An ion propulsion device including emission modules in an emission plane, each module having an insulating support, an emission electrode on the support, and a conductive liquid with a microfluidic channel depositing conductive liquid on the electrode; an extraction electrode common to the emission modules and facing the modules; and a control unit, in which each module is configured to emit an ion beam when an electric field is applied to the liquid; each control unit controls an ion emission current emitted by applying a potential difference between each emission electrode and the extraction electrode; the emission electrodes are spaced apart by a linear distance that is greater than a distance between two adjacent emission electrodes separated by an empty space; and a length of the insulating support between the electrodes is greater than a propagation distance of an electric leakage current by charge jumping along the support between the electrodes.