Although we’re no strangers to robotic hands here at Medgadget, we can’t say we’ve seen anything quite like what a team of researchers from the German Aerospace Center’s (DLR) Institute of Robotics and Mechatronics have come up with. Unlike existing robotic hands, DLR’s design incorporates tendons with variable stiffness. By changing the tension in its tendons, the hand is able to absorb high impact shocks, such as being hit with a baseball bat. In addition to its impressive resiliency, the hand has 19 degrees of freedom, and can exert up to 30 newtons of force at its fingertips.
From IEEE Spectrum:
Why build such a super strong hand?
Markus Grebenstein, the hand’s lead designer, says that existing robot hands built with rigid parts, despite their Terminator-tough looks, are relatively fragile. Even small collisions, with forces of a few tens of newtons, can dislodge joints and tear fingers apart.
“If every time a robot bumps its hand, the hand gets damaged, we’ll have a big problem deploying service robots in the real world,” Grebenstein says.
To change its stiffness, the DLR hand uses an approach known as antagonistic actuation. The joints of each finger are driven by two tendons, each attached to one motor. When the motors turn in the same direction, the joint moves; when they turn in opposite directions, the joint stiffens.