1-3 piezoelectric composites for high power ultrasonic transducer applications

The authors demonstrated that 1-3 PZT/polymer composites, fabricated using PZT-4 ceramic and a polymer possessing a high glass transition temperature and low loss, can be used as high power ultrasonic transducer materials for high intensity focused ultrasound (HIFU) applications. The mechanical quality factor of the 1-3 composite with 64% ceramic volume fraction is over 200. The dielectric loss tangent is the same as that of the ceramic used in the 1-3 composite at 1 kHz. The electromechanical coupling coefficients were 0.64 for pure epoxy filler and 0.68 for epoxy incorporating microspheres. The 1-3 composite transducers demonstrated a large operating bandwidth and elevated power capacity.