updated 12:00 pm EDT, Thu August 6, 2009
Touch holograms shown off
University of Tokyo researchers are demonstrating what they call an Airborne Ultrasound Tactile Display (PDF) at the currently ongoing SIGGRAPH event in New Orleans. The prototype uses ultrasound technology to create holograms that can be touched, or at least feel like they're being touched. Because holograms are nothing but light, the team has developed a way to produce tactile feedback. Instead of placing a physical object in the space of where the hologram is created to produce the touch sensation, as this would take away from the quality of the image, the Tokyo University team's solution is to radiate airborne ultrasound that creates pressure field on user's hands.
Users don't need to wear gloves or any other mechanical attachments. When a hand or other object interrupts the propagation of ultrasound, specifically called acoustic radiation pressure, a pressure field is applied on the hand that users can feel. Called acoustic radiation pressure, it varies directly in proportion to the energy density of the ultrasound. The airborne ultrasound can be applied directly onto the skin without any risk of penetration. Guidance for the system is done via what the team calls a vision-based hand tracking system so that the pressure is exerted only when users appears to touch the holograms.
It is not known what possible applications the prototype technology would be useful for in the short term, or when it could show in production form. [via ITVT]