The engine is expected deliver electric power in the range of milliwatts to watts while supplying voltages from 1 to 30 volts. The team, Dave Bahr, Teri Fiez, Karti Mayaram, Ben Li, Cill Richards and Bob Richards, are creating a totally new class of heat engine, an engine which takes advantage of thermophysical phenomena unique to small scales. The proposed engine is an external combustion engine, in which thermal power is converted to mechanical power through the use of a novel thermodynamic cycle which approaches the ideal vapor Carnot cycle.
Mechanical power is converted into electrical power through the use of a piezoelectric generator.
The generator, which takes the form of a flexible membrane, can be readily manufactured using MEMS fabrication techniques but still delivers high conversion efficiency. This approach eliminates the requirement to manufacture complex micromachines such as rotary compressors and turbines, resulting in a very simple but highly efficient device. The resulting micro heat engine is expected to significantly outperform any currently available power source for MEMS and microelectronic devices. Using high energy density hydrocarbon fuels, its power density is expected to be far above that possible for electrochemical batteries.