Microvalve device

• US 8,662,468 B2
• Filed: 07/09/2009
• Issued: 03/04/2014
• Est. Priority Date: 08/09/2008
• 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
• Primary Examiner(s): Rivell, John
• Assistant Examiner(s): JELLETT, MATTHEW WILLIAM
• Application Number:
  US13/058,146
• Publication Number:
  US 20110127455A1
• Time in Patent Office: 1,699 Days
• Field of Search: 251/129.01, 251/129.06, 251/284, 251/367, 251/11
• US Class Current: 251/11
• CPC Class Codes: B81B 2201/054 Microvalves
• CPC Class Codes: B81B 3/0051 For defining the movement, i.e. structures that guide or limit the movement of an element mechanical arrangements for preventing or damping vibration or shock H01H3/60
• 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 99/0044 using thermo-electric means
• CPC Class Codes: Y10T 29/49405 Valve or choke making

Abstract

A microvalve device includes a body, a valve element supported for movement relative to the body, and an actuator operatively coupled to the valve element for moving the valve element in a normal range of travel. A travel limiting structure operatively cooperates with at least one of the valve element and the actuator to effectively limit the magnitude of movement of the valve element or the actuator outside the normal range of travel to prevent failure of the body, the valve element, or the actuator due to exceeding failure stress limits. A method of forming a microvalve with such a travel limiting structure is also disclosed.

Claims

1. A microvalve device comprising:

a body;

a valve element supported by the body;

an actuator operatively coupled to the valve element for moving the valve element arcuately in a normal range of travel substantially within a plane defined in fixed relationship with the body; and

a travel limiting structure operatively cooperating with the valve element, the travel limiting structure being effective to limit movement of the valve element within the plane but outside the normal range of travel to prevent failure of the body, the valve element or the actuator due to exceeding failure stress limits.

2. The microvalve of claim 1, wherein:

the normal range of travel of the valve element defines a path of arcuate motion within the plane; and

the travel limiting structure is effective to limit movement of the valve element in a radial direction relative to the path of arcuate motion to prevent failure of the body, the valve element, or the actuator due to exceeding failure stress limits.

3. The microvalve of claim 1, wherein:

the normal range of travel of the valve element defines a path of arcuate motion; and

the travel limiting structure is effective to limit the magnitude of arcuate movement of the valve element, beyond the normal range of travel, to prevent failure of the body, the valve element, or the actuator due to exceeding failure stress limits.

4. The microvalve of claim 1, wherein the travel limiting structure includes at least one boss.

5. The microvalve of claim 2, wherein the travel limiting structure is effective to limit the magnitude of arcuate movement of the valve element beyond the normal range of travel to prevent failure of the body, the valve element, or the actuator due to exceeding failure stress limits.

6. The microvalve of claim 1, wherein

the normal range of travel of the valve element defines a path of arcuate motion within the plane;

and

the travel limiting structure is effective to limit at least one of;

movement of the valve element within the plane in a radial direction relative to the path of arcuate motion to prevent failure of the body, the valve element, or the actuator due to exceeding failure stress limits; and

arcuate movement of the valve element within the plane beyond the normal range of travel to prevent failure of the body, the valve element, or the actuator due to exceeding failure stress limits.

7. The microvalve of claim 4, wherein the boss is formed on a fixed portion of the body.

8. The microvalve of claim 4, the boss having a depth perpendicular to the plane and the fixed portion of the body having a depth perpendicular to the plane wherein the depth of the boss is less than the depth of the fixed portion.

9. The microvalve of claim 7, the boss having a depth perpendicular to the plane and the fixed portion of the body having a depth perpendicular to the plane, wherein the depth of the boss is less than the depth of the fixed portion.

10. The microvalve of claim 4, wherein the boss is formed on the valve element.

11. The microvalve of claim 10, the boss having a depth perpendicular to the plane and the valve element having a depth perpendicular to the plane, wherein the depth of the boss is less than the depth of the valve element.

12. A microvalve device comprising:

a body, the body having a fixed portion;

a plurality of movable elements including;

a valve element supported by the body; and

an actuator operatively coupled to the valve element for rotating the valve element in an arc within a normal range of travel, the arcuate movement of the valve element in the normal range of travel defining a plane; and

a travel limiting structure operatively coupled to at least one of the body, the valve element, and the actuator, the travel limiting structure being effective to limit the magnitude of a movement, in a direction which has a component that is in the plane, of at least one of the movable elements outside the normal range of travel to prevent failure of at least one of the body and the movable elements due to exceeding failure stress limits.

13. A method of manufacturing a microvalve device having fixed valve parts and movable valve parts comprising the steps of:

(a) determining a proper configuration of a travel limiting structure effective to permit arcuate movement of the moveable valve parts in a normal range of motion parallel to a plane that is fixed relative to the fixed valve parts and effective to limit movement of movable valve parts within the plane but outside the normal range of travel to prevent failure of the movable valve parts; and

(b) forming the travel limiting structure.

14. The method of claim 13, wherein step (b) includes etching a slot through a layer of material, the slot having a thinner slot width in at least one location such that the slot forms at least one boss.

15. The method of claim 13, wherein step (b) includes the steps of:

(b1) etching a first side of a layer of material to form a slot of varying width part way through the layer; and

(b2) etching the layer of material on a second side part way through the layer to form a slot of uniform width to a depth, such that the slot formed on the first side communicates with the slot formed on the second side to create a combined slot that extends through the layer of material with at least one boss extending into the combined slot.

16. A microvalve device comprising:

a body, the body having a fixed portion within which a plane is defined;

a plurality of movable elements including;

a valve element movable relative to the body; and

an actuator operatively coupled to the valve element for actuation of the valve element in a normal range of arcuate motion relative to the body when power is supplied to the actuator, the normal range of motion of the valve element lying substantially within the plane, the fixed portion, the valve element, and the actuator being designed such that actuation of the valve element by the actuator when power is supplied to the actuator causes stresses which are less than the yield point for the fixed portion, the valve element, and the actuator; and

a travel limiting structure operatively coupled to at least one of the body, the valve element, and the actuator, the travel limiting structure being effective to limit the magnitude of an uncommanded movement within the plane but outside the normal range of travel of at least one of the movable elements to prevent failure of at least one of the body and the movable elements due to exceeding failure stress limits, the uncommanded movement being caused by a factor other than intentional operation of the actuator.