Robotic Hands Learn to 'Feel': New Tactile Sensor Allows Dexterous Manipulation

Researchers have made great strides in creating robotic hands that can lift and grip, opening up a whole new wave of prosthetics. Yet what use is a hand if it can't feel how hard it's holding something? It could accidentally tip or crush the item, making it useless to the person controlling it. Now, though, researchers have developed a way for machines to "feel" the items that they hold.

The new tactile sensor, named TakkTile, is sensitive enough to turn a brute machine into a dexterous manipulator. Unlike other tactile sensors, it's not as fragile or as expensive; other sensors cost an average of $16,000 to be placed into a robotic hand. This new one, though, is based on much simpler and cheaper fabrication methods.

The sensor uses an existing device in its construction--a tiny barometer. Barometers have the ability to sense air pressure, which allows the sensor to detect the minute differences in force that a robotic hand applies. Yet these instruments can be delicate, which is why the researchers added a layer of vacuum-sealed rubber to it which protects the barometer from as much as 25 pounds of direct pressure. Because of this, TakkTile can survive a strike from a hammer or baseball bat.

In addition to the barometer and the rubber seal, the device also relies on standard methods used in printed circuit board fabrication, along with access to a vacuum chamber. Altogether, the technique creates something that could have wide applications.

In order to test TakkTile, the researchers added it to a mechanical hand. The creation could tell what it was touching; it could pick up a balloon without popping it and even use a key to unlock a door. The sensor could potentially allow those with prosthetic hands to manipulate small or fragile objects.

Yet the sensor doesn't only have applications for the use in prosthetics. It could also be used in a range of electronic devices, such as a laparoscopic gripper that's gentle enough to tease apart tissue during surgery.

"Not everyone has the bandwidth to do the research themselves, but there are plenty of people who could find new applications and ways of using this," said Yaroslav Tenzer, co-creator, in a news release.

Whatever it's used for, the device could provide a cheaper way to allow more dexterous movement in machines. Currently, the researchers are pursuing commercial opportunities with help from Harvard's Office of Technology Development.