10 years ago smartphones with touch screen was a gimmick, but today it is difficult to imagine a modern device without it. What is interesting in the future spread can get a fully contactless interfaces like gesture recognition system based on ultrasonic sensors.
The system is able to recognize not only individual motions, but away from the user's hand to the device it can also be used to administer. For example, in order to bring the smartphone from sleep mode, just bring a hand to the screen.
At the heart of the system are miniature MEMS microphones located in the four corners of the smartphone, and the ultrasonic speaker, developed by Murata. Microphones have low power consumption and can operate even in high background noise, catching the ultrasonic waves reflected from the bones of the hand of the user. Special software allows us to interpret the sensor data into control commands.