40KPa/V, and the receiving spectra magnitude was compared with a calibrated hydrophone under same test transducer transmitting. These results hold great potential for medical broadband imaging applications.