Holograms are cool. But holograms you can actually touch? A team of researchers from The University of Tokyo has created just such a technology. The tactile hologram, which is being shown-off this week at the SIGGRAPH conference in New Orleans, actually involves two basic pieces: A hologram, which is generated simply by shining an LCD projector onto a concave mirror, and a novel technique which creates ultrasonic waves.

The ultrasonic tech was first unveiled by the same team, led by Hiroyuki Shinoda at The University of Tokyo, at last year's SIGGRAPH conference. It uses low-energy ultrasound to create "pressure fields"--which feel akin to a blast of pressurized air. But unlike an air jet, which trails off as you get further from the source, the ultrasound waves can take on closed, localized shapes. Thus, an array of ultrasound transducers can even simulate the shape of a 3-D object:

Even if you've never heard of SIGGRAPH, you know some of the inventions that were first unveiled there (ever heard of the clickable graphic icon?). As always, this year includes a slew of amazing developments, and Tech Review has gathered five of them in this excellent post, including an augmented-reality display that lets you (virtually) redesign old toys; and a microphone device that can turn walls and tables into computer interfaces, using your fingernail as the stylus.

[Via MIT Tech Review]

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