Assembly and characterization of micromachined combustor

Abstract

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 /spl times/ 21.50 mm) and various thickness, ranging from 400 /spl mu/m to 800 /spl mu/m. Deep reactive ion etching (DRIE) process is employed to structure the silicon wafers from both sides. The combustion chamber measures about 94 mm/sup 3/. 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 /spl deg/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.