Fabrication and Characterization of a Low-Frequency Array for a Hybrid PZT-CMUT Transducer

Abstract

Piezocomposite materials consist of a periodic structure of active piezoelectric materials and passive polymer materials. Piezocomposite material is widely used in medical ultrasound transducers due to the advantages of piezocomposite over pure piezoelectric materials, such as high electromechanical coupling, reduction in lateral crosstalk, and low acoustic impedance for matching with human tissue. This work studies the design, modelling and fabrication of a 2 MHz 2-2 piezocomposite plate and array as the low frequency part of a DHUT structure at the USN ultrasound laboratory. The piezocomposites were designed and modelled in a 1D Mason equivalent circuit model and a 2D finite element model. The fabricated piezocomposites were characterized by its electrical impedance and phase angle and compared to the modelled result. The fabrication procedure for piezocomposite was also developed for the USN ultrasound laboratory and discussed in detail.