Investigation of the onset voltage for the design of a microfabricated colloid thruster

Onset voltage plays a crucial role in the design of a microcolloid thruster. This paper presents a methodology to estimate the onset voltage for the design of a new microfabricated colloid thruster. The basic idea of this method is to simplify the source emitter and the extractor of the microthruster as two hyperboloids of two sheets of a set of equal potential surfaces. The maximum electric field between electrodes is modeled using the Lame´ method, on which a method to estimate the onset voltage is developed. To avoid the aberration of electric field caused by protuberances on the surface of the source emitter, the height of the source emitter must be much greater than that of protuberance. Experiments conducted on the homemade microcolloid thrusters, designed based on the proposed onset voltage estimation, verify the correctness of the approach.