Electrospraying systems and associated methods
Electrospraying systems and associated methods are generally described.
1. An emitter configured for use in an electrospraying device, comprising:
an array of protrusions extending from an emitter substrate, at least a portion of the protrusions in the array comprising a plurality of elongated nanostructures extending from one or more external surfaces of the protrusions, wherein the nanostructures are arranged between the bases of the protrusions and the tips of the protrusions and are configured to transport fluid from bases of the protrusions to tips of the protrusions at least in part via capillary forces.
2. The emitter of claim 1 , wherein at least a portion of the elongated nanostructures are nanotubes.
3. The emitter of claim 2 , wherein at least a portion of the elongated nanostructures are carbon nanotubes and/or inorganic nanotubes.
4. The emitter of claim 1 , wherein at least a portion of the elongated nanostructures are nanofibers.
5. The emitter of claim 4 , wherein at least a portion of the elongated nanostructures are carbon nanofibers and/or silicon carbide nanofibers.
6. The emitter of claim 1 , wherein the elongated nanostructures are substantially aligned.
7. The emitter of claim 1 , wherein at least a portion of the emitter substrate and/or the protrusions are formed of a semiconductor.
8. The emitter of claim 1 , wherein at least a portion of the protrusions have maximum cross-sectional dimensions of at least about 1 micron.
9. The emitter of claim 1 , wherein the array comprises at least 10 protrusions having an aerial density of at least about 10 protrusions/cm 2 .
10. The emitter of claim 9 , wherein the protrusions have an aerial density of between about 10 protrusions/cm 2 and about 100,000 protrusions/cm 2 .
11. The emitter of claim 1 , wherein at least a portion of the protrusions do not contain internal fluid passageways.
12. A system, comprising: the emitter of claim 1 ; and
an electrode;
wherein, when a voltage is applied across the emitter and electrode and the emitter is exposed to a fluid, droplets of the fluid are emitted from at least a portion of the protrusions of the emitter toward the electrode.
13. A method, comprising applying a voltage across the emitter of claim 1 and an electrode such that fluid positioned between the emitter and the electrode is emitted from at least a portion of the protrusions of the emitter toward the electrode.
14. The emitter of claim 1 , wherein at least one of the protrusions in the array comprises at least about 100 elongated nanostructures extending from the one or more external surfaces of the protrusion.
15. The emitter of claim 6 , wherein the substantially aligned elongated nanostructures are non-parallel to the one or more external surfaces of the protrusion from which the substantially aligned elongated nanostructures extend.
16. The emitter of claim 6 , wherein the substantially aligned elongated nanostructures are substantially perpendicular to the one or more external surfaces of the protrusion from which the substantially aligned elongated nanostructures extend.
17. The emitter of claim 1 , comprising an intermediate material positioned between the elongated nanostructures and the protrusions.
18. The emitter of claim 17 , wherein the intermediate material comprises a catalyst capable of catalyzing the formation of the elongated nanostructures.
19. The emitter of claim 1 , wherein the elongated nanostructures comprise at least one of nanotubes, nanofibers, nanowires, nanopillars, and nanowhiskers.