Your fingerprint scanners are going down next summer. As in they're going below the glass and behind the back of your phone, according to Qualcomm. At Mobile World Congress Shanghai on Tuesday, the chipmaker announced new fingerprint sensors that can work underneath your phone's display, through metal and glass, and underwater. Qualcomm expects the first commercial devices using fingerprint sensors underneath glass and metal to start selling in early 2018, while sensors that go under the display should show up by the summer of 2018.