Science & Technology

Touch This

What is the essence of a car ashtray? That it opens and closes, and, most importantly, how big it is? How old-fashioned! At Audi right now, engineers are seriously at work on a decadent-sounding project: They are seeking the “perfect closing experience.” A new ashtray will go into mass production only when it provides “a perfect closing experience,” when the force the driver uses during its opening and closing is not too high, and when the “final snapping shut” provides satisfying feedback.

But this “closing experience” is not perceived through sight or hearing or smell—it is a haptic experience. Haptics is the field of touch, an organ that since the Middle Ages has been considered a “lower” sense. The humble sense of touch was until recently completely underestimated in the auto industry—and not just there. This organ, covering two square meters of our bodies, was experienced intuitively if at all.

Yet suddenly one hears of haptic laboratories, set up only to study touch. After exhaustive consumer testing, Mercedes will introduce new “softtouch paint” for its dashboards. Toggle switches will be evaluated for their “feeling of quality.” High-paid designers are at work on such trivial-seeming objects as the little wheel that controls the air conditioning. Audi is trying to find objective standards to measure the smoothness of surfaces and is creating a “haptic fingerprint.”

This is what they have belatedly discovered: Customers shop with their fingertips! It is trivial, of course. Just go to any auto show, and you can see how important touch is.To the dismay of the exhibitors, who constantly have to wipe and polish their cars, the first thing visitors do is touch the cars. People caress them with their hands, climb inside, rest the underside of their arms against the armrests. Even their backsides get a haptic experience. And this sensory experience is scarcely limited to drivers. Nestlé, for example, has analyzed and optimized the biting and chewing experience when it creates new snack foods. Haptic researchers discovered that in France people like their yogurt lumpier, in Switzerland, creamier. The sense of touch is undoubtedly in vogue. And it is only a question of time before “haptic design” will be a new discipline in schools.

“Cars are still full of haptic designs that have not been thought through,” says Martin Grunwald, a psychologist at the University of Leipzig and head of a lab devoted to electroencephalograms and haptic design. For example, there are seats that are manually adjustable—but not while you are driving. And the steering wheel! Is it sensible and safe to take this absolutely vital component and weigh it down with additional functions? In what car could you possibly honk the horn while turning and braking hard?

Almost every automaker producing cars today at last signed off on a very common and typical haptic paradox: to open a car door, you have to press in on the handle. Yet designers are hard at work on new paradoxes. Mercedes is testing trucks in which a single joystick will control turning, accelerating, and braking. When you brake—by pulling the joystick back, toward your body—your body slides forward, into the joystick, and gives the car more gas. “A typical case of haptic incongruence,” says Grunwald.

This psychologist is one of the few scientists in the German-speaking world working on studying the sense of touch, and he has been sought out by both car and plane manufacturers. His approach to the field, however, is medical. Grunwald got his doctorate in haptics back in the days of East Germany, in Jena. He tested people to find out how haptic information is processed and stored. The subjects, blindfolded, were asked to finger a raised surface, and later draw the surface on paper. He was struck by how one woman utterly failed the test. Her drawn reconstructions of the surface had nothing in common with reality. And she was obviously anorexic.

Since then Grunwald has researched the connection between dysfunctions in the brain region responsible for touch—the parietal cortex—and the resulting haptic problems, and anorexia, a disease that is still poorly understood.

A chance find catapulted the Leipzig researcher into the elite of international haptics studies last year. He found in his study of anorexics an effect ob-served with visual stimuli but unknown in tactile perception: The sense of touch does not operate continuously but with millisecond-long pauses, as if the brain occasionally has to commit some information to memory. This was exactly the effect that researchers at the Massachusetts Institute of Technology needed: Perfect haptic simulation, one of the top items on the agenda of MIT’s Touch Lab [Laboratory for Human and Machine Haptics], will be achieved only when we fully understand the brain’s processing of haptic information.

Researchers throughout the world are at work on haptic simulation. What they aim for is that virtual objects or processes will be not just seeable and hearable, but experienced through touch as well. The Rheinisch-Westfälische Technische Hochschule in Aachen is working on virtual tools for architects. When they model a building, they would like to be able to feel how firm or elastic its materials are. The University of Münster is working on ways to sense when fibers of the body change—by sensing their structural changes through holographic endoscopy.

A device that permits people to feel and manipulate virtual objects has been developed at MIT and is ready to be marketed by a company named SensAble Technologies. It is called Phantom, and is especially appropriate for use in medical education, where students will be able to learn unpleasant procedures such as palpitating the prostate, or difficult operations in brain surgery, through simulation. A doctor using it will not just see on the monitor what he is doing, he will feel it as well. One immediate application is in remote surgery, when a surgeon is controlling a robotic arm in a clinic far away, or in space stations—camera systems provide only relatively useful information. With Phantom, the teledoctor will be equipped with heretofore unachievable realistic conditions. If he encounters bone or cuts into a blood vessel, he will feel, through the Phantom simulation, a resistance, thanks to tactile feedback.

Martin Grunwald was able to work at the MIT Touch Lab for six months. There were some things there, and in nearby labs, that astonished him. One thing that seemed especially bizarre was a project to induce artificial haptic sensations, in which monkeys had microchips implanted in their brains. A tiny current to the brain, produced under remote control, was supposed to make the ape believe it had a banana in its hand—though there was none. There is speculation about practical applications. Some imagine that one day pilots will use this technique to fly planes remotely for thousands of kilometers. For this to work, the pilot would have to be provided with the most realistic possible inputs, from changes in pressure and position to oscillations and vibrations. These would be delivered directly, via a chip, to the region of the brain responsible for haptic information processing.

What interests researchers most is that touch is another channel for communication, one that until now has been overlooked. In this era of communication, when information input channels are notoriously overloaded and people are overstimulated, the possibility of a new communication channel has created a sensation. The pilot’s cockpit is especially interesting because fliers constantly have to deal with multiple information inputs. Some vital information is always in danger of being missed. Special suits—in which information would be input by vibrating regions or pressure points—are already under development. These vibrations and pressures would be produced in a vest that would alert a pilot’s skin that his fighter plane, for example, was flying upside-down. At night this is hard to determine, and overlooking it can be fatal.

A haptically optimized car of the future could communicate with us, too. There are 10,000 tactile receptors on the skin of one hand awaiting signals. Grunwald thinks it is ridiculous that in urban areas, where a child might jump into traffic at any moment, we are still relying on our overloaded visual sense—as we stare at the speedometer to maintain low speed.

Why not just produce a slight vibration in the steering wheel as the car goes over 30 kilometers per hour? Information could be sent to drivers via “haptic displays” that drivers could “read” with their fingertips. Or hazards could be announced by slight heat shocks in the steering wheel. Or, moving in the opposite direction, sensors could monitor the hearts and blood pressure of older drivers. And drivers who nod off could be awakened by a slap on the back.

The rehabilitation of touch, which the ancient world considered the premier sense, is apparently under way. New input channels, in a world where we are visually and acoustically overstimulated, are very welcome. Haptic displays attached to the forehead or chest with adhesives to deliver pressure and vibration information, or appropriately designed textiles, will initially be used by the military. But computer-game developers, who strive for greater realism, are just as interested.

And let us not forget those interested in virtual love games. It is already possible today for researchers to exchange haptic stimuli over the Internet to simulate handshakes. It cannot be long before people will happily throw themselves into haptic whole-body displays connected to the net. The partner at the other end will caress her opposite lasciviously with her data glove. And cybersex will finally feel right.