A PMN-PT Composite-Based Circular Array for Endoscopic Ultrasonic Imaging
Qi Zhang, Yongchuan Li, Jiamei Liu, Jiqing Huang, Qingyuan Tan, Congzhi Wang, Yang Xiao, Hairong Zheng, Teng Ma
Abstract
Endoscopic ultrasound (EUS), an interventional imaging technology, utilizes a circular array to delineate the cross-section almorphology of internal organs through the gastrointestinal (GI) track. However, the performance of conventional EUS transducers has scope for improvement because of the ordinary piezoelectric parameters of Pb(Zr, Ti)O3(PZT) bulk ceramic as well as its inferior mechanical flexibility which can cause material cracks during the circular shaping process. To achieve both prominent imaging capabilities and high device reliability, a 128-element 6.8-MHz circular array transducer is developed using a Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT) 1-3 composite with a coefficient of high electromechanical coupling (kt ~ 0.78) and good mechanical flexibility. The characterization results exhibit a large average bandwidth of 58%, a high average sensitivity of 100 mVpp, and a crosstalk of less than -37 dB near the center frequency. Imaging performance of the PMN-PT composite-based array transducer is evaluated by a wire phantom, an anechoic cyst phantom, and an ex-vivo swine intestine. This work demonstrates the superior performance of the crucial ultrasonic device based on an advanced PMN-PT composite material and may lead to the development of next-generation biomedical ultrasonic devices for clinical diagnosis and treatment.