Single element and linear array PZT ultrasound biomicroscopy transducers

PZT coatings have been produced in the thickness range of 5-200 microns using a composite sol gel process (M. Lukacs et al., 1996). The application of this process in the fabrication of high frequency transducers suitable for ultrasound biomicroscopy (UBM) has been investigated. Curved single element transducers have been produced in a range of 70-165 MHz with -6dB bandwidths as high as 52% and minimum insertion losses ranging from -47 to -58 dB. Laser micromachining techniques for patterning linear array structures to operate at similar frequencies have been developed. Trenches <10 μm wide with a 50% taper through 20 μm of ceramic have been achieved with a pulsed frequency doubled Nd:YAG laser. Trenches 5 μm wide with straight walls have been achieved using a pulsed KrF excimer laser