Novel PZT films for ultrasound biomicroscopy

Lead zirconate titanate (PZT) ceramic films of thickness 5-200 μm have been produced on various substrates using a modified sol gel process. A subset of these films (5-27 μm) open the possibility of fabricating ceramic ultrasound transducers in the frequency range of 80-200 MHz. The technique involves mixing PZT powder conventional PZT sol gel to form a paint which is then coated onto a flat substrate. Initial characterization has included the dielectric and impedance response of the PZT film supported by a metal substrate. The films resonate within the desired frequency range, but the substrate is not conducive for ultrasonic transducers. A technique has been developed to mount the PZT onto conductive silver epoxy using 80 μm aluminum foil as a sacrificial layer. The pulse echo response of this structure demonstrates the broadband response required for ultrasound imaging transducers