Methods, Systems, and Devices Relating to Open Microfluidic Channels

• US 20160051981A1
• Filed: 11/04/2015
• Published: 02/25/2016
• Est. Priority Date: 07/23/2012
• Status: Active Grant

• Current Assignee: Tasso, Inc.
• Original Assignee: Tasso, Inc.
• Inventors: Berthier, Erwin, Moga, Ben, Casavant, Ben
• Granted Patent: US 9,987,629 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150061 Means for enhancing collection
• CPC Class Codes: A61B 5/150221 Valves
• CPC Class Codes: A61B 5/150343 Collection vessels for collecting blood samples from the skin surface, e.g. test tubes, cuvettes sampling from within body cavities A61B5/150015, A61B5/150045
• CPC Class Codes: A61B 5/150419 comprising means for capillary action
• CPC Class Codes: A61B 5/150969 Low-profile devices which resemble patches or plasters, e.g. also allowing collection of blood samples for testing
• CPC Class Codes: A61B 5/150984 Microneedles or microblades
• CPC Class Codes: A61B 5/15105 Purely manual piercing, i.e. the user pierces the skin without the assistance of any driving means or driving devices
• CPC Class Codes: A61B 5/15146 Devices loaded with multiple lancets simultaneously, e.g. for serial firing without reloading, for example by use of stocking means. multiple simultaneous cutting or piercing A61B5/150977
• CPC Class Codes: B01L 2200/0621 Control of the sequence of chambers filled or emptied
• CPC Class Codes: B01L 2200/0684 Venting, avoiding backpressure, avoid gas bubbles
• CPC Class Codes: B01L 2300/0672 Integrated piercing tool
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0861 Configuration of multiple channels and/or chambers in a single devices
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• 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 3/502723 : characterised by venting arrangements
• 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 3/502738 : characterised by integrated valves microvalves F16K99/0001

Abstract

The various embodiments described herein relate to fabricating and using open microfluidic networks according to methods, systems, and devices that can be used in applications ranging from home-testing, diagnosis, and research laboratories. Open microfluidic networks allow the input, handling, and extraction of fluids or components of the fluid into or out of the open microfluidic network. Fluids can be inserted into an open microfluidic channel by using open sections of the open microfluidic network. Passive valves can be created in the microfluidic network, allowing the creation of logic circuits and conditional flow and volume valves. The fluid can be presented via the microfluidic network to diagnostic and analysis components. Fluids and components of the fluid can be extracted from the open microfluidic network via functional open sections that are easily interfaced with other microfluidic networks or common laboratory tools.

Claims

1. A fluid collection device for use with a patient comprising:

a. a body comprising a proximal body end, a distal body end and a lumen, wherein the distal body end is configured to be placed on the skin of the patient; and

b. a fluidic network comprising a first open channel disposed within the lumen, wherein the first open channel is configured to be capable of spontaneous capillary flow and at least one portion of the first open channel comprises a cross-section, the cross-section comprising;

i. at least one wetted surface;

ii. a wetted perimeter comprising a length;

iii. a contact angle; and

iv. at least one free surface comprising an open air-liquid; and

v. a free perimeter length,

wherein the ratio of the free perimeter length to the wetted perimeter length is less than the cosine of the contact angle.

2. The fluid collection device of claim 1,wherein the fluidic network further comprises a second open channel configured to be capable of spontaneous capillary flow.

3. The fluid collection device of claim 2, further comprising a plurality of apertures disposed about the distal body end.

4. The fluid collection device of claim 3, further comprising a plurality of lancets configured to pass through plurality of apertures and pierce the skin of the patient.

5. The fluid collection device of claim 4, further comprising a reservoir in fluidic communication with the fluidic network, wherein:

a. the plurality of apertures further comprises a first aperture and a second aperture,

b. the first aperture is in fluidic communication with the first open channel; and

c. the second aperture is in fluidic communication with the second open channel.

6. The fluid collection device of claim 5, further comprising a third channel, wherein the third channel is a combinatorial area in fluidic communication with the first channel and second channel.

7. The fluid collection device of claim 5, wherein the fluidic network further comprises:

a. a first plane comprising a first plane axis; and

b. a second plane comprising a second plane axis,

wherein the first plane axis and second plane axis are not co-axial.

8. The fluid collection device of claim 7, wherein the first plane is disposed adjacent to the plurality of apertures and the second plane is disposed between the first plane and the reservoir.

9. A fluid collection system comprising:

a. a body comprising;

i. a lumen; and

ii. a fluid extraction site; and

b. a first open channel disposed within the lumen and in fluidic communication with the fluid extraction site, the first open channel comprising a first cross-section comprising;

i. a wetted surface;

ii. a wetted perimeter defined by fluid contacting the channel on the wetted surface;

iii. a free interface comprising an open air-liquid interface; and

iv. a free perimeter defined by the open air-liquid interface,

wherein the fluid has a contact angle on the wetted surface, the contact angle comprising a cosine, and

further wherein the ratio of a cross-sectional length of the free perimeter to a cross-sectional length of the wetted perimeter is less than the cosine of the contact angle, thereby enabling spontaneous capillary flow from the extraction site.

10. The fluid collection system of claim 9, wherein the first open channel is configured to contact fluid pooling on the surface of the skin by way of the extraction site, thereby drawing the fluid into the first channel.

11. The fluid collection system of claim 10, wherein the fluid is blood.

12. The fluid collection system of claim 10, further comprising a second open channel.

13. The fluid collection system of claim 12, wherein the second channel comprises a second cross-section comprising:

a. a wetted surface, wherein the wetted surface defines a wetted perimeter and contacts fluid flowing through the channel at a contact angle; and

b. a free interface comprising an open air-liquid interface which defines a free perimeter,

wherein the second channel is in fluidic communication with the first channel so as to enable fluid flow between the channels, and

further wherein the second channel has a second cross-section with a ratio of a cross-sectional length of a free interface to a cross-sectional length of a wetted surface that is smaller than the ratio of the first cross-section.

14. The fluid collection system of claim 13, further comprising a reservoir.

15. The fluid collection system of claim 14, wherein the first open channel further comprises a first axis and the second open channel further comprises a second axis, wherein the first axis and second axis are not co-axial.

16. The fluid collection system of claim 15, wherein the first axis is disposed adjacent to the extraction site and the second axis is disposed between the first axis and the reservoir.

17. A medical device for collection of fluid from a patient comprising:

a. a body comprising a lumen and a plunger, the plunger comprising a plurality of lancets;

b. at least one fluid collection site disposed within the body; and

c. a microfluidic network disposed within the body and in fluidic communication with the at least one fluid collection site, the microfluidic network comprising a first open channel comprising;

i. a top portion comprising a first free surface defined by the top portion defining a first free perimeter; and

ii. a first wetted surface defining a first wetted perimeter, wherein the first wetted surface contacts fluid flowing through the first open channel at a first contact angle,

wherein the ratio of the first free perimeter to the first wetted perimeter is less than the cosine of the first contact angle, thereby enabling spontaneous capillary flow through the first open channel.

18. The device of claim 17, further comprising a second open channel.

19. The device of claim 18, wherein the medical device is configured to promote three-dimensional fluid flow by allowing fluidic travel in multiple planes relative to the body of the device.

20. The device of claim 18, wherein the medical device further comprises:

a. a reservoir; and

b. a plurality of apertures in fluidic communication with the first and second open channels,

wherein the device is configured to promote spontaneous capillary flow of fluid from the plurality of apertures to the reservoir.