Lead-free BSZT/Epoxy 1-3 Composites For Ultrasonic Transducer Applications

With high piezoelectric coefficient (d33> 300 pC/N) and electromechanical coupling factor (kt = 0.45), lead-free barium strontium zirconium titanate ((Ba0.95Sr0.05) (Zr0.05Ti0.95) O3, abbreviated as BSZT)was used to fabricate BSZT/epoxy 1-3 composites with different volume fractions of BSZT ranging from 0.55 - 0.85. The electromechanical properties of the 1-3 composites were determined by the resonance technique. It was found that the theoretical modeling of the 1-3 composites matches quite well with the measured material properties.The 1-3 composite with f = 0.65 was chosen to be fabricated as a transducer due to its comparatively high value of kt. The BSZT/epoxy 1-3 composite transducer demonstrates large bandwidth with good sensitivity, suggesting high potential in biomedical applications