We’ve written and talked a lot - in Display Daily and elsewhere - about the new generation of ePaper display technologies that promise to add full color and/or faster switching speeds to the conventional ePaper display qualities of very low power consumption, sunlight readability, light weight, ruggedness, and paper-like matte surface.

Ken Werner
Senior Analyst and Editor

Although these display technologies were initially positioned as next-generation displays for eBook readers, they are now drawing interest as possible replacements for TFT-LCDs in portable applications. Johan Feenstra of LiquaVista has called this application space "LCD 2.0."

Two of the most intriguing of these technologies are LiquaVista’s electrowetting technology and Qualcomm MEMS Technologies’ (QMT’s) mirasol technology, which uses optical interference to create both color and gray scale. Both technologies are in an advanced state of development.

(Before continuing, I should say E Ink/PVI, SiPix/AUO, and other electrophoretic display developers are grappling with their technology’s inherent difficulties with color and switching speed, and we should see eBook readers with color and some degree of video in the market this year. And - although they don’t fit the ePaper category comfortably - Pixel Qi, Pixtronix, and Unipixel are also developing interesting display alternatives of their own.)

Back to LCD 2.0. A new company, Gamma Dynamics, is commercializing a next-generation ePaper technology that has been under development for several years by Jason Heikenfeld, Director of the Novel Devices Laboratory at the University of Cincinnati. This is a technology in which the sub-pixel states are established by whether a liquid does or does not cover most of the sub-pixel’s area. You might think this is another flavor of electro-wetting, but it isn’t.

Electro-wetting uses an electrical potential to change the surface tension of the liquid. Gamma Dynamics uses electro-fluidic devices that pump the liquid onto the surface of the sub-pixel. The fluid, Heikenfeld told Insight Media, is similar to the fluid used in ink-jet printing, and the colorants are print-like pigments. Sun Chemical has been working with Heikenfeld on materials development since 2006, and they "are making strong progress on pigments and environmental specifications."

The technology will be able to deliver 65% white-state reflectivity in a full-color display and 40% NTSC color gamut, Heikenfeld said. Those numbers would be extremely competitive. Indeed, Heikenfeld said that Gamma Dynamics’ management team feels that when displays do reach the market, their performance will be so good, "it will silence the competition."

Gamma Dynamics is farther away from a production eBook panel than are QMT and LiquaVista, but the technology is clearly interesting. "We have a lot of work to do," said Heikenfeld, "but no breakthroughs are needed."