The substopic described the need for a multi-gas sensor that is power efficient, consistent with a wearable form factor, and can reliably operate under a wide range of temperature, humidity, and pressure conditions. We propose a CO2 gas sensor that maintains the required dynamic range, accuracy, and sensitivity even under significant environmental variations. We employ distributed feedback quantum cascade lasers (QCLs) to perform intrapulse spectroscopy in the mid-infrared, which allows us to reach targeted sensitivities with ultra-low duty cycle measurements to dramatically reduces power consumption and system complexity. Pendar’s expertise in monolithic quantum cascade laser integration will enable integration of multiple quantum cascade lasers to incorporate detection of up to 5 gases, including H2O and O2, all within an anticipated system footprint of 5 cm x 5 cm x 3 cm. Phase I will focus on building a breadboard prototype to experimentally verify that 1) the system draws <100 mW, and 2) CO2 detection accuracy is unaffected by varying pressure and temperature. A conceptual design of the Phase II miniaturized and integrated prototype will also be proposed at the end of Phase I.
The proposed system is directly relevant to the design of the new Exploration Extravehicular Mobility Unit (xEMU). The intended goal of the proposed gas measurements is to ensure that the spacesuit maintains a safe environment without drawing significant power.
The proposed CO2 sensor can be adopted for capnography (CO2 detection in breath, and for indoor/outdoor air quality control by measuring CO2 in ambient air. The miniaturized sensing platform can also be easily adapted to target chemical threats for Department of Homeland Security, and natural gas leaks for Department of Energy and the oil and gas industry.