Design and Implementation of a Miniaturized Photoacoustic Spectroscopy CO Sensor

In this work, a miniaturized photoacoustic carbon dioxide (CO₂) sensor is designed and implemented based on an all-in-one photoacoustic cell with a volume of 87 μL. The performance of the sensor is carefully optimized by comprehensively simulating the dependence of the photoacoustic signal's amplitude and frequency on the geometrical characteristics of the sensor. The designed gas sensor is then experimentally validated and calibrated, and a sensitivity of 70 μV/ppm to CO₂ is obtained. Furthermore, the Allan deviation of the sensor's output indicates a gas detection limit of less than 2 ppm.