Doped electrically actuatable (electrically addressable or switchable)
polymer flakes have enhanced and controllable electric field induced
motion by virtue of doping a polymer material that functions as the base
flake matrix with either a distribution of insoluble dopant particles or
a dopant material that is completely soluble in the base flake matrix.
The base flake matrix may be a polymer liquid crystal material, and the
dopants generally have higher dielectric permittivity and/or conductivity
than the electrically actuatable polymer base flake matrix. The dopant
distribution within the base flake matrix may be either homogeneous or
non-homogeneous. In the latter case, the non-homogeneous distribution of
dopant provides a dielectric permittivity and/or conductivity gradient
within the body of the flakes. The dopant can also be a carbon-containing
material (either soluble or insoluble in the base flake matrix) that
absorbs light so as to reduce the unpolarized scattered light component
reflected from the flakes, thereby enhancing the effective intensity of
circularly polarized light reflected from the flakes when the flakes are
oriented into a light reflecting state. Electro-optic devices contain
these doped flakes suspended in a host fluid can be addressed with an
applied electric field, thus controlling the orientation of the flakes
between a bright reflecting state and a non-reflecting dark state.