Microfluidics of Liquid Propellant Microthruster for Pico-Satellites

This paper treats a liquid propellant microthruster because its thrust flexibility and small tank are advantageous to pico-satellites for many types of missions. Two major fluidic concerns are investigated using test devices fabricated by MEMS technique. One is the catalytic decomposition of hydrogen peroxide in a microchannel. The other is the effect of wettability on two-phase flow. A platinum-coated channel with a height of 5 µm was found to work well because of its large surface-volume ratio. However, the heat dissipation into the structure components is critical especially for the starting period. An additional electric heater was tested and discussed for quick and effective operation. The dependence of boiling flow on surface wettability should be concerned for the fluidic design of microchannel-based liquid microthrusters. The test results showed that the electric heater is effective to obtain practical thrust from liquid propellant.