N E G R O P O N T E    Issue 3.01 - January 1997

Surfaces and Displays



Message 43:
Date: 1.1.97
From: nicholas@media.mit.edu
To: oem@wired.co.uk

Joe Jacobson, co-author of this article, believes that paper is a medium for the future, one that will build on its current ubiquity, but in an exciting and revolutionary way.

How important are paper and ink in today's world? One in seven US patents makes mention of either paper or ink - more than make mention of any type of electronics! Hard to believe? Look around your office or home and count the number of items that have some form of print on them, then compare that with the number containing chips.

The phenomenal readability and economy of printed ink on paper compels us, even in the digital age, to mark our behaviour in this age-old manner. There is no lag when going from page 1 to page 44 of a book. So, too, with a newspaper. The presentation is immediate. No start-up, no log on, no button click, just paper where and how you expect it. Ink is great because every page and object gets its own. You don't have to go to a special corner of your desk to see ink. It's everywhere.

Electronic ink

One disadvantage to ink is that it's tough to erase. We need electronic ink that can be printed as freely onto as many different surfaces as traditional ink, but that is electronically mutable. It should be able to get up and walk away and change its shape, colour or intensity.

Joe's ink can do all this. His secret takes a page from carbonless paper. The back of carbonless paper has a thin coating composed of tiny capsules filled with clear ink. These capsules, about 1 million per square inch, are then broken with the pressure of your pen. When the clear ink oozes out of the back, it chemically changes coloured ink on the page underneath.

Now, put that thin coating on the front of the page, and instead of putting ink in those capsules, imagine stuffing them with ping-pong balls one one-thousandth of their normal size, black on one side and white on the other. Then add some lubricant. Assuming you can control the rotation of the contents of each capsule - independently, electronically and with the knowledge of where it's facing - you have electronic and reusable paper.

Given that the flat-panel display market is worth US$30 billion per year and growing, Joe is not alone in his quest. Enormous energy and thought is being given worldwide to making better computer displays. The current standard is the thin-film transistor LCD. It draws 2.6 watts, costs about US$1,000 and is constructed on glass. TFT displays are expensive because their million or more transistors are spread over the large screens. They consume generous amounts of power because the TFT backplane eats about a watt, as does the required backlight (transmissive LCDs let through less than 20% of the light). Because of the glass sandwich they are packed in, LCDs are not as rugged and cannot be used as flexibly as they should be. Technical improvements can still be made, and electronics companies around the world are investing billions of dollars in research and manufacturing facilities to do so.

How can Joe compete with these deep-pocketed giants? Simple: he looks at the problem differently. It's not a display he's building, it's ink. The advantage of his mind-set is that ink is more general than paper, can go on almost anything, and is cheap. To make a display, just add a grid of addressing lines - which is just another type of ink (of the conductive variety) - to control the behaviour of your e-ink.

Once you've got e-ink that works properly, there's nothing to stop you binding several hundred e-pages to construct an e-book that is worthy of the name.

Coming from the flat-panel LCD point of view, one would never envision an electronic book containing hundreds of displays. It would be much too heavy, too power hungry and way too expensive, not to mention fragile. But e-ink gets you there. My grandchildren and Joe's children may carry around a single volume containing a whole library of books whose pages are used over and over again. No other book would be required.

But when your printer is loaded with conductor e-inks, you need not stop at books. Everyone agrees that shipping newsprint is absurd. Yet few people read their news on a screen (I may be one of the few). In general, the screen is not in the right place - you are forced into a specific position and cannot always take the monitor with you. What screens do allow is easy change, be that video, personalisation or up-to-the-minute news. Not a new concept, by the way. Thomas Edison set up his famous printing press in a baggage car, typesetting and distributing the daily news on the train to work. The same thing can be done with e-ink.

Radio paper

It turns out that the conductive inks used to make e-paper can function as radio antennas. Other inks used in e-paper can be turned into radio transistors. This makes "radio paper", which can be as thin as notepad stock and sits on a coffee table or in your pocket, receiving FM news broadcasts. It "typesets" itself, every hour or day, with the latest news. With e-ink, a single piece of paper displays the news for years.

By extension, any surface can now be modified into a display. Wallpaper of the future will be sold by the gallon in one customisable colour, billboards will be painted once, wine labels will tell you when to drink the bottle, T-shirts will be watches and our trees might live a little longer.

This paper was co-authored with Joe Jacobson, who is assistant professor of µMedia at the MIT Media Lab.