Imagine washing your car only with a hose without any soap or scrubbing the dirt off. A research team at the University College of London has developed a water-repelling paint. The active ingredient in the paint is coated titanium dioxide nanoparticles. These cause liquid to bead up and roll off the paint, instead of clinging to it. As those droplets roll across the painted surface, they suck up any dirt, viruses, bacteria or other non-liquid contaminants that are in their path—and cleaning becomes easy.