Boffins have come up with a cure for greasy fingerprint stained touch sceens.
German scientists have created a very precise coating that can be applied to a display that spurns oil as if it were a rabid dog.
It is pretty cheap too, as it has the secret ingredient of candle soot. While we don't have much candle soot about, it is still pretty cheap to make.
According to the Sydney Morning Herald it works because the oil on your paws has a much lower surface tension than water, making it difficult to create a surface that repels it. However, if you make the right kind of surface texture - which is like a tree branch - you can make it oil repelling.
The scientists held a glass slide over a candle so it could collect soot in spheres of between 30 and 40 nanometres in diameter. They coated the slide with a thin silica shell and baked the whole thing at 600 degrees Celsius which made the soot transparent.
The slide was taken out of the oven and cooled, the boffins then tried to iced it with various oils. Microscopic snaps showed the oil droplets bouncing off the surface.
The coating repels all organic substances so if you sneeze on your screen you will not have to scrape off the snot. But it will stick to glass, aluminium, steel, and copper.
Lead boffin Doris Vollmer told the Sydney Morning Herald that she was trying to find an improved eyeglass coating which did not need cleaning so often. But the discovery could have a wide range of applications, from electronics to medical devices that are sometimes clogged with organic material sticking to it.
The downside is that the oil-repelling surface is vulnerable to scratching. There may be alternative methods of creating the coating to bump up its toughness but the boffins have to work that out.