When the Botanist William Barthlott and his colleague Nesta Ehler in the middle of the seventies put a multiplicity of plant pages under a special microscope, first nothing pointed on a spectacular discovery. The investigations of the two scientists circle around the question whether one can detect the distorting shank between group of plants on the basis the different surface textures of pages.
Botanic routine task - in such a way it seems. Also the observation that some plants before each investigation must be cleaned, others not, makes the researchers not thoughtful first. Soon however the biologists detect that paradoxically in each case pages with smooth surfaces require a cleaning, while others, whose surface under the microscope appears rough, are always pore low clean. And still somewhat is noticeable to them: the most immaculate pages even repel water. At that time, clear-became fast to them that the self cleaning effect is connected with the wettability.
Particularly impressively this effect shows up with the Lotus Plant Nelumbo nucifera: From its microscopically finely napped and with tiny waxcristalls coated pages, the water trickles down as from a hot stove disk. Barthlotts diagnosis: On a smooth surface water "creeps" over the dirt away. On the rough, the droplets adhere more badly, form balls, roll over available dirt particle and take them thereby with. 1977, the biologists described this phenomenon - in a small marginal note. It seems too trivially to them, in order to attach greater importance to it. Also, on the obvious idea to develop from this as simple as ingenious principle of nature an artificial coating, they did not come. Only 1989, William Barthlott, in the meantime professor at the University of Bonn, took up the old discovery again and examinee the phenomenon together with his graduate student Christoph Neinhuis in the detail. The two succeed in not only decoding the "Lotos effect" in its meaning for biology, but also in transferring its dirt-deflecting principle at the same time to an artificial surface.
1996 Barthlott and Neinhuis demonstrated their meanwhile to the patent announced procedure at a white disk with the new coating: They dust it with a dirt mixture from fine soot and colour and let afterwards a few water drop over it. Fastly, the disk ist pore low clean again. On the comparison object, a high polished conventional film of varnish, the soot forms even after longer rinsing still another dirty-grey layer, to which with water is alone not to be gotten.
It remains still open whether first window cleaners or owners of car wash installations must fear for their businesses or whether an art break for Graffity Sprayer begins.
The history of the Lotus-effect is, from its discovery to application, typical for a research discipline, which follows the principle "technique learns from nature": the bionics.