Development of a MEMS based colloid thruster with sandwich structure

Design of a propulsion system with mini-size, high specific impulse and extremely low impulse bit is highly demanded by micro and nano spacecrafts. In this paper, a MEMS based micro colloid thruster has been developed by bulk silicon processing. The dimensions of the new thruster have been reduced considerably, which allows the micro thrusters to use a working voltage of 1-3 kV instead of 5-10 kV traditionally. The emitter of the thruster is designed to enable fine thrust control in the micro Newton range. A cantilever-based test facility is further developed to test the micro colloid thruster. Experimental results show that a thrust in the order of micro Newton can be produced by a single emitter, with a working threshold voltage as low as 1400 V.