The Meizu Zero is here - the world's first phone without physical buttons, speaker cutout and even without a USB port for conventional wired charging. The Meizu Zero uses touch capacitive panels on the side as replacements for the conventional power and volume buttons (similar to what HTC did with the U12+, only without the buttons protruding the frame). For a speaker the Meizu Zero uses a piezoelectric transducer under the display (akin to what Sharp and Xiaomi have done with phones like the Aquos Crystal and Mi Mix). Meizu Zero Removing the USB port is trickier to compensate...
Source: https://www.gsmarena.com/meizu_zero_has_no_buttons_speaker_or_even_a_charging_port-news-35194.php
