Method of authenticating an electro-optic device and any of its components

A method of authenticating an electro-optic device and any of its components comprising the steps of:

• providing an electro-optic device comprising, in order, an electrically-conductive light-transmissive layer, an electro-optic material layer, a first adhesive layer, and a backplane substrate comprising a plurality of pixel electrodes configured to apply an electrical potential between the electrically-conductive light-transmissive layer and the pixel electrodes, wherein the electro-optic device comprises an activation region having an identification marker that emits radiation of a characteristic wavelength profile upon activation, and wherein the activation region is located within or adjacent to one of the layers of the electro-optic device, wherein the electro-optic material layer comprises an electrophoretic medium, which comprises a plurality of a first species of particles dispersed in a hydrophobic oil, wherein the first species of particles is charged, wherein the electrophoretic medium further comprises a plurality of a second species of particles, wherein the second species of particles is the identification marker, having a content of from about 0.01 weight % to about 2 weight % by weight of the total particle content of the electrophoretic material, and wherein the second species of particles can be distinguished from the first species of particles and any other particles present in the electrophoretic medium via visual inspection, microscopic inspection, or spectrometric determination of the electro-optic device;
• activating the identification marker by a stimulus;
• detecting the emitted electromagnetic radiation caused by the identification marker;
• and
• determining the authenticity of the electro-optic device or any of its components or determining the manufacturing lot of the electro-optic device or any of its components.