Under Development

Paperless Paper

e-paper is a new concept that could do what e-books failed to do—provide a usable digital alternative to paper, says Sushma Naik

There is a buzz in the digital world that might just create a printing revolution. Unlike conventional e-books which flopped miserably, the concept of electronic paper has a better chance of succeeding as it mimics the conventional medium of paper but with a significant advantage. Electronic or e-paper is a display material that looks just like paper, but can be re-used thousands of times. The potential is not restricted to e-books but can be used in a variety of applications such as digital displays and educational kits. For instance, you could have digital libraries which charge your e-book with content in the future. You could read it just like you read an Amrita Pritam paperback today. After you have finished your e-book, all you need to do is log on to your library and download another book.

How e-Paper works

The material used in e-paper is a polymer film that resembles paper and contains millions of microcapsules. When charged these capsules create readable matter. Each microcapsule contains positively charged white particles and negatively charged black particles suspended in a clear fluid. When a negative electric field is applied, the white particles move to the top of the microcapsule where they become visible to the user. This makes the surface appear white at that spot. At the same time, an opposite electric field pulls the black particles to the bottom of the microcapsules where they are hidden. By reversing this process, the black particles appear at the top of the capsule, which now makes the surface appear dark at that spot. To form an e-ink electronic display, the ink is printed onto a sheet of plastic film that is laminated to a layer of circuitry. The circuitry forms a pattern of pixels that can then be controlled by a display driver. These microcapsules are suspended in a liquid “carrier medium” allowing them to be printed using existing screen printing processes onto virtually any surface, including glass, plastic, fabric— and paper.

LCD meets its match

The electronic display industry has been dominated by liquid crystal displays (LCD) that can strain the eye while reading. Electronic ink, which combines the look of ink on paper with the dynamic capability of an electronic display, could revolutionise the way that text is displayed. Electronic ink is three to six times brighter than reflective LCD. The displays can be read without backlighting, in dim light or bright sunshine.

What’s more, electronic ink allows a fixed image to remain on screen even after the power source is shut off. With less than 1/1000th the power required by a standard notebook computer screen, future portable devices could be less expensive and more portable, and have longer battery life.

Electronic ink displays could let manufacturers create dedicated devices that have the same power draw and weight but offer a larger screen. The result would be e-books that are thinner and lighter and easier on the eye to boot.

Who’s spilling the ink?

Two companies are simultaneously developing electronic ink, E Ink (of Cambridge) and Xerox, using different techniques. The three components of both the electronic inks that have the ability to rearrange upon command are millions of tiny microcapsules or cavities, an ink or oily substance filling the microcapsules and pigmented chips or balls with a negative charge floating inside the microcapsule.

Xerox is working on its own version of electronic ink, called electronic paper, which it first developed in the 1970s. However, instead of using paint chips floating in a dark liquid, it has produced microscopic balls that are black on one side and white on the other. Similar to E Ink’s technology, these microscopic balls respond to an electrical charge which rotates the ball from black to white to produce patterns on a page. To produce pages for digital books, Xerox is developing rubber sheets in which these microscopic balls will be suspended in an oily liquid.

One of the obstacles in developing a digital book out of electronic ink has been wiring the pages to create an electrical charge while still maintaining a paper-thin page. E Ink has taken the lead here by signing an agreement with Lucent Technologies that gives it the right to use plastic transistors developed by the latter. These tiny transistors can be printed onto a page to provide the charge needed to switch the E Ink chips from one colour to another. (E Ink, while currently working with white chips and blue ink, is working to develop inks in other colours that could lead to multicolour displays.)

Adding colour to e-paper is a New York-based company called Magink Display Technologies.

Imagination is the limit

E Ink and Xerox have already identified commercial markets. Electronic ink can be printed on any surface, including walls, billboards, product labels and T-shirts. The ink’s flexibility will also make it possible to develop roll-up displays for electronic devices. But before developing digital books and newspapers, E Ink will be developing a marketable electronic display screen for cellphones, PDAs, pagers and digital watches. The company has already received financial backing from Motorola. Meanwhile, Xerox has announced plans to insert a memory device into the spine of the book which will allow users to alternate between up to 10 books stored on a device.

The fine print

However, both Xerox and E Ink might need to improve the resolution of their products for them to be viable in book or publications where small fonts are used. Xerox has already made a display that has a 200 dots per inch resolution, which is more than twice the resolution of an average LCD display. Lucent’s printable transistors should allow E Ink to increase the resolution of its products to approximate the resolution of a printed book.

In the long run, electronic ink may have a lasting impact on the publishing industry. The use of electronic ink and two-way wireless communication could lead to the creation of electronic books that renew themselves with new selections when readers are finished with the current book or newspaper; indeed, newspapers might be able to update themselves with the latest news while being read. In May 1999, E Ink demonstrated the first commercial electronic ink product called Immedia—large indoor signs that can be changed automatically by remote two-way pagers controlled through the Internet.

In brief, the plastic sheets could be instantly updated

via computers, wireless and Internet connections, and end up in ultra-thin, lightweight displays for cellphones, PDAs and e-books. The paper could be updated or changed electronically by computers and wireless links, allowing consumers to carry e-books, newspapers and other documents that are refreshed with the latest content.

sushma@expresscomputeronline.com