Today, we have the ability to do almost everything paperless. We can pay all of our bills online or go mobile with tickets for concerts and flights. Although it’s true that digital media has lessened the use of paper materials, it still hasn’t ruled it out. That’s because paper has a much greater effect on people than digital media does. It’s been scientifically proven that the use of tangible materials and the information it displays resonates with people on a deeper emotional level, allows the brain to process messages faster, and is more memorable than anything digital. With that said, many in the science community believe it’s silly to think that the use of paper will ever die out, and therefore, continue to conduct research on how it can be reused in hopes of saving trees and helping the environment.

Recently, a new coating has been developed that allows for regular paper to be reused more than 80 times over. Unbelievable, right? Although it’s in the early stages, reprintable paper might be a reality sooner than later. Below, we’ve grouped together excerpts from the essay of Yadong Yin, one of the researchers from University of California, Riverside, whose team developed this incredible new substance:

What it is: 

  • “For many years, scientists have worked to develop reading media that have the format of conventional paper but can be reprinted without first having to be industrially recycled. One promising option has been to coat paper with a thin film of chemicals that change color when exposed to light. But previous efforts have encountered problems such as high cost and high toxicity—not to mention difficulty both remaining readable and being erased for reuse.”
  • “My research group at the University of California, Riverside, in collaboration with Wenshou Wang at Shandong University in China, has recently developed a new coating for regular paper that needs no ink, and can be printed on with light, erased and reused more than 80 times. The coating combines the functions of two types of nanoparticles, particles 100,000 times thinner than a piece of paper; one particle is able to get energy from light and initiates color change of the other. This represents an important step toward the development of reprintable paper.”
  • “Our method combines nanoparticles—particles between 1 and 100 nanometers in size—of two different materials that can change from clear to visible and back again.”

How it works:

  • The printing can be done through a mask, which is a clear plastic sheet printed with letters and patterns in black. The paper starts out entirely blue. When UV light passes through the blank areas on the mask, it changes the corresponding areas on the paper underneath into white, replicating the information from the mask to the paper. The printing is fast, taking only a few seconds to complete.”
  • “The resolution is very high: It can produce patterns as tiny as 10 micrometers, 10 times smaller than what our eyes can see. The paper will remain readable for more than five days. Its readability will slowly degrade, as the oxygen in the air takes electrons from the Prussian blue nanoparticles and turn them back to blue. The printing can also be done using a laser beam, which scans across the paper surface and exposes the areas that should be white, in a way similar to how today’s laser printers work.”
  • “Erasing a page is easy: Heating the paper and film to about 120 degrees Celsius (250 degrees Fahrenheit) speeds up the oxidation reaction, erasing the printed content completely within about 10 minutes. This temperature is far lower than the temperature at which paper ignites, so there is no danger of fire. It is also lower than the temperature involved in current laser printers, which need to reach about 200 degrees Celsius(392 degrees Fahrenheit) to instantly fuse the toner onto the paper.”

Read more about this new nanoparticle coating for reprintable paper in Yadong Yin’s full essay.

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