Piezoelectric thick film ultrasonic transducers fabricated by a spray technique

Thick film broadband ultrasonic transducers (UTs) produced using sol-gel spray technique, operating below 10 MHz are presented. These UTs are formed by dispersing PZT and LiTaO/sub 3/ particles, respectively in Al/sub 2/O/sub 3/ and PZT sol-gel solution. The 50-100 /spl mu/m thick films have been deposited on curved steel, flat steel and aluminum substrates and steel rods. Ultrasonic pulse-echo signals with a signal to noise ratio of more than 25 dB are experimentally obtained for the operating temperatures up to 250/spl deg/C.