Development of a Nonresonant Photoacoustic Gas Sensor for Ozone Detection

A nonresonant photoacoustic (PA) effect-based ozone (O3) gas sensor has been developed, with the potential for O3 concentration monitoring in various fields, including the semiconductor industry, water treatment, and O3 environmental science research. This sensor comprises a micro-electromechanical system (MEMS) emitter, a miniature PA cell, a MEMS microphone, and a circuit. By establishing a 3-D model and simulating the impact of structural parameters on sensor performance, this comprehensive approach successfully determined the optimal structural parameters. The sensor has a footprint of approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$12\times 12\times 5$ </tex-math></inline-formula> mm (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${L} \times {W} \times {H}$ </tex-math></inline-formula>), which is 10% of the size of traditional nondispersive infrared gas sensors. The sensor achieves an accuracy of ±50 ppm within an O3 concentration range of 0%–4%. The response time (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${t}_{{100}}$ </tex-math></inline-formula>) is 57 s, and the limit of detection (LOD) for O3 concentration is 36 ppm.