Palladium-Coated Laterally Vibrating Resonators (LVRs) for Hydrogen Sensing

Gaia Giubilei; Farah Ben Ayed; Yvonne Sautriot; Aurelio Venditti; Kun Zhang; Sila Deniz Calisgan; Pietro Simeoni; Zhenyun Qian; Matteo Rinaldi

arXiv · 2509.04511

Palladium-Coated Laterally Vibrating Resonators (LVRs) for Hydrogen Sensing

Gaia Giubilei·Farah Ben Ayed·Yvonne Sautriot·Aurelio Venditti·Kun Zhang·Sila Deniz Calisgan·Pietro Simeoni·Zhenyun Qian·Matteo Rinaldi

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Abstract

This work presents a novel hydrogen sensor based on 30% scandium-doped aluminum nitride (ScAlN) laterally vibrating resonators (LVRs) functionalized with a palladium (Pd) thin film. The micro-electro-mechanical system (MEMS) device operates by detecting shifts in resonant frequency resulting from hydrogen absorption in the Pd layer. The sensor demonstrates a high mechanical quality factor (Qm) of 820, an electromechanical coupling coefficient (kt2) of 3.18%, and an enhanced responsivity of 26 Hz/ppm in the low-parts per million (ppm) range, making it highly suitable for hydrogen leak detection. Compared to existing MHz-range technologies, the sensor achieves up to 50x higher sensitivity, while also offering multi-frequency definition in a single lithographic step, minimal footprint, and the highest quality factor among comparable miniaturized platforms.

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Gaia Giubilei, Farah Ben Ayed, Yvonne Sautriot, Aurelio Venditti, Kun Zhang, Sila Deniz Calisgan, Pietro Simeoni, Zhenyun Qian, Matteo Rinaldi. 2025-09-02. Palladium-Coated Laterally Vibrating Resonators (LVRs) for Hydrogen Sensing. https://arxiv.org/abs/2509.04511

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