Membrane-based fluid control in microfluidic devices

• US 9,046,192 B2
• Filed: 01/31/2008
• Issued: 06/02/2015
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Mescher, Mark J., Fiering, Jason O., Swan, Erin E.
• Primary Examiner(s): BOBISH, CHRISTOPHER S
• Application Number:
  US12/023,653
• Publication Number:
  US 20080249510A1
• Time in Patent Office: 2,679 Days
• Field of Search: 417/313, 417/540, 417/543, 138/26, 138/46, 251/7, 251/8, 251/4, 251/331
• US Class Current: 1/1
• CPC Class Codes: A61M 2039/226 Spindles or actuating means
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2206/22 eliminating pulsatile flows, e.g. by the provision of a dampening chamber
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: A61M 39/22 Valves or arrangement of valves A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405
• CPC Class Codes: A61M 5/141 with capillaries for restricting fluid flow
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/16809 by repeated filling and emptying of an intermediate volume pressure infusion using positive displacement pumps A61M5/142
• CPC Class Codes: A61M 5/16813 by controlling the degree of opening of the flow line
• CPC Class Codes: F16K 2099/0069 Bistable microvalves
• 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 2099/0088 Implanted devices
• 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 99/0034 Operating means specially adapted for microvalves
• CPC Class Codes: F16K 99/0042 Electric operating means therefor
• CPC Class Codes: F16K 99/0055 actuated by fluids
• CPC Class Codes: G05D 7/0113 the sensing element acting as a valve
• CPC Class Codes: G05D 7/012 the sensing element being deformable and acting as a valve
• CPC Class Codes: Y10T 137/0318 : Processes
• CPC Class Codes: Y10T 137/0396 : Involving pressure control

Abstract

A microfluidic device may include a substrate that defines a flow-control cavity and first and second channels in fluid communication with the flow-control cavity. A compliant membrane for regulating fluid flow through the flow-control cavity may surround at least a portion of the flow-control cavity.

Claims

1. A capacitive element for a microfluidic device, comprising:

a substrate including a channel within the substrate defining a flow-control cavity and a bypass structure, wherein the channel includes a bottom, side walls, and a partial ceiling, wherein the partial ceiling extends over at least a portion of the channel;

a compliant membrane, surrounding at least a portion of the flow-control cavity, for capacitively regulating fluid flow through the flow-control cavity;

wherein the bypass structure is separated from the membrane by the partial ceiling and is configured to allow the fluid to flow through the flow-control cavity when the compliant membrane is collapsed into the flow-control cavity; and

a displacement-limiting element, coupled to the substrate and uncoupled from the compliant membrane, for limiting the outward displacement of the compliant membrane away from the flow-control cavity.

2. The capacitive element of claim 1, wherein the substrate comprises a plurality of layers.

3. The capacitive element of claim 2, wherein at least one of the plurality of layers comprises a laminated plastic.

4. The capacitive element of claim 1, wherein the compliant membrane comprises at least one of a multi-layered structure or a composite structure.

5. The capacitive element of claim 1, wherein the compliant membrane comprises a polymer.

6. The capacitive element of claim 1, wherein the compliant membrane comprises a layer exhibiting at least one of a low vapor permeability or a low gas permeability.

7. The capacitive element of claim 1 further comprising an external fluid connection element having fine-bore tubing.

8. The capacitive element of claim 1, wherein the displacement-limiting element comprises a threaded element.

9. The capacitive element of claim 8, wherein the substrate comprises a plate with a threaded hole formed therethrough, and wherein the displacement-limiting element is positioned in the threaded hole.

10. The capacitive element of claim 1, wherein the displacement-limiting element is manually actuable.

11. A microfluidic device, comprising:

a discharge line;

a pump for discharging and retracting fluid through the discharge line; and

a capacitive element for modifying fluid flow through the discharge line, the capacitive element comprising;

a compliant membrane that surrounds at least a portion of a channel formed within a substrate of the capacitive element, the channel including a flow-control cavity and a bypass structure;

wherein the channel includes a bottom, side walls, and a partial ceiling extending over at least a portion of the channel, and wherein the bypass structure is separated from the membrane by the partial ceiling and is configured to allow the fluid to flow through the flow-control cavity when the compliant membrane is collapsed into the flow-control cavity; and

an adjustable displacement-limiting element, coupled to the substrate of the capacitive element and uncoupled from the compliant membrane, for limiting an outward displacement of the compliant membrane away from the cavity.

12. The microfluidic device of claim 11 further comprising a valve manifold.

13. The microfluidic device of claim 11, wherein the microfluidic device is a reciprocating drug delivery device for regulating a drug dosage delivered to a patient.

14. A method of controlling fluid flow within a microfluidic device, the method comprising:

a) passing fluid through a microfluidic device comprising i) a compliant membrane that surrounds at least a portion of a channel formed within a substrate of the microfluidic device, the channel including a flow-control cavity and a bypass structure, ii) wherein the channel includes a bottom, side walls, and a partial ceiling extending over at least a portion of the channel, and wherein the bypass structure is separated from the membrane by the partial ceiling and is configured to allow the fluid to flow through the flow-control cavity when the compliant membrane is collapsed into the flow-control cavity, and iii) a displacement limiting element coupled to the substrate of the microfluidic device and uncoupled from the compliant membrane; and

b) capacitively displacing at least a portion of the compliant membrane to control a rate of fluid flow through the microfluidic device while limiting an outward displacement of the compliant membrane away from the cavity with the displacement-limiting element.

15. A capacitive element for a microfluidic device, comprising:

a substrate including a channel within the substrate defining a flow-control cavity and a bypass structure, wherein the channel includes a bottom, side walls, and a partial ceiling, wherein the partial ceiling extends over at least a portion of the channel;

a compliant membrane, surrounding at least a portion of the flow control cavity, for capacitively regulating fluid flow through the flow-control cavity;

wherein the bypass structure is separated from the membrane by the partial ceiling and is configured to allow the fluid to flow through the flow control cavity when the compliant membrane is collapsed into the flow-control cavity.

16. The capacitive element of claim 15, wherein the substrate is comprised of a plurality of layers.

17. The capacitive element of claim 16, wherein at least one of the plurality of layers comprises a laminated plastic.

18. The capacitive element of claim 15, wherein the compliant membrane comprises at least one of a multi-layered structure or a composite structure.

19. The capacitive element of claim 15, wherein the compliant membrane comprises a polymer.

20. The capacitive element of claim 15, wherein the compliant membrane comprises a layer exhibiting at least one of a low vapor permeability or a low gas permeability.

21. The capacitive element of claim 15 further comprising an external fluid connection element having fine-bore tubing.

23. The microfluidic device of claim 21 further comprising a valve manifold.

24. The microfluidic device of claim 21, wherein the microfluidic device is a reciprocating drug delivery device for regulating a drug dosage delivered to a patient.

22. A microfluidic device, comprising:

a discharge line;

a pump for discharging and retracting fluid through the discharge line; and

a capacitive element for modifying fluid flow through the discharge line, the capacitive element comprising;

a compliant membrane that surrounds at least a portion of a channel formed within a substrate of the capacitive element, the channel including a flow-control cavity and a bypass structure; and

wherein the channel includes a bottom, side walls, and a partial ceiling extending over at least a portion of the channel, and wherein the bypass structure is separated from the membrane by the partial ceiling and is configured to allow the fluid to flow through the flow-control cavity when the compliant membrane is collapsed into the flow-control cavity.

25. A method of controlling fluid flow within a microfluidic device, the method comprising:

a) passing fluid through a microfluidic device comprising i) a compliant membrane that surrounds at least a portion of a channel formed within a substrate of the microfluidic device, the channel including a flow-control cavity and a bypass structure, ii) wherein the channel includes a bottom, side walls, and a partial ceiling extending over at least a portion of the channel, and wherein the bypass structure is separated from the membrane by the partial ceiling and is configured to allow the fluid to flow through the flow-control cavity when the compliant membrane is collapsed into the flow-control cavity, and iii) a displacement limiting element coupled to the substrate of the microfluidic device and uncoupled from the compliant membrane; and

b) capacitively displacing at least a portion of the compliant membrane to control a rate of fluid flow through the microfluidic device.