This paper reports an aluminum nitride (AlN) multi-frequency piezoelectric micromachined ultrasound transducers (MF-PMUT) array for photoacoustic (PA) imaging, where the broadened bandwidth is beneficial to improve imaging resolution. Specifically, PMUT based on micro-electromechanical systems (MEMS) technology is suitable for PA endoscopic imaging of blood vessels and bronchi due to its miniature size. More importantly, AlN is a non-toxic material, which makes it harmless for biomedical applications. In this work, a MF-PMUT array are designed and fabricated for PAI. The device's vibration mode impedance and bandwidth are analyzed. The MF-PMUT sensor provides a wider bandwidth (65%) signal detection, which increases the resolution of PAI compared with traditional PMUT. We conduct an experiment on agar sample to present sensor's performance in images' axial resolution.
@article{arxiv.2203.16806,
title = {Photoacoustic Imaging Based on AlN MF-PMUT with Broadened Bandwidth},
author = {Junxiang Cai and Yiyun Wang and Daohuai Jiang and Yuandong and Gu and Liang Lou and Fei Gao and Tao Wu},
journal= {arXiv preprint arXiv:2203.16806},
year = {2022}
}