Vibrotactile Suit
Image courtesy of Jeff Lieberman

When roboticists make the clothes, the clothes might improve the man. New vibrating robotic suits could teach wearers to perform complex movements faster and more accurately.

If you have ever struggled to learn a sport, you know that new motor skills don’t come easy. Your coach may shout commands or demonstrate her technique, but both oral and visual instructions require an awkward translation—a mapping of movements from the teacher’s body to your own. When all else fails, the coach might stand behind you, pushing and pulling your limbs through the proper motions. Research shows that this student-teacher puppetry is the most effective teaching method, but also the most difficult since no single instructor can steer all of your joints simultaneously.

Enter the robotic suit. Conforming to your body, it is a suit that can provide instantaneous feedback to every joint and help a variety of users—to tango or to recover from a stroke. “We have massage and we have sex—and basically that’s what people are used to for touch,” says Jeff Lieberman, the roboticist who envisioned this suit as a member of MIT’s Personal Robots Group. For Lieberman, the vibrotactile suit is an untapped learning tool. “It’s low-hanging fruit. It’s just waiting to be used,” he says.

Lieberman tested a suit sleeve with eight tactors—or vibration points. Wearers watched a video of a teacher’s arm performing a certain motion and then mimicked that motion. The sleeve created the equivalent of an invisible, vibration “force field.” Bending the arm too far down, for example, started a vibration on the sleeve’s bottom—too far up, started one on the sleeve’s top. At the end of test, those performing the motions with no mistakes felt no vibrations. “Here you are learning by definition,” Lieberman said. “When you are doing it right, the machine is off.”

Lieberman tested 40 subjects, 20 receiving only visual instruction and 20 visual instruction and the suit’s vibrating reminders. Over 6 repetitions, those who received the suit’s vibro-nagging learned bending motions 23 percent faster and showed a 27 percent improvement in accuracy in performing the taught motions, compared to those that only received visual instruction.

A researcher at the University of Pennsylvania’s GRASP (General Robotics, Automation, Sensing, Perception) Laboratory, Katherine Kuchenbecker, also believes in the teaching power of vibrotactile suits. “Touch has an advantage over visual and auditory communication,” says Kuchenbecker. “It’s in the framework of your body. You use it all the time to move around the world.” She will lead a National Science Foundation-funded project to develop and test a similar suit to Lieberman’s, to see if it can help stroke victims improve their reaching abilities.

Kuchenbecker describes a variety of suits now under development for a variety of purposes—almost a roboticist’s Project Runway. “This is a tipping point,” she says. “The number of new technologies and capabilities is exploding.” If these suits continue their current evolution, Kuchenbecker imagines they will appear in rehabilitation clinics within the next ten years.

Lieberman believes an essential step in that evolution is a new tracking system for the suit’s movements, as current systems have a $100,000 price tag. “No one is going to buy that for their back problems,” says Lieberman.

Dennis Miaw, a member of MIT’s Media Lab, is working on a cheaper solution, called Second Skin, which will cost a few thousand dollars. Second Skin is also more versatile. “It works in the dark. It works in sunlight . . . We are developing a motion capture system that can be used anywhere without a lot of hassle,” says Miaw.

Instead of using cameras, Second Skin will have tiny projectors that will “beam-up” individual patterns to photodetectors. Eventually, expanding on Lieberman’s research, the system will also use vibrations to teach; Miaw imagines Tai Chi.

Lieberman is now a freelance roboticist, artist, and co-host of The Discovery Channel television show Time Warp. Working with posture expert Esther Gokhale, he hopes to apply his research, engineering a suit to improve the way wearers sit, stand, and recline.

He foresees a wide variety of applications for vibrotactile technologies. “It’s just sitting there, waiting to happen,” he says. “It’s kind of nice . . . a lot of the time you have to make some sort of crazy machine.”