Researchers from the University of Cincinnati and startup Gamma Dynamics have developed a new Electrofluidic display. The display can retain images without power consumption (like e-paper), has a >70% white reflectance and is fast enough for video. The idea is to use a colored fluid between the front and the backside of a reflective sheet. The space above and beneath this special sheet is similar in geometrPixel Structurey enabling the fluid to remain stationary in any position without an applied voltage.
The concept has been realized years ago, but the manufacturing process was only developed recently - in a collaboration between the Univ. of Cincinnati, Gamma Dynamics, DuPont and Sun Chemical.
Electrofluidic displays are a variant of electrowetting displays - which do require power to hold an image. LiquaVista are working on Electrowetting displays - here's an interview we published with their CTO back in March 2010, describing their technology and upcoming products.