This paper presents the development of a bimorph piezoelectric micromachined ultrasonic transducer (PMUT) based on X-cut lithium niobate (LN) with a periodically poled piezoelectric film (P3F) structure. The use of opposite in-plane polarizations in the stacked LN film enables efficient lateral-field excitation of the flexural mode, making it a high-performance platform for ultrasonic sensing and actuation.
Key points include:
Material Properties: The X-cut LN was chosen for its high piezoelectric coefficient and low dielectric loss, ensuring high figure-of-merit (FoM) values for both sensors and transducers.
Device Structure: The device consists of a bi-layer LN film with reversed crystal orientations, promoting constructive charge buildup and suppressing undesired overtones, leading to enhanced out-of-plane actuation.
Performance: The fabricated PMUT achieved a resonance frequency of approximately 1 MHz with an electromechanical coupling of 3.6%, demonstrating strong actuation capabilities. The displacement reached 8 nm/V, and the simulated and measured results showed excellent agreement.
Applications: This work establishes the bi-layer P3F LN PMUTs as a promising platform for compact and high-performance ultrasonic transducers, suitable for applications such as medical imaging, wireless communications, and flow sensing.
Future Work: Future efforts will focus on improving the design topology, mitigating feedthrough effects, and enhancing the device’s performance by refining the modeling and fabrication processes.
This study contributes to the development of high-performance, compact ultrasonic transducers with enhanced capabilities for both sensing and actuation.
OMeda (Shanghai Omedasemi Co.,Ltd) was founded in 2021 by 3 doctors with more than 10 years of experience in nanpfabrication. It currently has 15 employees and has rich experience in nanofabrication (coating, lithography, etching, two-photon printing, bonding) and other processes. We support nanofabrication of 4/6/8-inch wafers.
