Thesis defense by Nate Ambler on Nov. 21: Solid-State Nanocrystalline Gas Sensor Array Demonstration
Solid-State Nanocrystalline Gas Sensor Array Demonstration
Sensors allow us to perceive and make sense of the environment around us. They are essential components for information in any dynamic control system for biological, environmental, physiological, and chemical processes. These environments include future extra-terrestrial habitation and greenhouse environments necessary to the fulfillment of the mandated Vision for Space Exploration (VSE) laid out by President George W. Bush on January 14, 2001. Several solid-state sensors, such as the complementary metal oxide semiconductor (CMOS) indium tin oxide (In2O3:SnO2) sensor, demonstrate key benefits in response rates and sensitivity when compared to highly temperature and pressure dependent sensor technologies. Suitability testing of these sensor archetypes involved developing circuitry and testing at the University of North Dakota (UND), heritage data from testing at the Kennedy Space Center, and a flight aboard the National Aeronautics and Space Administration's (NASA) High Altitude Student Platform (HASP). This presentation also covers the large science-technology-engineering-mathematics (STEM) promotion effort in postsecondary education.
Utilized in testing included indium tin oxide (ITO) thin film sensors for the measurement of ozone, developed by the University of North Florida (UNF). These sensors represent a unique, easily produced in mass, and newly designed solid-state nanocrystalline gas sensor array (patent pending). During testing, these sensors demonstrated detection to the parts per billion by volume (ppbv) level. Testing for ozone quantitatively agreed with calibration to within 15%. Flight data acquired aboard HASP produced a highly accurate ozone profile for the flight to over 120,000 feet. In all, this research addresses many serious unmet needs for miniature sensors capable of in-situ and real-time detection of gasses (e.g. carbon monoxide (CO), volatile organic compounds (VOCs), and carbon dioxide (CO2)) in reduced pressure and low temperature environments. Because these ITO sensors do not require the high operating temperatures of previous sensors and because these sensors maintain good stability under harsh atmospheric conditions, gas sensors of this type appear as good candidates for use in extraterrestrial applications, and in space flight instrumentation. These sensor archetypes help satisfy the rigorous demands of space flight technologies and the future demands of human exploration while improving the detail of the picture and perception of Earth.