Chip-Scale, Nanoengineered CO2 Gas Sensors for Integrated Spacesuit Monitoring

NASA and N5 Sensors, Inc. through a STTR program are jointly developing ultra-small, low-power carbon dioxide (CO2) and oxygen (O2) gas sensors, ideally suited for integrated space suit monitoring. During extravehicular activities, it is vital to monitor the effectiveness of the Portable Life Support System (PLSS) in real-time to ensure the safety of the astronaut. Due to the unique environmental conditions within the space suit such as high humidity, large temperature swings, and operating pressure swings, measurement of key gases such as carbon dioxide relevant to astronaut’s safety and health are quite challenging. Additionally, size, weight, and power constraints on such detection devices make it impractical to use conventional sensors. Unique chip-scale, nanoengineered chemiresistive gas sensor architecture has been developed for this application, which can be operated in the typical space suit environmental conditions. Unique design combining the selective adsorption properties of the nanoclusters of metal-oxides and metals, provides selective detection of CO2 in high relative-humidity conditions. Future works will focus on sensor design refinement as well as implementation of other on-chip components for reliable operation. In addition, a fully-integrated prototype system will be developed that can be tested in a simulated environment to evaluate the figures of merit.