ENG-SEMICON: Meshed chemical sensor network for targeted monitoring of environmental VOCs of concern

University Of California-Davis, Davis CA

Investigators

Abstract

Across the United States, wildfires are increasing in frequency, size, and duration. They blanket huge regions of the US with fire smoke, exposing millions of Americans across multiple states to dangerous air quality for days or even weeks. Currently, Americans have access to systems like the EPA’s AirNow to check current air pollution levels in their community, known as the AQI (Air Quality Index) score, to see if they should take any precautions before going outside. However, this score only considers certain types of pollution like ozone or particulate matter but does not consider a specific type of pollution: certain chemicals found in fire smoke known as volatile organic compounds (VOCs) that are known to cause cancer. Currently, there is no technology available to monitor our air for this type of VOC pollution. This project will develop devices that can monitor VOC pollution outdoors so that, long term, Americans can have a more complete picture of air quality in their region, and know when to take action to keep themselves safe and healthy. The team in this award will assemble a network of portable chemical sensors that can continuously monitor outdoor air, targeting specific carcinogenic VOCs such as benzene, toluene, and xylene. Devices can be set outside and will continuously measure VOCs, relaying data to a cloud for data processing to provide quantitative concentrations. Targeted VOC measurements will be accomplished using gas chromatography coupled with a differential mobility spectrometer chemical detector. First, the team will test different sensor packaging that ensures devices can survive harsh outdoor conditions long term such as heat, rain, or wind, while making accurate measurements. Also, the team will develop wireless communication capabilities for the chemical sensor network, which will relay data over long ranges using the LoRa radio communication technique. The team will test a prototype sensor network under controlled conditions using controlled releases of VOCs inside an airplane hangar, and outside using controlled burns. They will also test the sensor network in an actual wildfire event, to track the real time distribution of cancer causing VOCs within the afflicted community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.