Ultrathin, flexible electronic displays that look like print on paper are of great interest for potential applications in wearable computer screens, electronic paper, smart identity cards, store shelf labels and other signage applications. Electrophoretic or electrokinetic displays are an important approach to this type of medium. Electrophoretic/kinetic actuation relies on particles moving under the influence of an electric field, so the desired particles must exhibit good dispersibility and charge properties in non-polar dispersing media. Non-polar dispersing media are desirable because they help minimize the leakage currents in electrophoretic/kinetic devices.
Current commercial products based on electrophoretic display technology are only able to provide color and white states or black and white states. They cannot provide a clear, or transparent, state, which prevents use of a stacking architecture design. Such a stacking architecture of layered colorants would allow the use of transparent to colored state transitions in each layer of primary subtractive color to show print-like color in one display.