An anonymous reader quotes a report from The Guardian: Researchers in Southampton have built a device that displays 3D animated objects that can talk and interact with onlookers. A demonstration of the display showed a butterfly flapping its wings, a countdown spelled out by numbers hanging in the air, and a rotating, multicolored planet Earth. Beyond interactive digital signs and animations, scientists want to use it to visualize and even feel data. While the images are similar, the device is not the sort of holographic projector that allowed a shimmering Princess Leia to enlist Obi-Wan Kenobi’s help in Star Wars. Instead, it uses a 3D field of ultrasound waves to levitate a polystyrene bead and whip it around at high speed to trace shapes in the air.
The 2mm-wide bead moves so fast, at speeds approaching 20mph, that it traces out the shape of an object in less than one-tenth of a second. At such a speed, the brain doesn’t see the moving bead, only the completed shape it creates. The colors are added by LEDs built into the display that shine light on the bead as it zips around. Because the images are created in 3D space, they can be viewed from any angle. And by careful control of the ultrasonic field, the scientists can make objects speak, or add sound effects and musical accompaniments to the animated images. Further manipulation of the sound field enables users to interact with the objects and even feel them in their hands. “The images are created between two horizontal plates that are studded with small ultrasonic transducers,” reports The Guardian. “These create an inaudible 3D sound field that contains a tiny pocket of low pressure air that traps the polystyrene bead. Move the pocket around, by tweaking the output of the transducers, and the bead moves with it.”
In the journal Nature, researchers describe how they’ve improved the display to produce sounds and tactile responses to people reaching out to the image.
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