Something you will find in many examples of science fiction are technologies that allow a user to interact with a system, without directly touching it. What you do not see with these technologies very often though is haptic feedback. Researchers at the University of Bristol decided to do something about that by developing UltraHaptics, so uses can interact with a device in mid-air, while also getting feedback.
With the right sound and sound system, you may be familiar with how sounds can exert enough force to be felt by the body. By creating a phased array of ultrasonic transducers, the researchers are able to focus the force of the sound waves into specific areas, thereby providing tactile feedback in mid-air. Above the transducers is an acoustically transparent display and a Leap Motion sensor to allow control of the device.
The researchers envision their UltraHaptics technology being integrated into public interactive surfaces, where it will provide haptic feedback without compromising simplicity or accessibility.
Source: University of Bristol