Electrically Switched Liquid Crystal Color and Device Applications
We demonstrate a polymer-stabilized cholesteric liquid crystal (PSChLC) where the reflected color can be electrically-switched to reflect a different color at a shorter wavelength (blue-shift). A polymerizable additive formulation is used to ensure a wider range of color tuning and anisotropic reflection where on side reflects and the other side transmits the incident light in response to applied voltage. A second electrically switched color based on polymer-stabilized blue phase (PSBP) liquid crystal is also demonstrated. Applying an electric field across the cell results in a red-shift in Bragg reflected wavelength due to the electrostriction effect. These switchable color devices of are color filters and polarizers free which are suitable for electronic papers.
Yuan Ming Huang
S. Y. Lu and L. C. Chien, "Electrically Switched Liquid Crystal Color and Device Applications", Key Engineering Materials, Vols. 428-429, pp. 24-28, 2010