A shadow-mask evaporated pyroMEMS igniter
A reliable pyroMEMS igniter was successfully demonstrated based on shadow-mask evaporation of metal directly onto solid propellant drops. In this way, intimate contact between the fuel and the igniter was guaranteed. No visible degradation of the fuel was observed after the evaporation. A preliminary process-parameter study was carried out. Two different ignition regimes were observed depending on the input power and igniter thickness: Joule heating and spark-induced ignition. Steady combustion in air was obtained and ignition delay time variability of less than 1 ms (std. dev.) was achieved. The igniter described herein potentially enables the wafer-level fabrication of pyroMEMS devices without any manual post-processing, thus increasing fabrication yield and device reliability.