Development of dual-layer micromachined composite transducers for broadband ultrasound imaging

We presented in this paper the development of micromachined 1-3 composite dual layer transducers for multifrequency imaging. The effective electromechanical coupling coefficient and acoustic impedance of the micromachined PMN-PT 1-3 composite material was measured to be 0.73 and 18 MRayl, respectively. Based on the material, a dual-layer transducer prototype was developed. The probe was operated at both 15 MHz and 48 MHz. To characterize the transducer, pulse echo test was conducted, achieved a 73% and 70% bandwidth at low and high resonance, respectively. At fundamental mode, it showed transmitting sensitivity of 26 KPa/V, These results suggested great potential for medical broadband imaging applications.