A new class of Fano-based hydrogen sensor

Traditional hydrogen sensors face critical limitations, including poor selectivity, slow response times and instability, hindering the safe deployment of hydrogen technologies in the emerging green economy. This work introduces a novel Fano-based hydrogen sensor integrating palladium’s hydrogen-reactive properties with sharp asymmetric spectral characteristics of Fano resonance for ultrasensitive hydrogen detection through electromagnetic interaction. A microstrip Fano resonator was fabricated on Rogers’s substrate and coated with palladium. The sensor was characterized using Vector Network Analyzer (VNA) measurements and validated through High-Frequency Structure Simulator (HFSS) electromagnetic simulations across 1–3 GHz frequency range. Hydrogen-induced permittivity changes in palladium were measured at concentrations from 0.16 to 0.82. The sensor demonstrated measurable resonance frequency shifts from 2.025 GHz baseline to 2.06–2.125 GHz range, corresponding directly to hydrogen concentration variations. Phase response analysis revealed characteristic steep-to-shallow slope transitions, confirming hydrogen absorption-induced changes in palladium’s electromagnetic properties. The effective electrical length of the palladium-coated structure increased proportionally with hydrogen exposure, validating material-level uptake mechanisms. The Fano-palladium integration achieves dual-mode sensing through simultaneous frequency and phase monitoring, offering superior sensitivity and selectivity compared to conventional resistive sensors. This approach enables compact, scalable hydrogen detection for next-generation safety and industrial monitoring systems.