The magical properties of coffee stains have already spurred on some researchers to develop a better coating for TV screens, and it looks like they've now inspired a few folks to create a new type of touchscreen as well. This latest instance apparently began when Hebrew University professor Shlomo Magdassi was working to develop a touchscreen using silver nanoparticles but ran into trouble making the screen conductive while still remaining transparent. As it happens, the coffee-like stains that he and his colleagues had been trying to remove with fast-drying solvents was actually the solution to his problem, since they remained in contact with each other as they dried and preserved conductivity, but left about 95 percent of the light through the holes in the center, thereby making the screen itself almost fully transparent. Of course, there's still quite a bit more work to be done before the screens move beyond the lab, but Magdassi has apparently already found that copper nanorings can be used in similar manner, and says that the screens could even double as solar panels to give devices a bit of added juice.