Yadong Yin [...] and his colleagues at the University of California at Riverside have invented a type of paper that can be printed on using just light, erased by heating, and reused up to 80 times.
Yin created nanoparticles, which are a million times smaller than the thickness of human hair, with the dye Prussian blue, or its chemical analogues, and titanium oxide, which is commonly used in white wall paint. This mixture is then applied to normal paper.
When the coating is exposed to ultraviolet light, electrons from titanium oxide move to the dye in the nanoparticle. This addition of electrons makes the blue dye turn white. Focusing the ultraviolet light into shapes, you can print white words on a blue background—or blue words on a white background, which are easier to read.
If left alone, the paper reverts to its original state in five days. That process can be accelerated by heating the paper to 120 °C (250 °F) for 10 minutes.
(Score: 0) by Anonymous Coward on Monday February 06 2017, @01:37AM
I can write on it with compressed minerals and wash/wipe it off and reuse it forever.
(Score: 0) by Anonymous Coward on Monday February 06 2017, @03:11AM
That requires chalk, which creates dust.[1]
The new notion requires a light-producing device which, in turn, requires a power source (batteries?).
Now, would you call that gizmo a "light pen"??
I'm reminded once again of the story of the zero-g pen that the USA developed.
(The final line of the story notes that the Soviets simply used pencils.)
[1] There's an audio clip of John Lennon describing how they had reached the end of the day and had everything figured out about how they were going to record a tune the next day.
The cleaning woman came in that night and cleaned all the chalk marks off the mixing board.
Said John to the interviewer's audience, "Well, I guess now you'll get what you get."
-- OriginalOwner_ [soylentnews.org]