Sol-gel PZT thick films for ultrasonic imaging

Ultrasound transducers for B-mode medical imaging are typically operated between 1 and 10 MHz. Research has been directed towards developing transducers that are sensitive in the 10-100 MHz range because a number of clinical problems require higher resolution than can be achieved at the lower frequencies. Using a modified sol-gel technique developed at Queen´s University, lead zirconate titanate (PZT) thin films of 45±5 μm in thickness have been successfully coated on aluminum foil. The technique allows the fabrication of thin films of arbitrary thickness in the range of 1 to 60 μm. This PZT provides an alternative transducer material in the 10-100 MHz range and may also produce sensitive transducers operating above 100 MHz. This will increase the available resolution of ultrasound backscatter microscopy and narrows the gap between lower resolution clinical systems and high resolution transmission scanning acoustic microscopy. The evaluation of the electrical and mechanical properties of these PZT films and the ability to pattern them are described