Ink-free rewritable paper can be used 80 times

A process developed by researchers in China and California uses UV light to print on reusable, specially coated paper, helping to drastically reduce waste.

So much pollution is clogging the world’s environments that a huge variety of projects and processes are removing some of that waste by creating new products. From old clothing used for airplane biofuel to wastewater turned into furniture, businesses and consumers now have a much wider selection of sustainable options. Paper contributes both to landfill and deforestation, so a new method of coating paper with nano-particles that allows it to be printed with UV light, over and over, could substantially reduce both problems.

A team of researchers from China’s Shandong University; the University of California, Riverside; and Lawrence Berkeley National Laboratory; has developed a method for reprinting paper up to 80 times without any ink. Using inexpensive, nontoxic Prussian Blue pigment, combined with titanium dioxide, traditional paper is coated to create the reprintable surface. The new, layered piece of paper, when exposed to UV light, releases electrons that turn the blue surface colorless.

The printed text slowly breaks down over five days, eventually returning the paper to its original blue state. To more quickly erase the printing, the paper needs to be heated. Researchers believe the development could substantially reduce waste in a range of ways, including labeling, news and presentations (such as those frequently given in teaching and businesses). How could consumer ownership of such paper expand the use of this technology?