When Johannes Gutenberg invented the printing press in 1448, he sparked widespread sharing of knowledge throughout the world. Nearly 550 years later, American inventors Joseph M. Jacobson and Barrett Comiskey started another revolution with electronic ink for thin, lightweight electronic-paper displays.
Their patent launched the creation of electronic readers, portable devices that can store thousands of books. E-readers have forever changed the publishing industry and transformed education while easing the global demand for paper and benefitting the environment.
In 1993, postdoctoral physics student Joseph M. Jacobson at Stanford University was looking for a challenge: "A book that typeset itself sounded difficult enough to be interesting," he later recalled in an interview with Wired magazine.
Jacobson dreamed of putting the world's entire repository of knowledge in the hands of readers, contained in a single book. He envisioned a device that could hold thousands of texts and possibly even the largest library in the world, the Library of Congress.
The challenge was to develop the right imaging technology: a screen that could display such a book within an efficient, easy-to-read portable device. Unbeknownst to Jacobson, a research team at Xerox PARC had already created a prototype two decades earlier. But their reader was too bulky for the consumer market.
In 1995, Jacobson started as assistant professor at the Massachusetts Institute of Technology (MIT) Media Lab in Boston and joined forces with Barrett Comiskey, an MIT mathematics undergraduate who shared his vision.
Within two years, they developed a method for manipulating black and white particles contained within tiny bubbles attached to thin sheets of plastic film - a crude precursor of today's electronic ink displays.
The underlying principle has been the same from the start: Applying electrical charges causes the particles to move around, change colour and appear like ink on a printed page. One short jolt of electricity, and the content of a page changes, creating an electronic display with the look of real paper.
The economic advantages of Jacobson and Comiskey's invention became apparent early on. Not only could electronic ink displays be produced in a simple, low-cost manufacturing process. Their low power consumption also soon emerged as a major success factor.
E-ink displays only consume power when readers "flip" the page and the constellation of particles is changed into new words. This is a major advantage over backlit devices, whose displays contribute to as much as 40% of total battery consumption. In contrast, e-readers like the current Amazon Paperwhite Kindle offer up to eight weeks of battery life.
E-ink displays also prevent eye fatigue because they reflect ambient light from the display's surface back to the reader's eyes. The more light is present in the environment, the brighter the screen appears - similar to a printed book, and perfect for reading in bright sunlight.
E-ink technology has transformed reading into an interactive experience. At the touch of a button, e-readers offer interactive features like photo galleries and data graphs - a great appeal to children and young adults.
E-ink has also changed the publishing industry. Digital books are comparatively cheap because they save costs for paper, printing and distribution. What's more, the e-reader makes it more economical to share information. Instead of picking up books at a store, readers can download them with a mere click of the mouse.
While today's e-readers don't yet live up to Jacobson's vision of holding the Library of Congress' entire catalogue of 34.5 million books, their storage capacity is still almost limitless for individual readers. The current generation of e-readers can store up to 6,000 books at a time, while online stores offer more than 1.8 million different books in digital formats.
In the bigger picture, the technology has the potential to reduce textbook prices and make education more accessible across the globe. A growing number of literary works is already available free of charge as public domain titles via sites such as Project Gutenberg.
From an environmental angle, e-readers greatly diminish the publishing industry's environmental footprint by replacing the need for paper with energy-efficient devices.
Other industries are also turning a new page thanks to electronic ink. E-ink display technology is becoming a popular choice in retail displays, watches, cell phones and smart cards.
Many retailers have already incorporated large programmable e-ink billboards in stores to inform and engage consumers with up-to-the-minute information.
Environmentally friendly and durable, e-ink watches and cell phones offer low power consumption and excellent visibility in various environments, while smart cards allow people to securely carry private information in their wallet.
In the marketplace, a large number of companies are benefitting from Jacobson and Comiskey's patented invention. Initially, the e-ink project was funded by the MIT Media Lab's News in the Future group and its Things that Think consortium, which consists of about 40 companies, including Microsoft and other heavyweights.
Each of the participating corporations paid up to €115,000 per year and thus obtains the right to use any patents awarded to MIT without paying additional royalties.
Today, companies such as Amazon, Sony and Barnes & Noble have employed e-ink technology in their e-readers. As the most popular choice, Amazon's Kindle reader, first released in 2007, had a 48% share of the e-reader market in 2011.
While some readers are holding on to printed books, acceptance of e-readers is steadily growing: Consumers around the globe purchased 14.7 million e-readers in 2011, up from 12 million e-readers in 2010.
In the United States, e-books already account for 15% of all book sales, while Great Britain leads the charge in Europe with 13%. Nearly 3 billion e-books are currently sold every year.
As we speak, the story of the digital publishing is written in electronic ink, made possible by Jacobson and Comiskey's development of e-ink display technology.
An electronic ink paper display consists of thin layers of plastic film, which are laminated to a layer of electronic circuitry and hold electronic ink. The e-ink features millions of tiny bubbles filled with white and black particles.
Suspended in a clear liquid, the positively charged white particles and the negatively charged black particles move to the top of the microcapsule based on the type of charge applied.
When a negative charge is applied, the white particles rise to the top of the bubble and become visible to the user, while the black particles sink to the bottom. In contrast, the black particles come into view at the top of the microcapsule and the white particles fall to the bottom when applying a positive charge.
The electronic paper display shows white or black electronic ink pixels, which collectively form letters, numbers and images. Once the image appears on the display, no power is needed to maintain it because the particles remain in position without additional electricity.
Instead of relying on a built-in power source, ambient light is reflected off the screen back to the eyes of the user, thereby removing the need for a backlight. Power is consumed only when the image changes - allowing for weeks of battery life on a single charge.
An early precursor to modern-day e-readers, the Apple Newton MessagePad was released in 1993. At a weight of 640 grams, it offered only 24 hours of battery life (with backlight activated) and 4 MB of storage, the equivalent of 40 e-books. Meanwhile, today's e-readers can store up to 6,000 e-books, with up to eight weeks battery life, weighing around 200 grams.
Electronic readers are also lighter on the wallet. Thanks to constant advancements, the average price of e-readers has declined through the years. While the first-generation Kindle reader sold for $399.00, entry-level models currently start at $69.00.