Nature's True Colors: Nanotechnology and 3-D Printing Color Replication

Inspired by the vivid colors of the blue tarantula, scientists from Karlsruhe Institute of Technology, with the help of their international colleagues, have discovered a method to replicate nanostructures that generate the same color regardless of the viewing angle.

Industrial production has thus far been unable to successfully replicate very vivid colors. The vibrant colors of the blue tarantula do not result from pigments. Rather, they come from nanostructures that cause the reflected light waves to overlap and produce extraordinarily dynamic color effects. Industrially produced colors have the disadvantage of being strongly iridescent; meaning the color perceived depends on which angle it is seen. Bright colors seen on animals, however, do not change when viewed from a different angle. These structural colors are also non-toxic, more vibrant and durable.

Radwanul Hasan Siddique, a researcher from Karlsruhe Institute of Technology, collaborated with scientists from USA and Belgium and discovered that the blue tarantula's hairs have a multilayered, flower-like structure. Through computer simulations, they studied its reflection behavior and built models of these structures using nano-3-D printers. As a result, they were able to produce a flower-like structure that generated the same color over a viewing angle of 160 degrees, the largest viewing angle of any synthetic structural color reached so far.

Dr. Hendrik Hölscher of Karlsruhe Institute of Technology's Institute of Microstructure Technology thinks that the scalability of nano-3D printing is the biggest challenge on the way towards industrial use. Only a few companies in the world are able to produce such prints. In his opinion, however, rapid development in this field will certainly solve this problem in the near future.

"This could be a key first step towards a future where structural colorants replace the toxic pigments currently used in textile, packaging, and cosmetic industries," said Siddique, who now works at the California Institute of Technology. He considers short-term application in textile industry feasible.