Multi-phase liquid composition and optical electrowetting device that incorporates the same

Abstract

The present invention relates to a multi-phase liquid composition comprising a conductive fluid and a non-conductive fluid, the non-conductive fluid being immiscible in the conductive fluid, the composition having a mean arithmetic cinematic viscosity of between about 1.5 cSt and about 40 cSt, within a temperature range of about −20° C. to about +70° C. The invention also pertains to an optical electrowetting device comprising said multi-phase liquid composition, as well as an optical lens driven by electrowetting, and apparatus comprising the same.

Description

The present invention is now described in further details by way of non-limiting examples and by reference to the attached drawings.

FIG. 1 is a simplified cross-section view of a variable-focus liquid lens according to the invention.

FIG. 2 is an illustration of the turbidity and transparency recovery of the non-conductive fluid, depending on the nature of the conductive fluid.

Claims

1. A multi-phase liquid composition comprising a conductive fluid and a non-conductive fluid, the non-conductive fluid being immiscible in the conductive fluid, the composition having a mean arithmetic cinematic viscosity of between 1.5 cSt and 40 cSt, within a temperature range of −20° C. to +70° C.

2. The multi-phase liquid composition of claim 1, wherein the composition has a cinematic viscosity of between 1.5 cSt and 20 cSt, within the temperature range of −20° C. to +70° C.

3. The multi-phase liquid composition of claim 1, wherein the composition has a cinematic viscosity of between 3 cSt and 10 cSt, within the temperature range of −20° C. to +70° C.

4. The multi-phase liquid composition according to claim 1, wherein the difference of viscosity between the conductive fluid and the non-conductive fluid is comprised between 0 cSt and ±10 cSt, within a temperature range of −20° C. to +70° C.

5. The multi-phase liquid composition of claim 1, wherein the conductive fluid comprises water and at least one organic or inorganic ionic or ionizable salt.

6. The multi-phase liquid composition of any of claim 1, wherein the conductive fluid further comprises at least one freezing-point lowering agent.

7. The multi-phase liquid composition of claim 1, wherein the conductive fluid further comprises an alcohol, a glycol, a glycol ether, a polyol, a poly ether polyol and the like, or mixtures thereof, as viscosity-adjusting agent.

8. The multi-phase liquid composition of claim 1, wherein the non-conductive fluid comprises a Si-based compound, and/or a Ge-based compound, and/or a Si—Ge-based compound, a hydrocarbon or a mixture thereof.

9. The multi-phase liquid composition of claim 8, wherein the non-conductive fluid comprises a Si- and/or Ge-based compound substituted by one or more phenyl groups and/or other groups like fluorinated or non fluorinated alkyl (ethyl, n-propyl, n-butyl), linear or branched alkyls, chlorinated or brominated phenyl groups, benzyl groups, halogenated benzyl groups; or a mixture of Si- and/or Ge-based compounds wherein at least one compound is substituted by one or more phenyl groups and/or other groups like fluorinated or non fluorinated alkyl (ethyl, n-propyl, n-butyl), linear or branched alkyls, chlorinated or brominated phenyl groups, benzyl groups, halogenated benzyl groups.

10. The multi-phase liquid composition of claim 9, wherein the non conductive fluid comprises siloxane and/or aryl siloxane compound(s) and the ratio of the total number of aryl groups carried by the Si-based compound(s) to the total number of Si atoms is equal to or less than 1.33, preferably equal to or less than 1, and more preferably equal to or less than 0.8.

11. The multi-phase liquid composition of claim 9, wherein the non conductive fluid comprises mono germane compounds, preferably diphenyldimethylgermane or phenyltrimethylgermane.

12. The multi-phase liquid composition of claim 8, wherein the non-conductive fluid comprises a linear or branched alkane, an alkane comprising one or more rings, a fused ring system, a mixture of hydrocarbons, and mixtures thereof.

13. The multi-phase liquid composition of claim 1, wherein the non-conductive fluid comprises a wetting agent.

14. The multi-phase liquid composition of claim 13, wherein the non-conductive fluid comprises a monohalogenated aromatic compound, a α,ω-dihalogenated alkyl compound or a mixture thereof, as a wetting agent.

15. The multi-phase liquid composition of claim 13, wherein the non-conductive fluid comprises 1-bromo-4-ethylbenzene, α,ω-dichloro-octane or a mixture thereof as a wetting agent.

16. The multi-phase liquid composition of claim 1, wherein the non-conductive fluid further comprises at least one hydrolysis-resistant compound.

17. The multi-phase liquid composition of claim 16, comprising, as an hydrolysis-resistant compound, a compound of formula (I), a compound of formula (II) or a mixture thereof:

18. The multi-phase liquid composition of claim 17, wherein X, X1 and X2 are Cl or Br.

19. The multi-phase liquid composition of claim 17, wherein Ak is ethyl.

20. The multi-phase liquid composition of claim 17, wherein the non-conductive fluid comprises α,ω-dichloro-octane as an hydrolysis-resistant compound.

21. The multi-phase liquid composition of claim 17, wherein the non-conductive fluid comprises 1-bromo-4-ethylbenzene as an hydrolysis-resistant compound.

22. The multi-phase liquid composition of claim 1, wherein the non-conductive fluid and/or the conductive fluid further comprise(s) an anti-oxidant.

23. The multi-phase liquid composition of claim 1, wherein the non-conductive fluid and/or the conductive fluid further comprise(s) a biocide compound.

24. The multi-phase liquid composition of claim 1, wherein the non-conductive fluid and the conductive fluid have substantially the same density.

25. A use of a mono germane compound substituted by one or more aryl groups in the non-conductive fluid of an optical electrowetting device, especially an optical lens driven by electrowetting.

26. The use of claim 25, wherein the mono germane compound is diphenyldimethylgermane or phenyltrimethylgermane.

27. A use of a compound of formula (I), a compound of formula (II) or a mixture thereof, in the non-conductive fluid of an optical electrowetting device, especially an optical lens driven by electrowetting, as hydrolysis-resistant compound:

28. The use of claim 26, wherein the hydrolysis-resistant compound is 1-bromo-4-ethylbenzene or α,ω-dichloro-octane.

29. An optical electrowetting device comprising a multi-phase liquid composition of claim 1.

30. The optical electrowetting device of claim 29 which is a variable focus liquid lens, an optical diaphragm, an optical zoom.

31. An apparatus comprising an optical electrowetting device of claim 29 and a driver or electronic means for controlling said device.

32. The apparatus of claim 31, which is a camera, a cell phone, an endoscope or a telemeter, a dental video.