I-Corps: Chemical sensors for airborne detection

University Of Alabama Tuscaloosa, Tuscaloosa AL

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is to enable airborne chemical sensors that are smaller, lighter, and lower cost than existing technology. The devices developed here enable low-power chemical sensing on ultralight drones, in wearable technology, and in small spaces where current technology would not fit or would be prohibitively expensive. The global chemical sensors market, including defense (chemical weapons, explosives), domestic security/first responders (opioids, bomb detection, breath sensors) and industrial hygiene (toxic industrial chemicals) sectors, produces more than $5B in annual revenue, with toxic gas sensors representing $1.5B. This project looks serve markets in the defense, domestic security, and first response sectors due to the size and weight advantages. This I-Corps project further develops an alternating current impedance technology to detect dielectric changes in custom designed sensor materials. Tuning the probe frequency to target specific chemical interactions allows our sensor to be more selective: For instance, probe frequencies can be chosen to avoid environmental interference, such as water vapor which typically manifests only low-frequency (<100Hz) impedance changes. The method allows greater selectivity with fewer probe elements, allowing simpler devices that can be made smaller, and at lower cost, compared to devices of similar performance. The project incorporates frequency selection into a device that uses an interdigitated capacitor with overlaid thin film of colorimetric material. A microcontroller controls input, feedback, and an impedance analyzer for continuous measurements at targeted frequencies. 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.