Skylark vocalization-inspired photoacoustic spectroscopy dual-component sensor based on a double-helix Helmholtz photoacoustic cell

Inspired by the principles of skylark vocalization, this paper presents a photoacoustic spectroscopy (PAS) sensor based on a double-helix Helmholtz photoacoustic cell (DHH-PAC) for the simultaneous detection of methane (CH₄) and carbon dioxide (CO₂). Finite element analysis was employed to explore the acoustic characteristics of the DHH-PAC. The experimental investigation demonstrates that the DHH-PAC-based PAS sensor exhibits excellent linear concentration responses for both CH₄ and CO₂ detection. According to Allan deviation analysis, the minimum detection limit (MDL) for the CH₄ and CO₂ paths were optimized to 91.86 ppb and 7.69 ppm, respectively, by increasing the system’s integration time. This study demonstrates that biomimetic strategies can significantly enhance the performance of PAS sensors.