Printed Gas Sensors for Crew Cabin Air Quality Monitoring

Abstract

Air quality monitoring in the crew cabin is important for crew health and safety. In the past, bulky instruments such as mass spectrometer have been used but simple sensors, which are small and consume low power can be used to get variation of gas concentrations across the cabin. Availability of such sensor chips would be useful for planetary exploration that involves mapping the atmosphere. We have been developing printed sensors that can be printed on demand using the future “ Fablab “ facilities being planned for the International Space Station. We use single-walled carbon nanotubes as the primary sensing material and use variations such as doping, functionalization etc. to incorporate multiple sensors in a sensor array. Since commercial nanomaterials lack consistency in quality, we have also developed a multielectrode system that gives N(N-1)/2 data points for N number of electrodes to provide a stochastic system instead of a single deterministic data point from a two-electrode system. This “ Single Input Multiple Output (SIMO)” system provides a better sensor-to-sensor variation and results for sensing CO2 and ammonia will be presented. This work was supported by the NASA In Space Manufacturing program.