SBIR Phase I: MEMS Gas Sensor

This Small Business Innovation Research Phase I SBIR research project will prototype a MEMS-based hydrocarbon gas sensor. The MEMS-based gas sensor uses a microfabricated photonic crystal to emit infrared light in a specific portion of the electromagnetic spectrum. The wavelength can be tuned by design to overlap an absorption band of methane, for example, to make a small, sensitive, efficient detector of methane or other toxic or flammable gas. The MEMS-based approach also includes a microfabricated anti-reflective surface, which uses microfabricated sub-wavelength features to reduce the effective index of refraction of the wafer material. The broader impact of this approach is to produce MEMS-based gas sensors having a well defined absorption band in the infrared. The technique may be readily adapted to make other gas sensors, such as carbon dioxide, carbon monoxide, hydrocarbons, nitric oxide, nitrogen dioxide and sulphurous compounds. The microfabricated anti-reflective structures may be applied to infrared devices such as spectrometers, optical elements, and other infrared emitters and detectors. Methane sensors may be made which are inexpensive enough to equip individual members of a mining team, greatly improving mining safety.