A laser device that vaporizes photocopied ink from paper soon could be in offices worldwide. The laser “unprinter,” developed by engineers at the University of Cambridge in the UK, removes toner from scraps of paper without damaging them so that they can be reused. Dr. Julian Allwood, leader of the Low Carbon Materials Processing Group at the university, and doctoral candidate David Leal-Ayala used a variety of lasers to test toner-print removal. With the aid of the Bavarian Laser Centre, the scientists investigated 10 laser setups spanning a range of strengths and pulse durations in the ultraviolet, visible and infrared spectra. Standard Canon copy paper and HP Laserjet black toner, found in most offices around the world, were used to test the lasers. A laser “unprinter” that vaporizes photocopied ink from paper could help save the forests and reduce carbon emissions by 50 to 80 percent over recycling. A scanning electron microscope was used to study the paper samples’ color, and its mechanical and chemical properties after laser exposure. The researchers discovered that toner could be removed effectively without causing significant paper damage, allowing paper to be reused without being discarded, shredded or sent to a recycling plant. “What we need to do now is find someone to build a prototype,” Allwood said. “Thanks to low-energy laser scanners and laser-jet printers, the feasibility for reusing paper in the office is there.” Implications of the study extend beyond the workplace into the forest, where paper reuse could greatly reduce the need for cutting down trees. Besides saving trees, reusing paper could save an additional 50 to 80 percent in carbon emissions over recycling. What would happen, however, if paper were unprinted and reused instead of recycled? By using the laser unprinter, four steps from the paper production cycle would be saved: forestry, pulping, papermaking and disposal by incineration or landfill. “Material recovery through reusing eliminates the forestry step from the life cycle of paper and eradicates emissions arising from paper incineration or decomposition in landfills,” Allwood said. The study predicts that the emissions produced by the pulp and paper recycling industry could be at least halved as a result of paper reuse. “This could represent a significant contribution toward the cause of reducing climate change emissions from paper manufacturing,” Allwood said.