So we get it, buttons are on the way out as far as smartphones are concerned. And today, Reuters reports about a company called Sentons that is trying to replace all buttons on all handsets. The start-up company’s founder is an engineer named Jess Lee, who sold his previous firm, InVisage Technologies, to Apple. Sentons new system uses ultrasound to replace button touches and swipes on a smartphone’s metal edge. The technology relies on a custom chip that sends out ultrasonic sound waves. The component also includes a processor and uses algorithms to interpret a number of different gestures. The technology is already used on the Asus ROG Phone II Tencent Edition sold only in China. The gaming phone can be held in landscape and as users tap the screen with their thumbs to play a game, their index fingers press virtual buttons on the top edge of the device called “Air Triggers.” Besides Asus, Sentons says that it is working with two other smartphone manufacturers that the company wouldn’t name.