Microfluidic flow control device

• US 20020197167A1
• Filed: 06/26/2001
• Published: 12/26/2002
• Est. Priority Date: 06/26/2001
• Status: Active Grant

• Current Assignee: Micralyne, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: Micralyne, Inc. (Teledyne Technologies Incorporated)
• Inventors: Kornelsen, Kevin E.
• Granted Patent: US 6,629,820 B2
• Time in Patent Office: Days
• US Class Current: 417/53
• CPC Class Codes: F04B 43/043 Micropumps
• 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 2099/0076 using electrical discharge machining [EDM], milling or drilling
• 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 99/0005 Lift valves
• CPC Class Codes: F16K 99/0034 Operating means specially adapted for microvalves
• CPC Class Codes: F16K 99/0036 operated by temperature variations
• CPC Class Codes: F16K 99/0046 using magnets
• CPC Class Codes: F16K 99/0048 using piezoelectric means
• CPC Class Codes: F16K 99/0059 actuated by a pilot fluid
• CPC Class Codes: Y10T 137/2224 Structure of body of device

Abstract

A method of controlling fluid flow in a channel in a microfluidic flow control device by introducing fluid to the channel, with the fluid flowing in a flow direction and controllably deforming material defining the channel in a direction perpendicular to the flow direction to control fluid flow in the channel. The channel is formed between a first plate and a second plate and controllably deforming material defining the channel comprises deforming at least one of the first and second plates. Material defining the channel extends continuously between an inlet port and an outlet port. Controllably deforming material defining the channel preferably comprises deforming the first plate into contact with a seat formed in the second plate to close the channel. The seat may be formed by a ridge having a smoothly changing profile in section across the channel. The method may be operated to generate a pumping, filtering, trapping or mixing function. Apparatus for carrying out the method is also disclosed.

Claims

1. A method of controlling fluid flow in a channel in a microfluidic flow control device, the method comprising the steps of:

introducing fluid to the channel, with the fluid flowing in a flow direction; and

controllably deforming material defining the channel in a direction perpendicular to the flow direction to control fluid flow in the channel.

2. The method of claim 1 in which the channel is formed between a first plate and a second plate and controllably deforming material defining the channel comprises deforming at least one of the first and second plates.

3. The method of claim 2 in which controllably deforming material defining the channel comprises deforming the first plate into contact with a seat formed in the second plate to close the channel.

4. The method of claim 3 in which the seat is formed of a ridge.

5. The method of claim 4 in which the ridge has a smoothly changing profile in section across the channel.

6. The method of claim 1 in which controllably deforming the channel comprises deforming the channel at successively at spaced apart positions along the channel to drive fluid along the channel.

7. The method of claim 1 further comprising:

closing the channel at a first position by deformation of the channel;

compressing the channel in a compression region adjacent the first position to drive fluid in the channel along the channel away from the first position past a second position in the channel;

closing the channel at the second position by deformation of the channel to prevent fluid flow past the second position into the compression region while the compression region is decompressed; and

opening the channel at the first position to allow fluid to flow into the compression region while the compression region is decompressed.

8. The method of claim 1 in which the fluid contains particles and controllably deforming material defining the channel comprises the step of restricting the channel sufficiently to selectively prevent and allow the particles to move with the fluid in the channel.

9. The method of claim 1 in which the material defining the channel extends continuously between an inlet port and an outlet port.

10. The method of claim 1 in which the channel is formed partly in a top plate and partly in a bottom plate.

11. The method of claim 10 in which the bottom plate contains a weir and controllably deforming material defining the channel comprises deforming material of the top plate across from the weir.

13. The microvalve of claim 12 further comprising an actuator positionable against one of the first plate and the second plate for deforming the one of the first plate and the second plate.

14. The microvalve of claim 13 in which the valve seat is formed by a ridge extending transversely across the channel.

15. The microvalve of claim 14 in which the ridge is flat topped in section and a groove in the second plate is located opposite the valve seat to form a gap between the ridge and the second plate.

16. The microvalve of claim 15 in which the groove is formed of linearly ramped sidewalls.

17. The microvalve of claim 14 in which ridge drops in height to be flush with the channel at the center of the channel.

19. The microvalve of claim 13 in which a bypass channel is formed in one or both of the first plate and the second plate on at least one side of the valve seat.

20. The microvalve of claim 18 in which bypass channels are formed in one or both of the first plate and the second plate on opposed sides of the valve seat.

22. The microfluidic trapping device of claim 17 in which the body comprises a first plate and a second plate, with the channel being formed between the first plate and the second plate, and the first gate is actuated by moving the first plate towards and away from the second plate.

23. The microfluidic trapping device of claim 17 in which the second gate is actuated by moving the first plate towards and away from the second plate.

25. The method of claim 24 further comprising the steps of:

merging a third fluid stream with the first fluid stream and the second fluid stream, the first fluid stream being located between the first fluid stream and the second fluid stream; and

forcing fluid in the first fluid stream into the third fluid stream by repeatedly blocking and unblocking the first fluid stream.

26. The method of claim 25 in which blocking and unblocking the first fluid stream comprises the step of deforming material defining the channel to close a portion of the channel.

27. The method of claim 26 in which the first fluid stream has a width and the portion of the channel extends widthwise beyond the width of the first fluid stream.

29. The method of claim 28 in which opening and closing the channel is carried out, in each instance of opening and closing the channel, by deformation of material defining the channel.

12. A microvalve, comprising:

a first plate and a second plate placed together to form a channel between them;

a valve seat formed in the first plate on one side of the channel, the valve seat having a valve seat profile; and

the second plate being deformable opposite to the valve seat into a deformation profile that matches the valve seat profile.

18. A microvalve, comprising:

a first plate and a second plate placed together to form a channel between them;

a valve seat formed in the first plate on one side of the channel, the valve seat having a valve seat profile, the valve seat profile being U-shaped;

deformable material in the second plate opposite to the valve seat, the deformable material being deformable into a deformation profile that matches the valve seat profile; and

an actuator positionable against one of the first plate and the second plate for deforming the one of the first plate and the second plate.

21. A microfluidic trapping device, comprising:

a body having a channel extending through the body, the channel having a first end and a second end;

a first gate at the first end of the channel;

a first gate actuator operably connected to the first gate;

a second gate at the second end of the channel; and

a second gate actuator operably connected to the second gate.

24. A method of controlling fluid flow in a channel in a microfluidic flow control device, the method comprising the steps of:

merging a first fluid stream and a second fluid stream in the channel; and

forcing fluid in the first fluid stream into the second fluid stream by repeatedly blocking and unblocking the first fluid stream.

28. A method of pumping fluid in a channel in a microfluidic device, the method comprising the steps of:

repeatedly deforming material defining the channel to compress and decompress the channel at a compression chamber having an upstream side and a downstream side;

closing the channel on the upstream side of the compression chamber and opening the channel on the downstream side of the compression chamber during compression of the compression chamber; and

opening the channel on the upstream side of the compression chamber and closing the channel on the downstream side of the compression chamber during de-compression of the compression chamber.