A Ceramic PZT-Based PMUT Array for Endoscopic Photoacoustic Imaging
Haoran Wang, Zhenfang Chen, Hao Yang, Huabei Jiang, Huikai Xie
Abstract
In this paper, we present the design, fabrication, and characterization of a compact 4 × 4 piezoelectric micromachined ultrasonic transducer (pMUT) array and its application to photoacoustic imaging. The uniqueness of this pMUT array is the integration of a 4 μm-thick ceramic PZT, having significantly higher piezoelectric coefficient and lower stress than sol-gel or sputtered PZT. The fabricated pMUT array has a small chip size of only 1.8 × 1.6 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with each pMUT element having a diameter of 210 μm. The fabricated device was characterized with electrical impedance measurement and acoustic sensing test. Photoacoustic imaging has also been successfully demonstrated on an agar phantom with a pencil lead embedded using the fabricated pMUT array.