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The green laser that can erase printer ink
Scientists have a bold new plan to slash CO2 emissions from recycling in half — with a laser "unprinter" that wipes documents clean
A newly developed laser "unprinter" would be able to wipe clean the dried ink on paper so it can be re-used.
A newly developed laser "unprinter" would be able to wipe clean the dried ink on paper so it can be re-used.
Lawrence Manning/Corbis
T

he recycling industry's goal is to make the world a greener place, but the actual process comes at a price — namely in gas and carbon dioxide emissions. But a promising new technology from the University of Cambridge aims to cut down on excessive energy use by employing lasers to remove ink from used paper, allowing it to be reused. Here, a quick guide to this experimental concept:

What is this new device, exactly?
Its creators are calling it a "laser unprinter," and it works by vaporizing the toner from traditional printers without damaging or discoloring the paper underneath. The device uses ultrashort pulses of green laser light — each flash is four billionths of a second — to remove (or ablate, in scientific terms) dried toner ink. It "simply deletes sheets of paper," says Sebastian Anthony at ExtremeTech, wiping them clean for reuse. 

Is this concept new?
Not quite. Toshiba already sells a printer that utilizes a special type of blue toner that can be almost be completely erased with heat treatment, says Paul Marks at New Scientist. This new device, however, takes the technology one step further by zapping off ink from any normal office document. 

And it's good for the environment?
In more ways that you'd think. "The primary goal of unprinting is to cut down on the carbon footprint of the paper and printing industries," says Anthony. The recycling industry, with its multitude of trucks and factories, produces millions of tons of CO2 every year. This laser concept cuts down on electricity use, CO2 emissions, and takes the gallons of fresh water used to re-pulp recycled paper out of the equation entirely. In a conservative, worst-case scenario, the team from the University of Cambridge estimates their "unprinter" could cut carbon emissions in half while making the recycling process 20 times more efficient, making their laser "green" in more ways than one. 

When can we get one?
That's the only problem, says Keith Wagstaff at TIME. The team has yet to secure patents for the idea, and they haven't approached copier makers about utilizing the technology — so don't expect a laser unprinter in your office anytime soon.

Sources: ExtremeTech, Los Angeles TimesNew Scientist, PC Mag, TIME

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