LAYERED ELECTROOSMOTIC STRUCTURE AND METHOD OF MANUFACTURE

Abstract

A layered electroosmotic structure for transporting fluid by electroosmotic transport includes a porous layer; a first electrode located on a first side of the porous layer; and a second electrode located on a second side of the porous layer. The first electrode may include a first surface that faces the porous layer, wherein the first surface of the first electrode includes a region that is electrically insulating. The first electrode and/or the second electrode may not be in electrical contact with an edge region of the porous layer. Methods of manufacturing the layered electroosmotic structures are also provided.

Claims

1. A layered electroosmotic structure for transporting fluid by electroosmotic transport, the layered structure comprising: a porous layer, wherein the porous layer is a non-conductive electroosmotic layer; a first electrode located on a first side of the porous layer; and a second electrode located on a second side of the porous layer; wherein the first electrode comprises a first surface that faces the porous layer, wherein the first surface of the first electrode comprises a region that is electrically insulating.

2. A layered electroosmotic structure according to claim 1, wherein the first surface of the first electrode comprises a region that is electrically conductive and wherein the region that is electrically insulating provides a greater resistance to the flow of charge than the region that is electrically conductive.

3. A layered electroosmotic structure according to claim 1, wherein the insulating region is provided by the surface of the electrode comprising a non-conductive material.

4. A layered electroosmotic structure according to claim 3, wherein the non-conductive material is a layer of non-conductive material with apertures therethrough that is fixed to a conductive layer to form the electrode.

5. A layered electroosmotic structure according to claim 3, wherein the non-conductive material is a non-conductive coating that is coated onto a conductive material.

6. A layered electroosmotic structure according to claim 1, wherein the first electrode is a fabric formed from conductive and non-conductive fibres, wherein the non-conductive fibres provide the region that is electrically insulating.

7. A layered electroosmotic structure according to claim 1, wherein the structure comprises an edge at which the region that is electrically insulating is located.

8. A layered electroosmotic structure according to claim 1, wherein the second electrode comprises a surface facing the porous layer that has a region that is insulating.

9. A layered electroosmotic structure according to claim 8, wherein the region that is electrically insulating on the first electrode may at least partially overlap the location where the region that is electrically insulating of the second electrode is located.

10. A layered electroosmotic structure according to claim 1, wherein a first surface of the electrode(s) that faces the porous layer comprises a plurality of conductive regions, and wherein the conductive regions are electrically connected at a location other than the first surface of the electrode(s).

11. A method of transporting fluid by electroosmotic transport, the method comprising providing the layered electroosmotic structure of claim 1 and applying a voltage between the two electrodes.

12. A method of manufacturing a layered electroosmotic panel for transporting fluid by electroosmotic transport, the method comprising: providing a layered electroosmotic structure comprising: a porous layer; a first electrode located on a first side of the porous layer; and a second electrode located on a second side of the porous layer; wherein the first electrode comprises a first surface that faces the porous layer, and wherein the first surface of the first electrode comprises a region that is electrically insulating; and cutting the layered structure at the region that is electrically insulating of the first surface of the first electrode to form the layered electroosmotic panel.

13. A method according to claim 12, wherein the layered electroosmotic structure is formed by laminating together layers from rolls of material.

14. A method according to claim 12, wherein the layered electroosmotic structure and/or the layered electroosmotic panel is a structure comprising: a porous layer, wherein the porous layer is a non-conductive electroosmotic layer; a first electrode located on a first side of the porous layer; and a second electrode located on a second side of the porous layer; wherein the first electrode comprises a first surface that faces the porous layer, wherein the first surface of the first electrode comprises a region that is electrically insulating.

15. A layered electroosmotic structure for transporting fluid by electroosmotic transport, the layered structure comprising: a porous layer, wherein the porous layer is a non-conductive electroosmotic layer; a first electrode located on a first side of the porous layer; and a second electrode located on a second side of the porous layer; wherein the first electrode and/or second electrode is not in electrical contact with an edge region of the porous layer and in electrical contact with the porous layer at a non-edge region.

16. A layered electroosmotic structure according to claim 15, wherein the first electrode and/or second electrode is not in electrical contact with an edge region of the porous layer because the porous layer extends beyond the edge of the first electrode and/or second electrode.

17. A layered electroosmotic structure according to claim 15, wherein the porous layer is larger than the first electrode and/or second electrode.

18. A layered electroosmotic structure according to claim 15, wherein the first electrode and/or second electrode is not in electrical contact with an edge region of the porous layer because the first electrode and/or second electrode comprises a first surface that faces the porous layer, wherein the first surface of the first electrode and/or second electrode comprises a region that is electrically insulating at the edge region of the porous layer.

19. A layered electroosmotic structure according to claim 15, wherein conductive material of the first electrode and/or second electrode is spaced from an edge of the porous layer and in contact with the porous layer at a non-edge region of the porous layer.

20. (canceled)

21. A method of manufacturing a layered electroosmotic structure for transporting fluid by electroosmotic transport, the method comprising: providing a porous layer, wherein the porous layer is a non-conductive electroosmotic layer; providing a first electrode; and providing a second electrode; locating the first electrode on a first side of the porous layer and locating the second electrode on a second side of the porous layer to form a layered electroosmotic structure, wherein the first electrode and/or second electrode is not in electrical contact with an edge region of the porous layer and in electrical contact with the porous layer at a non-edge region.

22. (canceled)

Description

[0142] Certain preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0143] FIG. 1 shows an electroosmotic structure;

[0144] FIGS. 2, 3, 4, 5, 7 and 8 show various electroosmotic structures and panels;

[0145] FIG. 6 shows an exploded version of some of the components of the structure of FIG. 5;

[0146] FIGS. 9 and 10 show an exemplary electrode;

[0147] FIG. 11 shows schematically a method of manufacturing the structure and panels; and

[0148] FIGS. 12 and 13 illustrate an electroosmotic structure that is to be cut into a panel with multiple conductive regions that are electrically connected

[0149] FIG. 1 shows an electroosmotic device that comprises an electroosmotic (EO) membrane 1, and a first and second electrode 2, 3 either side of the membrane 1. The device also comprises a carbon coating 4, 5 on each of the electrodes 2, 3. On the outer surfaces are additional layers 6, 7 that may have additional functions such as providing thermal insulation and/or waterproofing.

[0150] When a voltage is applied to the electrodes 2, 3 across the electroosmotic membrane 1 fluid will flow through the membrane 1 by means of electroosmosis.

[0151] This structure may be formed by individually cutting each of the EO membrane 1, electrodes 2, 3 and additional layers 6, 7. The electrodes 2, 3 may be coated with the carbon coating 4, 5 before or after being cut to the desired size for the application.

[0152] Once the components are appropriately sized they are aligned and attached together to form the structure.

[0153] So as to prevent a short circuit due to the conductive electrodes 2, 3 coming into electrical contact the porous layer 1 is sized to be larger than the electrodes.

[0154] This method of manufacture is expensive, as it will take an operator an estimated 12 minutes per panel to manufacture, or would require large investments in order to automate. However, such a structure may reliably ensure that there is not a short circuit between the electrodes 2, 3. Such a method of manufacture may be acceptable in low or medium volume applications.

[0155] Alternatively to this structure and method for minimising the risk of a short circuit, the inventors have further realised that by having one or both of the electrodes have an insulating region facing the porous layer, manufacture can be simplified (and thus made cheaper). This is because the structure can be made by making large electroosmotic structures that can be cut to the desired size at the regions that are insulating without risking creating a short circuit between the electrodes.

[0156] FIG. 2 shows an exemplary layered structure 10 in which the electrodes comprise conductive regions 8 and non-conductive regions (i.e. insulating regions) 9. The non-conductive regions 9 are at least non-conductive on the surface of the electrode 2, 3, that faces the porous layer 1.

[0157] The layered structure can be cut through the insulating regions 9 (as indicated by the dotted lines) to form a plurality of panels 11. Due to the presence of the insulating regions 9 the risk of there being a short circuit between the electrodes 2, 3 at the cut surface may be significantly reduced. This is because the first electrode and second electrode 2,3 are not in electrical contact with the edge region of the porous layer 1.

[0158] FIG. 3 shows a layered structure 20 that further compared to FIG. 2 comprises a carbon coating 4, 5 on the electrodes 2, 3 and additional outer layers 6, 7. Due to the presence of the insulating regions 9 this structure can safely be cut into panels 21 comprising the porous layer 1, electrodes 2, 3 and carbon coating 4, 5 and additional layers 6, 7 without risk of a short circuit.

[0159] FIG. 4 shows a variation of the electroosmotic structure 30 in which only one of the electrodes 2 comprises insulating regions 9. Such a structure 30 can still safely be cut into panels 31 without risk of a short circuit between the electrodes 2, 3 at the cut edge.

[0160] FIG. 5 shows another variation of the electroosmotic structure 40. In this structure 40 the electrodes 2, 3 each comprise a conductive layer 8 and a non-conductive layer 12, 13. The non-conductive layers 12, 13 are attached to the respective conductive layers 8 to form an electrode with a region facing the porous layer 1 that is insulating. As shown most clearly in FIG. 6 that shows an exploded version of the components of the structure 40, the non-conductive layers may be a frame/grid of material, i.e. a layer with apertures therethrough. Alternatively the non-conductive layers 12, 13 may be provided by a coating that is coated onto the conductive layers 8. The non-conductive layers 12, 13 provide insulating regions through which the structure can be cut to form panels 41 without risk of a short circuit between the conductive parts of the two electrodes 2, 3. A carbon coating 4, 5 may be provided between the conductive layer 8 and non-conductive layer 12, 13 of the electrodes 2, 3.

[0161] FIG. 7 shows another variation 50 in which only one of the electrodes 2 comprises a layer 12 that creates insulating regions. Despite the insulating regions only being on one electrode 2 the structure 50 can still be cut into panels 51 without risk of a short circuit between the electrodes 2, 3.

[0162] FIG. 8 shows another variation 60. In this case the insulating regions 9 are provided by an insulating coating deposited on the conductive layers 8 of the electrodes 2, 3. In this case there may be carbon coating 4, 5 deposited between the regions with the insulating coating.

[0163] FIGS. 9 and 10 illustrate an exemplary electrode 2 that is formed from a weave of conductive fibres 18 and non-conductive fibres 19. The fibres are woven such that on one surface of the electrode there are conductive regions 8 and non-conductive regions 9. The non-conductive regions 9 can provide a cutting zone through which a structure formed with such an electrode 2 can be cut without risk of forming a short circuit.

[0164] FIG. 11 illustrates a method of manufacturing an electroosmotic structure 70 that can be cut into panels 71 without risk of the conductive parts of the electrodes 2, 3 coming into contact.

[0165] The method comprises providing a plurality of rolls of material wherein there is one roll with material for forming the porous layer 1, and two rolls for forming each of the electrodes 2, 3. One roll for forming the electrodes provides a layer of conductive material 8 and one roll provides a non-conductive layer 12, or 13 with apertures therethrough. The material from the plurality of rolls are laminated together by passing them through laminating rollers 22 to form an electroosmotic layered structure 70. The structure 70 can then be cut into panels 71 using a cutter 24 such as a laser cutter. The presence of the insulating regions on the surface of the electrodes 2, 3 means that the structure 70 can be cut into panels 71 without risk of a short circuit between the electrodes 2, 3.

[0166] The roll with material for forming the porous layer 1 may be wider than one or both of the rolls with material for the layer of conductive material 8. This is so at least at the side edges of the formed layered structure the conductive part of the first and/or second electrode is spaced from the edge of the porous layer 1. This is to minimise the risk of a short circuit at the side edges which will not be cut edges.

[0167] FIGS. 12 and 13 show an electoosmotic structure 80 in which the conductive regions 8 are electrically connected together by electrical connections 26. This arrangement has on the surface of the electrode(s) 2, 3 that face the porous membrane 1 a region 9 that is insulating through which the material can be cut. The region 9 that is insulating on the surface that faces the porous membrane 1 surrounds the conductive regions 8. This means that a panel 81 can be cut out in which all of the cutting is at a location in which the surface of the electrode that faces the porous membrane 1 is electrically insulating. Thus the panel 81 can have electrodes with multiple conductive regions 9 that face the porous layer 1 that are electrically connected together. This gives the possibility of the electroosmotic structure 80 being cut into panels 81 of various sizes and shapes.

[0168] Whilst the figures show a gap between the porous layer 1 and the surfaces of the electrodes 2, 3 (or any coating thereon), this gap is present for clarity purposes. In practice the electrodes 2, 3 will be in contact with or at least very close to the surfaces of the porous layer 1.