Fabrication and performance of endoscopic ultrasound radial arrays based on PMN-PT single crystal/epoxy 1-3 composite

In this paper, 0.7Pb(Mg1/3Nb2/3)O3-0. 3PbTiO3(PMN-PT) single crystal/epoxy 1/3 composite was used as the active material of the endoscopic ultrasonic radial array transducer, because this composite exhibited ultrahigh electromechanical coupling coefficient (kt= 0.81%), very low mechanical quality factor (Qm= 11) and relatively low acoustic impedance (Zt= 12 MRayls). A 6.91 MHz PMN-PT/epoxy 1/3 composite radial array transducer with 64 elements was tested in a pulseecho response measurement. The -6-dB bandwidth of the composite array transducer was 102%, which was ∼30% larger than that of traditional lead zirconate titanate array transducer. The two-way insertion loss was found to be -32.3 dB. The obtained results show that this broadband array transducer is promising for acquiring high-resolution endoscopic ultrasonic images in many clinical applications.