US Patent 7675672 Non-volatile addressable electronic paper for disposable flexible displays

In accordance with the invention, there are systems for electronic paper, apparatus for electrophoretic display, and methods of making an electrophoretic display. The system for electronic paper can comprise an electret substrate wherein the electret substrate comprises an inhomogeneous distribution of charges and a plurality of capsules disposed in the electret substrate, wherein each of the plurality of capsules comprises a first plurality of charged pigments having a first color and a first charge, wherein the first charge has a polarity opposite to that of the charges in the electret substrate, a fluid having a second color contrasting to the first color, and a housing configured to house the plurality of charged pigments and the fluid.