Gating apparatus and method of manufacture

• US 7,025,324 B1
• Filed: 01/03/2003
• Issued: 04/11/2006
• Est. Priority Date: 01/04/2002
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Slocum, Alexander H., White, James R.
• Primary Examiner(s): Bastianelli, John
• Application Number:
  US10/336,625
• Time in Patent Office: 1,194 Days
• Field of Search: 251/129.06, 251/11, 251/231, 251/236, 251/248, 251/368
• US Class Current: 251/11
• CPC Class Codes: B01L 2200/0647 Handling flowable solids, e.g. microscopic beads, cells, particles
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/0622 distribution valves, valves having multiple inlets and/or outlets, e.g. metering valves, multi-way valves
• CPC Class Codes: B01L 2400/0655 pinch valves
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: F16K 2099/0074 using photolithography, e.g. etching
• CPC Class Codes: F16K 2099/0078 using moulding or stamping
• CPC Class Codes: F16K 2099/0084 Chemistry or biology, e.g. "lab-on-a-chip" technology
• CPC Class Codes: F16K 99/0001 Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0009 the valve element held by multiple arms
• CPC Class Codes: F16K 99/0046 using magnets
• CPC Class Codes: F16K 99/0048 using piezoelectric means
• CPC Class Codes: F16K 99/0051 using electrostatic means
• CPC Class Codes: G01N 2015/0038 Investigating nanoparticles

Abstract

A gating apparatus for controlling the gap between two surfaces that includes an upper structure having a polished central region portion, an elastically deformable fulcrum structure, and an elastically deformable lever region. The upper structure can be fabricated from silicon using microelectromechanical system (MEMS) fabrication techniques. The gating apparatus also includes a lower structure coupled to the upper structure at the elastically deformable fulcrum structure. The upper structure, in response to a force, can bend about the fulcrum structure, thereby forming a variable gap between the polished central region portion and the lower structure. The variable gap can be used as a filter to filter fluids and mixed phase fluids. The structures can be made from a wide variety of materials including silicon, glass, ceramic, metal, and plastic.

Claims

1. An apparatus for controlling the flow of gases, fluids and mixed phase fluids, the apparatus comprising:

an upper structure having an elastically deformable lever region and a polished central region; and

a lower structure having a polished surface facing the upper structure;

a fulcrum structure disposed between the upper structure and the lower structure such that the fulcrum structure acts as a fulcrum about which the upper structure can be elastically deformed, to cause said upper structure central region to separate from the lower structure surface; and

a deflection mechanism, wherein the deflection mechanism provides a deflection force upon the upper structure proximate the lever region and in a direction essentially perpendicular to the upper structure so as to bend the upper structure about the fulcrum structure.

2. The apparatus of claim 1, wherein the upper and lower structures are circularly symmetric shapes.

3. The apparatus of claim 1, wherein the fulcrum structure is provided as part of the upper structure and is bonded to the lower structure.

4. The apparatus of claim 1, wherein the upper structure is made from silicon.

5. The apparatus of claim 1, wherein the lever region is segmented to provide a pre-determined mechanical impedance.

6. The apparatus of claim 1, wherein the upper structure has a round shape.

7. The apparatus of claim 1, wherein the upper structure has a polygonal shape.

8. The apparatus of claim 1, wherein the central region has a round shape.

9. The apparatus of claim 1, wherein the central region has a polygonal shape.

10. The apparatus of claim 1, wherein the fulcrum structure has a round shape.

11. The apparatus of claim 1, wherein the fulcrum structure is provided as an elastically deformable fulcrum structure so as to form a flexural pivot.

12. The apparatus of claim 1, wherein the fulcrum structure is provided as a rigid structure and the apparatus further includes a mechanical pivot disposed at an interface between the fulcrum and the upper structure.

13. The apparatus of claim 1, wherein the fulcrum structure has a polygonal shape.

14. The apparatus of claim 1, wherein the fulcrum structure is segmented.

15. The apparatus of claim 1 wherein the fulcrum structure has a linear beam shape.

16. The apparatus of claim 1 wherein the fulcrum structure has a discrete number of points of support.

17. The apparatus of claim 1, wherein the lower structure has a round shape.

18. The apparatus of claim 1, wherein the lower structure has a polygonal shape.

19. The apparatus of claim 1, wherein the polished central region comprises a layer deposited on the central region.

20. The apparatus of claim 19, wherein the deposited layer has a surface finish better man five angstroms.

21. The apparatus of claim 19, wherein the deposited layer has a surface finish better than five nanometers.

22. The apparatus of claim 19, wherein the deposited layer comprises at least one of a metal layer, a ceramic layer, an organic layer, and an inorganic layer.

23. The apparatus of claim 1, wherein a seated cavity structure is bounded by the central region, the lever region, the fulcrum structure, and the lower structure.

24. The apparatus of claim 1, wherein the lower structure is comprised of glass or ceramic.

25. The apparatus of claim 1, further comprising an anodic bond between the fulcrum structure and the lower structure.

26. The apparatus of claim 1, wherein the lower structure is comprised of silicon.

27. The apparatus of claim 26, wherein the coupling between the fulcrum structure and the lower structure is provided by a fusion bond between the fulcrum structure and the lower structure.

28. The apparatus of claim 1, wherein the lower structure polished surface is disposed toward the polished central region of the upper structure;

the fulcrum structure and the polished central region are disposed toward the lower structure polished surface, and the polished central region of the upper structure and the lower structure polished surface have a variable gap therebetween.

29. The apparatus of claim 28, wherein the polished lower structure surface has a surface finish better than five angstroms.

30. The apparatus of claim 28, wherein the polished lower structure surface has a surface finish better than five nanometers.

31. The apparatus of claim 28, further comprising:

a first fluid flow channel through the lower structure, wherein the first fluid flow channel is disposed into the variable gap.

32. The apparatus of claim 31, further comprising:

a second fluid flow channel through the lower structure, wherein the second fluid flow channel is disposed into a sealed cavity structure, the sealed cavity structure bounded by the central region, the lever region, the fulcrum structure, and the lower structure polished surface, and wherein the variable gap connects the first and second fluid flow channels.

33. The apparatus of claim 1, wherein the lever region in combination with the fulcrum structure provide a mechanical advantage to the deflection mechanism of between two to one and one hundred to one.

34. The apparatus of claim 1, wherein the deflection mechanism is a piezoelectric actuator mechanism.

35. The apparatus of claim 1, wherein the deflection mechanism is a thermoelectric expansion actuator mechanism.

36. The apparatus of claim 1, wherein the deflection mechanism is a electrostatic actuator mechanism.

37. The apparatus of claim 1, further comprising:

a deflection sensor coupled to at least one of the upper structure and the lower structure, provided to sense the position of the upper structure relative to the lower structure.

38. The apparatus of claim 37, wherein the deflection sensor comprises:

a first capacitive plate disposed upon the upper structure surface and directly opposing a second capacitive plate disposed upon the lower structure, wherein the first and the second capacitive plates are electrostatically coupled to each other.

39. The apparatus of claim 38, wherein the deflection sensor further comprises:

deflection sensor electronics coupled to the first and second capacitive plates and further coupled to the deflection mechanism to provide control of the variable gap.