London: Scientists claim to
have developed a new technique that can remove ink from printed
papers so they can be reused in printers and photocopiers.
The technique, developed by a team at the University of
Cambridge, uses short pulses of laser light to delete words and
images printed on paper. The laser vaporizes the toner ink
without damaging the paper and opens up the prospect of future
computer printers and photocopiers having an ‘unprint’ function
to allow paper to be reused, the researchers claimed.
Julian Allwood, who led the research, said it could
drastically reduce the number of trees cut down to produce paper
and even provide a cheaper alternative to recycling.
“The process works on a wide range of toners. It does not
damage the paper so the feasibility for reusing paper in the
office is there,” Allwood was quoted as saying by the Sunday
He added that he has now been approached by several
commercial firms expressing interest in producing the first
The researchers, who detailed their work in the journal
Proceedings of The Royal Society A, found they could remove
toner ink from a range of printers and photocopiers by heating
it with short pulses of laser light lasting for just four
billionths of a second. This removed the ink without causing any
physical damage to the paper or discolouration. Filters can be
used to capture the vaporized ink, which is given off as a gas.
Allwood and colleagues estimate it would cost £19,000 to
build a prototype unprinter but that the costs would come down
as technology improves and it is commercialized.