This tiny tab could one day allow us to charge our devices without having to plug them into an outlet. The secret is an effect called triboelectric charging. Triboelectric charging happens when a material becomes electrically charged after coming into frictional contact with another material. The tab features two thin layers of gold that sandwich a slab of a silicon-based polymer called polydimethylsiloxane, which is typically used in contact lenses and Silly Putty. One layer of gold is stretched and then released, causing it to crumple. Upon applying force again, movement between the layers of gold and the polymer creates friction. The small tab generated 124 volts, with a maximum current and density that was enough to light 48 red LED lights at the same time. Though the tech is not quite there yet, the researchers hope that their material could soon charge smartphones and other smart gadgets using just movement.