A Low SWaP, Low-Cost, Multi-Chemical Monitoring System

Prior research has shown that ambient air contains more than 3,000 different pollutants. However, current environmental sensor networks (ESNs) predominantly focus on monitoring only six pollutants, as guided by the EPA and WHO. This leaves numerous other chemicals unmonitored, resulting in limited knowledge about their background levels and safe thresholds. To address this, we propose an innovative system focusing on collecting data on a wide range of chemicals that are not commonly measured. The proposed system can be deployed independently or be integrated into currently deployed ESN nodes to broaden the range of chemicals they monitor. To enable this, it features a compact form factor with low weight, power consumption, and a small manufacturing cost. The system implements up to 12 chemiresistive nanofiber sensors designed to target different chemicals. These sensors are interfaced by a specially designed ASIC optimized to accommodate the sensors’ wide range of resistance values, up to ten gigaohms, while maintaining low power consumption and high measurement accuracy. The 15 g chemical monitoring front-end operates on a mere 52 mW total using only 4.3 mW per sensor and occupies a volume of 30 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>, with an affordable cost of $95 per each system. An exploratory trial of the system demonstrate 86.69% accuracy on average in differentiating exposed chemicals.