The leaves of the Lotus plant (Nelumbro speciosum) are coated with minute wax crystals around 1nm in diameter which repel water. Droplets of water falling onto the leaves bead up and when the surface slopes slightly the droplets roll off picking up small particles of dirt at the same time. As a result the surfaces stay dry even in heavy showers. At this nanoscale a rough surface can be demonstrated to be more effective at repelling water than a smooth one and essential in the self-cleaning effect. As a result BASF in Germany have developed a 'Lotus-effect' aerosol spray that combines nanoparticles with water repelling polymers and waxes and a propellant gas. As the spray dries, the coating develops a nanostructure through self-assembly mimicking the Lotus leaf surface. BASF +49 6216099938 www.nanotecweb.org