3-D Computer Designs Take Form With Magnetic Device3-D Computer Designs Take Form With Magnetic Device

Carnegie Mellon University researchers have developed a device that could allow people to feel textures and shapes of 3-D designs created on computers -- without awkward mechanical gear.

The university announced Tuesday that it could soon be possible to feel objects created on computers through a touch-based, or haptic, interface, without using gloves, similar equipment, or force feedback. One lightweight moving part floats on magnetic fields and simulates various sensations people experience when they touch real objects.

"We believe this device provides the most realistic sense of touch of any haptic interface in the world today," Ralph Hollis, a research professor in Carnegie Mellon's robotics institute, said in a news announcement.

Users move a control handle while optical sensors measure the position and orientation of the bowl-shaped device in relation to objects displayed on the computer. Electrical coils inside the device receive signals and interact with magnets, causing the unit to levitate.

Hollis developed the device, which uses only one moving part and responds quickly to movement. He has started a company to build more of the devices.

His research group created an early model in 1997 but they only recently improved its performance and lowered the cost. They also built 10 copies, which will allow distribution of six devices to university researchers and Magnetic Levitation Haptic Consortium members at Harvard, Stanford, Purdue, and Cornell, as well as universities in Utah and British Columbia.

One of the researchers, Hong Tan, studies perception of fine textures, which requires highly detailed simulation. The associate professor of electrical and computer engineering at Purdue University said Hollis' device exceeds the capability of most similar devices sold commercially.

Rob Conway, project manager in Carnegie Mellon's center for technology transfer, said that magnetic levitation eliminates the need for mechanical devices, thereby doing away with friction, backlash, jump, sticking, and similar problems created by other simulation tools. He said it allows users to feel "only the artificial environment in complete accuracy down to the micro scale."

Haptic interfaces could advance several fields, including engineering design, medical and dental training, product assembly, entertainment, and robotics. Since robotics already have improved artificial prosthetics and limbs, the combination could one day truly be remarkable.

Hollis' device has a limited range of motion compared with other haptic interfaces, but Carnegie Mellon researchers believe that can be overcome with scaling, indexing, and other methods. A $300,000 National Science Foundation grant supported recent development.

Hollis and his colleagues will demonstrate the device at the IEEE 16th Symposium on Haptic Interfaces for Virtual Environments and Teleoperator Systems, in Reno, Nev., on March 13 and 14.