GADGET-makers have long promised us a flexible electronic book, but actually producing a robust, bendy screen has proved tough – until now. Plastic Logic, a display technology company based in Cambridge, UK, says it will launch the first flexible electronic book in January.
The two most popular e-books on the market, the Sony Reader and Amazon Kindle, are paperback book-sized devices that use first-generation black and white electronic “ink” displays. These consist of a plastic sheet containing pixel-sized voids, each filled with black and white ink particles. Electric fields attract the ink to the top of these voids to display print. The problem is, the transistors that apply these electric fields sit on a layer of glass, making the displays fragile.
Plastic Logic says it has now perfected a way of printing polymer transistors onto a layer of bendy plastic – allowing the screens to flex and bounce. “Screen breakage is the number one complaint with today’s e-reader technology. Our display can take a lot of rough and tumble,” says Joe Eschbach of Plastic Logic.
To produce the transistors, the company prints a droplet of conducting polymer and a surfactant onto the plastic substrate. The surfactant makes the droplet water-repellent, so when a second droplet of polymer – without surfactant – is dropped on top of the first, it slides off and lands next to it, ending up precisely 60 nanometres away because of the size of the droplets. This close proximity is important for producing transistors with fast display switching speeds.
The company says it is now ramping up to commercial production of the screens, which will be just under A4 in size. “It’ll be a much better e-reading experience at this magazine size – keeping layouts and graphics intact without converting them to small and unattractive formats,” Eschbach claims.
The device will have wireless internet connection and a touch screen, allowing use of a virtual keyboard for annotating text. In contrast, the latest Sony Reader has a touch screen but no wireless connection, while the latest Kindle, which was launched this week in the US, connects to a book download store via 3G but wastes screen space with a manual keyboard.