e-paper is a new concept that could do what e-books failed
to doprovide a usable digital alternative to paper, says Sushma Naik
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
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.
Whats 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.
Whos 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 Inks 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 inks 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. Lucents
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
Immedialarge 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