Imagine studying to be a surgeon, and using a computer simulation that can accurately convey the sensation of cutting into flesh or applying pressure to human organs.

The field of haptics, which refers to devices that can convey this sense of touch, took a big step forward March 4 when researchers at Carnegie Mellon University demonstrated a controller that allows computer users to manipulate three-dimensional images and explore virtual environments not only through sight and sound, but also by using their sense of touch.

The controller, which is expected to be used mainly for research, training, and industrial purposes, comes very close to the sensitivity of the human hand.

Using magnetic fields, the haptic device replicates the response a hand might have to textures and gravitational forces, said Ralph L. Hollis, the Carnegie Mellon professor who developed the controller.

“We believe this device provides the most realistic sense of touch of any haptic interface in the world today,” he said.

The controller—like a joystick topped with a block that can be grasped—has just one moving part and rests in a bowl-like structure connected to a computer. Two of the controllers can be used simultaneously to pick up and move virtual objects on a monitor.

In a March 4 demonstration, visitors to Hollis’s lab were invited to move an image of a pin across a plate of various textures, causing the controller to bump along ripples, vibrate across fine striations, and glide across smooth areas.

On one computer, users could “feel” the contours of a virtual rabbit.

Hollis said his researchers have built 10 of the devices, six of which were to be sent to other universities across the United States and Canada: Stanford, Harvard, Purdue, Cornell, Utah, and the University of British Columbia. Hollis also has formed a new company, called Butterfly Haptics, that will begin marketing the device commercially in June or July.

The controller, which Hollis said will cost “much less” than $50,000, could enable a would-be surgeon to operate on a virtual human organ and sense the texture of tissue, for example, or give a designer the feeling of fitting a part into a virtual jet engine.

Hollis and his research team built an initial version of the device in 1997, but refined it—and lowered its cost—in recent years with the help of a National Science Foundation grant.

“We have gone from the prototype to a much more advanced system that other researchers can use,” he said in a statement.

Haptic devices are not new, and such technology is fast becoming more sophisticated, Hollis noted. Vibrating cell phones and some automotive accessories and video games already convey physical sensations to users.

In 2003, eSchool News reported on a haptic device created by researchers at the University of Buffalo that enables one person to experience the sense of touch felt by another across the internet.

But according to Hollis, the system developed at Carnegie Mellon differs from other technologies that simulate hand responses to touch, because it relies on a part that floats in a magnetic field rather than on mechanical linkages and cables.

This so-called magnetic levitation, or maglev, technology is more accurate and precise, essentially creating a direct connection between the computer and the hand, Hollis said.


Butterfly Haptics LLC

Carnegie Mellon University’s Robotics Institute