Most flexible electronic paper yet revealed
14:02 26 January 04
NewScientist.com news service
The most flexible electronic display yet developed has been revealed by researchers at electronics giant Philips. The company says it plans to begin mass producing such displays within a few years.
There are many projects aiming to develop "electronic paper". Such a display could, for example, be used create a fully updatable newspaper which could rolled up into a coat pocket. Flexible displays could also be used to create new mobile phones and other easily collapsible gadgets.
Philips's new display was made possible by the development of a way to print organic electronics onto a thin plastic film - previously, it was only possible to print these components on glass. However, after experimenting with various different plastics, Philips now has a technique that works on polyimide film.
Precise details of the fabrication method have not been revealed due to their commercially sensitive nature, says the company. But the process has enabled the company to produce a screen that can be rolled into a tube just two centimetres in diameter - the most flexible electronic display ever made. The use of organic electronics should also make the device cheap.
The square display measures 12 centimetres diagonally and consists of 80,000 pixels. It produces a greyscale image and can refresh in about a second - far too slow to display moving images.
Size and resolution
A new company called Polymer Vision has been set up to bring the displays to market. Its general manager, Bas Van Rens, says the flexible displays are far more advanced than other bendy screens in terms of size, resolution and the complexity of the organic electronics used.
"We're able to do this because we've scaled up to production levels," he told New Scientist.
Joe Jacobson, a researcher at Massachusetts Institute of Technology says electronic paper must be thin, flexible, low power and low cost to become a commercial reality. He says the new research "represents an important milestone and another step closer towards 'real' electronic paper".
The Philips screen consists of an organic circuit printed on a polyimide layer 25 microns thick. In front of this is a 200 micron thick layer containing "electronic ink", developed by a company called E Ink.
This "ink" consists of thousands of capsules containing positively charged white particles and negatively charged black ones. Applying an electric field through the organic circuit to a particular area of the display attracts either the black or white particles, causing that part of the screen to turn either white or black.
Journal reference: Nature Materials (DOI:10.1038/nmat1061)
Will Knight
