Olga Saukh helds the keynot speech at the 7th International Workshop on Real-World Embedded Wireless Systems and Networks (RealWSN) that takes place in Shenzhen, China, on Nov 4th, 2018.
Ambient air is a complex mixture of chemicals with poorly understood interactions and feedbacks. Car exhaust, secondhand smoke, factory emissions, cosmetics, glues, paints, etc. constitute the air we breathe and we probably don’t even know about the chemical cocktail we are inhaling next. For over 30 years engineers have been working on an affordable technology to read and understand the composition of ambient air in place, but only recently have low-cost solid state gas sensors become available on the market.
The first generation of these sensors were designed to measure high gas concentrations in car exhaust, but the technology has been improving rapidly and today we can measure polluting substances in ambient air by integrating low-cost sensors into IoT devices and rolling out large-scale deployments. The very same sensors can also be used to build an electronic nose for early disease diagnosis. After having been processed by our body, exhaled air contains numerous markers about the state of our health. Fruity odours in the breath, for example, relate to diabetics; foul ones to respiratory tract infections. Also in daily lives, we use smell to test the freshness and quality of food and beverages.
There is hope that one day gas sensing technology will lead to breakthroughs in personalized medicine and environmental science. However, the problem of understanding ambient air quality is more difficult than it seems: 1) low-cost gas sensors suffer from hysteresis and lack selectivity forcing us to deploy sensor arrays to compensate for these effects, 2) chemical composition of ambient air is highly dynamic with invisible chemical reactions taking place all the time, and 3) existing measures and limits of air pollution exposure are as good as our understanding of the negative impact air pollution has on human health. In this talk, I would like to take you for a journey into the world of low-cost gas sensors and their applications by sharing my experience using these sensors to monitor air quality at scale, and discuss research challenges that arise when putting this technology in wider contexts.