Broadband ultrasonic transducer based on nested composite structure with gradient acoustic impedance

This study introduces an innovative Broadband Ultrasonic Transducer employing a Nested Composite Structure with Gradient Acoustic Impedance, significantly enhancing the performance in medical diagnostics and non-destructive testing. The developed transducer, based on a unique nested PZT/epoxy composite design, achieves an optimized acoustic impedance gradient from 36.56 MRayls to 4.53 MRayls. This strategic design effectively addresses the impedance mismatch, a long-standing challenge in ultrasonic imaging. Rigorous Finite Element Analysis (FEA) using PZFlex software indicates that the transducer offers a −6 dB bandwidth of 69.31%, a substantial improvement over the existing models. Experimental results corroborate with theoretical predictions, demonstrating enhanced bandwidth (∼71.24%) and transmission efficiency. This advancement highlights the potential of gradient impedance in fabricating high-performance ultrasonic transducers, setting a new benchmark for ultrasonic imaging applications.