This Small Business Technology Transfer (STTR) Phase I research project will develop a self-aspirating microelectromechanical (MEMS) atomizer for timed fuel injection into carbureted engines. The liquid fueled carburetor most commonly used in small gasoline fueled engines meters, injects and mixes the fuel with the air flowing to the engine. However, the system cannot time the injection, so the engines suffer from relatively poor fuel economy and high emission levels. Unfortunately, small engines account for significant amounts of HC, CO, NOx, and Particulate Matter emissions, which form smog and contain toxic compounds such as benzene, toluene, formaldehyde, acetaldehyde, and acrolein. Due to this significant amount of pollution, the EPA has mandated emissions regulations for these engines, which existing technology will be unable to meet in a cost effective manner. The proposed work will develop low-cost MEMS fuel atomizers for timed injection. This Phase I project will determine the feasibility of this new technology and proposed a design for its manufacture.
Low-cost small engines have enabled a large number of recreational vehicles and equipment for home use; the U.S. market is about $20M per annum for the engines alone. These engines are fueled with simple carburetors, which are reliable and cost little. Unfortunately, the emissions from these engines are too high to meet EPA regulations that will be in place in the next two years. Fuel control technologies to lower the emissions must still be inexpensive and robust like the carburetors or they will not see widespread use. Actively controlled and self-aspirating MEMS fuel atomizers to be developed under this effort can be built in large numbers with low-cost IC microfabrication facilities. Therefore, the proposed atomizers will improve fuel economy and reduce emissions at much lower cost than the competing technologies.
