Washington, March 5 : Carnegie Mellon University researchers have developed a touch-based computer interface that may soon provide people with a way to sense the texture of three-dimensional objects, and feel how they fit together.
Ralph Hollis, a research professor in Carnegie Mellon's Robotics Institute who has developed the new interface, says that his device uses magnetic levitation and a single moving part to give users a highly realistic experience.
He says that such features make his device quite different from most other haptic interfaces, scientific term for touch-based interface, which rely on motors and mechanical linkages to provide some sense of touch or force feedback.
The researcher says that a user can perceive textures, feel hard contacts, and notice even slight changes in position while using an interface that responds rapidly to movements.
"We believe this device provides the most realistic sense of touch of any haptic interface in the world today," said Hollis, whose research group built a working version of the device in 1997.
He and his colleagues have now improved its performance, enhanced its ergonomics, and lowered its cost. They have also built 10 copies, six of which are being distributed to haptic researchers across the U.S. and Canada.
Haptic interfaces have uses in engineering design, entertainment, assembly, remote operation of robots, and in medical and dental training.
Hollis, however, says that the full potential of haptic technology is yet to be explored, and that is why putting the instrument in the hands of other researchers is critical.
He has revealed that six devices will be delivered to researchers at Harvard, Stanford, Purdue and Cornell, as well as to the universities of Utah and British Columbia. All of them are members of the Magnetic Levitation Haptic Consortium, an international group dedicated to fostering increased use of this technology.
Hong Tan, associate professor of electrical and computer engineering at Purdue University, studies human perception of fine surface textures, something that requires simulation resolution at the micron level.
"This is beyond the capability of most commercially available haptic devices, but the maglev device developed by Dr. Hollis will make it possible for us to continue this research," she said.
Rob Conway, project manager in Carnegie Mellon's Center for Technology Transfer, said: "Carnegie Mellon's research opens new possibilities by joining the world of haptic feedback with a comfortable magnetic levitation interface. The magnetic levitation decouples the interface device from the mechanical world, eliminating friction, backlash, jump, sticking and other interfering effects, so that the user feels only the artificial environment in complete accuracy down to the micro scale."
The system eliminates the bulky links, cables and general mechanical complexity of other haptic devices on the market today in favour of a single lightweight moving part that floats on magnetic fields.
A bowl-shaped device called a flotor, which is embedded with six coils of wire, is at the heart of the maglev haptic interface. Electric current flowing through the coils interacts with powerful permanent magnets underneath, and thereby causes the flotor to levitate.
A user moves the control handle attached to the flotor much like a computer mouse, but in three dimensions with six degrees of freedom - up/down, side to side, back/forth, yaw, pitch and roll.
Optical sensors measure the position and orientation of the flotor, and this information is used to control the position and orientation of a virtual object on the computer display. As this virtual object encounters other virtual surfaces and objects, corresponding signals are transmitted to the flotor's electrical coils, resulting in haptic feedback to the user.
Hollis' team will demonstrate the new maglev haptic interfaces at the IEEE 16th Symposium on Haptic Interfaces for Virtual Environments and Teleoperator Systems, March 13-14 in Reno, Nevada.