Ultra-Haptics is a system for creating haptic feedback in mid-air. Waves of ultrasound displace the air, creating a pressure difference. By causing many waves to arrive at the same place simultaneously, a noticeable pressure difference is created at that point. With this method, we are able to create multiple, concurrent points of haptic feedback in mid-air.

For more information see the Ultra-Haptics project page on the Bristol Interaction and Graphics group website.