American mobile startup uBeam, which is behind a new type of charging technology, has announced its first fully-functional prototype. Invented by young entrepreneur Meredeith Perry, uBeam is a charging system that allows you to top up your smartphone cordlessly. It converts electricity into sound, which can then be sent through the air over ultrasound. The prototype is a positive step-forward for uBeam, with hopes of it being launched in stores within two years. It’s protected by 18 patents.