Microfabrication of Capillary Electrospray Emitters and ToF Characterization of the Emitted Beam
نویسندگان
چکیده
Microfabrication, assembly, and characterization of internally fed arrays of electrospray emitters for spacecraft propulsion are discussed. Several different emitter geometries were fabricated, and the sprayed beams from these emitters are characterized for their ion/droplet composition. It is shown that with smaller inner diameters, ionic mode of operation can be achieved more easily, due to the increase in the hydraulic impedance. Up to 2000 s Isp was measured from capillaries with 5 μm inner diameter and 100 μm with 750V extraction voltage using EMI-BF4. Due to the small dimensions of the microfabricated capillaries, the onset and ionic mode operation voltages can be significantly lower than macroscopic emitters. The major failure mode for the emitters was the liquid overflow from the capillary tip, which can be resolved through coatings that wet the ionic liquids differently. A detailed study of the wetting behavior of two ionic liquids is also presented for various materials compatible with silicon microfabrication technology.
منابع مشابه
Microfabricated electrospray emitter arrays with integrated extractor and accelerator electrodes for the propulsion of small spacecraft
Microfabricated electrospray thrusters could revolutionize the spacecraft industry by providing efficient propulsion capabilities to micro and nano satellites (1–100 kg). We present the modeling, design, fabrication and characterization of a new generation of devices, for the first time integrating in the fabrication process individual accelerator electrodes capable of focusing and accelerating...
متن کاملProgress Towards a Miniaturized Electrospray Thruster for Flexible Propulsion of Small Spacecraft
Miniaturized electrical thrusters based on electrospray (or colloid) emitters could revolutionize the spacecraft industry by providing e cient propulsion capabilities to micro and nano satellites (1-100 kg). We report on our recent advances in the development of this technology within the MicroThrust (www.microthrust.eu) European consortium. We present the design and operation of the currently ...
متن کاملCapillary Extraction of the Ionic Liquid [Bmim][DCA] for Variable Flow Rate Operations
The ionic liquid [Bmim][DCA] is a propellant candidate in a standalone electrospray thruster or in a dual-mode propulsion system consisting of a chemical system and an electrospray system. Since limited published data exists for [Bmim][DCA], the electrospray characteristics are relatively unknown. Emission testing of the ionic liquid has been conducted to characterize the [Bmim][DCA] electrospr...
متن کاملMicroThrust MEMS electrospray emitters – integrated microfabrication and test results
With the growth of interest in small satellites (<10kg), there is a particular need to provide a propulsion element for this class of spacecraft. Microfabricated electrospray thrusters offer a solution to this problem. By using ionic liquids as the propellant solely ions can be emitted, resulting in a large specific impulse [1]. The thrust from an individual emitter is though a fraction of a μN...
متن کاملDesign and fabrication of an integrated MEMS-based colloid micropropulsion system
The design, microfabrication and initial performance results of a prototype electrospray thruster with integrated individual extractor electrodes are reported in this paper. The aim was to demonstrate increased thrust with an array of emitters spraying simultaneously. Micromachining technologies were employed to achieve large emitter density per surface area, simple integration and good structu...
متن کامل