Proof-of-concept demonstration of a vaporizing liquid micro-thruster

Proof-of-concept testing of a microfabricated vaporizing liquid thruster was performed. In this liquid-fed thruster concept, propellant vaporization is achieved in a microfabricated thin film heater arrangement. Chip temperatures of 100, 150 and 200 C were achieved at power levels of 3.5, 5.5 and 7.5 W. Voltage requirements were below 5 V for these temperature values. A substantial fraction of the heat was believed to have been conducted into the packaging material. Thermal characterization tests of chips placed onto insulating Pyrex blocks resulted in temperatures of about 90 and 150 C for power levels of 1.2 and 2.5 W, respectively, thus cutting thermal losses by more than half. One thruster chip was tested using water as a liquid propellant and vaporization was achieved at 7 W electric input power.