An evaluation of PZT5A, PIN-PMN-PT Single Crystal, and High-Dielectric PZT for a 5mm x 5mm Histotripsy Transducer

Three 5 MHz, 1-3 piezoelectric-epoxy composites with a volume fraction of approximately 40 percent were fabricated using the dice-and-fill technique. The composites, made from PZT-5A, single crystal PIN-PMN-PT, and CTS 3257HD, a high-dielectric piezoelectric, were cut to 5 mm x 5 mm a mounted to an aluminum lens of the same dimensions with a 5 mm focus, and the focal pressure as a function of drive voltage was measured using a 40 um needle hydrophone from Precision Acoustics while driving the transducer to steady-state using a custom, in-house adjustable voltage pulser with a peak voltage of 600 V. The focal pressure for each device was found to increase as, 6.6, 8.6, 9.0 MPa/100V for the PZT-5A, PIN-PMN-PT and CTS 3257 HD, respectively. It is expected that the CTS 3257 HD and PIN-PMN-PT should be capable of generating cavitation within the range of the current pulser, while we expect the PIN-PMN-PT could generate more pressure with higher voltages, but a new pulser would be required. The PZT-5A composite has been shown to reach its saturation limit at 500 V (1.5V/ μm) and, at this voltage, may not always be capable of generating cavitation consistently.