Endoscopic ultrasound radial arrays fabricated with high-performance piezocrystal and piezocomposite

In this work, we develop the fabrication process of the radial array transducers, which are used to combine the gastroscope for acquiring ultrasound images of the surrounding organs, tissues and vessels. The PMNPT piezocrystal and its 1-3 piezocomposite were used as the active elements, respectively. High acoustic attenuation and flexibility composite material was used as the backing layers. The matching layers were specially designed according to the acoustic impedance of array elements. The pulse-echo responses acquired in water tank show that the PMNPT piezocrystal radial array transducer exhibits -80 % bandwidth and PMNPT/Epoxy 1-3 piezocomposite radial array transducer exhibits -100 % bandwidth, which has much broader bandwidth than commercial PZT array transducers (-70 %). Thus, high resolution endoscopic ultrasonic images are expected for many clinical applications.