Advanced combustion systems, including gas turbines, internal combustion engines, and furnaces, often require continuous monitoring of exhaust gas composition for control and optimization, to achieve high efficiency and low emissions. In this project, a sensor will be developed for the detection of emissions and intermediate species important in combustion processes. The sensor is based on the absorption of terahertz (THz) wave radiation by the gaseous combustion molecules, known as THz wave absorption spectroscopy. A sensor will be engineered using silicon microelectronics, the THz spectroscopy of target compounds will be discovered and characterized. The sensor will be demonstrated in a combustion environment. The outcome of this project will impact a broad range of sectors where gas sensing is important, e.g., energy, transportation, manufacturing, oil and gas, and air quality control.
The research team will develop the scientific foundation and technology necessary for quantitative speciation measurements in combustion environments via THz wave absorption. For many species of interest in combustion, the resonant frequencies associated with molecular rotations are in the THz frequency band, and the absorption strength of these transition is often larger than those found in either the microwave or infrared regions. Additionally, THz wave absorption is effectively immune to scattering from particles and aerosols that hinder infrared absorption in combustion environments. The project addresses three research tasks. First, the THz wave spectroscopy of volatile organic compounds and three nitrogen-containing species will be experimentally investigated and characterized in the 180-360 GHz frequency range. Second, a THz radiation source for spectroscopy, consisting of single microchip fabricated using standard silicon technology, will be designed, fabricated, and tested in the same frequency range. Finally, the sensor will be demonstrated by measuring emissions in a burner exhaust stack. The science and technology developed as part of this project has a strong potential for commercialization due to the industrial need for gas sensing in combustion and the low cost of electronic THz technologies relative to competing infrared-based sensor technologies.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
