Anti-reflective coatings: Beauty is in the moth's eyes

Some of the most efficient ARCs are made by mother nature and are found in the eyes of insects. The eyes of moths, for example, are covered with a layer of tiny bumps which are smaller than the wavelength of incoming light. This natural coating eliminates glare, hiding the moths from predators and improving their nocturnal vision. Some types of ARCs actually mimic the moth's eye. These coatings are effective, but they are relatively expensive and difficult to customize.

A group at the Max Planck Institute for Intelligent Systems in Stuttgart, coordinated by Joachim P. Spatz, has developed a new way to produce moth eye-like coatings. According to the inventors, the resulting coatings have a cost similar to that of classic ARCs and can be easily customized.

The manufacturing process developed at the Max Planck Institute -- which uses gold nanoparticles -- produces regular, tiny bumps similar to that found in the moths' eyes. Structural parameters such as period, height and shape of these structures can be easily controlled, say the German group. Researchers have formed a spin-off team to exploit and commercialise their solution.