Synaptics' latest fingerprint sensor for mobile devices measures only 3.5 mm wide. It's so thin and tiny, it can fit inside a volume rocker switch on the side of your smartphone or tablet. The company is no stranger to developing sensors for various parts of the phone, such as the one it supplied for the HTC One Max that's located on the device's back plate. You might have to wait until next year to see the tiny scanner in action, though, since it's not slated to enter mass production until the third quarter of 2016. Besides the new product, Synaptics has also upgraded its SentryPoint security suite with an anti-spoofing feature.