With the development of miniaturized electronics, nanosatellites have demonstrated their capabilities to complete satellite missions at a fraction of the cost of a conventional satellite. In the past decade, CubeSats have developed from an educational tool to more sophisticated commercial and scientific applications, such as formation flying missions [1], low-earth-orbit constellations [2] and deep space explorations [3]. Although not prevalent currently, being equipped with an onboard propulsion system CubeSats can further improve their mission competence. For example, in low earth orbit, a micro-propulsion system can compensate for atmospheric drag on a CubeSat and extend its orbiting lifetime. For a remote sensing or imaging nanosatellite, the pointing accuracy can be improved by using thrusters for precise attitude control. Missions requiring high-velocity changes, such as orbit changing, can be enabled using a propulsion system with high specific impulse. However, the development of micro-propulsion technologies is challenging due to the size and power supply constraints on a nanosatellite. Among all the micro-propulsion systems currently being developed [4, 5], including cold-gas, monopropellant and electric micro-propulsion systems, electrospray propulsion [6] and field emission electric propulsion [7] are particularly promising due to their high specific impulse and high power efficiency at low power. In general, electrospray thrusters are capable of achieving high specific impulse over 1000 s while maintaining a relatively high efficiency around 40% at power lower than 20 W [8]. The efficiency of electrospray