Methods of operating microvalve assemblies and related structures and related devices

• US 20060016481A1
• Filed: 07/22/2005
• Published: 01/26/2006
• Est. Priority Date: 07/23/2004
• Status: Active Grant

• Current Assignee: AFA Controls LLC (IMI PLC)
• Original Assignee: AFA Controls LLC (IMI PLC)
• Inventors: Douglas, Kevin R., Gibson, Paul W., Harris, Donald C., Teach, William O., Dettloff, Wayne D., Goodwin, Scott H., Dausch, David E.
• Granted Patent: US 7,753,072 B2
• Time in Patent Office: Days
• US Class Current: 137/487.500
• CPC Class Codes: F15C 5/00 Manufacture of fluid circuit elements; Manufacture of assemblages of such elements integrated circuits
• CPC Class Codes: F16K 2099/0074 using photolithography, e.g. etching
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• 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 99/0007 of cantilever type
• CPC Class Codes: F16K 99/0028 Valves having multiple inlets or outlets
• CPC Class Codes: F16K 99/0051 using electrostatic means
• CPC Class Codes: G05D 7/0694 by action on throttling means or flow sources of very small size, e.g. microfluidics microvalves F16K99/0001; microstructural devices per se B81B
• CPC Class Codes: Y10T 137/0491 Valve or valve element assembling, disassembling, or replacing
• CPC Class Codes: Y10T 137/0497 Fluid actuated or retarded
• CPC Class Codes: Y10T 137/2213 Electrically-actuated element [e.g., electro-mechanical transducer]
• CPC Class Codes: Y10T 137/2224 Structure of body of device
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/86558 Plural noncommunicating flow paths
• CPC Class Codes: Y10T 137/87169 Supply and exhaust
• CPC Class Codes: Y10T 137/87217 Motor
• CPC Class Codes: Y10T 137/87225 Fluid motor

Abstract

A valve assembly may include a main housing and first and second electro-statically actuated valves. The main housing may define at least three chambers, with a first chamber configured to be coupled to a high pressure supply port, a second chamber configured to be coupled to an output port, and a third chamber configured to be coupled to a low pressure exhaust port. The first electro-statically actuated valve may be provided between the first and second chambers, and the first electro-statically actuated valve may allow or substantially block fluid communication between the first chamber and the second chamber responsive to a first electrical signal. The second electro-statically actuated valve may be provided between the second and third chambers, and the second electro-statically actuated valve may allow or substantially block fluid communication between the second chamber and the third chamber responsive to a second electrical signal. Related methods are also discussed.

Claims

1. A valve assembly comprising:

a main housing defining at least three chambers, a first chamber configured to be coupled to a high pressure supply port, a second chamber configured to be coupled to an output port, and a third chamber configured to be coupled to a low pressure exhaust port;

a first electro-statically actuated valve between the first and second chambers wherein the first electro-statically actuated valve allows or substantially blocks fluid communication between the first chamber and the second chamber responsive to a first electrical signal; and

a second electro-statically actuated valve between the second and third chambers wherein the second electrostatically actuated valve allows or substantially blocks fluid communication between the second chamber and the third chamber responsive to a second electrical signal.

2. A valve assembly according to claim 1 wherein the main housing further defines a fourth chamber configured to be coupled to a second output port, and a fifth chamber configured to be coupled to a low pressure exhaust port, the valve further comprising:

a third electro-statically actuated valve between the first and fourth chambers wherein the third electro-statically actuated valve allows or substantially blocks fluid communication between the first chamber and the fourth chamber responsive to a third electrical signal; and

a fourth electro-statically actuated valve between the fourth and fifth chambers wherein the fourth electro-statically actuated valve allows or substantially blocks fluid communication between the fourth chamber and the fifth chamber responsive to a fourth electrical signal.

3. A valve assembly according to claim 2 wherein the first, second, third, and fourth electro-statically actuated valves are provided on a same substrate.

4. A valve assembly according to claim 2 wherein the third and fifth chambers are coupled to a same low pressure exhaust port.

5. A valve assembly according to claim 2 wherein the third and fifth chambers are coupled to different low pressure exhaust ports.

6. A valve assembly according to claim 1 wherein the first and second electro-statically actuated valves comprise respective first and second valve chips with each valve chip including at least one respective electro-statically actuated valve flap thereon.

7. A valve assembly according to claim 6 wherein the first valve chip is spaced apart from the second valve chip.

8. A valve assembly according to claim 6 wherein the first valve chip is non-parallel with respect to the second valve chip.

9. A valve assembly according to claim 6 wherein the first valve chip comprises,

a substrate having first and second opposing faces, at least one hole through the substrate between the first and second faces, and a pair of input pads thereon, and

at least one electrostatically actuated valve flap on the substrate with the at least one valve flap being associated with the at least one hole in the substrate, wherein the at least one flexible valve flap is configured to open or substantially block the at least one hole responsive to the first electrical signal applied to the pair of input pads, wherein the substrate is supported in the housing at edges thereof so that central portions of the first and second faces of the substrate are respectively exposed to the first and second chambers and so that a fluid seal is provided between the housing and edges of the substrate.

10. A valve assembly according to claim 1 wherein the main housing further defines a fourth chamber configured to be coupled to a second output port and a fifth chamber configure to be coupled to a low pressure exhaust port, the valve assembly further comprising:

a third electro-statically actuated valve between the first and fourth chambers wherein the third electro-statically actuated valve allows or substantially blocks fluid communication between the first chamber and the fourth chamber responsive to a third electrical signal;

a fourth electro-statically actuated valve between the fourth and fifth chambers wherein the fourth electrostatically actuated valve allows or substantially blocks fluid communication between the fourth chamber and the fifth chamber responsive to a fourth electrical signal; and

a controller configured to generate the first, second, third, and fourth electrical signals for the respective electrostatically actuated valves.

11. A valve assembly according to claim 1 further comprising:

a controller configured to generate the first and second electrical signals for the respective electro-statically actuated valves.

12. A valve assembly according to claim 11 wherein the controller includes memory programmed with first operating instructions defining a first sequence of operations and second operating instructions defining a second sequence of operations, wherein one of the first and second operating instructions are selected for operation at a given time.

13. A valve assembly according to claim 12 wherein the first operating instructions are selected for use during a first time period and wherein the second operating instructions are selected for use during a second time period.

14. A valve assembly according to claim 11 wherein the controller generates the electrical signals using electrical energy from at least one of a battery, a capacitor, a fuel cell, a radio isotope.

15. A valve assembly according to claim 11 wherein the controller includes a rechargeable power supply, wherein the controller generates the electrical signals using electrical energy from the rechargeable power source.

16. A valve assembly according to claim 11 wherein the controller generates the electrical signals using an external power source.

17. A valve assembly according to claim 16 wherein the external power source comprises a DC power source in the range of about 3 volts DC to about 48 volts DC and/or an AC power source in the range of about 24 volts AC to about 240 volts AC.

18. A valve assembly according to claim 11 wherein the controller includes a transistor coupled in series with a power source and a coil wherein the transistor and the coil are configured to generate electrical power for the electrical signals having a higher voltage than the power source.

19. A valve assembly according to claim 11 wherein the controller includes a capacitive charge pump configured to generate electrical power for the electrical signals having a higher voltage than the power source.

20. A valve assembly according to claim 11 wherein the controller includes a transistor coupled in series with a power source and a transformer wherein the transistor and the transformer are configured to generate electrical power for the electrical signals having a higher voltage than the power source.

21. A valve assembly according to claim 11 wherein the controller includes a transistor coupled in series with a power source and an autotransformer wherein the transistor and autotransformer are configured to generate electrical power for the electrical signals having a higher voltage than the power source.

22. A valve assembly according to claim 11 wherein the controller generates the electrical signals using electrical energy generated using at least one of light, heat, and/or mechanical vibration.

23. A valve assembly according to claim 11 wherein the controller generates the electrical signals using electrical energy generated using an environmental source of energy proximate to the controller.

24. A valve assembly according to claim 22 wherein the controller generates the electrical energy using at least one of light, heat, and/or mechanical vibration, and wherein the electrical energy is stored using at least one of a battery, capacitor, and/or inductor.

25. A valve assembly according to claim 1 further comprising:

a controller configured to generate the electrical signals for the respective electro-statically actuated valves wherein the controller includes memory configured to be programmed with first operating instructions defining a first sequence of operations and to be reprogrammed with second operating instructions defining a second sequence of operations.

26. A valve assembly according to claim 1 further comprising:

a controller configured to generate the electrical signals for the respective electro-statically actuated valves, the controller being further configured to apply a first electrical potential as the first electrical signal to actuate the first electro-statically actuated valve thereby substantially blocking fluid communication between the first chamber and the second chamber, removing the first electrical potential as the first electrical signal, and after removing the first electrical potential, applying a second electrical potential as the first electrical signal to actuate the first electro-statically actuated valve thereby substantially blocking fluid communication between the first chamber and the second chamber wherein the first and second electrical potentials have reversed polarities.

27. A valve assembly according to claim 1 wherein the first electro-statically actuated valve comprises a valve chip having an electrostatically actuated valve flap thereon, the valve assembly further comprising:

a controller configured to generate the electrical signals for the respective electro-statically actuated valves, the controller being further configured to apply a first electrical potential having a first magnitude as the first electrical signal when the valve flap is spaced apart from the valve chip to actuate the valve flap to a position more closely adjacent the substrate, and after actuating the valve flap to the position more closely adjacent the valve chip, to apply a second electrical potential having a second magnitude as the first electrical signal to maintain the valve flap in the position more closely adjacent the substrate, wherein the first magnitude is greater than the second magnitude.

28. A valve assembly according to claim 1 wherein the first and second electro-statically actuated valves are provided on a same substrate.

29. A valve assembly according to claim 1 wherein the first and second electro-statically actuated valves are provided on respective first and second substrates.

30. A valve assembly according to claim 29 wherein the first and second substrates are provided in a non-parallel arrangement.

31. A valve assembly according to claim 1 further comprising:

a pressure sensor configured to measure a pressure in the second chamber; and

a controller coupled to the pressure sensor and to the first and second electro-statically actuated valves, wherein the controller is configured to generate the first and second electrical signals for the respective electro-statically actuated valves to maintain a pressure in the second chamber responsive to the pressure measured in the second chamber.

32. A valve assembly according to claim 1 further comprising:

a spool-type valve including a body defining a central cavity and a supply and actuator ports coupled to the central cavity and including a spool in the central cavity, wherein the spool is moveable between first and second positions in the central cavity so that in the first position of the spool fluid communication is provided between the supply and actuator ports and so that in the second position of the spool fluid communication is substantially blocked between the supply and actuator ports, and wherein an end of the cavity is in fluid communication with the second chamber; and

a controller coupled to the first and second electro-statically actuated valves, wherein the controller is configured to generate the first and second electrical signals for the respective electro-statically actuated valves to control movement of the spool between the first and second positions.

33. A mass flow controller comprising:

a body including a high pressure supply chamber and a low pressure output chamber;

a valve chip separating the high pressure supply chamber and the low pressure output chamber, the valve chip including a first side facing the high pressure supply chamber, a second side facing the low pressure output chamber, a hole between the first and second sides, and an electrostatically actuated valve member associated with the hole, wherein the valve member is configured to open or substantially close the hole responsive to electrical signals applied thereto; and

a controller configured to control opening and closing the valve member to maintain a mass flow through the valve chip.

34. A mass flow controller according to claim 33 wherein the valve member comprises a flexible valve flap.

35. A mass flow controller according to claim 33 wherein the controller is configured to provide a first duty cycle greater than 0% and less than 100% of opening and closing at least one valve member during a first interval and to provide a second duty cycle greater than 0% and less than 100% of opening and closing at least one valve member during a second interval with the first and second duty cycles being different.

36. A mass flow controller according to claim 35 wherein the first duty cycle is greater than the second duty cycle so that the valve chip provides a lower resistance to flow during the first interval.

37. A mass flow controller according to claim 33 wherein the valve chip includes a plurality of holes and respective valve members wherein the controller is configured to provide a first number of the valve members open during a first interval and to provide a second number of the valve members open during a second interval with the first and second numbers of valve members being different.

38. A mass flow controller according to claim 37 wherein the controller is configured to provide a first voltage to all of the valve members during the first interval and to provide a second voltage to all of the valve members during the second interval wherein the first and second voltages are different.

39. A mass flow controller according to claim 37 wherein the first number of valve members open is greater than the second number of valve members open so that the valve chip provides a lower resistance to flow during the first interval.

40. A mass flow controller according to claim 33 wherein the controller is configured to provide a first voltage to close the valve member, to provide a second voltage to open the valve member to a first position, and to provide a third voltage to open the valve member to a second position so that the valve member in the second position provides a lower resistance to flow than the valve member in the first position, and wherein the first voltage is greater than the second voltage and wherein the second voltage is greater than the third voltage.

41. A mass flow controller according to claim 33 further comprising a first sensor configured to measure a condition of the high pressure supply chamber and a second sensor configured to measure a condition of the low pressure output chamber, wherein the controller is configured to control opening and closing the respective valve members responsive to measurements from the first and second sensors.

42. A mass flow controller according to claim 41 wherein each of the first and second sensors is configured to measure at least one of a respective temperature and/or pressure.

43. A method of controlling an electro-static valve including a substrate having a hole therein and an electro-statically actuated valve member with the valve member being associated with the hole in the substrate with the valve member being configured to open or substantially close the hole responsive to electrical signals applied thereto, the method comprising:

opening and closing the electrostatically actuated valve member so that the valve provides a first resistance to flow during a first interval, a second resistance to flow during a second interval, and a third resistance to flow during a third interval, with the first, second, and third resistances being different.

44. A method according to claim 43 wherein the valve member comprises a flexible valve flap.

45. A method according to claim 43 wherein opening and closing the electro-statically actuated valve member includes,

providing a first duty cycle greater than 0% and less than 100% of opening and closing the valve member during the first interval;

and

providing a second duty cycle greater than 0% and less than 100% of opening and closing the valve member during the second interval with the first and second duty cycles being different.

46. A method according to claim 45 wherein the first duty cycle is greater than the second duty cycle so that the valve chip provides a lower resistance to flow during the first interval.

47. A method according to claim 43 wherein providing the first resistance to flow comprises providing a first voltage to the valve member, wherein providing the second resistance to flow comprises providing a second voltage to the valve member, wherein providing the third resistance to flow comprises providing a third voltage to the valve member, and wherein the first, second, and third voltages are different.

48. A method according to claim 43 wherein the substrate has a plurality of holes therein and a respective plurality of valve members wherein modulating the opening and closing the plurality electro-statically actuated valve members includes, providing a first number of the valve members open during the first interval, and providing a second number of the valve members open during the second interval with the first and second numbers of valve members being different.

49. A method according to claim 48 wherein providing a first number of valve members open comprises providing a first voltage to the plurality of valve members during the first interval, wherein providing a second number of valve members open comprises providing a second voltage to the plurality of valve members during the second interval, and wherein the first and second voltages are different.

50. A method according to claim 48 wherein the first number of valve members open is greater than the second number of valve members open so that the valve chip provides a lower resistance to flow during the first interval.

51. A method according to claim 43 further comprising:

measuring a condition on at least one side of the substrate wherein modulating opening and closing the electro-statically actuated valve member includes modulating opening and closing the electrostatically actuated valve member responsive to the measured condition.

52. A method according to claim 51 wherein the measured condition comprises at least one of a temperature and/or pressure.

53. A method according to claim 51 wherein opening and closing the electro-statically actuated valve member comprises maintaining a mass flow through the valve.

54. A method of operating an electro-statically actuated device including a fixed electrode on a substrate and a flexible member having a flexible electrode, the method comprising:

applying a first electrical potential between the fixed and flexible electrodes to actuate the flexible member;

after applying the first electrical potential, removing an electrical potential between the fixed and flexible electrodes; and

after removing an electrical potential, applying a second electrical potential between the fixed and flexible electrodes wherein the first and second electrical potentials have reversed polarities.

55. A method of operating an electrostatically actuated device including a fixed electrode on a substrate and a flexible member having a flexible electrode, the method comprising:

applying a first electrical potential having a first magnitude between the fixed and flexible electrodes when the flexible member is spaced from the substrate to actuate the flexible member to a position more closely adjacent the substrate; and

after actuating the flexible member to the position more closely adjacent the substrate, applying a second electrical potential having a second magnitude between the fixed and flexible electrodes to maintain the flexible member in the position more closely adjacent the substrate, wherein the first magnitude is greater than the second magnitude.

56. A valve assembly comprising:

a main housing defining at least three chambers, a first chamber configured to be coupled to a high pressure supply port, a second chamber configured to be coupled to an output port, and a third chamber configured to be coupled to a low pressure exhaust port;

a first photo-lithographically fabricated valve between the first and second chambers wherein the first photo-lithographically fabricated valve allows or substantially blocks fluid communication between the first chamber and the second chamber responsive to a first electrical signal; and

a second photo-lithographically fabricated valve between the second and third chambers wherein the second photo-lithographically fabricated valve allows or substantially blocks fluid communication between the second chamber and the third chamber responsive to a second electrical signal.

57. A valve assembly according to claim 56 wherein the first photo-lithographically fabricated valve comprises a substrate of at least one of glass, silicon, and/or quartz having at least one hole through the substrate.

58. A valve assembly according to claim 57 wherein the first photo-lithographically fabricated valve comprises at least one electro-statically actuated valve member adjacent to the at least one hole through the substrate.

59. A valve assembly according to claim 58 wherein the valve member comprises a flexible valve flap.

60. A method of forming a valve assembly comprising:

forming a main housing defining at least three chambers, a first chamber configured to be coupled to a high pressure supply port, a second chamber configured to be coupled to an output port, and a third chamber configured to be coupled to a low pressure exhaust port;

placing a first valve between the first and second chambers so that the first valve allows or substantially blocks fluid communication between the first chamber and the second chamber responsive to a first electrical signal; and

placing a second valve between the second and third chambers wherein the second valve allows or substantially blocks fluid communication between the second chamber and the third chamber responsive to a second electrical signal.

61. A method according to claim 60 wherein the first valve is photo-lithographically formed on the first substrate and wherein the second valve is photo-lithographically formed on the second substrate.

62. A method according to claim 60 the first substrate comprises at least one of glass, silicon, and/or quartz, and wherein the first substrate includes at least one hole there through.

63. A method according to claim 62 wherein photo-lithographically forming the first valve comprises forming at least one electro-statically actuated valve member adjacent to the at least one hole through the substrate.

64. A method according to claim 63 wherein the at least one electro-statically actuated valve member comprises at least one flexible valve flap.

65. A method according to claim 60 wherein forming the main housing comprises molding the main housing.