Robotic Hand Grabs for More Flexibility

A robotic hand that could clean up messes would be a welcome roommate for any dorm-room dweller. And far from being a pipe-dream, such a hand may soon be on the market, say Harvard researchers.

The new robotic hand comes after years of work by researchers in the lab of Robert D. Howe, a professor of engineering at the School of Engineering and Applied Sciences.

Unlike most robotic hands—which are made of rigid steel—Howe’s SDM Hand is polymer-based and has flexible joints, according to Aaron M. Dollar, who helped develop the technology as a graduate student at Harvard and is now a Yale assistant professor.

“They asked, ‘How can you make the most simple hand possible that will work?’” said Leif P. Jentoft, a graduate student in Howe’s biorobotics lab.

Last week, robotics firm Barrett Technology, Inc. licensed the SDM Hand for an undisclosed sum—drawn by the hope that the hand’s novel structure could find use in a wide variety of applications.

Researchers conceived of the hand in response to a common problem in earlier models. Unlike human hands, the steel versions weren’t able to adapt to unexpected variations in their environments.

Human hands, for example, have little issue adjusting when an object—say, a mug of coffee—turns out to be smaller or in a different location than expected. But a steel hand, because of its rigidity, would likely spill the coffee or even break the mug.

The flexibility of the SDM Hand lets it conform to and grasp objects of different sizes and shapes that may not be in the position predicted—in other words, the environment found outside of the laboratory, added Dollar.

“The net result is something that is very simple but is very robust in different grasping scenarios,” Jentoft said. “As a result, in the real world, when your object isn’t exactly where you expect it to be, the hand can adapt to it and doesn’t end up damaging itself or the object.”

The potential solution has ramifications outside the household as well, since rigid hands used in manufacturing often break whenever they are struck by heavy objects, said Barrett President and CEO William T. Townsend.

Barrett expects the first robotic hands to be available in 2011, and the researchers envision the robotic hand will find uses in the household—such as helping elderly people pick up dropped objects—in prosthetics, and in factories.

“The Harvard hand is a pretty bold new approach to the whole problem,” said Townsend. “It went against everything everyone else was trying to do.”

—Staff writer Alissa M. D’Gama can be reached at adgama@fas.harvard.edu.

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