Electrospray devices and methods of fabricating electrospray devices are described.

The invention relates to a liquid metal-ion beam system (1) or liquid metal electron beam system, including: a conductive emitter electrode (2), a conductive extractor electrode (3) opposite to the emitter electrode (2), a liquid metal reservoir (4) which is fluidically connected to the emitter electrode (2) for transporting liquid metal to the emitter electrode (2), a control unit (5) which is configured to apply a periodically varying operating voltage between emitter electrode (2) and extractor electrode (3).

An ion beam generator includes an emission electrode, an extraction electrode, and an electricity generator. The emission electrode includes a substrate and a plurality of nanowires extending away from the substrate, substantially towards the extraction electrode, the nanowires having a length of 50 nm to 50 μm. The emission electrode has a source of ions including a sheet of ionic liquid formed on the substrate and at least partially immersing the nanowires. The nanowires and the substrate are electrically insulating or semiconducting, and the electricity generator is connected to the sheet of ionic liquid. The emission electrode is thus capable of sending ion beams from the ionic liquid to the extraction electrode.

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.

The present invention relates to a neutralizer (4) for an ion thruster (1) of a spacecraft (S), comprising: a cathode (5) for emission of electrons (6), a support (7) with an opening (8) inside which the cathode (5) is supported in a radially spaced manner, and an electrically conductive shielding (9) which surrounds said opening (8) and is electrically insulated from the support (7), wherein a ring (11) is mounted between the shielding (9) and the cathode (5) and is electrically insulated from the shielding (9) and radially spaced from the cathode (5).

The invention relates to a liquid metal-ion beam system (1) or liquid metal electron beam system, comprising: a conductive emitter electrode (2), a conductive extractor electrode (3) opposite to the emitter electrode (2), a liquid metal reservoir (4) which is fluidically connected to the emitter electrode (2) for transporting liquid metal to the emitter electrode (2), a control unit (5) which is configured to apply a periodically varying operating voltage between emitter electrode (2) and extractor electrode (3).

A method for controlling an ion thruster including an emission electrode, an extraction electrode and a conductive liquid which is deposited on the emission electrode, the ion thruster configured for emitting an ion beam when an electric field is applied to the conductive liquid, the ion beam providing thrust to the thruster, the thrust depending on an emission current I.sub.em and an ion emission speed, the method including the following steps: adjusting the emission current to a setpoint value I.sub.c by applying a threshold emission potential V.sub.thresh to the emission electrode by means of a current generator; and when the setpoint value I.sub.c of the emission current is reached, adjusting the emission speed by applying an extraction potential V.sub.ext to the extraction electrode by means of a voltage generator in order to bring the emission potential V.sub.em to a predetermined value V.sub.empr=V.sub.thresh+V.sub.ext.

Electrical propulsion systems and related methods are generally described. In some embodiments, an electrical propulsion system may include an electrically-actuated valve to selectively permit flow of propellant from a reservoir tank to a thruster. The valve may physically isolate the propellant from the thruster when inactivated, exhibiting a non-wetting surface which may inhibit propellant from passing through the valve towards the thrusters. In some embodiments, a valve may be activated through application of a voltage potential to the valve relative to the propellant, which may change the wettability of the valve, permitting propellant to wet and subsequently pass through the valve. The voltage potential may be adjusted to vary the wettability of the valve, resulting in the valve effectively regulating propellant flow rate. The valve may include a conductive layer, a dielectric or insulating layer, and a non-wetting layer to enhance the non-wetting behavior of the valve.

The present invention relates to an ion thruster for propulsion of spacecrafts, including: a reservoir for a propellant, an emitter for emitting ions of the propellant, the emitter having one or more projections of porous material and a base with a first side supporting said projections and a second side connected to the reservoir, and an extractor facing the emitter for extracting and accelerating the ions from the emitter, wherein the base is impermeable to the propellant at least on said first side and has pores or channels for providing flow of propellant from the reservoir to said projections.

Electrical propulsion systems and related methods are generally described. In some embodiments, an electrical propulsion system may include an electrically-actuated valve to selectively permit flow of propellant from a reservoir tank to a thruster. The valve may physically isolate the propellant from the thruster when inactivated, exhibiting a non-wetting surface which may inhibit propellant from passing through the valve towards the thrusters. In some embodiments, a valve may be activated through application of a voltage potential to the valve relative to the propellant, which may change the wettability of the valve, permitting propellant to wet and subsequently pass through the valve. The voltage potential may be adjusted to vary the wettability of the valve, resulting in the valve effectively regulating propellant flow rate. The valve may include a conductive layer, a dielectric or insulating layer, and a non-wetting layer to enhance the non-wetting behavior of the valve.