However well the paper industry’s sustainability plans are going, there comes a point when we have to admit that printing out memos, emails and other temporary items is more or less indefensible. Some estimates suggest that up to 40% of what we print is for “one-time use”. Now Chinese researchers say they might have hit upon a solution to this: a reusable sheet that changes color when moist.
The process, laid out in the Jan. 28th issue of Nature Communications (heavens, we never miss an issue), replaces the ink cartridges in an inkjet printer with cartridges filled with water. As Gizmodo explains:
“The paper is made with dyes that are invisible when dry but reveal colors when wet. Water acts as a key for the dye, opening up closed and colorless molecules when it is present to trigger coloration.”
Tests show that each sheet of paper can be reused up to 50 times; prints last for up to 22 hours. Researchers deemed the printing results of a good enough resolution for general reading purposes, but already have improvements in mind.
It’s been an interesting month for Chinese researchers. Earlier scientists in the Shanghai Institute of Ceramics at the Chinese Academy of Sciences developed a fire-resistant paper. Guess that’s two elements down and two to go….
