Performance of a high dielectric constant piezoelectric ceramic for ultrasound transducers

A high dielectric material suitable for medical imaging arrays has been investigated. Resonance techniques were used to characterize the complete set of electromechanical properties. Compared to Navy Type VI material a two-fold increase in clamped permittivity was observed (ε₃₃^S/ε₀ of 2730 vs. 1470), while the coupling coefficient for linear array elements was almost identical (k₃₃´ of 0.68 vs. 0.69 for Navy Type VI). Measurements indicated high coupling and permittivity at frequencies up to at least 60 MHz. Models for 1-3 composites incorporating this material revealed an effective thickness coupling of 0.68 at a 55% volume fraction of ceramic. Simulated device performance indicated a 4 dB sensitivity increase for array elements incorporating this material when compared to conventional materials