Electrohydrodynamic spraying system

• US 7,748,343 B2
• Filed: 11/22/2004
• Issued: 07/06/2010
• Est. Priority Date: 11/22/2004
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of The University of Illinois
• Original Assignee: Board of Trustees of The University of Illinois
• Inventors: Singh, Ravindra Pratap, Kim, Kyekyoon
• Primary Examiner(s): Tadesse; Yewebdar T
• Application Number:
  US10/995,049
• Publication Number:
  US 20060110544A1
• Time in Patent Office: 2,052 Days
• Field of Search: 118/621, 118/625, 118/627, 118/629, 118/638, 118/504, 118/505, 427/457, 427/458, 427/475, 427/483, 427/485, 427/486, 427/468, 427/421, 239/698, 239/692, 239701-704, 239/706, 239/707, 239/690, 239/697, 239/548, 239/550, 239/556, 239/557, 239/566, 96/27, 96/53, 96/71, 128/200.14, 250/281, 250/285, 250/288, 385/12, 385/117, 385/118, 435/285.2, 435/285.3, 361/228, 361/235
• US Class Current: 118/621
• CPC Class Codes: B05B 5/0255 spraying and depositing by electrostatic forces only
• CPC Class Codes: B05B 5/0533 Electrodes specially adapted therefor; Arrangements of electrodes

Abstract

An electrohydrodynamic spray apparatus includes a liquid inlet and a spray nozzle in fluid communication with the liquid inlet, where the spray nozzle has an opening downstream of the liquid inlet. An inner electrode is situated at least partially inside the spray nozzle. An outer electrode is situated external to the spray nozzle and within about 100 mm of the opening of the nozzle. The electrohydrodynamic spray apparatus can be combined with a substrate to form an electrohydrodynamic spray system. The electrohydrodynamic spray apparatus or system can be used to form nanostructures such as nanodrops, nanoparticles and thin films.

Claims

1. An electrohydrodynamic spray system, comprising:

an electrohydrodynamic spray apparatus having

a liquid inlet;

a spray nozzle in fluid communication with the liquid inlet, the spray nozzle comprising an opening downstream of the liquid inlet;

an inner electrode inside the spray nozzle;

an outer electrode external to the spray nozzle, and detached from the spray nozzle while the electrohydrodynamic spray apparatus is in operation, and

a substrate positioned downstream of the spray nozzle,

wherein

an end of the inner electrode is completely inside the nozzle, and wherein said end of the inner electrode is in the form of a needle point that applies a field injection charge to a liquid flowing through the spray nozzle to produce nanodrops; and

wherein the spray nozzle is electrically insulated.

2. The electrohydrodynamic spray system of claim 1, wherein the substrate is electrically grounded.

3. The electrohydrodynamic spray system of claim 1, wherein the substrate is connected to a voltage source.

4. The electrohydrodynamic spray system of claim 1, wherein the substrate is non-conductive.

5. The electrohydrodynamic spray system of claim 1, wherein the outer electrode is positioned from 15 mm upstream of the opening to 15 mm downstream of the opening.

6. The electrohydrodynamic spray system of claim 1, wherein the outer electrode is configured as an open geometrical shape.

7. The electrohydrodynamic spray system of claim 6, wherein the outer electrode comprises at least two electrode portions.

8. The electrohydrodynamic spray system of claim 7, wherein the at least two electrode portions are electrically isolated from each other.

9. The electrohydrodynamic spray system of claim 1, wherein the outer electrode is configured as a closed geometrical shape.

10. The electrohydrodynamic spray system of claim 1, wherein the electrohydrodynamic spray apparatus further comprises

a plurality of spray nozzles in fluid communication with the liquid inlet, each spray nozzle comprising an opening downstream of the liquid inlet;

an inner electrode at least partially inside each spray nozzle; and

an outer electrode external to each spray nozzle, and within 100 mm of the opening.

11. The electrohydrodynamic spray system of claim 1, wherein the electrohydrodynamic spray apparatus and the substrate are moveably positioned relative to each other.

12. The electrohydrodynamic spray system of claim 1, further comprising a mask positioned between the electrohydrodynamic spray apparatus and the substrate.

13. The electrohydrodynamic spray system of claim 12, wherein the mask is connected to a voltage source.

14. The electrohydrodynamic spray system of claim 12, wherein the mask is non-conductive.

15. The electrohydrodynamic spray system of claim 1, wherein the outer electrode is configured as a cup, ring, cone, an elliptical ring, a polygon, a semicircle, a line, or a point.

16. The electrohydrodynamic spray system of claim 1, wherein the outer electrode has a diameter from 2 mm to 70 mm.

17. The electrohydrodynamic spray system of claim 1, wherein the end of the inner electrode is from about 0 mm to about 10 mm from the nozzle opening.

18. The electrohydrodynamic spray system of claim 1, wherein the end of the inner electrode is from about 0.5 mm to about 7.0 mm from the nozzle opening.

19. The electrohydrodynamic spray system of claim 1, wherein the end of the inner electrode is from about 1.5 mm to about 4.0 mm from the nozzle opening.