Re-writable Paper Which Can Be Wiped Clean, Used Again and Again

Scientists have recorded a major breakthrough by developing a long-lasting re-writable paper that can be wiped and used again and again.

The scientists developed an easy-to-make and re-writable paper which can be drawn or printed on over and over again, report’s India Today.
The deal with printed materials is that they get used once and then are scrapped. This process creates waste and has the potential to create pollution.
Researchers including those from the Fujian Normal University in China wanted to develop a simple method for making long-lasting re-writable paper which can be wiped clean simply by changing the temperature, according to a PTI report.
The messages can last more than half a year, compared to other re-writable papers whose messages fade after a few days or a few months, according to a study published in the journal ACS Applied Materials & Interfaces.
The idea for re-writable paper is not new, with several research groups pursuing different development strategies over the past few decades.

However, many of these approaches have drawbacks, such as complex fabrication, the chemistry which relies on ultraviolet light to erase the writing or a constant need for energy to maintain the document.

The new material consisted of three layers in a sandwich-like structure. The researchers painted one side of a piece of paper with a blue dye which becomes colourless upon heating, just like the T-shirts popular in the 1990s that changed colour when they were touched with a warm hand.
Then, the other side of the paper was coated with a black toner layer which produces heat upon the application of energy of light.
Using a pen that applies heat, a thermal printer or a source of near-infrared light, the team created images and words that remained legible for more than six months.
They also produced a re-writable cell phone case. To reset the paper, the researchers cooled it down to minus 10 degrees Celsius.
This process could be repeated more than 100 times.

(This article was first published on India Today)