The format and size specifications of the CubeSat platform require highly miniaturized subsystems, one of the most challenging ones being the propulsion system. Up to date, according to the authors' knowledge, only two CubeSats have successfully operated a propulsion system in space: CanX-2 in 2008 and Defil-n3Xt in 2013. The importance of a miniaturized propulsion system becomes even more apparent when taken into consideration that most, if not all, of the CubeSats launched to date, due to budget constraints, have been piggybacking their launches into space and therefore they may end up in a non-optimal orbit. As a next step, a formation flying technology demonstration mission is planned by the Delft University of Technology (DelFFi), as part of the QB50 project. This thesis gives an outline of the present development status of micro-propulsion systems at Delft University of Technology. The main design driving criteria are provided by the DelFFi satellites requirements. Keeping in mind the educational environment in which the work is performed, safety drives the requirements: thus, propellants have to be non-toxic and easy to handle. Additionally, present requirements aim at a thrust level in the range of 1 to 10 [mN] and a total ?V of 15 [m/s] or more. Wet mass, when installed in triple-unit CubeSats, shall be less than 450 [g], and peak power consumption less than 10 [W]. A number of Commercial-Off-The-Shelf (COTS) systems have been investigated to find suitable candidates that fulfil these minimum requirements. However, it has been concluded that all presently available systems have low Technology-Readiness-Level (TRL) or their performance is out of the required range. It was thus necessary to start working at custom designed system. The design process and decisions made will be presented in this thesis. Furthermore for testing purposes also a test setup and an engineering model propulsion system was made. A general test program using LabVIEW was made that can automate the testing process of the thruster. The system was then tested and from the results, recommendations and conclusions were made for the next iteration of the thruster.