Miniaturized Electrospray Thrusters

Electrospray thrusters are a promising micropropulsion technology for CubeSats, among others, because they have the potential to provide high specific impulse. They avoid moving parts and allow a high degree of miniaturization. In combination with fabrication technologies from microelectromechanical systems (MEMS), miniaturization of individual emitters to the range of tens of micrometers brings with it a new concept of constructing and scaling thrusters, namely, by numbering-up the microthrusters to a device of suitable thrust. The current state of the art is briefly reviewed with an emphasis on MEMS technology. Furthermore, preliminary results, which indicate the feasibility of fabricating electrospray emitters in nonsilicon MEMS technology, notably by 3-D microlithography (two-photon lithography) are presented.