The Next Big Sensation?

Aren't surgeons wary of robot assistance invading their turf?

"Not here," says Okamura. "We've got the best in the world. They're real cowboys. They want the newest and best. They come down here and try the stuff out, and no matter what we're working on, they say, 'Can't you make it feel more realistic?'

"I look at them and say, 'That's my life's work.' "

Meanwhile, Kathryn Smith, the undergrad observed messing around with people's feet, wants to know if she can record the feeling of something and convey it to your brain through your skin's sense of touch, the way a microphone and speakers can pick up sound and engage your ears.

When you feel the difference between a sheet of notepaper and a sheet of sandpaper, it's because you're judging which causes your skin to vibrate more. Those skin vibrations are what your nerve endings pick up, causing your brain to read "rough."

Can a prosthetic hand be made to feel? The haptics lab's fingerlike probe can pick up the vibrations caused by rough surfaces, but how do you get that useful information to the brain? Suppose you connect the probe to what amounts to a sophisticated vibrator not unlike the one that drives an audio speaker. Suppose you place that at a sensitive part of your body -- such as your foot. Would your brain be able to use the nerve receptors there to read the roughness signal correctly?

Our touch is also exquisitely sensitive to temperature. How would you make a computer convey that? Put your hand on one of the concrete uprights on the lab's wall. It's cool to the touch. Then put your hand on a metal chase. It feels colder. A wooden desk feels warmer. Actually, they are all the same -- room temperature.

The metal "feels cold because the heat rapidly moves from my hand into the object," says David Grow, one of the haptics lab's grad students. "But it's no colder than the concrete next to it," says Okamura.

How do you teach a computer to tell your brain all that?

Okamura offers her cowl-neck sweater as an example of the difficulties. It looks like silk, but feels a little like nylon. Sure enough, the label shows plenty of silk, but also 12 percent nylon. And a little spandex. The brain's ability to process touch is an astonishing thing.

There are far more females in the haptics lab than is typical of mechanical engineering departments. Why is that?

"Part of it," says Okamura, "is that I encourage them. But it may not be too far-fetched to think that females are drawn to the idea of engineering touch. The reason I'm in mechanical engineering is that I like to put stuff together and make it work. But haptics also slops over into fields like physiology and psychology -- it's grounded in the business of figuring out exactly how humans tick. Psychology, as a field, is loaded with women."