Recent advancements in Integrated Metal Oxide Semiconductor (MOS) sensor arrays have made them valuable technologies for advanced environmental monitoring, as they can detect multiple gases simultaneously on a single chip. Specifically, MOS sensor arrays have the potential to detect carbon monoxide (CO), nitrogen dioxide (NO₂), methane (CH₄), ammonia (NH₃), and volatile organic compounds (VOCs). Applications such as urban air quality monitoring, industrial site safety, and various smart city infrastructures can utilize multi-gas sensors. This paper examines the design, fabrication, and field deployment of multi-gas MOS sensor arrays from the perspectives of device architecture, transduction material selection, microfabrication strategies, and signal processing. The major challenges, including issues of cross-sensitivity, selectivity, drift, and size reduction, have been covered. Additionally, ways to mitigate these challenges through methods such as operational temperature modulation, temperature-assisted nanostructured materials, and machine-learning-based calibration have been discussed. This work provides a comprehensive overview of important technologies, methods, and concepts, highlighting the real capabilities of integrated MOS sensor arrays. These arrays could be utilized to create reliable, scalable, and cost-effective multi-gas sensing systems for next-generation environmental monitoring.
Amrutha Sampath (Tue,) studied this question.