Electrohydrodynamic atomization nozzle emitting a liquid sheet

Abstract

Embodiments for producing un-agglomerated, monodisperse droplets using a liquid sheet are provided. Nozzles with exit slit openings shape a spray liquid into a thin liquid sheet as the spray liquid exits from the slit opening. Stable multi-jet operation is achieved by including notches along the edge of the slit. The notches separate the liquid sheet into multiple jets to provide anchoring and stable multi jet operation. In some embodiments, the liquid sheet electrospray techniques and nozzles described herein provide high mass throughput and versatile multiplexing spray systems while reducing the engineering effort and high manufacturing cost

What is claimed is: 
     
         1 . A nozzle for electrohydrodynamic atomization, said nozzle comprising:
 an inner rod;   an outer tube concentrically aligned with said inner rod;   an annular channel defined between said inner rod and said outer tube, said annular channel forming a circular slit at a spray end of said nozzle; and   at least one electrically chargeable notch located on at least one of said inner rod and said outer tube proximate said circular slit.   
     
     
         2 . A nozzle in accordance with  claim 1 , wherein said inner rod comprises a central flow channel defined therethrough. 
     
     
         3 . A nozzle in accordance with  claim 2 , wherein said central flow channel is configured to facilitate flow of at least one of a stabilizing gas and a stabilizing liquid therethrough. 
     
     
         4 . A nozzle in accordance with  claim 1  further comprising an outermost tube concentrically aligned with said inner rod and said outer tube such that an outer flow channel is defined between said outer tube and said outermost tube. 
     
     
         5 . A nozzle in accordance with  claim 4 , further comprising at least one electrically chargeable notch located on said outermost tube. 
     
     
         6 . A nozzle in accordance with  claim 1 , wherein said at least one electrically chargeable notch is located on only one of said inner rod and said outer tube. 
     
     
         7 . A nozzle in accordance with  claim 1 , wherein said inner rod comprises a center piece at the spray end of said nozzle and said outer tube comprises an end portion at the spray end of said nozzle, said center piece recessed with respect to said end portion. 
     
     
         8 . A nozzle in accordance with  claim 1 , wherein said inner rod comprises a center piece at the spray end of said nozzle and said outer tube comprises an end portion at the spray end of said nozzle, said center piece extended with respect to said end portion. 
     
     
         9 . A nozzle in accordance with  claim 1 , wherein said at least one electrically chargeable notch comprises a plurality of notches, said plurality of notches spaced a distance apart from one another such that when said plurality of notches are electrically charged, an electric field produced by one notch of said plurality of notches does not interfere with an electric field produced by an adjacent notch of said plurality of notches. 
     
     
         10 . A system for electrohydrodynamic atomization, said system comprising:
 a nozzle comprising:
 a source end; 
 a spray end; 
 a first component comprising a first surface; 
 a second component comprising a second surface; 
 a fluid channel defined between said first surface and said second surface, said fluid channel forming an exit slit at said spray end of said nozzle; and 
 at least one electrically chargeable notch located on at least one of said first component and said second component proximate said exit slit; 
 a voltage source electrically coupled to said nozzle and configured to supply a voltage to said at least one electrically chargeable notch; and 
 a syringe pump in flow communication with said source end of said nozzle, said syringe pump configured to propel a spray liquid through said nozzle. 
   
     
     
         11 . A system according to  claim 10 , wherein said first component comprises a first plate and said second component comprises a second plate, such that said fluid channel is substantially planar. 
     
     
         12 . A system according to  claim 10 , further comprising a nozzle means for emitting a liquid sheet. 
     
     
         13 . A system in accordance with  claim 10 , further comprising notch means for separating a liquid sheet emitted from said nozzle into multiple jets. 
     
     
         14 . A system in accordance with  claim 10 , further comprising means for maintaining a shape of a liquid sheet emitted from said nozzle. 
     
     
         15 . A system in accordance with  claim 10 , wherein said at least one electrically chargeable notch comprises a first notch and a second notch, said first and second notches spaced a distance apart from one another such that when a voltage is supplied to said first and second notches, an electric field produced by said first notch does not interfere with an electric field produced by said second notch. 
     
     
         16 . A method for electrohydrodynamic atomization, said method comprising:
 providing a nozzle comprising an inner rod, an outer tube concentrically aligned with the inner rod, an annular channel defined between the inner rod and the outer tube, the annular channel forming a circular slit at a spray end of the nozzle, and a plurality of notches located on at least one of the inner rod and the outer tube proximate the circular slit;   supplying a voltage to the plurality of notches; and   pumping a spray liquid through the annular channel of the nozzle.   
     
     
         17 . A method in accordance with  claim 16 , wherein the inner rod includes a central flow channel defined therethrough, said method further comprising pumping a stabilizing gas through the central flow channel. 
     
     
         18 . A method in accordance with  claim 16 , wherein the inner rod includes a central flow channel defined therethrough, said method further comprising pumping a stabilizing liquid through the central flow channel. 
     
     
         19 . A method in accordance with  claim 16 , further comprising:
 providing an outermost tube concentrically aligned with the inner rod and the outer tube, such that a outer flow channel is formed between the outer tube and the outermost tube; and   pumping a sheath liquid through the outer flow channel.   
     
     
         20 . A method in accordance with  claim 16 , wherein supplying a voltage comprises supplying a voltage such that a jet of spray liquid is formed at each of the plurality of notches.