Sunscreen, tennis balls and water repellent clothing. All these products have one thing in common: nanoparticles. Nano-what? Nanotechnologist Femke Witmans (University of Twente) will explain that to you in this episode. She works with nano wires that are 1000 times thinner than a human hair. For the naked eye, these are invisible. Still they're a hot topic in science. Because nanotechnology might be the future of your smarthphone.