Assembly and characterization of micromachined combustor

As part of an effort to develop MEMS-based power generation system, we present the assembly solution and the combustion test results of a recent-developed micro combustion device micromachined from single crystal silicon. Comprising the non-rotating components of a micro turbine engine, each micro combustor is constructed by 7 stacking dies, which are diced from 7 pieces of bulk-micromachined silicon wafer. Each die has identical size (21.50 mm × 21.50 mm) and various thickness, ranging from 400 μm to 800 μm. Deep reactive ion etching (DRIE) process is employed to structure the silicon wafers from both sides. The combustion chamber measures about 94 mm³. The micro combustor is assembled through seamless mechanical clamping by a customized jig, which fixed the dies and provides gas transportation in and out of the micro combustor. Some combustion experiments have been conducted after igniting the fuel/air mixture in the micro chamber. Stable hydrogen-air combustion has been observed to sustain inside the combustion chamber with exit temperature over 1200 °C. During the combustion experiments, the silicon dies keep good mechanical integrity under assembly and no gas leakage is observed. These results show the feasibility of using this micro combustor as a part of micro power generation system.