This work demonstrates a prototype bi-layer piezoelectric micromachined ultrasonic transducer (PMUT) based on transferred periodically poled piezoelectric film (P3F) X-cut lithium niobate (LN). Opposite in-plane polarizations in the piezoelectric film stack are employed to enable efficient lateral field excitation of the flexural mode. Thanks to its high piezoelectric coefficient and low dielectric loss, the X-cut LN exhibits high figure of merits (FoMs) as both sensors and transducers. The fabricated PMUT demonstrates an out-of-plane mode near 1 MHz with an electromechanical coupling of 3.6\%. Laser Doppler vibrometry further validates the finite element analysis, showing a peak center displacement of 340 pm/V. These results establish bi-layer P3F LN PMUTs as a promising platform for compact and high-performance ultrasonic transducers. Future work will focus on theoretical analysis, modeling of the measured data, improving the design of the transducer topology, and mitigating feedthrough effects.
@article{arxiv.2509.00600,
title = {Bimorph Lithium Niobate Piezoelectric Micromachined Ultrasonic Transducer},
author = {Ziqian Yao and Vakhtang Chuluhadze and Zihuan Liu and Xiaoyu Niu and Tzu-Husan Hsu and Byeongjin Kim and Neal Hall and Ruochen Lu},
journal= {arXiv preprint arXiv:2509.00600},
year = {2025}
}