E-paper moves a step nearer

The new display is printed onto plastic...

By BBC News Online's Ivan Noble

Electronic paper has taken a step closer with the development of a prototype flexible electronic display.

It has only a few hundred pixels, but, say its inventors, it shows that high quality displays could be built cheaply.

All of the pieces are there

John Rogers, Bell Labs

The aim of E-paper is to show electronic text on thin, flexible sheets that look and feel like paper.

It would be put together in the form of a book or newspaper, with electronic pages downloaded using wireless technology.

"There is no fundamental technology hurdle. All of the pieces are there," John Rogers of Bell Labs told BBC News Online.

His team, from Bell Labs and E Ink Corporation in the United States, have pictures of their display showing simple words and images while being flexed by hand.

Battery life

It runs for several months on a small battery pack, they report in the journal Proceedings of the National Academy of Sciences.

...and can display simple images.

The key step forward with this new prototype is that it uses a very simple manufacturing technique called microcontact printing.

This process, similar to rubber stamping, means that the makers of the display will not need the expensive clean rooms used to build today's electronic components.

"Electronic inks are not new, but this is the first time that they've been integrated with rubber-stamped plastic drive circuitry," explained John Rogers.

Flexible plastic

The display components are stamped on to a thin, flexible sheet of plastic less than a millimetre thick. And the inventors are confident that their technology will scale down to the sizes needed to make useful electronic paper.

"Moving it out of the research lab will require some development, but we think it'll scale in a very straightforward way.

"The actual transistors are around 50 microns across, so we could have pixels of a couple of hundred microns, pretty close to the size of those on a laptop display," John Rogers explained.

It is not possible to write on the prototype display, but there is no reason why a production display could not be written upon.

The pixels on the prototype are switched electrically, but a charged stylus would do the same job, he added.