Design, fabrication and characterization of a solid propellant micro-Thruster

A MEMS-based solid propellant micro-thruster is presented in this paper. The prototypes with 4times4, 6times6 and 8times8 propulsion elements are designed, fabricated and tested. Cr is used as ignition resistor material in the ignition layer, which hasn't been reported by other researchers. Compared with the ignition resistors fabricated by poly-silicon or noble metal Pt, the Cr resistor has lower ignition voltage and lower cost. Two types of ignition resistors are designed, fabricated and compared: single resistor and parallel resistor. The latter one is expected to have higher reliability. BTATZ is used as the solid propellant which has high nitrogen content and high burning speed. It has been proved that the propulsion elements can be ignited successfully under the ignition voltage of no more than 30 V. The power of the ignition resistor is lower than 5 W. Test results show that the propulsion force is about 0.12mN, which is appropriate for the application in micro-spacecraft.