This Small Business Innovation Research (SBIR) Phase I project will demonstrate the feasibility of a miniaturized fast-response oxygen sensor. Fuel efficiency of automotive engines and power generating systems improve when operated under lean-burn conditions. Oxygen monitoring in industrial processes promise higher productivity while effective fire fighting requires information regarding local combustion conditions. These applications all require in-situ oxygen sensors that combine rapid response, sensitivity, selectivity, resistance to fouling, and thermal and chemical robustness. The firm proposes to develop an Oxygen Sensor by combining key innovations including (1) unique thin-film semiconducting metal-oxides (SMO) sensitive to oxygen concentration in the 0.001-21 percent range, with rapid (10-100 ms) response time, and temperature insensitivity in the 700-1000....C range, and (2) refractory SiC microhotplate gas sensor platform capable of operating to 1000....C, with only 20 mW power consumption. <br/><br/>Commercial application of the proposed oxygen sensors includes automotive and aeronautic propulsion systems, power generation, incineration, food packaging technology, and fire fighting.