Voltage-Modulated Flow Rate for Precise Thrust Control in Colloid Electrospray Propulsion

We describe a feature of electrospray operation that allows precise control of flow rate through an electrospray emitter by use of the extraction voltage. The effect of extractor voltage on the propellant flow rate through an electrospray emitter has been determined for triethylene glycol and ethylene glycol solutions doped with varying levels of sodium iodide and the ionic liquid 1-ethyl-3-methyl imidazolium tetrafluoroborate using an in-line high-accuracy flow measurement system. In these experiments, a nominally fixed flow rate, obtained by providing a fixed supply pressure, is observed to be influenced by the applied voltage during stable cone-jet electrospray production. The relative sensitivity of flow rate to applied voltage was found to be higher as the nominal flow rate decreased. This method of flow rate control holds particular significance for colloidal electrospray thruster systems, which operate at or near minimum flow rate conditions.

[1]  J. Mora,et al.  The current emitted by highly conducting Taylor cones , 1994, Journal of Fluid Mechanics.

[2]  Arnold Weissberger,et al.  Organic solvents;: Physical properties and methods of purification , 1970 .

[3]  Manuel Gamero-Castaño,et al.  Direct measurement of ion evaporation kinetics from electrified liquid surfaces , 2000 .

[4]  M. Edirisinghe,et al.  Evaporation of liquid during cone-jet mode electrospraying , 2002 .

[5]  C. Hendricks,et al.  Charged droplet experiments , 1962 .

[6]  G. Valaskovic,et al.  Ultra-low flow nanospray for the normalization of conventional liquid chromatography/mass spectrometry through equimolar response: standard-free quantitative estimation of metabolite levels in drug discovery. , 2006, Rapid communications in mass spectrometry : RCM.

[7]  M. Mann,et al.  Electrospray ionization for mass spectrometry of large biomolecules. , 1989, Science.

[8]  J. Goldman,et al.  Electrochemical properties of imidazolium salt electrolytes for electrochemical capacitor applications , 1999 .

[9]  Katharine Smith,et al.  The sensitivity of volumetric flow rate to applied voltage in cone-jet mode electrospray and the influence of solution properties and emitter geometry , 2006 .

[10]  Katharine Smith,et al.  Voltage Effects on the Volumetric Flow Rate and Thrust produced in Electrospray Propulsion Systems , 2005 .

[11]  Katharine Smith,et al.  Electrospray Performance of Microfabricated Colloid Thruster Arrays , 2006 .

[12]  K. Okuyama,et al.  Preparation of ZnS Nanoparticles by Electrospray Pyrolysis , 2000 .

[13]  A. Bailey,et al.  ELECTROSTATIC SPRAYING OF LIQUIDS , 1988 .

[14]  Julius Perel,et al.  Research on a charged particle bipolar thrustor , 1967 .

[15]  Katharine Lucy Smith.  Characterisation of electrospray properties in high vacuum with a view to application in colloid thruster technology , 2005 .

[16]  S. P. Thompson.  Neutral emissions from liquid metal ion sources , 1984 .

[17]  John P. W. Stark,et al.  A MEMS Based Experimental Colloid Thruster Package for Nano Satellites , 2004 .

[18]  J. Stark,et al.  Pulsation modes and the effect of applied voltage on current and flow rate in nanoelectrospray. , 2006, Analytical chemistry.

[19]  A. Engel,et al.  Mass transport in liquid gallium ion beam sources , 1981 .

[20]  J. Stark,et al.  The role of molar conductivity in electrospray cone-jet mode current scaling , 2006 .

[21]  B. Thomson,et al.  Efficiency of nano-electrospray ionization , 2005, Journal of the American Society for Mass Spectrometry.

[22]  Katharine Smith,et al.  Voltage effects on the volumetric flow rate in cone-jet mode electrospraying , 2006 .

[23]  Alfonso M. Gañán-Calvo,et al.  Current and droplet size in the electrospraying of liquids. Scaling laws , 1997 .