Investigation on the ignition of a MEMS solid propellant microthruster before propellant combustion

A MEMS-based solid propellant microthruster with thin film Au/Ti igniter has been fabricated for micropropulsion applications in microspacecraft. Since the propellant ignition process is crucial to the development of solid propellant microthrusters, finite-element based electro-thermal modeling is performed to predict and optimize the transient propellant ignition process. The model is implemented to determine the evolution of the propellant temperature with time, space and voltage and the ignition power, ignition delay and ignition energy. The difference in property between thin film Au/Ti and bulk Au/Ti and heat transfer in the micro-scale thruster are highlighted. A custom-built interface circuitry is employed to measure the igniter temperature experimentally. The electro-thermal model can be employed to find the optimum ignition subsystem for the solid propellant microthruster.