Micro fluidic structures

• US 20050042766A1
• Filed: 06/04/2003
• Published: 02/24/2005
• Est. Priority Date: 06/07/2002
• Status: Active Grant

• Current Assignee: Crimson International Assets LLC (The Carlyle Group LP (Corporate Private Equity))
• Original Assignee: Åmic AB
• Inventors: Mendel-Hartvig, Ib, Ohman, Ove
• Granted Patent: US 8,025,854 B2
• Time in Patent Office: Days
• US Class Current: 436/174
• CPC Class Codes: B01L 2200/0668 Trapping microscopic beads
• CPC Class Codes: B01L 2300/18 Means for temperature control
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• 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: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: G01N 2030/525 surface properties, e.g. porosity
• CPC Class Codes: G01N 30/6065 with varying cross section
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize
• CPC Class Codes: Y10T 436/25 including sample preparation

Abstract

The invention relates to a micro fluidic system comprising a substrate, and, provided on said substrate, at least one flow path interconnecting with functional means in which liquid samples can be treated by desired procedures. The flow paths are laid out to form a pattern for the transport of liquid samples to and from said functional means. These flow paths comprise a plurality of micro posts protruding upwards from said substrate, the spacing between the micro posts being small enough to induce a capillary action in a liquid sample applied anywhere within any of said flow paths, so as to force said liquid to move from where said liquid sample was applied.

Claims

1. A micro fluidic system comprising a substrate (2), and, provided on said substrate, at least one flow path and functional means in which liquid samples can be treated by desired procedures, wherein said at least one flow path is/are laid out to form a pattern for the transport of liquid samples to, through and from said functional means;

characterized in that the flow path consists of a plurality of micro posts (1) protruding upwards from said substrate;

wherein the spacing between the micro posts is such as to induce a capillary action in a liquid sample applied anywhere to said flow path, so as to force said liquid to move from where said liquid sample was applied.

2. The micro fluidic system according to claim 1, wherein the functional means (5) comprise one or more of chemical reactors, separation means, heating means, means for irradiation with electromagnetic radiation, magnetic means for trapping magnetic components of said liquid within said functional means, electrodes for applying voltage to the liquid over a selected region, or any other device or means for chemically, biologically or physically treating liquid samples located within said functional means.

3. The micro fluidic system according to claim 1 or 2, wherein said substrate (2) is provided with grooves having a bottom surface and side walls, and wherein the flow paths consist of micro posts (1) protruding from the bottom surface of said grooves.

4. The micro fluidic system according to claim 3, wherein said flow paths are covered by a top or lid (15), said top or lid not significantly contributing to the capillary action in said flow channel.

5. The micro fluidic system according to claim 4, wherein the lid (15) has access openings for enabling introduction of reagents, gas, liquids, samples into said flow paths.

6. The micro fluidic system according to claim 1 or 2, wherein the substrate (2) is essentially flat and the micro posts (1) protrude from said substrate.

7. The micro-fluidic system according to any one of the preceding claims, wherein the micro posts are grouped in adjacent segments so as to provide a spacing or discontinuity between such segments, the discontinuity having a finite distance, which is large enough to prevent capillary flow between said segments, thereby providing a flow stop.

8. The micro fluidic system according to claim 7, wherein there are provided means for applying energy to one or more selected segments so as to induce a forced transport across the flow stop.

9. The micro fluidic system according to claim 8, wherein said energy applying means is selected from a pressure pulse generator, an ultrasound generator, an electromagnetic radiation means.

10. The micro fluidic system according to claim 7, comprising means for applying liquid to said discontinuity in order to provide a bridge across said discontinuity so as to induce a flow there across.

11. The micro fluidic system according to claim 1, wherein the surfaces of the micro posts in said fluid paths have a chemical, biologic or physical functionality.

12. The micro fluidic system according to claim 11, wherein the micro posts have chemically reactive groups on their surface.

13. The micro fluidic system according to claim 11, wherein the micro posts have substances with biological affinity bound to their surface.

14. The micro fluidic system according to claim 11, wherein the micro posts have hydrophilic groups on their surface.

15. The micro fluidic system according to claim 11, wherein the micro posts have positively and/or negatively charged groups on their surface.

16. The micro fluidic system according to claim 12, wherein the micro posts have hydrophobic structures on their surface.

17. The micro fluidic system according to claim 12, wherein said functionality is applied to the micro posts in the entire flow paths or limited to a discrete region or portion of the flow path.

18. The micro fluidic system according to claim 12, wherein said properties are selected from the micro post diameter, height, shape, cross section, surface coating, number of micro-posts per unit area, wetting behavior of the micro-post surface, or a combination thereof.

19. The micro fluidic system according to any one of the preceding claims, wherein particles are provided within said at least one flow path.

20. The micro fluidic system according to claim 19, wherein said particles are chemically or physically bound to the substrate, or mechanically trapped within a region comprising a plurality of micro posts.

21. The micro fluidic system according to any one of the preceding claims, wherein said flow paths have integrated zones or delimited surfaces containing electrodes or other means for electrical manipulation of liquids and/or reagents.

22. The micro fluidic system according to any one of the preceding claims, wherein said flow paths have integrated zones or delimited surfaces containing optical elements or other means for transmitting, focusing, reflecting or absorbing light.

23. The micro fluidic system according to any one of the preceding claims, wherein said flow paths have integrated zones or delimited surfaces containing magnetic functionalities or means for the manipulation and/or detection of magnetic substances.

24. The micro fluidic system according to any one of the preceding claims, wherein said flow paths have integrated zones or delimited surfaces containing means for the regulation of the temperature in said zone, e.g. heating or cooling said zone.

25. A method for performing micro scale chemical or biochemical processes, characterized in that micro fluidic system according to claim 1 is used.

26. A method for performing ion-exchange chromatography, characterized in that a micro fluidic system according to any one of claim 1, 2, 11, 15, or 19, is used in the separation step for said chromatography.

27. A method for performing hydrophobic interaction chromatography, characterized in that a micro fluidic system according to claim 1 is used in the preparatory steps for said chromatography.

28. A method for the concentration of samples in the performance of micro scale physical, chemical or biochemical processes, characterized in that a micro fluidic system according to claim 1 is used.

29. A method for the separation of cells or other microscopic biological entities in the performance of micro scale physical, chemical or biochemical processes, characterized in that a micro fluidic system according to claim 1 is used.