Electrowetting pumping device and use for measuring electrical activity
The invention relates to a method for pumping through an orifice ( 30, 31 ) of a first substrate ( 1 ), a first volume of liquid ( 2 ) in contact with a first hydrophobic surface of said substrate, wherein a pressure variation between the first volume of liquid and a second volume of liquid ( 2 ′), located in contact with said orifice and a second hydrophobic surface of said substrate, is achieved by electrowetting.
1. An apparatus comprising:
a substrate, having a first and a second surface, at least one of which is hydrophobic or covered with a hydrophobic layer, and at least one orifice crossing through said substrates;
means for displacing, by electrowetting, a volume of liquid on one of said faces of the substrate through said orifice; and
first and second electrodes configured to be in direct contact with the volume of liquid as the volume of liquid is displaced through said orifice, to be controlled by a computer, and to supply said computer with data regarding a variation of an electric characteristic of the volume of liquid as the volume of liquid is displaced through said orifice.
2. The apparatus according to claim 1 , wherein the second surface of the substrate is hydrophobic or includes the hydrophobic layer, and the apparatus includes a plurality of electrodes, other than the first and second electrodes, disposed under said hydrophobic layer or surface.
3. The apparatus according to claim 1 , wherein the first and second surfaces of the substrate are parallel to each other.
4. The apparatus according to claim 1 , wherein the first surface of the substrate is parallel to a plane defined by the substrate, and the second surface is defined by at least one portion of a wall of said orifice.
5. The apparatus according to claim 1 , wherein the electric characteristic is resistance or resistivity.
6. The apparatus of claim 1 , further comprising the computer.
7. The apparatus of claim 1 , wherein at least one of the first and the second electrodes is disposed at an edge of the orifice.
8. The apparatus of claim 1 , wherein the first and the second electrodes are outside of the substrate and on the first and second surfaces of the substrate.
9. The apparatus according to claim 1 , wherein said orifice includes a first portion, with a first maximum dimension, and a second portion, having a second maximum dimension, larger than the first.
10. The apparatus according to claim 1 or 9 , wherein the means for displacing includes a plurality of electrodes disposed under said hydrophobic layer or surface.
11. The apparatus according to claim 1 , further comprising a first dielectric layer, in part under the hydrophobic layer or surface.
12. The apparatus according to claim 11 , further comprising a second dielectric layer, disposed on a surface parallel to the first surface.
13. The apparatus according to claim 1 , further comprising at least one reservoir of liquid and means for bringing drops of liquid from the at least one reservoir towards the at least one orifice.
14. The apparatus according to claim 13 , wherein the means for bringing the drops of liquid towards the at least one orifice includes another plurality of electrodes, other than the first and second electrodes.
15. The apparatus according to claim 1 , further including a second substrate disposed to face at the first or the second surfaces.
16. The apparatus according to claim 15 , wherein the second substrate includes a hydrophobic surface layer.
17. The apparatus according to claim 15 or 16 , wherein the second substrate includes an electrode.