When your GPS device in your car wants you to turn right, it says “turn right” and shows the directions on a screen. The next generation of devices could tell you to turn right by letting you “feel” your way around.
Vibrations from a wearable GPS device would give directions with a pattern of pulses that the wearer would feel. Not only does this eliminate the use of maps (distracting to drivers) but for those who are visually or hearing impaired it would bypass the two most common ways devices display information.
The idea comes from Lynette Jones, a senior research scientist in MIT’s Department of Mechanical Engineering. She decided to study how sensitive skin is to vibrations, where people are most sensitive, and how touch is perceived.
To get the data she wanted, Jones designed a belt that contained small motors similar to those that cause a cell phone to vibrate and a set of sensors that tracked the vibrations as they traveled across a person’s skin. She tested the sensors on the palm of the hand, the forearm and the thigh.
She found that people actually feel the “tickling” further away than the vibrations actually transmit. On average, the “ripples” in the skin generated by the motors died down no more than eight millimeters in any direction. But the people in the study felt the motors as much as three times further away.
Another twist was which motors people were more sensitive to. They felt the vibrations from the motors as the edges than those in the center.
Skin also did funny things to vibrating motors. Since it’s relatively soft, vibrations faded out more or less quickly depending on the frequency and where on the body the scientists were looking.
Such information on skin responsiveness could help designers determine the best configuration of motors, depending where on the skin a device would be worn. And vibrations could do more than give directions. For example, while a buzz on the left may be a signal to turn that way, one that starts out soft and gets steadily more insistent could be a signal to slow down, or a way to tell a blind person that there’s an obstacle ahead.
Credit: Lynette Jones, MIT