Miniaturized SMD-Reflow-Capable Photoacoustic CO2-Sensor Using a Dual-Chamber Approach

The increasing interest in monitoring indoor air quality has led to a growing demand for simple and smallscale gas sensors. We present a miniaturized photoacoustic dual chamber sensor module that includes an infrared hotplate emitter and a wafer-level manufactured photoacoustic detector. The sensor module was controlled by a PSoC 4200M microcontroller and is capable of being soldered in a SMD reflow soldering process. The sensor prototype achieves a 3‑sigma noise level of 138 ppm CO2, which is suitable for most consumer applications.