Crystal Ink Detects Funny Money

By Chemical Processing Staff

Dec 22, 2014

If you want to know if that $100 bill is counterfeit or the real deal, simply blow on it. New photonic crystal ink developed by a team of Chinese researchers reveals intricate patterns when breathed on, a technology that would be extremely hard for fraudsters to reproduce, according to an article in Scientific American. The ink mimics the way a certain species of beetle changes color in response to the humidity in the environment.

Ling Bai and Zhongze Gu and colleagues at Southeast University in Nanjing, China have discovered a method of integrating the crystals into an inkjet printing system, producing complex patterns on rigid and flexible materials and controlling their color in response to nitrogen and ethanol vapors – or by someone breathing on them.  Researchers believe the low-cost, scalable technology with its multiple security features could be useful for antifraud applications in the future.

Read the entire article here.