Patent ID: 7023600

Claim:
A bistable electro-optical device comprising: a first transparent substrate, having an interior and exterior surface; a second transparent substrate, having an interior and exterior surface; a transparent electrically conductive layer on the interior surface of each of the first and second flexible substrates; a cholesteric liquid crystal material comprising a nematic liquid crystal material, a chiral material and an ionic additive, wherein the cholesteric liquid crystal material comprises a polymeric matrix having cholesteric liquid crystals stabilized and supported therein and is positioned between the electrically conductive layers of the first and second transparent flexible substrates; wherein the first and second transparent substrates are spaced apart a predetermined distance; and wherein the cholesteric liquid crystal material is switched from a transparent state to a light scattering state and from a light scattering state to a transparent state upon application of an electric field to the cholesteric liquid crystal material, and wherein an electric field is not required to maintain either the transparent state or the light scattering state.