Un-Printing Ink Off Paper


You’ve heard of laser printers — and now a team of researchers from the University of Cambridge in England have created a laserunprinter that can remove ink without damaging the paper. In the laser unprinter, unlike laser printer, very short pulses of laser light — on the order of picoseconds; there are one billion picoseconds in a millisecond — are used to vaporize the toner, or ablate in scientific terms. The trick here is ablating the toner without damaging the paper; to do this, the team uses green laser light that is readily absorbed by dark toner, but which passes harmlessly through cellulose fibers in paper.

The primary goal of unprinting is to cut down on the carbon footprint of the paper and printing industries. Manufacturing paper is incredibly messy business that produces millions of tons of CO2 every year. Recycling paper is definitely a step in the right direction, but it’s still a very resource-intensive process. If we could simply delete sheets of paper, rather than re-pulping them, we could cut down on electricity usage, CO2 output, and most importantly fresh water, which is growing more scarce by the year. It would also be rather handy if you never had to buy another ream of paper, too. It’s now a matter of building the technology into a commercial device.

via ExtremeTech