The motion-sensing and "bump" feedback of Nintendo's Wii video game is only a baby step compared to a magnetic-levitation device developed at Carnegie Mellon University. Most haptic, or touch, feedback interfaces use motors and mechanical linkages to provide a sense of touching or pushback. But Ralph Hollis, a research professor at the university's Robotics Institute, uses a single moving element that offers rapid responses to movements.
The result, according to the university, is a "highly realistic experience." Instead of just the bump that Wii gamers feel, users of the Hollis device can discern textures, hard contacts, and even small changes in position.
Rob Conway, a project manager at Carnegie Mellon's Center for Technology Transfer, said removing friction, backlash and sticking means the user "feels only the artificial environment in complete accuracy down to the micro scale."
A single lightweight bowl-shaped device, called a flotor, is embedded with six coils of wire. When electric current is sent through the coils, the flotor floats over the coil magnets and the user holds a control handle attached to the flotor.
The handle can be used like a computer mouse, but in three dimensions with up/down, side to side, back/forth, yaw, pitch and roll. Optical sensors measure the flotor's movement, which are reflected in its corresponding virtual object on the screen.
'Most Realistic Sense of Touch'
Hollis said that "this device provides the most realistic sense of touch of any haptic interface in the world today." The device was first constructed as a prototype in 1997, but now, with the aid of a $300,000 National Science Foundation grant, its performance has improved and its cost is lower.
Ten devices have been built and six have been distributed to other researchers in the U.S. and Canada. The researchers, at Harvard, Stanford, Purdue, Cornell, the University of Utah and the University of British Columbia, are all members of the Magnetic Levitation Haptic Consortium.
Carnegie Mellon said that, while haptic interfaces are beginning to appear in gaming systems and remote operations, there have been few opportunities for researchers to experiment with advanced magnetic-levitation devices. In addition to the continuing research, a spin-off company has been started to commercialize its use.
Richard Shim, an analyst with industry research firm IDC, pointed out that touch feedback could definitely have a broad appeal, since we "live in a touchable world." Some people have considered haptic feedback to be a gimmick, he said, but "clearly it's not." He noted that, while there are many obvious applications in gaming or training, there might be some in business as well -- such as "feeling" a graph to emphasize a point.