SHEFFIELD, England, May 18 (UPI) -- British scientists say a new pigment-free, intensely colored material can defeat counterfeiting of passports or banknotes because it's so difficult to copy.
Researchers at the University of Sheffield say the new polymer materials do not use pigments but instead produce intense color due to their structure, in the same way nature creates color for beetle shells and butterfly wings, a university release reported Tuesday.
By using highly ordered polymer layers, the researchers were able to create any color in the rainbow from two non-colored materials. The color also changes depending on the viewing angle.
The complexity of the chemistry involved in making the polymer means they are very difficult for counterfeiters to copy, they said, making them ideally suited for use on passports or banknotes.
"Our aim was to mimic the wonderful and funky colored patterns found in nature, such as Peacock feathers," Sheffield researcher Andrew Parnall, from the department of physics and astronomy, said. "We now have a painter's palette of colors that we can choose from using just two polymers to do this. We think that these materials have huge potential to be used commercially."