Solid Propellant Microthrusters on Silicon: Design, Modeling, Fabrication, and Testing

The design, modeling, fabrication, and characterization of solid propellant microthrusters for space application is presented. The operational concept of solid propellant thruster is simply based on the combustion of a solid energetic material stored in a micromachined chamber. Each thruster contains four main parts (nozzle, heater, chamber, seal). Thrusters presented in this paper have a chamber area of 2.25 mm². Throat diameters (160, 250, and 500 mum) have been calculated to generate thrusts in the range from 0.3 to 30 mN that meets station keeping requirements for micro satellites. Fabrication processes for each part of the thruster are presented as well as the assembling procedure and the electronic module implementation. Characterizations give ignition power between 80 and 150 mW depending on the energetic material contained in the igniter´s cavity. The ignition success is of 100% when using a Zirconium Potassium Perchlorate propellant. Thrust balance is presented as well as the thrust measurements that validate our model