Characterization of Linear Array Based on PZT Thick Film

Multi-element transducers enabling novel cost-effective fabrication of imaging arrays for medical applications have been presented earlier. Due to favorable low lateral coupling of the printed PZT, the elements can be defined by the top electrode pattern, leading to a kerf-less design with low crosstalk between the elements. The linear arrays have proved to be compatible with a commercial ultrasonic scanner and to support linear array beamforming as well as phased array beamforming. The main objective of the presented work is to investigate the performance of the devices at the transducer level by extensive measurements of the prototype structures. The arrays have been characterized at the transducer level by several different measurement techniques. Firstly, electrical impedance measurements on several elements in air and liquid have been conducted. The arrays have also been characterized by a pulse-echo system. The measured sensitivity is around -60 dB, the fractional bandwidth is close to 60%, while the center frequency is about 12 MHz over the whole array. Finally, laser interferometry measurements have been conducted. The in-depth characterization of the array structure have given insight into the performance parameters for the array based on PZT thick film and the obtained information will be used to optimize the key parameters for the next generation of arrays based on piezoelectric thick film.