Microfluidic systems and components

• US 7,351,303 B2
• Filed: 10/09/2003
• Issued: 04/01/2008
• Est. Priority Date: 10/09/2002
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of The University of Illinois
• Original Assignee: Board of Trustees of The University of Illinois
• Inventors: Liu, Chang, Ryu, Kee, Fan, Zhifang, Bullen, David, Goluch, Edgar, Shaikh, Kashan
• Primary Examiner(s): Tucker; Philip
• Assistant Examiner(s): Mazumdar; Sonya
• Application Number:
  US10/683,473
• Publication Number:
  US 20080017306A1
• Time in Patent Office: 1,636 Days
• Field of Search: 156/244.19, 156/290, 156/292, 156/297, 156/308.2, 156/309.6, 216/2, 216/33, 216/41, 216/52, 438/738, 435/287.2, 436/180, 417/413.1, 366/340, 366/341, 204/600, 204/601, 422/50, 422/99, 422/100, 422/103
• US Class Current: 156/297
• CPC Class Codes: B01F 2101/23 Mixing of laboratory samples e.g. in preparation of analysing or testing properties of materials
• CPC Class Codes: B01F 27/1125 with vanes or blades extending parallel or oblique to the stirrer axis
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01F 33/453 using supported or suspended stirring elements
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• 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 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0874 Three dimensional network
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/123 Flexible; Elastomeric
• CPC Class Codes: B01L 2400/0418 electro-osmotic flow [EOF]
• CPC Class Codes: B01L 2400/0475 specific mechanical means and fluid pressure
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• 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 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 2099/0084 Chemistry or biology, e.g. "lab-on-a-chip" technology
• 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 99/0015 : Diaphragm or membrane valves
• CPC Class Codes: F16K 99/0036 : operated by temperature variations
• CPC Class Codes: F16K 99/0046 : using magnets
• CPC Class Codes: F16K 99/0051 : using electrostatic means
• CPC Class Codes: F16K 99/0055 : actuated by fluids
• CPC Class Codes: Y10T 156/1089 : of discrete laminae to single face of additional lamina
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

Microfluidic systems and components. A microfluidic system includes one or more functional units or microfluidic chips, configured to perform constituent steps in a process and interconnected to form the system. A multi-layer microfluidic system includes a separate dedicated fluid layer and dedicated electromechanical layer connected via through-holes. Electromechanical components are formed on the electromechanical layer.

Claims

1. A method of fabricating a microfluidic device that performs a multistep process, the method comprising the steps of:

partitioning the process into a plurality of sequential steps;

providing a plurality of stand-alone functional units, each of said plurality of functional units having at least an inlet, an outlet, and at least one microfluidic channel disposed between the inlet and the outlet, the at least one microfluidic channel being enclosed by joined upper and lower surfaces, each of said plurality of functional units being configured for performing each of said plurality of sequential steps, respectively, between the inlet and the outlet and within the at least one microfluidic channel;

arranging said plurality of functional units vertically so that at least one of said inlet and outlet for each functional unit is vertically aligned with at least one of said inlet and outlet of an adjacent one of said functional units to form at least one junction that allows fluid communication between adjacent functional units; and

combining said arranged plurality of functional units to permit fluid communication between said plurality of functional units to form the microfluidic device.

2. The method according to claim 1 further comprising the step of:

bonding said plurality of provided functional units directly together.

3. The method according to claim 1 wherein each of the functional units comprises at least a first plate and a second plate.

4. The method according to claim 3 wherein said providing comprises bonding said first plate and said second plate to one another.

5. The method according to claim 3 wherein said providing comprises clamping said first plate and said second plate to one another.

6. The method according to claim 1 wherein each of said functional units include at least one element for performing a step in the process other than fluid flow.

7. The method according to claim 1 wherein each of said inlet and outlet ports is disposed in a standardized location for each of said functional units.

8. The method according to claim 1 further comprising the steps of:

determining a sequence of said plurality of steps; and

arranging said functional units vertically according to said determined sequence.

9. The method according to claim 1 wherein said providing step comprises the step of:

selecting said plurality of functional units from a greater plurality of prefabricated functional units.

10. The method according to claim 1 wherein said providing step comprises the step of:

fabricating at least one of said plurality of functional units.

11. The method according to claim 10 wherein said step of fabricating comprises the steps of:

providing a first plate and a second plate; and

bonding said first plate and second plate together to form said functional unit;

wherein said at least one microfluidic channel is provided between said first plate and said second plate, and wherein said first plate and said second plate provide said first surface and said second surface, respectively.

12. The method according to claim 11 wherein said step of fabricating further comprises the step of:

forming at least one element on at least one of said first plate and second plate, each of said at least one element being configured to perform at least part of one of said plurality of steps.

13. The method according to claim 12 wherein said step of fabricating further comprises the step of:

forming said microfluidic channel on at least one of said first plate and said second plate.

14. The method according to claim 13 wherein said bonding step compresses said microfluidic channel so that said microfluidic channel is sealed between said first plate and said second plate.

23. The method of claim 1

wherein each of said plurality of functional units further comprises an O-ring seal disposed around at least one of the inlet and the outlet;

wherein the at least one junction includes at least one of the O-ring seals; and

wherein said combining provides a fluid seal for the fluid communication between said plurality of functional units.

15. A method of designing a microfluidic system to perform a process having a plurality of steps, the method comprising the steps of:

providing a set of pre-fabricated stand-alone functional units, each of said functional units having at least an inlet port, an outlet port, and at least one microfluidic channel disposed between the inlet port and the outlet port and enclosed by joined upper and lower surfaces, each of said functional units being configured for performing a specific process step between the inlet port and the outlet port and within the at least one microfluidic channel;

selecting two or more of said set of functional units, each of said selected functional units being configured for performing one of the plurality of steps;

arranging said two or more selected functional units vertically so that at least one of the inlet port and the outlet port for each arranged functional unit is vertically aligned with at least one of the inlet port and the outlet port of an adjacent one of said two or more functional units to form at least one junction that allows fluid communication between adjacent functional units; and

combining said arranged two or more selected functional units to form the microfluidic system.

16. The method according to claim 15 wherein said inlet port and said outlet port are disposed at a standardized location, and wherein adjacent functional units when combined allow fluid communication directly between aligned inlet and outlet ports.

24. The method of claim 15

wherein each of said plurality of functional units further comprises an O-ring seal disposed around at least one of the inlet port and the outlet port;

wherein the at least one junction includes at least one of the O-ring seals; and

wherein said combining at least partially compresses the at least one O-ring seal to provide a fluid seal for the fluid communication between said plurality of functional units.

17. A method of producing a microfluidic system comprising:

providing an electromechanical layer including a plurality of electromechanical components formed on a back side of the electromechanical layer;

forming a fluid layer having a plurality of channels;

providing a plurality of through-holes in the electromechanical layer registered with one or more of the electromechanical components;

bonding the formed fluid layer to a front side of the electromechanical layer so that the channels of the fluid layer are connected to the one or more electromechanical components via one or more of the through-holes.

18. The method of claim 17 wherein said fluid layer is made from an elastomer.

19. The method of claim 18 wherein said step of forming the fluid layer comprises:

forming a reverse mold on a surface of a substrate corresponding to the channels;

pouring a precursor onto the substrate;

curing the precursor;

removing the precursor to provide the fluid layer.

20. The method of claim 19 wherein said step of forming the reverse mold comprises distributing a material of the mold onto the substrate through a nozzle.

21. The method of claim 17 further comprising:

connecting at least one of the one or more electromechanical components to a processor.

22. A method of forming a microfluidic system that performs a multistep process, the method comprising the steps of:

partitioning the process into a plurality of sequential steps;

providing a plurality of stand-alone microfluidic chips, each of said plurality of microfluidic chips having at least an inlet port, an outlet port, and at least one microfluidic channel disposed between the inlet port and the outlet port and enclosed by an upper surface and a lower surface, each of said plurality of microfluidic chips being configured for performing each of said plurality of sequential steps, respectively, between the inlet port and the outlet port and within the at least one microfluidic channel;

vertically stacking the plurality of provided microfluidic chips, wherein at least one of the inlet port and the outlet port for each microfluidic chip is vertically aligned with at least one of the inlet port and the outlet port for an adjacent one of the microfluidic chips to form at least one junction that allows fluid communication between adjacent functional units;

joining the plurality of microfluidic chips to provide a fluid seal for the at least one junction and permit fluid communication between said plurality of microfluidic chips to form the microfluidic system.