CHECK VALVE DIAPHRAGM MICROPUMP

• US 20090188576A1
• Filed: 09/29/2008
• Published: 07/30/2009
• Est. Priority Date: 03/30/2006
• Status: Active Grant

• Current Assignee: Wayne State University
• Original Assignee: Wayne State University
• Inventors: Kang, Jianke, Auner, Gregory W.
• Granted Patent: US 8,475,144 B2
• Time in Patent Office: Days
• US Class Current: 137/831
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/0294 Piezoelectric materials
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: F04B 43/046 with piezoelectric drive
• CPC Class Codes: Y10T 137/2191 By non-fluid energy field affecting input [e.g., transducer]
• CPC Class Codes: Y10T 137/2213 Electrically-actuated element [e.g., electro-mechanical transducer]
• CPC Class Codes: Y10T 137/2218 Means [e.g., valve] in control input
• CPC Class Codes: Y10T 29/49229 Prime mover or fluid pump making
• CPC Class Codes: Y10T 29/49236 Fluid pump or compressor making

Abstract

A micropump device including a first wafer and a second wafer attached to the first wafer. The first and second wafers are configured to define a chamber therebetween having a predetermined volume. A third wafer is attached to the second wafer to define an inlet section and an outlet section in fluid communication with the chamber. At least one of the second and third wafers are formed to define a moveable diaphragm configured to change the predetermined volume of the chamber for pumping a fluid between the inlet section and the outlet section.

Claims

1. A micropump device comprising:

a first wafer and a second wafer attached to the first wafer, the first and second wafers defining a chamber therebetween having a predetermined volume; and

a third wafer being attached to the second wafer to define an inlet section and an outlet section in fluid communication with the chamber, the second and third wafers being formed to define a moveable diaphragm configured to change the predetermined volume of the chamber for pumping a fluid between the inlet section and the outlet section.

2. The device of claim 1 wherein the first wafer is chosen from one of silicon and glass.

3. The device of claim 1 wherein each of the second and third wafers include a buried layer disposed between a device layer and a handle layer.

4. The device of claim 3 wherein the buried layer is chosen from one of silicon dioxide and germanium.

5. The device of claim 1 wherein the inlet section comprises an inlet port and an inlet valve.

6. The device of claim 5 wherein the inlet valve comprises an inlet valve structure and an inlet valve seat, the inlet valve structure being configured to move away from the inlet valve seat.

7. The device of claim 6 wherein the inlet valve structure includes an inlet valve edge extending from the inlet valve structure toward the inlet valve seat.

8. The device of claim 1 wherein the outlet component comprises an outlet port and an outlet valve.

9. The device of claim 8 wherein the outlet valve comprises an outlet valve structure and an outlet valve seat, the outlet valve structure being configured to move away from the outlet valve seat.

10. The device of claim 9 wherein the outlet valve structure includes an outlet valve edge extending from the outlet valve structure toward the outlet valve seat.

11. The device of claim 1 wherein the diaphragm is configured to be actuated such that the diaphragm moves away from the chamber during a first predetermined period and to move toward to the chamber during a second predetermined period.

12. The device of claim 11 wherein the diaphragm is actuated by at least one of piezoelectric actuation, electromagnetic actuation, external position-fixed electromagnetic actuation, pneumatic actuation, and thermo-pneumatic actuation.

13. The device of claim 12 wherein a piezoelectric plate is attached to the diaphragm for piezoelectric actuation.

14. The device of claim 13 wherein the device layer of the third wafer is configured as a first electrode for piezoelectric actuation and the piezoelectric plate is configured as a second electrode for piezoelectric actuation.

15. The device of claim 12 wherein magnetic material is attached to the diaphragm for electromagnetic actuation with a coil disposed about a yoke operatively engaged with the magnetic material.

16. The device of claim 15 wherein the coil is connected to an AC source to provide AC current, and a changing direction of the AC current generates alternating magnetic flux causing the magnetic force on the magnetic material to change, making the diaphragm of the micropump move periodically.

17. A method of fabricating micropump device, the method comprising:

forming an inlet valve and an outlet valve in device layers of a second wafer and a third wafer;

connecting the device layers of the second and third wafers;

removing a handle layer of the second wafer;

forming an inlet port, an outlet port, and a diaphragm releasing hole in a handle layer of the third wafer;

removing exposed buried layers of the second and third wafers; and

forming a cavity between a first wafer and the second wafer such that the diaphragm, the inlet valve, and the outlet valve are arranged in a predetermined relationship to the cavity.

18. The method of claim 17 further comprising depositing a thin film on the device layer of at least one of the second wafer or third wafer before connecting the device layers.

19. The method of claim 18 further comprising removing the thin film from between an inlet and outlet valve structure and a respective inlet and outlet valve seat to allow the inlet and outlet valve structures to move relative to the valve seats.

20. The method of claim 17 wherein forming the inlet valve includes providing an inlet gap for an inlet valve structure in the device layer of the second wafer or third wafer and providing an outlet gap for an outlet valve structure in the device layer of the second wafer or third wafer.

21. The method of claim 18, wherein a thickness of the diaphragm is reduced in a diaphragm thinning area provided in the device layer of the second wafer or the device layer of the third wafer, or the device layers of the second and third wafers.

22. The method of claim 17 wherein forming the inlet valve includes providing an inlet gap for an inlet valve structure in the device layer of the second wafer or third wafer, and providing an outlet gap for the outlet valve structure in the device layer of the second wafer or third wafer, forming the inlet valve structure and outlet valve seat in the device layer of the second wafer, and forming an outlet valve structure and an inlet valve seat in the device layer of the third wafer.

23. The method of claim 17 wherein forming the inlet valve includes providing an inlet gap for an inlet valve structure in the device layers of both the second wafer and the third wafer, providing an outlet gap for an outlet valve structure in the device layers of both the second wafer and the third wafer, forming the inlet valve structure and outlet valve seat in the device layer of the second wafer, and forming the outlet valve structure and inlet valve seat in the device layer of the third wafer.

24. The method of claim 17 wherein forming the inlet valve includes providing an inlet valve structure and an outlet valve seat in the device layer of the second wafer, providing an outlet valve structure and an inlet valve seat in the device layer of the third wafer and forming an inlet gap for the inlet valve structure in the device layer of the second wafer or the third wafer, and forming an outlet gap for the outlet valve structure in the device layer of the second wafer or the third wafer.

25. The method of claim 17 wherein forming the inlet valve includes providing an inlet valve structure and an outlet valve seat in the device layer of the second wafer, providing an outlet valve structure and an inlet valve seat in the device layer of the third wafer, forming an inlet gap for the inlet valve structure in the device layers of both the second wafer and the third wafer, and forming an inlet gap for the outlet valve structure in the device layers of both the second wafer and the third wafer.

26. The method of claim 17 wherein the thin film includes silicon dioxide.

27. The method of claim 17 wherein connecting the device layers comprises connecting the device layers of the second and third wafers such that the respective valve structures are arranged in a predetermined relationship with a respective valve seat.

28. The method of claim 17 wherein the device layers are connected by at least one of anodic bonding and fusion bonding.

29. The method of claim 17 wherein the diaphragm is formed of the device layers of the second and third wafers.

30. The method of claim 17 wherein a thickness of the diaphragm is less than a thickness of the remaining device layers of the second and third wafers.

31. The method of claim 17 wherein the inlet port and outlet port are respectively aligned with the inlet valve and outlet valve.

32. The method of claim 17 wherein the inlet port, outlet port, and the diaphragm releasing hole are respectively aligned with the inlet valve, outlet valve, and the diaphragm thinning area.

33. The method of claim 17 wherein the handle layer and the thin film are removed simultaneously.

34. The method of claim 17 wherein forming the cavity includes making a part of the cavity spanning the inlet section deeper than a part of the cavity spanning the diaphragm and the outlet section.

35. The method of claim 17 wherein forming the cavity includes making a part of the cavity spanning the diaphragm shallower than a part of the cavity spanning the inlet and outlet components to reduce the chamber volume.

36. The method of claim 17 wherein the device layers are connected by at least one of anodic bonding, fusion bonding, and gluing.

37. The method of claim 17 wherein the cavity is sized to span the diaphragm, the inlet section and the outlet section.