Hermetic electrowetting device
The invention concerns an electrowetting device comprising first and second immiscible fluids, the liquids being sealed within a structure comprising a cap portion, a base portion, a gasket formed of a first material positioned between a first contact surface on said cap portion and a second contact surface on said base portion, and a first film formed of a second material between said gasket and one of said first contact surface and said second contact surface.
1. An electrowetting device, comprising: first and second immiscible fluids defining an interface moveable by electrowetting, the liquids being sealed within a structure comprising:
a cap portion;
a base portion;
a gasket formed of a first material positioned between a first contact surface on said cap portion and a second contact surface on said base portion; and
a first film formed of a second material between said gasket and one of said first contact surface and said second contact surface.
2. The electrowetting device of claim 1 , wherein said first material is comprised of a first polymer material and said second material is comprised of a second polymer material.
3. The electrowetting device of claim 1 , wherein said first material is harder than said second material.
4. The electrowetting device of claim 1 , wherein said first film is formed between said gasket and said first contact surface, and further comprising a second film formed of said second material between said gasket and said second contact surface.
5. The electrowetting device of claim 4 , wherein said first film is made of a polymer coating applied to at least one of a first side of said gasket and said first contact surface, and said second film is made of a polymer coating applied to at least one of a second side of said gasket and said second contact surface.
6. The electrowetting device of claim 4 , wherein said first and second films have a Shore hardness (A) in the range of 20 to 40.
7. The electrowetting device of claim 1 , wherein said gasket has a Shore hardness (D) in the range of 40 to 70.
8. The electrowetting device of claim 1 , wherein said second material comprises a fluorinated elastomer.
9. The electrowetting device of claim 1 , wherein said first film comprises a polymer having a perfluoropolyether backbone with a terminal silicone cross-linking group.
10. The electrowetting device of claim 1 , wherein said first material is comprised of a non-elastomer.
11. The electrowetting device of claim 1 , wherein said gasket is formed of PTFE.
12. The electrowetting device of claim 1 , wherein said cap portion is crimped such that it is fixed to said base portion.
13. The electrowetting device of claim 1 , wherein said gasket is annular in shape and essentially “L”-shaped in cross-section.
14. A method of manufacturing an electrowetting device that contains first and second immiscible fluids, the method comprising:
providing a cap portion having a first contact surface, a base portion having a second contact surface and a gasket formed of a first material having a first side for contact with said first contact surface and a second side for contact with said second surface;
forming at least a first film of a second material on at least one of said first contact surface, said first side of said gasket, said second contact surface, and said second side of said gasket;
positioning said gasket between said cap portion and said base portion and positioning said first and second fluids between said base and cap portions; and
applying an amount of pressure such that said gasket and said first film are compressed sufficiently to create a seal between said cap portion and said base portion for sealing said first and second fluids within.
15. The method of claim 14 , wherein said first material is harder than said second material.
16. The method of claim 14 , wherein said at least first film is formed by applying a polymer diluted with a solvent.
17. The method of claim 14 , wherein said step of applying pressure comprises crimping said cap portion such that it is fixed to said base portion.
18. The method of claim 14 , wherein said step of forming said at least first film comprises forming said first film on at least one of said first contact surface and said first side of said gasket, and further comprising the step of forming a second film comprising forming said second film on at least one of said second contact surface and said second side of said gasket.
19. A variable focus lens, comprising: first and second immiscible fluids having different refractive indices, defining a light-focusing interface moveable by electrowetting, the liquids being sealed within a structure comprising:
a cap portion;
a base portion;
a gasket formed of a first material positioned between a first contact surface on said cap portion and a second contact surface on said base portion;
a first film formed of a second material between said gasket and one of said first contact surface and said second contact surface.
20. An optical diaphragm, comprising: first and second immiscible fluids, defining an interface moveable by electrowetting, the liquids being sealed within a structure comprising:
a cap portion;
a base portion;
a gasket formed of a first material positioned between a first contact surface on said cap portion and a second contact surface on said base portion; and
a first film formed of a second material between said gasket and one of said first contact surface and said second contact surface.
21. A camera module comprising the variable focus lens of claim 19 .
22. A mobile phone comprising the camera module of claim 21 .