Magnetically-actuated micropump

• US 20020098097A1
• Filed: 01/22/2001
• Published: 07/25/2002
• Est. Priority Date: 01/22/2001
• Status: Abandoned Application

• Current Assignee: MicroGen Systems, Inc.
• Original Assignee: MicroGen Systems, Inc.
• Inventors: Singh, Angad
• Application Number:
  US09/766,740
• Publication Number:
  US 20020098097A1
• Time in Patent Office: Days
• US Class Current: 417/413.1
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2200/143 Quality control, feedback systems
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2400/0439 ultrasonic vibrations, vibrating piezo elements
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 2400/0605 check valves
• CPC Class Codes: B01L 2400/0638 membrane valves, flap valves
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 7/52 with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• CPC Class Codes: F04B 43/046 with piezoelectric drive

Abstract

A microfluidic pump having a substrate with a pump chamber and at least one channel in communication with the pump chamber for transporting a substance into or out of the pump chamber. A flexible diaphragm overlies the pump chamber, and a magnetic member is attached to the diaphragm. A magnet, such as an electromagnet, is positioned to attract and repel the magnetic member, thereby actuating the diaphragm, and causing a substance to be drawn into or out of the channel. A uni-directional or bi-directional check valve can be positioned in the channel to prevent backflow into the pump chamber. A control system can be coupled to the pump to adjust actuation rate of the diaphragm.

Claims

1. A microfluidic pump comprising:

a substrate including a chamber;

at least one channel in communication with the chamber;

a flexible diaphragm forming a wall of the chamber; and

a magnetic member attached to the diaphragm.

2. The pump of claim 1 further comprising:

a check valve positioned in the channel.

3. The pump of claim 2 wherein the check valve is unidirectional.

4. The pump of claim 2 wherein the check valve includes a flap having one end movably attached to one sidewall of the channel.

5. The pump of claim 1 further comprising an electromagnet positioned to attract and repel the magnetic member.

6. The pump of claim 5 further comprising:

a current source coupled to supply electric current to the electromagnet.

7. The pump of claim 6 further comprising:

a control system coupled to adjust the current output by the current source.

8. The pump of claim 1 further comprising a protective layer covering the top of the diaphragm.

9. The pump of claim 1 further comprising a protective layer covering the bottom of the substrate.

10. The pump of claim 5 wherein the electromagnet is positioned adjacent the magnetic member.

11. The pump of claim 5 wherein the electromagnet is positioned separate from the magnetic member.

13. The pump of claim 12 wherein the means for actuating the flexible diaphragm includes an electromagnet.

14. The pump of claim 12 wherein the means for actuating the flexible diaphragm includes a permanent magnet.

15. The pump of claim 13 further comprising:

a current source coupled to supply electric current to the electromagnet.

16. The pump of claim 15 further comprising:

a control system coupled to adjust the current output by the current source.

17. The pump of claim 12 further comprising:

a check valve positioned in the channel.

18. The pump of claim 12 wherein the substrate is a polymer material.

19. The pump of claim 12 wherein the substrate is injection molded.

20. The pump of claim 12 wherein the channel and the pump chamber are embossed in the substrate.

12. A microfluidic pump comprising:

a substrate including a pump chamber;

at least one channel in communication with the pump chamber;

a flexible diaphragm overlying the pump chamber; and

means for actuating the flexible diaphragm.

21. A system for transporting a substance, the system comprising:

a substrate including a pump chamber;

at least one channel in communication with the pump chamber;

a flexible diaphragm forming a wall of the pump chamber;

means for actuating the flexible diaphragm; and

a control system coupled to control the means for actuating the flexible diaphragm.

22. The system of claim 21 wherein the means for actuating the flexible diaphragm includes an electromagnet.

23. The system of claim 21 wherein the means for actuating the flexible diaphragm includes a permanent magnet.

24. The system of claim 22 further comprising:

a current source coupled to supply electric current to the electromagnet.

25. The system of claim 21 further comprising:

a check valve positioned in the at least one channel.

26. The system of claim 21 wherein the substrate is a polymer material.

27. The system of claim 21 wherein the substrate is injection molded.

28. The system of claim 21 wherein the channel and the pump chamber are embossed in the substrate.

30. The method of claim 29, wherein the pump system further includes a check valve positioned in the channel, the method further comprising:

opening the check valve while attracting the magnetic member; and

closing the check valve while repelling the magnetic member.

31. The method of claim 30 wherein the check valve is unidirectional.

32. The method of claim 30 wherein the check valve includes a flap having one end movably attached to one sidewall of the channel.

33. The method of claim 29, wherein the pump system further includes an electromagnet positioned to attract and repel the magnetic member, the method further comprising:

adjusting current supplied to the electromagnet to control attracting and repelling the magnetic member.

35. The method of claim 34 further comprising:

positioning a magnet to attract and repel the magnetic member.

36. The method of claim 34, wherein the magnet is an electromagnet, the method further comprising

coupling a control system to control current to the electromagnet.

37. The method of claim 34 further comprising:

positioning a check valve in the at least one channel.

38. The method of claim 34 further comprising:

using a polymer material for the substrate.

39. The method of claim 34 further comprising:

injection molding the substrate.

40. The method of claim 34 further comprising:

embossing the pump chamber in the substrate.

41. The method of claim 34 further comprising:

positioning a protective layer over the pump system.

42. The pump of claim 34 further comprising:

positioning a protective layer under the pump system.

29. A method for transporting a substance using a pump system, wherein the pump system includes a chamber, at least one channel in communication with the chamber, a flexible diaphragm forming a wall of the chamber, and a magnetic member attached to the diaphragm, the method comprising:

attracting the magnetic member to cause the substance to flow into the chamber; and

repelling the magnetic member to cause the substance in the chamber to flow out of the chamber.

34. A method of fabricating a pump system for transporting a substance, the method comprising:

forming a pump chamber in a substrate;

positioning at least one channel in communication with the pump chamber;

forming at least a portion of a wall of the pump chamber with a flexible diaphragm; and

attaching a magnetic member on the flexible diaphragm.