A Low-Cost Full-Range Hydrogen Sensor Based on Quartz Tuning Fork

Hydrogen (H2) sensors have a wide range of applications in green energy, including fuel cell monitoring, hydrogen storage safety, and leak detection in renewable energy systems. This article reports a quartz tuning fork (QTF)-based low-cost full-range H2 sensor with a detection range of 0%–100%. The system features a simple structure and easy fabrication. Firstly, the relationship between H2 concentration and the characteristics of QTF was theoretically analyzed. The influence of hydrogen viscosity on QTFs was used as a sensing mechanism. Three QTFs with different resonant frequencies of 8, 32, and 100 kHz were experimentally compared, and the results indicated that the 100-kHz QTF exhibits the best performance, achieving a frequency sensitivity of 200 mHz/% and the fastest response. The findings revealed that higher-frequency QTFs exhibit superior sensitivity to H2 detection. The designed sensor platform enables H2 sensing at a low manufacturing cost and the sensors are easily replaceable, which opens up great potential for mass production and use in industry. The experiments also revealed that the quality factor (Q-factor) significantly increases when the QTF is immersed in an H2 environment, attributed to the low density and low viscosity of H2.