Demonstration of a Microscale Heat Exchanger for a Silicon Micro Gas Turbine Engine

The design, fabrication, modeling, and testing of silicon counterflow heat exchanger for use in the MIT micro gas turbine engine is discussed. Although silicon is the preferred material in microfabricated devices, it is not the ideal choice for recuperative heat exchanger applications. Its high thermal conductivity allows heat transfer between opposite ends of the device, reducing the overall effectiveness. Designing and fabricating a heat exchanger that can overcome this behavior poses several challenges that are described herein.