Integrated MOS Sensor Arrays: Multi-Gas Detection onA Single Chip for Environmental Monitoring

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.