A computer controller levitated by magnets provides a new way to physically experience virtual objects.
The “maglev” system has benefits over more mechanical haptic controllers – computer interfaces that stimulate the user’s sense of touch – and its inventors are now working to commercializing the technology.
Haptic technology has uses ranging from remote medical breast checks and exploring distant lands, to recreating the feel of fabrics.
But most haptic interfaces to date rely upon gloves or robotic arms to provide feedback to a user. The complex mechanics involved increases weight and friction that can make it difficult to provide a natural feel.
To solve that, Ralph Hollis and colleagues at Carnegie Mellon University, Pittsburgh, US, developed a haptic device with just one moving part (see video, top right).
A bowl with electromagnets concealed below its base contains a levitating bar that is grasped by a user and can be moved in any direction. The magnets exert forces on the bar to simulate the resistance of a weight, or a surface’s resistance or friction. LEDs on the bar’s underside feed back its position to light sensors in the bowl.
This approach has “huge potential”, says Anthony Steed, a haptics researcher at University College London, UK. “This system gets rid of the mechanical linkages that are a major constraint on most haptic devices.”
The maglev interface can exert enough force to make objects feel reassuringly solid, says Hollis, resisting as much as 40 newtons of force before it shifts even a millimeter.
That’s enough to feel the same as a hard surface and better than most existing interfaces, he says. “Current devices feel very mushy, so it’s hard to simulate a hard surface.”
The device can track movements of the bar as small as two microns, a fiftieth the width of a human hair. “That’s important for feeling very subtle effects of friction and texture,” says Hollis.
And it can exert and respond to all six degrees of freedom of movement – moving along or rotating about each of the three dimensions of space (forward/backwards, left/right, up/down).
Via New Scientist
