A super-hydrophobic paint developed by scientists in UCL Chemistry could have great promise for commercial self-cleaning coatings. It can be applied to many surfaces (in this case, glass), and forms a tough surface that resists abrasion, and repels water extremely effectively. As the water forms a bead and rolls off the surface, it dislodges any dust, dirt, bacteria or viruses that are present. Here, a pattern has been drawn on the glass using the coating, and water is repelled from the painted areas and is restricted to the untreated areas.