Scientists in California have created rewritable paper, printed using light instead of ink, that can be erased and reused up to 80 times. Jane Ross reports.
Scientists in California have created rewritable paper, printed using light instead of ink. Despite the rise of e-readers and smartphones, the United States still uses 70 million tons of paper each year. The chemists at the University of California, Riverside, hope their new paper, which can be erased and reused up to 80 times, can help cut down that amount. At the heart of the new technology are nanoparticles, materials thousands of times smaller than the width of a human hair. (SOUNDBITE) (English) CHEMISTRY STUDENT RASHED AL EISA, WHO WORKED ON REPRINTABLE PAPER, SAYING: "So this is actually the nanoparticles that I'm talking about. So what we do is we mix this one with this dye, which has the blue color and then we coat it on any kind of substrate we want. We can coat it on paper, we can coat it on glass or plastic. And then we can use some sort of mask with the writings we want, and when we shine a light on top of it, then after a couple of minutes, then we can see that the writings remain on this material." The writing fades in five days, as oxygen in the air takes electrons from the dye nanoparticles and turns them back to their original color. The process can be accelerated by heating the paper, making it reusable in a matter of minutes. And taking the idea of a paperless society one step closer to reality.