Elastomeric optical device and related methods

Patent metadata

Field	Value
Publication number	US-10775649-B2
Application number	US-201815982677-A
Country	US
Kind code	B2
Filing date	May 17, 2018
Priority date	May 17, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

The invention provides an elastomeric optical device having a first optical state and a second optical state. The device is transparent when in the first optical state and is translucent or opaque when in the second optical state. The device comprises, in sequence, an optional substrate, a first transparent electrode, an optional dielectric layer, an elastomer layer, and a second transparent electrode. In some embodiments, the second transparent electrode comprises an electrically-conductive polymer, transparent electrically-conductive nanoparticles, or both. In such embodiments, the second transparent electrode is configured to compress the elastomer layer in response to an electric field between the first and second transparent electrodes, such that when the elastomeric optical device is in the second optical state the elastomer layer is compressed between the first and second transparent electrodes. One or both of the elastomer layer and the second transparent electrode has one or more non-uniformity features.

First claim

What is claimed is:

1. An elastomeric optical device, the elastomeric optical device having a first optical state and a second optical state, the elastomeric optical device being transparent when in the first optical state and being translucent or opaque when in the second optical state, the elastomeric optical device comprising, in sequence, a first transparent electrode, an elastomer layer, and a second transparent electrode, the second transparent electrode comprising an electrically-conductive polymer, electrically-conductive nanoparticles comprising a metal oxide, or both, the second transparent electrode configured to compress the elastomer layer in response to an electric field between the first and second transparent electrodes, such that when the elastomeric optical device is in the second optical state the elastomer layer is compressed between the first and second transparent electrodes, wherein at least certain portions of the second transparent electrode are closer to the first transparent electrode when the elastomeric optical device is in the second optical state than they are when the elastomeric optical device is in the first optical state, the elastomeric optical device having a surface topography that is characterized by greater roughness when the elastomeric optical device is in its second optical state than when it is in its first optical state.

2. The elastomeric optical device of claim 1 wherein the surface topography of the elastomeric optical device when in its second optical state is characterized by wrinkles, the wrinkles including both dimples and bulges.

3. The elastomeric optical device of claim 1 wherein the second transparent electrode is characterized by a Young's modulus of less than 5 GPa, a yield strength of greater than 0.5 MPa, a loss coefficient of less than 0.3, and a fatigue ratio of greater than 0.1.

4. The elastomeric optical device of claim 3 wherein the second transparent electrode has an electrical conductivity in a range of 10-1000 ohms/square, an emissivity of less than 0.5, and a visible absorption of less than 6%.

5. The elastomeric optical device of claim 1 wherein the second transparent electrode is characterized by a Young's modulus of less than 1.2 GPa, a yield strength of greater than 2 MPa, a loss coefficient of less than 0.06, and a fatigue ratio of greater than 0.5.

6. The elastomeric optical device of claim 5 wherein the second transparent electrode has an electrical conductivity in a range of 10-60 ohms/square, an emissivity of less than 0.3, and a visible absorption of less than 2%.

7. The elastomeric optical device of claim 1 wherein the second transparent electrode comprises the electrically-conductive polymer, and the electrically-conductive polymer includes a mixture of two ionomers.

8. The elastomeric optical device of claim 1 wherein the second transparent electrode comprises the electrically-conductive polymer, and the electrically-conductive polymer comprises poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate).

9. The elastomeric optical device of claim 1 wherein the second transparent electrode comprises the electrically-conductive nanoparticles in a matrix of the electrically-conductive polymer.

10. The elastomeric optical device of claim 9 wherein the second transparent electrode has a loading of the electrically-conductive nanoparticles in the matrix of the electrically-conductive polymer in a range of from 50% to 90%.

11. The elastomeric optical device of claim 9 wherein the electrically-conductive nanoparticles comprise indium tin oxide.

12. The elastomeric optical device of claim 1 wherein the elastomer layer has a thickness in a range of 5-75 microns.

13. The elastomeric optical device of claim 1 wherein the elastomer layer comprises a material selected from the group consisting of EVA, urethane, acrylic, PVB, and silicone.

14. The elastomeric optical device of claim 1 wherein the second transparent electrode comprises both the electrically-conductive polymer and the electrically-conductive nanoparticles, the electrically-conductive polymer provided as an electrically-conductive polymer layer over the electrically-conductive nanoparticles.

15. The elastomeric optical device of claim 1 wherein the second transparent electrode comprises the electrically-conductive nanoparticles, the electrically-conductive nanoparticles being in contact with the elastomer layer.

16. The elastomeric optical device of claim 1 wherein, when the elastomeric optical device is in the first optical state, the second transparent electrode has one or more non-uniformity features.

17. The elastomeric optical device of claim 16 wherein the one or more non-uniformity features comprise a plurality of nanoparticle regions each having some of the electrically-conductive nanoparticles, such that at regions of the second transparent electrode outside the nanoparticle regions either there are none of the electrically-conductive nanoparticles or there is a lesser concentration of the electrically-conductive nanoparticles than at the nanoparticle regions.

18. The elastomeric optical device of claim 17 wherein the nanoparticle regions have an average major dimension of greater than one micron and less than 100 microns.

19. The elastomeric optical device of claim 18 wherein the average major dimension of the nanoparticle regions is greater than one micron and less than 50 microns.

20. The elastomeric optical device of claim 17 wherein the nanoparticle regions are arranged in a pattern.

21. The elastomeric optical device of claim 16 wherein the one or more non-uniformity features of the second transparent electrode comprise non-uniform surface roughness.

22. The elastomeric optical device of claim 21 wherein the non-uniform surface roughness is arranged in a pattern.

23. The elastomeric optical device of claim 1 wherein the elastomer layer has one or more non-uniformity features.

24. The elastomeric optical device of claim 23 wherein the one or more non-uniformity features comprise non-uniform thickness of the elastomer layer.

25. The elastomeric optical device of claim 24 wherein the non-uniform thickness of the elastomer layer is arranged in a pattern.

26. The elastomeric optical device of claim 24 wherein the non-uniform thickness of the elastomer layer is characterized by a minimum peak-to-valley distance in a range of 25 nm to 50 nm.

27. The elastomeric optical device of claim 1 further comprising a glass substrate that carries the first transparent electrode, the elastomer layer, and the second transparent electrode.

28. The elastomeric optical device of claim 1 wherein the second transparent electrode comprises the electrically-conductive nanoparticles, and the electrically-conductive nanoparticles of the second transparent electrode consist essentially of the metal oxide.

29. The elastomeric optical device of claim 1 wherein the second transparent electrode comprises the electrically-conductive nanoparticles, and the electrically-conductive nanoparticles each have an average major dimension of less than 150 nm.

30. The elastomeric optical device of claim 1 wherein the elastomeric optical device is part of a privacy glazing smart window, such that the elastomeric optical device when in the second optical state has a frosted or white opaque appearance.

Assignees

• Cardinal Cg Co

Inventors

• Switzer Iii James Clark
• Burrows Keith James

Classifications

• G02F1/0131 Primary

  based on photo-elastic effects, e.g. mechanically induced birefringence · CPC title

• G02F2202/022

  polymeric · CPC title

• G02F2201/12

  electrode · CPC title

• G02B26/02

  for controlling the intensity of light {(G02B26/004 takes precedence)} · CPC title

• G02B5/0294

  adapted to provide an additional optical effect, e.g. anti-reflection or filter · CPC title