Display element
View Patent ↗A display element comprising at least two conductive porous layers and a conductive liquid, the conductive porous layers comprising a plurality of connected conductive particles insulated from the conductive liquid by a dielectric and lyophobic covering, and means for separately connecting a voltage across the at least two porous layers and the liquid such that on sequential application of a voltage to each conductive layer the liquid is displaced from one location to another location, the liquid only returning to the original location upon alternate sequential application of a voltage.
1. A display element comprising at least two conductive porous layers and a conductive liquid, the conductive porous layers comprising a plurality of connected conductive particles insulated from the conductive liquid by a dielectric and lyophobic covering, and means for separately connecting a voltage across the at least two porous layers and the liquid such that on sequential application of a voltage to each conductive layer the liquid is displaced from one location to another location, the liquid only returning to the original location upon alternate sequential application of a voltage.
2. A display element as claimed in claim 1 wherein at least one further layer is provided adjacent to the at least two conductive porous layers, the liquid having a contact angle with the material of the further layer of less than 60°, the thickness of the further layer being greater than the thickness of each conductive porous layer but less than the combined thickness of the two conductive porous layers.
3. A display element as claimed in claim 1 wherein the at least one further layer comprises a plurality of particles.
4. A display element as claimed in claim 1 wherein the conductive particles are metallic.
5. A display element as claimed in claim 4 wherein the conductive particles are organic or inorganic particles covered with a conductive shell.
6. A display element as claimed in claim 5 wherein the thickness of the conductive shell is chosen to create a coloured particle.
7. A display element as claimed in claim 1 wherein the dielectric covering is a polymer, a polyelectrolyte, a fluoropolymer, a self assembled monolayer (SAM) or an inorganic shell.
8. A display element as claimed in claim 7 wherein the self assembled monolayer comprises a molecule with a group that bonds to the conductive particles and a group that provides a high contact angle with the liquid.
9. A display element as claimed in claim 2 wherein an intermediate layer of coloured material is provided between the further layer and one of the conductive porous layers.
10. A display element as claimed in claim 9 wherein the material of the intermediate layer comprises a plurality of particles providing an average pore size substantially the same as that of the upper layer, the liquid having a contact angle with the plurality of particles of less than 60°.
11. A display element as claimed in claim 1 wherein each layer has a pore size greater than 30 nm and less than 2 μm.
12. A display element as claimed in claim 2 wherein the conductive liquid and the material of the further layer have substantially the same refractive index.
13. A display element as claimed in claim 1 wherein the conductive liquid is created by adding ions to a solvent.
14. A display element as claimed in claim 1 wherein the conductive liquid is an ionic liquid.
15. A display element as claimed in claim 1 wherein the conductive liquid contains a dye or pigment to provide a coloured liquid.
16. A display element as claimed in claim 2 wherein the further layer comprises a photonic crystal structure.
17. A device comprising at least one display element as claimed in claim 1 including means for connection of each element to a circuit to create a matrix display.
18. A device comprising at least one element as claimed in claim 1 , the materials of each layer being coated onto a support material.
19. A device as claimed in claim 18 wherein each element is environmentally sealed.