Microstructures For Fluidic Ballasting and Flow Control

• US 20110126929A1
• Filed: 08/14/2008
• Published: 06/02/2011
• Est. Priority Date: 08/15/2007
• Status: Abandoned Application

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Velasquez-Garcia, Luis F., Akinwande, Akintunde I.
• Application Number:
  US12/673,191
• Publication Number:
  US 20110126929A1
• Time in Patent Office: Days
• US Class Current: 137/561.R
• CPC Class Codes: B01L 2400/027 electrostatic forces between substrate and tip
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/0268 using pulse dispensing or spraying, eg. inkjet type, piezo actuated ejection of droplets from capillaries
• CPC Class Codes: B05B 5/0255 spraying and depositing by electrostatic forces only
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10T 137/8593 Systems

Abstract

In one example hydraulic ballast of the invention there is provided an input port and an output port through which a prespecified output flow rate is required. There is provided between the input and output ports a ballasting array of columns having a cross-sectional column extent, W, a column pitch, P, and an array length, L, selected based on the required output flow rate, to produce a prespecified pressure drop that enforces the required output flow rate.

Claims

1. Hydraulic ballast structure comprising:

an input port;

an output port through which a prespecified output flow rate is required; and

a ballasting array of columns disposed between the input port and the output port and having a cross-sectional column extent, W, a column pitch, P, and an array length, L, selected based on the required output flow rate, to produce a prespecified pressure drop that enforces the required output flow rate.

2. The hydraulic ballast structure of claim 1 wherein the column extent, W, is at least about 50% of column pitch, P.

3. The hydraulic ballast structure of claim 1 wherein the array length, L, is at least about 10 times the column pitch, P.

4. The hydraulic ballast structure of claim 1 wherein the ballasting array is characterized by a height, H, that is at least about 10 times the column extent, W.

5. The hydraulic ballast structure of claim 1 wherein the ballasting array is characterized by a height, H, that is substantially that height of an internal fluidic flow channel in which the ballasting array is disposed.

6. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are substantially square.

7. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are substantially round.

8. The hydraulic ballast structure of claim 1 wherein the ballasting array columns have a cross section that is star-shaped.

9. The hydraulic ballast structure of claim 1 wherein the ballasting array columns have a cross section that is hexagonal.

10. The hydraulic ballast structure of claim 1 wherein the input port is substantially parallel to the output port.

11. The hydraulic ballast structure of claim 1 wherein the input port is substantially perpendicular to the output port.

12. The hydraulic ballast structure of claim 1 wherein the ballasting array is substantially square.

13. The hydraulic ballast structure of claim 1 wherein the ballasting array is substantially circular.

14. The hydraulic ballast structure of claim 1 wherein the ballasting array is substantially hexagonal.

15. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are substantially untapered.

16. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are substantially tapered.

17. The hydraulic ballast structure of claim 1 wherein the ballasting array columns comprise a microelectronic material.

18. The hydraulic ballast structure of claim 1 wherein the ballasting array columns comprise silicon.

19. The hydraulic ballast structure of claim 1 wherein the ballasting array columns each comprise at least one carbon nanotube.

20. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are disposed on a semiconductor substrate.

21. The hydraulic ballast structure of claim 20 wherein the semiconductor substrate comprises a silicon substrate.

22. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are disposed on a polymer substrate.

23. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are disposed on a ceramic substrate.

24. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are disposed on a metallic substrate.

25. The hydraulic ballast structure of claim 1 wherein the ballasting array columns comprise a material layer coated on the columns.

26. The hydraulic ballast structure of claim 1 wherein the ballasting array columns include a metal coating.

27. The hydraulic ballast structure of claim 1 wherein the ballasting array columns include a dielectric coating.

28. The hydraulic ballast structure of claim 27 herein the dielectric coating comprises an oxide coating.

29. The hydraulic ballast structure of claim 27 wherein the dielectric coating comprises a nitride coating.

30. The hydraulic ballast structure of claim 1 wherein the ballasting array columns include a polysilicon coating.

31. The hydraulic ballast structure of claim 1 wherein the ballasting array columns include a plastic coating.

32. The hydraulic ballast structure of claim 1 wherein the ballasting array columns include a coating that is chemically functional for a fluid selected to flow through the ballasting array.

33. The hydraulic ballast structure of claim 1 wherein the ballasting array columns include a coating that targets the mobility of a species present in a fluid selected to flow through the ballasting array.

34. The hydraulic ballast structure of claim 1 wherein the ballasting array is characterized by a column pitch that is less than about 500 μ

m.

35. The hydraulic ballast structure of claim 1 wherein the ballasting array columns are characterized by a height that is less than about 1 millimeter.

36. The hydraulic ballast structure of claim 1 wherein the ballasting array columns cross-sectional extent is less than about 500 μ

m.

37. A fluidic element array comprising:

a plurality of fluidic elements, each element including an input port and an output port through which a prespecified output flow rate is required;

a reservoir connected for delivery of a fluid from the reservoir to each fluidic element input port; and

an hydraulic ballast structure provided for each fluidic element and connected between the input port and the output port of each fluidic element, distinct to that element, the hydraulic ballast structure comprising an array of columns having a column extent, W, a column pitch, P, and an array length, L, selected based on the required output flow rate of that element, to produce a prespecified pressure drop that enforces the required output flow rate for that element.

38. The fluidic element array of claim 37 wherein each output port comprises an electrospray emitter.

39. The fluidic element array of claim 37 wherein each output port comprises a chemical reactor.

40. The fluidic element array of claim 37 wherein each output port comprises a fuel cell.

41. The fluidic element array of claim 37 wherein each output port comprises a chamber for biological cells and tissues.

42. The fluidic element array of claim 37 wherein each output port comprises a hollow needle for liquid delivery.

43. The fluidic element array of claim 37 wherein each output port comprises a solid needle for liquid delivery.

44. The fluidic element array of claim 37 wherein each output port comprises a spout for fluid delivery.

45. The fluidic element array of claim 37 wherein the fluidic elements are disposed in a hexagonal arrangement.

46. The fluidic element array of claim 37 wherein the fluidic elements are disposed in a square arrangement.

47. The fluidic element array of claim 37 wherein the fluidic elements comprise a microelectronic material.

48. The fluidic element array of claim 37 wherein the fluidic elements comprise silicon.

49. The fluidic element array of claim 37 wherein the ballasting array columns comprise a material layer coated on the columns.

50. The fluidic element array of claim 37 wherein the ballasting array columns include a coating that is chemically functional for a selected fluid to flow through the ballasting array.