Effects of the electrical limit conditions on the electromechanical behavior of piezoelectric transducer arrays

Abstract

Crosstalk is an undesirable phenomenon having a negative impact on the electroacoustic performance of ultrasonic transducer arrays, utilized in medical imaging and NDT applications. Indeed, when one element of a transducer array is excited, it generates parasitic voltages and/or displacement fields on the adjacent passive elements. Consequently, these interactions between elements (crosstalk) are responsible for anomalous in the electromechanical behavior of the transducer array. The goal of this paper is to investigate the effects of the electrical limit conditions, i.e. when the passive neighboring elements are considered in Open-Circuit or Short-Circuit (as in the case of the crosstalk’s active cancellation techniques), on the physical behavior of the array elements. This research work also studies the impact of the limit conditions on the crosstalk’s evaluation. In this context, a piezoelectric transducer array composed of seven elements made of PZ27 ceramic is modeled using a two-dimensional finite elements method. A prototype is then fabricated and experimental measurements, i.e. electrical impedance, displacement, and crosstalk measurements are realized and successfully compared to the numerical results.