Method and apparatus for a porous electrospray emitter

Patent metadata

Field	Value
Publication number	US-9478403-B2
Application number	US-201414336814-A
Country	US
Kind code	B2
Filing date	Jul 21, 2014
Priority date	May 6, 2008
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

An ionic liquid ion source can include a microfabricated body including a base and a tip. The body can be formed of a porous material compatible with at least one of an ionic liquid or room-temperature molten salt. The body can have a pore size gradient that decreases from the base of the body to the tip of the body, such that the at least one of an ionic liquid or room-temperature molten salt is capable of being transported through capillarity from the base to the tip.

First claim

What is claimed is:

1. An electrospray emitter comprising:
a porous emitter body with a base and a tip, wherein the porous emitter body is formed at least partially from a porous xerogel.

2. The electrospray emitter of claim 1 , wherein the porous xerogel is a porous ceramic xerogel.

3. The electrospray emitter of claim 2 , wherein the porous ceramic xerogel is an alumina xerogel.

4. The electrospray emitter of claim 1 , wherein a pore size gradient of the porous emitter body decreases in a direction from the base of the porous emitter body toward the tip of the porous emitter body.

5. The electrospray emitter of claim 1 , further comprising a source of ions in fluid communication with the porous emitter body.

6. The electrospray emitter of claim 5 , further comprising a first electrode electrically connected to the porous emitter body through the source of ions and a second electrode positioned downstream relative to the porous emitter body and the first electrode.

7. An electrospray emitter array comprising:
a porous substrate; and
a plurality of porous emitters, wherein each porous emitter extends up from the porous substrate to a tip, and wherein the plurality of porous emitters are formed at least partially from a porous xerogel.

8. The electrospray emitter array of claim 7 , wherein the porous xerogel is a porous ceramic xerogel.

9. The electrospray emitter array of claim 8 , wherein the porous ceramic xerogel is an alumina xerogel.

10. The electrospray emitter array of claim 7 , and wherein each porous emitter has a pore size gradient that decreases in a direction from the substrate toward the tip of the porous emitter.

11. The electrospray emitter array of claim 7 , further comprising a source of ions in fluid communication with the plurality of porous emitters through the porous substrate.

12. The electrospray emitter array of claim 11 , further comprising a first electrode electrically connected to the plurality of porous emitters through the source of ions and at least a second electrode positioned downstream relative to the porous emitters and the first electrode.

13. A method of forming an electrospray emitter comprising:
pouring a gel solution into a mold shaped to form one or more emitter bodies with a base and a tip;
drying the gel solution in the mold to form the one or more emitter bodies at least partially from a porous xerogel.

14. The method of claim 13 , wherein the porous xerogel is a porous ceramic xerogel.

15. The method of claim 14 , wherein the porous ceramic xerogel is an alumina xerogel.

16. The method of claim 13 , wherein the gel solution is a sol gel solution.

17. The method of claim 16 , wherein the sol gel solution includes a solvent, an acidic aluminum salt, a polymer, and a proton scavenger.

18. A method of forming an electrospray emitter comprising:
pouring a slurry including ground porous xerogel into a mold shaped to form one or more emitter bodies with a base and a tip;
freezing the slurry in the mold to form a frozen slurry;
freeze-drying the frozen slurry to form the one or more emitter bodies at least partially from a porous xerogel.

19. The method of claim 18 , wherein the porous xerogel is a porous ceramic xerogel.

20. The method of claim 19 , wherein the porous ceramic xerogel is an alumina xerogel.

21. The method of claim 18 , further comprising sintering the one or more emitter bodies.

22. The method of claim 18 , wherein freezing the slurry further comprises freezing the slurry in the mold with a temperature gradient that increases in a direction from the tip of the one or more emitter bodies toward the base of the one or more emitter bodies.

Assignees

• Massachusetts Inst Technology

Inventors

• Lozano Paulo C
• Arestie Steven Mark

Classifications

• H01J2237/0802

  Field ionization sources · CPC title

• H01J1/05

  characterised by material · CPC title

• B01L3/502715

  characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces · CPC title

• H01J37/08 Primary

  Ion sources; Ion guns · CPC title

• H01J49/0445 Primary

  with means for introducing as a spray, a jet or an aerosol (electrospray ion sources H01J49/165) · CPC title