In the January 2015 issue of ITS News, we ran an amazing story about the way the nanostructures and iridescence of butterfly wings, could eventually lead to paint that does not fade. Butterfly wings are again the focus of research, this time for air purification.
Now scientists at the Wyss Institute and Harvard SEAS (School of Engineering & Applied Sciences) are developing a new type of coating for catalytic converters that is inspired by the same nano-scale structure of a butterfly’s wing. It is claimed the new coating could significantly improve performance at the same time as reducing costs of air purification technologies.
Every year over 5 million people worldwide die due to exposure to air pollution. The most widely used air purification devices are catalytic converters. They convert pollutants and the toxic gases produced by fuel combustion into benign chemicals prior to the exhaust being discharged into the environment.
Currently catalytic converters are expensive with up to 90% of the cost made up from the precious metals used for the cleaning reactions within the systems. They are also inefficient as the valuable metals are embedded randomly in the catalytic coating, with many never touching the pollutants, that they should be cleaning.
The new coating is inspired by the honeycomb like nanostructure of the butterfly’s wing. Air flows freely and unimpeded through the channels within the structure.
The catalysts are precisely placed on the structure, maximising efficiency and reducing the amount of precious metals required by up to 80%.
The new coating could significantly reduce costs within the huge catalytic converter industry, with the possibility of extending the existing market for catalytic converters into lower income countries, plus consumers for home air purification useage.