Digital micropropulsion

Arrays of Digital Propulsion microthrusters have been fabricated and tested. A three-layer sandwich is fabricated containing microresistors, thrust chambers, and rupture diaphragms. A propellant is loaded into each individually sealed chamber. When the resistor is energized, 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(6) thrusters can be fabricated on a single wafer. Initial tests, using lead styphnate as the propellant, have produced 10(-4) N s of impulse and about 100 W of power. (C) 2000 Elsevier Science S.A. All rights reserved.