Hydrogen has been widely used in many applications from aerospace and chemicals to fuel cells and satellite power supply. Although hydrogen is not toxic, it has a very broad flammability range (4%-74% concentration in air and 4%-94% in oxygen), leading to explosion in the presence of heat source. Thus, hydrogen monitoring is of paramount importance during the processes of hydrogen production, transportation, storage, and all kinds of hydrogen use. However, current hydrogen sensors are not delivering a real-time response, and their sensing performance degrade gradually. Moreover, their sensing responses depend on the temperature change and the deviceâs sensitivity are not quite satisfactory for long-term industrial applications. This Phase I project proposes to develop a new type of hydrogen sensors that allows continuous monitoring of hydrogen concentration or leakage in a broad range of conditions (e.g., inert conditions without presence of oxygen or ambient conditions at a wide range of hydrogen concentrations). The new sensors are based on the innovative ionic liquid (IL) electrochemical gas sensing technology. The hydrogen sensor can sensitively detect hydrogen in a real-time manner with negligible baseline drift, thus allowing continuous monitoring of hydrogen in a quantitative way and maintaining strong reliability under both nitrogen and ambient conditions. The proposed hydrogen sensor is very selective to hydrogen gas in the presence of other interference gases (e.g., oxygen, methane, carbon dioxide, and volatile organic compounds), and can work well under different environmental conditions. Furthermore, the sensor has a long lifetime due to the reversible sensing mechanism, high sensitivity, and specificity to hydrogen sensing, and the stability of the sensing materials at harsh environments. The final miniaturized sensor prototypes will be in cm scale and able to detect hydrogen existence and oxygen concentration simultaneously and quantitatively in the range of interests for industrial applications. During Phase I, we will focus on: 1) the development, fabrication, and optimization of a robust sensor prototype, and 2) the miniaturization, system integration and testing, and validation of a full-scale workable sensor prototype for potential pipeline applications. We will perform a series of experimental tests of the full-scale sensor prototypes, including specific characterization and validation under practical conditions. This Phase I project together future Phase II work will also develop a protocol for both lab and field testing, and perform device validation through field benchmark tests with gas chromatography (GC) and current commercial gas sensors. This new hydrogen sensor is expected to be operated in a wide range of working conditions including an explosive environment in Phase II tasks. With this new device, we expect to achieve a real-time sensing network platform with robust low-cost and low-power electrochemical sensors, providing future area-wide sensing instead of point detecting of current technologies
