Lotus-effect laser engraving heralds self-cleaning, low-drag aircraft

The lotus effect has been known for many years. The leaves of the lotus plant have a waxy covering that, when viewed under a microscope, can be seen to consist of many microscopic structures in an ordered array. When water falls on these leaves, rather than wetting the surface, it forms beads that role off, taking dust and dirt with them. Coatings that mimic the lotus effect have been developed and applied to window glass and building exterior materials, to make them self-cleaning.

Another application for the lotus effect is in aircraft. Filigree micro patterns on the aircraft skin encourage smooth airflow in flight and reduce drag; a similar effect is exploited in high-tech swimwear for elite athletes, which have "shark tooth" patterns on their surface. Researchers at the Fraunhofer Institute for Material and Beam Technology (IWS) in Dresden, working with the city's Technical University and with Airbus, have now devised a method to use lasers to etch such patterns directly into metal surfaces.