Digital MicroPropulsion

Arrays of "Digital Propulsion" micro-thrusters have been fabricated and tested. A three-layer sandwich is fabricated containing micro-resistors, thrust chambers, and rupture diaphragms. A propellant is loaded into the chambers, which are then sealed. When the resistor is heated sufficiently, the propellant ignites raising the pressure in the chamber and rupturing the diaphragm. An impulse is imparted as the high-pressure fluid is expelled from the chamber. On the order of 10/sup 6/ thrusters can be fabricated on a single wafer. Initial tests, using lead styphnate as the propellant, have produced 10/sup -4/ Newton-seconds of impulse and about 100 Watts of power.