Thermally actuated microvalve with multiple fluid ports

• US 20080047622A1
• Filed: 03/30/2007
• Published: 02/28/2008
• Est. Priority Date: 11/24/2003
• Status: Active Grant

• Current Assignee: Dunan Microstaq, Inc. (Zhejiang Dun'an Artificial Environment Co., Ltd.)
• Original Assignee: Dunan Microstaq, Inc. (Zhejiang Dun'an Artificial Environment Co., Ltd.)
• Inventors: Hunnicutt, Harry, Fuller, Edward
• Granted Patent: US 8,011,388 B2
• Time in Patent Office: Days
• US Class Current: 137/625.18
• 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: Y10T 137/2213 Electrically-actuated element [e.g., electro-mechanical transducer]
• CPC Class Codes: Y10T 137/86558 Plural noncommunicating flow paths
• CPC Class Codes: Y10T 137/86622 Motor-operated
• CPC Class Codes: Y10T 137/87209 Electric

Abstract

A MEMS device is disclosed having a single microvalve actuator for controlling multiple microvalves.

Claims

1. A MEMS device that comprises:

a valve body formed of multiple planar layers, including an upper layer, a lower layer and an intermediate layer disposed between the upper layer and the lower layer, the intermediate layer defining a cavity therein;

an actuator disposed in the intermediate plate layer;

an elongated beam, having a first end, a second end, and a central portion disposed between the first end and the second end, the beam being disposed in the cavity, the central portion of the beam being attached to the actuator whereby the actuator can be selectively actuated to move the beam in a plane parallel to the planar layers between a first unactuated position and a second actuated position;

a first microvalve integrally formed with the first end of the beam for controlling a first fluid flow path through the cavity;

a second microvalve integrally formed with the second end of the beam for controlling a second fluid flow path through the cavity, there being substantially no fluid communication between the first fluid flow path and the second fluid flow path through the cavity;

a first port communicating with the cavity being defined by one of the upper layer and the lower layer in a location where communication between the first port and the cavity is one of substantially permitted and substantially blocked by the first microvalve when the beam is in the first position thereof and where communication between the first port and the cavity is the other of substantially permitted and substantially blocked by the first microvalve when the beam is in the second position thereof;

a second port communicating with the cavity being defined by one of the upper layer and the lower layer, the first fluid flow path through the cavity being defined between the first port and the second port;

a third port communicating with the cavity being defined by one of the upper layer and the lower layer in a location where communication between the third port and the cavity is one of substantially permitted and substantially blocked by the second microvalve with the beam when the beam is in the first position thereof; and

a fourth port communicating with the cavity being defined by one of the upper layer and the lower layer, the second fluid flow path through the cavity being defined between the third port and the fourth port.

2. The MEMS device according to claim 1, wherein communication between the third port and the cavity is substantially permitted by the second microvalve when the beam is in the first position thereof, and communication between the third port and the cavity is substantially blocked by the second microvalve when the beam is in the second position thereof.

3. The MEMS device according to claim 1 wherein

communication between the first port and the cavity is substantially permitted by the first microvalve when the beam is in the first position thereof, and communication between the third port and the cavity is substantially permitted by the second microvalve when the beam is in the first position thereof, and

communication between the first port and the cavity is substantially blocked by the first microvalve when the beam is in the second position thereof, and communication between the third port and the cavity is substantially blocked by the second microvalve when the beam is in the second position thereof.

4. The MEMS device according to claim 3 wherein

communication between the second port and the cavity is substantially permitted by the first microvalve when the beam is in the first position thereof, and communication between the fourth port and the cavity is substantially permitted by the second microvalve when the beam is in the first position thereof, and

communication between the second port and the cavity is substantially blocked by the first microvalve when the beam is in the second position thereof, and communication between the fourth port and the cavity is substantially blocked by the second microvalve when the beam is in the second position thereof.

5. The MEMS device according to claim 4, further comprising:

a fifth port communicating with the cavity being defined by one of the upper layer and the lower layer in a location where communication between the fifth port and the first flow path in the cavity is substantially permitted by the first microvalve when the beam is in the first position thereof, and communication between the fifth port and the cavity is substantially blocked by the first microvalve when the beam is in the second position thereof, and

a sixth port communicating with the second flow path in the cavity being defined by one of the upper layer and the lower layer in a location where communication between the sixth port and the second flow path in the cavity is substantially permitted by the second microvalve when the beam is in the first position thereof, and communication between the sixth port and the cavity is substantially blocked by the second microvalve when the beam is in the second position thereof.

6. The MEMS device of claim 5 wherein

the first microvalve comprises an enlarged body on the first end of the beam, the body of the first microvalve having a central aperture defined by a peripheral structure, the first fluid flow path being contained within the central aperture of the first microvalve, the peripheral structure of the first microvalve moving to block and unblock the first port when the beam is in the second and first positions thereof, respectively, an inwardly extending protrusion being formed on the peripheral structure of the first microvalve in a position to block and unblock the fifth port when the beam is in the second and first positions thereof, respectively;

and

the second microvalve comprises an enlarged body on the second end of the beam, the body of the second microvalve having a central aperture defined by a peripheral structure, the second fluid flow path being contained within the central aperture of the second microvalve, the peripheral structure of the second microvalve moving to block and unblock the second port when the beam is in the second and first positions thereof, respectively, an inwardly extending protrusion being formed on the peripheral structure of the second microvalve in a position to block and unblock the sixth port when the beam is in the second and first positions thereof, respectively.

7. The MEMS device of claim 3 wherein

the first microvalve comprises an enlarged body on the first end of the beam, the body of the first microvalve having a central aperture defined by a peripheral structure, the first fluid flow path being contained within the central aperture of the first microvalve, the peripheral structure moving to block and unblock the first port when the beam is in the second and first positions thereof, respectively;

and

the second microvalve comprises an enlarged body on the second end of the beam, the body of the second microvalve having a central aperture defined by a peripheral structure, the second fluid flow path being contained within the central aperture of the second microvalve, the peripheral structure moving to block and unblock the second port when the beam is in the second and first positions thereof, respectively.

8. The MEMS device of claim 6, wherein at least one micro vent is formed in the peripheral structure of the first microvalve and at least one micro vent is formed in the protrusion formed on the peripheral structure of the first microvalve;

and

at least one micro vent is formed in the peripheral structure of the second microvalve and at least one micro vent is formed in the protrusion formed on the peripheral structure of the second microvalve.

9. The MEMS device of claim 1, wherein a plurality of apertures are formed in the beam, resulting in a mass reduction of at least 10 percent compared to a beam of the same size without the apertures formed therein.

10. The MEMS device of claim 9, wherein the plurality of apertures are oval in plan view, resulting in a mass reduction of at least 20 percent compared to a beam of the same size without the apertures formed therein.

11. The MEMS device of claim 9, wherein the plurality of apertures are oval in plan view and are arranged in a double row, resulting in a mass reduction of at least 40 percent compared to a beam of the same size without the apertures formed therein.

12. The MEMS device of claim 9, wherein the plurality of apertures are one of oval and triangular in plan view, resulting in a mass reduction of at least 20 percent compared to a beam of the same size without the apertures formed therein.

13. The MEMS device of claim 1, further comprising a flexible hinge attaching the beam to a fixed portion of the intermediate plate layer, the hinge flexing to accommodate motion of the beam as the beam is actuated between the first and second positions thereof.

14. The MEMS device of claim 1, wherein the beam is a first beam, further comprising:

a second elongated beam having a first end, a second end, and a central portion disposed between the first end and the second end, the second beam being disposed in the cavity and fixed to the actuator so as to be moved simultaneously with the first beam when the actuator is actuated;

a third microvalve integrally formed with the first end of the second beam for controlling a third fluid flow path through the cavity;

a fourth microvalve integrally formed with the second end of the second beam for controlling a fourth fluid flow path through the cavity, there being substantially no fluid communication between the first fluid flow path, the second fluid flow path, the third fluid flow path or the fourth fluid flow path through the cavity.

15. The MEMS device of claim 14, further comprising:

a fifth microvalve integrally formed with the first end of the first beam for controlling a fifth fluid flow path through the cavity;

a sixth microvalve integrally formed with the second end of the first beam for controlling a sixth fluid flow path through the cavity,

a seventh microvalve integrally formed with the first end of the second beam for controlling a seventh fluid flow path through the cavity;

an eighth microvalve integrally formed with the second end of the second beam for controlling an eighth fluid flow path through the cavity, there being substantially no fluid communication between the first fluid flow path, the second fluid flow path, the third fluid flow path, the fourth fluid flow path, the fifth fluid flow path, the sixth fluid flow path, the seventh fluid flow path, or the eighth fluid flow path through the cavity.

22. The MEMS device of claim 1, wherein the actuator is a thermal actuator.

16. A microvalve that comprises:

a valve body formed of multiple planar layers, including an intermediate layer defining a cavity therein;

an actuator disposed in the intermediate plate layer;

an elongated beam having a first end, a second end, and a central portion disposed between the first end and the second ends which beam is disposed in the cavity, a first point on the central portion of the beam being attached to a fixed portion of the intermediate plate layer by a flexible hinge, a second point on the central portion of the beam being attached to the actuator disposed in the intermediate plate layer whereby the actuator can be selectively actuated to move the beam in a plane parallel to the planar layers between a first and a second position, while the hinge flexes to accommodate motion of the beam;

a first port communicating with the cavity being formed in one of two plate layers on opposite sides of the intermediate plate layer, in a location where communication between the first port and the cavity is substantially blocked by the first end of the beam when the beam is in the first position thereof; and

a second port communicating with the cavity is formed in one of the two plate layers on opposite sides of the intermediate plate layer, in a location where communication between the second port and the cavity is substantially blocked by the second end of the beam when the beam is in one of the first position and the second position thereof.

23. The microvalve of claim 16, wherein the actuator is a thermal actuator.

17. A microvalve device for controlling fluid flow comprising:

a two-way pilot operated microvalve; and

a four-way pilot microvalve for controlling the two-way pilot operated microvalve.

24. The microvalve device of claim 17, further including a thermal actuator for positioning the four-way pilot microvalve.

18. A microvalve device comprising two three-way microvalves actuated by a common microvalve actuator.

25. The microvalve device of claim 18, wherein the actuator is a thermal actuator.

19. A four-way microvalve for controlling fluid flow comprising:

a body having an intermediate plate layer with a cavity formed therein, the body defining an inlet connection, an outlet connection, and first and second load connections in fluid communication with the cavity;

a moveable microvalve element disposed in the cavity moveable between a first position and a second position, the moveable element being operable to allow fluid communication between the inlet connection and the first load connection and between the outlet connection and the second load connection when the moveable element is in the first position and being operable to allow fluid communication between the inlet connection and the second load connection and between the outlet connection and the first load connection when the moveable element is in the second position; and

a microvalve actuator operable to move the moveable element between the first position and the second position.

20. A two-way microvalve for controlling fluid flow comprising:

a multilayer plate valve body having an intermediate plate layer with a cavity formed therein, the body defining an inlet connection and an outlet connection in fluid communication with the cavity;

a moveable microvalve element disposed in the cavity moveable between a first position and a second position, the moveable element being operable to allow fluid communication between the inlet connection and the outlet connection when the moveable element is in the first position and being operable to block fluid communication between the inlet connection and the outlet connection when the moveable element is in the second position; and

a feedback port formed in the moveable element operable to regulate the pressure on an end of the moveable element relative to the movement of the moveable element between the first position and the second position.

21. The two-way microvalve of claim 20 wherein the moveable microvalve element comprises a spool blocking portion defining a recessed portion, the recessed portion slidably engaging a spool beam attached to layers of the multilayer plate valve body adjacent to the intermediate plate layer.