Integrated electrokinetic devices and methods of manufacture

• US 8,007,648 B2
• Filed: 04/05/2007
• Issued: 08/30/2011
• Est. Priority Date: 06/04/2001
• Status: Active Grant

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Epocal Incorporated (Siemens AG)
• Inventors: Lauks, Imants R.
• Primary Examiner(s): Olsen; Kaj K
• Application Number:
  US11/697,116
• Publication Number:
  US 20070170062A1
• Time in Patent Office: 1,608 Days
• Field of Search: 204/450, 204/600, 422/100, 422/504, 422/505
• US Class Current: 204/600
• CPC Class Codes: B01J 2219/00783 Laminate assemblies, i.e. the reactor comprising a stack of plates
• CPC Class Codes: B01J 2219/00831 Glass
• CPC Class Codes: B01J 2219/00853 Employing electrode arrangements
• CPC Class Codes: B01J 2219/0086 Dimensions of the flow channels
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2200/16 Reagents, handling or storing thereof
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/10 Means to control humidity and/or other gases
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0418 electro-osmotic flow [EOF]
• 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 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: G01N 2035/00158 Elements containing microarrays, i.e. "biochip"

Abstract

Devices with electrokinetic elements are disclosed as well as their method of microfabrication for use in micro-scale analysis, mixture separation and reaction. The devices consist of solid hydrophilic-matrix films that have been microfabricated into a variety of micro-scale structures. These structures include hydrophilic-matrix conductors for electrokinetic species transport and separation. They also include hydrophilic-matrix cladding containing chemical species adjacent to either an open conduit or a hydrophilic matrix conductor. Also described are other integrated microstructures consisting of hydrophilic-matrix materials such as micro-reaction zones for retaining chemical species for on-chip chemical reactions and integrated detection structures for on-chip species detection. In general, a hydrophilic matrix on a substrate functions as a conductor that is covered by an electrically insulating, preferably water permeable material.

Claims

1. A device for electrokinetic transport of an aqueous solute, comprising

an electrically insulating substrate;

a conductor element for electrokinetic transport of the solute, the conductor element being in the form of a solid hydrophilic-matrix layer on the substrate, the matrix layer being in a substantially dry, inactive state wherein electrokinetic transport is substantially prevented;

a pair of spaced apart electrodes in electric contact with the conductor element at spaced apart locations for applying an electric potential across the conductor element; and

a cover layer for electrically insulating and encapsulating the conductor element on the substrate, the cover layer being made of an encapsulating material which is water vapour permeable, but impermeable to the solute;

whereby exposure of the hydrophilic matrix to water converts the matrix from the inactive state to a hydrated, active state permitting electrokinetic transport of the solute.

2. The device of claim 1, further comprising a means for introducing water into the conductor element.

3. The device of claim 2, further comprising a means for introducing the aqueous solute into the conductor element.

4. The device of claim 1, wherein the solid hydrophilic-matrix layer is micro-fabricated onto the substrate.

5. The device of claim 1, wherein the solid hydrophilic-matrix layer is a dry reagent film.

6. The device of claim 1, wherein the cover layer is micro-fabricated onto the conductor element and the substrate.

7. The device of claim 1, wherein at least one of the cover layer and the substrate has at least one portion which is permeable to water vapor.

8. The device of claim 1, wherein the substrate consists of electrically insulating material.

9. The device of claim 1, wherein the substrate includes a layer of electrically conductive material and a layer of electrically insulating material intermediate the layer of conductive material and the conductor element.

10. The device of claim 1, wherein one of the substrate and the cover layer has a pair of openings for input and output of the solute species to be transported through the conductor element.

11. The device of claim 1, comprising at least one region for introducing the solute for one of transport, separation and chemical reaction within the conductor element, and a separate means for introducing water only into the conductor element.

12. A device for electrokinetic transport of an aqueous solute, comprising

an electrically insulating substrate;

a conductor element for electrokinetic transport of the solute, the conductor element being in the form of a solid hydrophilic-matrix layer on the substrate, the matrix layer being in a substantially dry, inactive state wherein electrokinetic transport is substantially prevented and having a first surface engaging the substrate and a second surface;

a cover layer for electrically insulating and covering the second surface, the cover layer being impermeable to the solute; and

a pair of spaced apart electrodes in electric contact with the conductor element at spaced apart locations for applying an electric potential across the conductor element;

whereby exposure of the hydrophilic matrix to water converts the matrix from the inactive state to a hydrated, active state permitting electrokinetic transport of the solute and wherein the electrodes are applied to the substrate and the device further includes an insulator layer for electrically insulating each electrode, the insulator layer having an opening in each region of overlap between one of the electrodes and the conductor element for permitting electric contact of the conductor element with the integral electrodes for electrokinetic pumping.

13. A device for electrokinetic transport of an aqueous solute, comprising

an electrically insulating substrate;

a conductor element for electrokinetic transport of the solute, the conductor element being in the form of a solid hydrophilic-matrix layer on the substrate, the matrix layer being in a substantially dry, inactive state wherein electrokinetic transport is substantially prevented and having a first surface engaging the substrate and a second surface;

a cover layer for electrically insulating and covering the second surface, the cover layer being impermeable to the solute; and

a pair of spaced apart electrodes in electric contact with the conductor element at spaced apart locations for applying an electric potential across the conductor element;

whereby exposure of the hydrophilic matrix to water converts the matrix from the inactive state to a hydrated, active state permitting electrokinetic transport of the solute and the device further comprising an input region for supply of solute into the conductor element and an output region spaced apart therefrom for removal of transported solute from the conductor element.

14. The device of claim 13, wherein the hydrophilic matrix of the conductor element is water insoluble in the input and output regions.

15. The device of claim 14, wherein the conductor element further comprises a reservoir region intermediate the input and output regions and including at least one chemical reactant for interaction with the transported solute.

16. The device of claim 15, further comprising an electrode for applying an electric potential to the reservoir region.

17. The device of claim 15, wherein the conductor element includes a plurality of the reservoir regions.