Hydrophobic surface with a plurality of electrodes

• US 20050142037A1
• Filed: 12/17/2002
• Published: 06/30/2005
• Est. Priority Date: 12/17/2001
• Status: Abandoned Application

• Current Assignee: Qiagen GmbH (Qiagen NV)
• Original Assignee: Qiagen GmbH (Qiagen NV)
• Inventors: Reihs, Karsten
• Application Number:
  US10/499,607
• Publication Number:
  US 20050142037A1
• Time in Patent Office: Days
• US Class Current: 422/100
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2300/166 Suprahydrophobic; Ultraphobic; Lotus-effect
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 3/0241 Drop counters; Drop formers making arrays for combinatorial libraries B01J19/0046; automation of dispensing for analysis G01N35/10
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: H02N 11/006 Motors

Abstract

The invention relates to a device for manipulating minuscule fluid drops with an open-top ultraphobic surface. Said device comprises a grid with essentially evenly spread electrodes in the area of the hydrophobic surface. An electric field can be generated by means of said electrodes. At least one electrode can be controlled by an automated control device for a specific period of time with a given voltage in such a way that each fluid drop follows a very specific path at a very specific speed on the ultraphobic surface.

Claims

1. An apparatus for manipulating minuscule fluid drops with an open-top ultraphobic surface which apparatus is characterised in that, in the area of the ultraphobic surface, it comprises a grid with substantially uniformly distributed electrodes with which an electric field may in each case be generated, and in that at least one electrode may in each case simultaneously be actuated individually for a specific period with an electrical voltage by an automated control unit in such a manner that the fluid drops in each case proceed over the ultraphobic surface along a very specific track at a very specific speed.

2. An apparatus according to claim 1, characterised in that two or more electrodes may simultaneously be actuated.

3. An apparatus according claim 1, characterised in that the period is of such a length that a drop is kept in the zone of the actuated electrode(s) for this period.

4. An apparatus according to claim 1, characterised in that at least 2, preferably at least 4, electrodes are simultaneously actuated.

5. An apparatus according to claim 1, characterised in that the electrodes are arranged at a spacing of ≦

100 μ

m and in that the largest dimension thereof is preferably ≦

150 μ

m.

6. An apparatus according to claim 1, characterised in that the ultraphobic surface has a surface topography in which the spatial frequency f of the individual Fourier components and their amplitudes a(f) expressed by the integral S(log (f))=a(f)·

f, calculated between the integration limits log (f₁/μ

m<sup>−

1</sup>)=−

3 and log (f₁/μ

m<sup>−

1</sup>)=3, is at least 0.3, and which consists of ultraphobic polymers or durably ultraphobic materials.

7. An apparatus according to claim 1, characterised in that the ultraphobic surface is a preferably self-adhesive film.

8. An apparatus according to claim 1, characterised in that it comprises a fluid reservoir.

9. An apparatus according to claim 1, characterised in that it comprises a removable lid.

10. A method for setting down fluid drops with an apparatus for manipulating minuscule fluid drops with an open-top ultraphobic surface which apparatus is characterised in that, in the area of the ultraphobic surface, it comprises a grid with substantially uniformly distributed electrodes with which an electric field may in each case be generated, and in that at least one electrode may in each case simultaneously be actuated individually for a specific period with an electrical voltage by an automated control unit in such a manner that the fluid drops in each case proceed over the ultraphobic surface along a very specific track at a very specific speed, characterised in that:

an electric field is generated with at least one electrode,

in each case a fluid drop is deposited on the ultraphobic surface and

the fluid drop is immobilised by the electric field.

11. A method according to claim 10, characterised in that the drop is dispensed by a metering pump onto the ultraphobic surface and is attracted by the electric field.

12. A method according to claim claim 10, characterised in that two or more fluid drops are set down each at different points on the ultraphobic surface.

13. A method according to claim 10, characterised in that the fluid drops are mixed, combined, and/or divided.

14. A method for displacing fluid drops with an apparatus for manipulating minuscule fluid drops with an open-top ultraphobic surface which apparatus is characterised in that, in the area of the ultraphobic surface, it comprises a grid with substantially uniformly distributed electrodes with which an electric field may in each case be generated, and in that at least one electrode may in each case simultaneously be actuated individually for a specific period with an electrical voltage by an automated control unit in such a manner that the fluid drops in each case proceed over the ultraphobic surface along a very specific track at a very specific speed characterised in that:

a track and a speed of a fluid drop (2) on the ultraphobic surface (3) is programmed with the automated control unit,

an electric field is generated with at least one electrode,

the fluid drop is set down on the ultraphobic surface (3) and the electrodes along the predetermined track are actuated in such a manner that the fluid drop is displaced at the predetermined speed and is preferably held at its desired final position.

15. A method for locating fluid drops with an apparatus for manipulating minuscule fluid drops with an open-top ultraphobic surface which apparatus is characterised in that, in the area of the ultraphobic surface, it comprises a grid with substantially uniformly distributed electrodes with which an electric field may in each case be generated, and in that at least one electrode may in each case simultaneously be actuated individually for a specific period with an electrical voltage by an automated control unit in such a manner that the fluid drops in each case proceed over the ultraphobic surface along a very specific track at a very specific speed, characterised in that the electrical voltage between in each case two of the electrodes in the vicinity of a fluid drop is modified, preferably periodically, and the change in current and, preferably, the phase shift between the periodic voltage change and current change is measured.

16. A method for locating fluid drops on a surface, characterised in that light is emitted with at least one light source and the position of the fluid drop is determined on the basis of the reflected portions.

17. A method for locating fluid drops on a surface, with an apparatus characterized in that the electrical voltage between in each case two of the electrodes in the vicinity of a fluid drop is modified, preferably periodically, and the change in current and, preferably, the phase shift between the periodic voltage change and current change is measured characterized in that light is emitted with at least one light source and the position of the fluid drop is determined on the basis of the reflected portions.

18. A method according to claim 17, characterised in that the fluid drops are additionally located by an optical microscope.

19. A method for determining the size of a fluid drop with an apparatus for manipulating minuscule fluid drops with an open-top ultraphobic surface which apparatus is characterised in that, in the area of the ultraphobic surface, it comprises a grid with substantially uniformly distributed electrodes with which an electric field may in each case be generated, and in that at least one electrode may in each case simultaneously be actuated individually for a specific period with an electrical voltage by an automated control unit in such a manner that the fluid drops in each case proceed over the ultraphobic surface along a very specific track at a very specific speed, characterised in that the electrical voltage between in each case two electrodes in the vicinity of the fluid drop is modified, preferably periodically, and the variable change in current and, preferably, the phase shift between the periodic current change and the voltage change is measured, this being a measure of the size of the drop.

20. A method for determining the size of a fluid drop with a light source characterised in that light is emitted with at least one light source and the size of the fluid drop is determined on the basis of the reflected portions, it being necessary to know the precise position of the light source.

21. A method for determining the size of a fluid drop on a surface with an apparatus characterized in that the electrical voltage between in each case two electrodes in the vicinity of the fluid drop is modified, preferably periodically, and the variable change is current and, preferably, the phase shift between the periodic current change and the voltage change is measured, this being a measure of the size of the drop, characterized in that light is emitted with at least one light source and the size of the fluid drop is determined on the basis of the reflected portions, it being necessary to know the precise position of the light source.

22. A method according to claim 21, characterised in that the fluid drops are additionally measured by an optical microscope.