Mixing in microfluidic devices

• US 20050041525A1
• Filed: 08/19/2003
• Published: 02/24/2005
• Est. Priority Date: 08/19/2003
• Status: Active Grant

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Inventors: Blankenstein, Gert, Pugia, Michael J., Schulman, Lloyd S., Kuo, Hai Hang
• Granted Patent: US 7,347,617 B2
• Time in Patent Office: Days
• US Class Current: 366/341
• CPC Class Codes: B01F 2215/0431 Numerical size values, e.g. diameter of a hole or conduit, area, volume, length, width, or ratios thereof
• CPC Class Codes: B01F 25/4323 using elements provided with a plurality of channels or using a plurality of tubes which can either be placed between common spaces or collectors
• CPC Class Codes: B01F 25/433 Mixing tubes wherein the shape of the tube influences the mixing, e.g. mixing tubes with varying cross-section or provided with inwardly extending profiles
• CPC Class Codes: B01F 25/4335 Mixers with a converging-diverging cross-section
• CPC Class Codes: B01F 25/4338 Mixers with a succession of converging-diverging cross-sections, i.e. undulating cross-section
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01F 35/71725 using centrifugal forces
• CPC Class Codes: B01J 2219/00837 comprising coatings other than catalytically active coatings
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0409 centrifugal forces
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• 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 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: Y10S 366/03 Micromixers: variable geometry from the pathway influences mixing/agitation of non-laminar fluid flow

Abstract

Mixing of liquids in a microfluidic device is accomplished by dispensing the liquids into a first chamber to produce combined liquid. The liquids are thereafter discharged through at least one capillary from the first chamber into a second chamber for complete mixing.

Claims

1. A method of mixing liquids in microfluidic devices comprising:

(a) dispensing at least a first liquid and a second liquid into a first chamber to form combined liquid;

(b) discharging said combined liquid of (a) from said first chamber into a second chamber via at least one capillary passageway in liquid communication with said first chamber, to complete mixing of said combined liquids.

2. A method of mixing liquids of claim 1 wherein said combined liquid of (a) is discharged into said second chamber through more than one capillary passageway.

3. A method of mixing liquids of claim 2 wherein said combined liquid of (a) is discharged into said second chamber through at least two capillary passageways.

4. A method of mixing liquids of claim 1 wherein said second chamber is in liquid communication with at least a third chamber through at least one capillary passageway.

5. A method of claim 1 wherein said combined liquid of (a) is discharged into said second chamber in the form of droplets.

6. A method of claim 1 wherein said first chamber has a volume of at least about twice that of the combined liquid of (a).

7. A method of claim 1 wherein said second chamber has a volume of at least about twice that of the combined liquid of (a).

8. A method of claim 6 wherein said first chamber has a depth of at least about twice that required to hold the combined volume of (a).

9. A method of claim 7 wherein said second chamber has a depth of at least about twice that required to hold the combined volume of (a).

10. A method of claim 1 wherein a space of at least 100 μ

m is above the level of liquid in the first chamber.

11. A method of claim 1 wherein a space of at least 100 μ

m is above the level of liquid in the second chamber.

12. A method of claim 1 wherein said at least one capillary passageway has a cross-sectional dimension of 1 to 2000 μ

m.

13. A method of claim 12 wherein said at least one capillary passageway has a cross-sectional dimension of 200 to 1000 μ

m.

14. A method of claim 1 wherein said at least one capillary passageway has a length of 0.5 to 100 mm.

15. A method of claim 14 wherein said at least one capillary passageway has a length of 1 to 50 mm.

16. A method of claim 1 wherein three or more capillary passageways are in liquid communication between said first and second chambers.

17. A method of claim 1 wherein at least one of said first and second chambers contains steps or ramps to assist mixing of said combined liquids.

18. A method of claim 1 wherein the velocity of said combined liquids of (a) in said at least one capillary passageway is at least 1 mm/sec.

19. A method of claim 1 wherein said first and second liquids are dispensed from wells into said first chamber through capillary passageways.

20. A method of claim 1 wherein the combined liquids are completely mixed and thereafter moved to downstream chambers for further processing.

21. A microfluidic device comprising:

(a) a first chamber for receiving and combining at least a first liquid and a second liquid;

(b) a second chamber for complete mixing of said at least first and second liquids, said second chamber being in liquid communication with said first chamber via at least one capillary passageway.

22. A microfluidic device of claim 21 wherein said first and second chambers are in liquid communication through more than one capillary passageway.

23. A microfluidic of claim 22 wherein said first and second chambers are in liquid communication through at least two capillary passageways.

24. A microfluidic device of claim 21 wherein said second chamber is in liquid communication with at least a third chamber through at least one capillary passageway.

25. A microfluidic device of claim 21 wherein said first chamber has a volume of at least about twice that of the combined volume of said first and second containers.

26. A microfluidic device of claim 21 wherein said second chamber has a volume of at least about twice that of the combined volume of said first and second containers.

27. A microfluidic device of claim 25 wherein said first chamber has a depth of at least about twice the required to hold the combined volume of said first and second containers.

28. A microfluidic device of claim 26 wherein said second chamber has a depth of at least about twice that required to hold the combined volume of said first and second containers.

29. A microfluidic device of claim 21 wherein a space of at least 100 μ

m is above the level of liquid in the first chamber.

30. A microfluidic device of claim 21 wherein a space of at least 100 μ

m is above the level of liquid in the second chamber.

31. A microfluidic device of claim 21 wherein said at least one capillary passageway has a cross-sectional dimension of 1 to 2000 μ

m.

32. A microfluidic device of claim 31 wherein said at least one capillary passageway has a cross-sectional dimension of 200 to 1000 μ

m.

33. A microfludic device of claim 21 wherein said at least one capillary passageway has a length of 0.5 to 100 mm.

34. A microfluidic device of claim 33 wherein said at least one capillary passageway has a length of 1 to 50 mm.

35. A microfluidic device of claim 21 wherein three or more capillary passageways are in liquid communication between said first and second chambers.

36. A microfluidic device of claim 21 wherein said at least one passageway is sized to provide a velocity of combined liquids of at least 1 mm/sec.

37. A microfluidic device of claim 21 wherein at least one of said first and second chambers contains steps or ramps to assist mixing or removal of said first and second liquids.

38. A microfluidic device of claim 21 wherein said first chamber is in liquid communication through capillary passageways with wells containing said at least first and second liquids.

39. A microfluidic device of claim 21 wherein said second chamber contains means for preventing premature movement of said liquids before mixing is complete.