(Disclaimer: I had a fair share of sucker punches with self-cleaning surfaces..)<p>Approaches towards self cleaning surfaces have been seen in the lab since a long, long time: They range from photocatalytic concepts (e.g. TiO2/SiO2/polymer hybrid coatings for house paint) to surfaces with a mixture of -OH/-CH3/-F (hydro-/lipophilic and mostly repellent) end groups that can be produces by plasma treatment, and many more.<p>There is a good reason that very little of these applications have ended up in mass production: The stability and durability of the film surfaces. Once you get a surface structure damage on, say, your "lotus effect functionalized" bathtub, house wall, car body, dirt starts to accumulate on this spot. The german car industry had quite a bunch of projects with car windows without front wipers (minimum speed 20 km/h to be effective), there have been a lot of projects for self cleaning house paints using the sun - but so far there is no effective product on the market. But of course there are a lot of patents..<p>I have no idea if Nissan found a way to make a cost effective, self cleansing film coating that can stand the test of gravel, acid, and time. If they succeeded, then it is a true accomplishment. But for the reasons listed above, I somehow doubt that.