Touchable Holography

Recently, mid-air displays are attracting a lot of attention in the fields of digital signage and home TV, and many types of holographic displays have been proposed and developed. Although we can "see" holograhpic images as if they are really floating in front of us, we cannot "touch" them, because they are nothing but light.
This project adds tactile feedback to the hovering image in 3D free space. Tactile sensation requires contact with objects, but including a stimulator in the work space dilutes the appearance of holographic images. The Airborne Ultrasound Tactile Display solves this problem by producing tactile sensation on a user's hand without any direct contact and without diluting the quality of the holographic projection.

SIGGRAPH 2009 - Emerging Technologies