Touchable 3D: is it possible?

At first, I would say no. There is no technology right now that will let you touch a 3D object but we are not that far from seeing that. A group of scientists from the University of Tokyo showed at SIGGRAPH 2009 a pretty cool device. Actually, it is a combination of devices: a Wii controller, a holographic system and an Airborne Ultrasound Tactile Display. What are those things for? To create touchable holography!

 They actually use a Wiimote (Nintendo) to track their hand in the area of the holographic display. And then a holographic system will create floating images 30 cm from the surface. The cool part is coming next: the Airborne Ultrasound Tactile Display uses acoustic radiation pressure (an ultrasound phenomenon) to provide tactile sensation from the hologram! You can feel holographic objects with your bare hands!

The developers talk about possible applications in video games and CAD. They still have to do some work to make it truly functional for various types of 3D objects but the demos are already pretty impressive: