Nanomaterials Based Gas Sensor for ISRU Process Contaminants

NASA is seeking sensing technologies for In Situ Resource Utilization (ISRU) process gases. One particular need is monitoring impurities such as hydrogen sulfide (H2S), hydrogen chloride (HCl) and hydrogen fluoride (HF) in the ISRU oxygen stream. Such sensors serve as both safety and process monitoring devices and are critical for the successful operation of ISRU systems. InnoSense, in collaboration with the University of Virginia (UVA), is developing an innovative process gas monitoring (PROMON�) device. PROMON builds on InnoSense�s proprietary single walled carbon nanotube � based sensor platform. It is further enabled by novel intermetallic nanoparticles (NPs) with precise size and composition control, serving as the key sensing element. Additionally, PROMON will include a ruggedized in-line design, providing real-time monitoring under harsh environment without reactant loss from slipstream. A similar sensor using different NPs has been developed by the team for regenerative fuel cell oxygen stream, demonstrating its capability of monitoring H2 in the concentration range of 12.5 � 12500 ppm under both ambient and high pressure (up to 300 PSI), at high temperature (up to 85�C) and high humidity (near condensing). This sets up the basis for PROMON development. In this STTR project, the initial focus is to validate the PROMON proof-of-principle, demonstrating sensor resolution, sensitivity, selectivity and durability, targeting H2S. This includes the development of (1) core sensing materials, (2) sensor units, (3) sensor test platform, and (4) benchtop prototype. In the future, we will expand targets to HCl and HF, optimize the sensor and prototype design, recognition chemistry and algorithm, and perform rigorous characterization. During future moon and mars missions, PROMON will serve as a robust sensor capable of monitoring contaminants in ISRU process gas. With its versatility, PROMON can also be adapted as a general gas detector or monitor for other analytes, toward meeting NASA needs.