Experts at the Harvard University have recently announced the development of inexpensive color display-like structures, entirely made of paper and thermochromic ink. The latter substance is the one found in 'mood rings' and disposable thermometers, and its basic property is that it changes color whenever temperature around it changes. In the innovative construct, ordinary paper, the variety that can be found at any book store and library, was used, with the express goal of producing the most inexpensive product possible. Over the past years, scientists at Harvard have spent a lot of time and resources on devising all sorts of low-cost, high-tech equipment for the developing world.

“The goal here is to get people to think outside the silicon box. That is, to think that simple, everyday materials like paper can be used in very technologically-sophisticated ways,” HU graduate student Adam Siegel explains. He is the electrical engineer who has led the current study on paper color displays. “At first, paper may not sound like exciting, state-of-the-art stuff, but it is in fact, a very interesting material,” he adds, quoted by Wired. Siegel works in the lab of professor George Whitesides.

The graduate student reveals that the inspiration for the new devices came to him after browsing through a modern science catalog, which featured thermochromic ink that changed color. He thought that this property could eventually be turned into a fast and easy way of producing colors, and one that did not require an expensive substrate. Most modern displays have a plasma or liquid crystal layer, on which the image is formed. Thanks to Siegel's innovation, people who cannot afford them could soon benefit from easy-to-carry and light displays, to use wherever they want.

“I thought it might be possible to pattern this ink on one side of a sheet of paper and then use electrical current to heat the paper and ‘write’ a message on the other side in plain English, or another language for that matter,” he explains. Basically, on a sheet of paper, he added metal heating elements, and then used an electrical current to control them in such a manner that a message appeared on the other side. He believes that this type of displays most likely won't catch in home entertainment, but that they could offer much-needed risk assessments of water analyzed with equally inexpensive, high-tech tools.