Imagine a newspaper that you never need to throw away. Instead, the ink rearranges itself each morning to form new headlines. Or maybe you've just finished poring over a new best seller. No need to pass it along to a friend; the print can morph Harry Potter style into a new book. Sound unreal? Welcome to the world of electronic ink.
Though the concept of electronic ink is not new, inroads to making it a reality are more recent. Many herald this ink, sometimes called electronic paper, as the most promising new development in publishing since the invention of paper nearly two millennia ago.
In some version of electronic ink, it ink looks unremarkable to the naked eye, but within its dark, oily substance countless microcapsules flow. E Ink has likened these round microcapsules to clear, minuscule beach balls filled with dark fluid. Within the dark fluid, charged white particles float. If the charged particles rise to the top of the microcapsule, that spot on the paper appears as a white dot. If the particles fall to the bottom, the dark liquid forms a black dot. Applying negative and positive charges across a back pixel-grid supplied by a thin transistor film forms text. Therefore, unlike traditional ink that only appears where a letter is printed, electronic ink covers the entire page, revealing white or dark pigment depending on the individual pixel's electronic charge.
Electronic ink is much crisper than LCD displays, rivaling printed text on white paper. It is easier on the eyes than a display, and you can curl up in bed with a book minus a power source. Once set, the charged particles in the ink stay put. It can be read in low lighting conditions and from nearly any angle. The scalable technology requires a minuscule amount of power to change particle charge, perfect for large commercial applications. One of the goals in developing electronic ink is to provide a medium that can "coat" any surface — turning anything into a virtual display, including paper.
A thin film of mini-transistors forms the laminated back-grid, which supplies charge to the microcapsules. The idea is to make electronic paper thin enough to roll up under your arm, or unroll onto the wall of a building. With an embedded wireless uplink implanted in the back of a sign or the spine of a book, for example, electronic ink can be changed via a simple wireless signal.
Several different electronic book applications use electronic ink, and it has even appeared on the cover of Esquire magazine. Other products are also in the marketplace. Select grocery chains and department stores use signs made for this ink to keep information about specials current for customers. One of the great advantages is that every sign in every outlet can be updated simultaneously. It only takes one simple command issued from the chain's headquarters via computer.