A Triple-Layered Microcavity Structure for Electrophoretic Image Display

An electrophoretic display (EPD) cell with a triple-layered microcavity structure was fabricated using a convenient dry film resist. The inherent structural advantage arising from the function of the middle channel layer as a background colored state enabled the EPD to operate with two different-colored states by using a single type of electronic-ink particles, thereby eliminating the possible agglomeration of oppositely charged ink particles and supporting the potential application of the proposed structure to color the electronic paper. The preliminary operation of this new EPD structure was demonstrated as white and blue display states on a rigid glass exhibiting a contrast ratio of 1.5 : 1 with saturation voltages of + 30 and -30 V, respectively. Successful demonstrations on both the indium-tin-oxide-patterned glass and flexible polyethylene substrates are also provided.