Boston Dynamics Drops the Pinky on Atlas' New Humanoid Hand

Boston Dynamics has unveiled the newest hand for its Atlas humanoid. The four-fingered hand has 13 degrees of freedom (DOF), is directly actuated, and is designed for mass manufacturing.

The company said it did not set out to build a complicated hand. Instead, it aimed for a reliable one capable of using tools.

Earlier versions of the Atlas hand had seven degrees of freedom and were built to grasp a wide variety of objects. With the new design, Boston Dynamics is shifting its focus from grasping to manipulating those objects.

Alberto Rodriguez, director of robot behavior for Atlas, said the team weighed questions such as whether the hand should have one thumb or two, or a pinky at all. He said most of those questions have no straight answers and come down to trading off competing objectives.

The hand omits the pinky entirely and is built for high-fidelity simulation, enabling sim-to-real reinforcement learning (RL). Boston Dynamics said it kept transparent direct actuation at the joints, using a single actuator type.

As in the Atlas body, the actuators are fully encapsulated, with no fragile cables crossing the joints.

The new hand can slide its thumb tip along the length of all other fingers and across their width. It can perform dexterous pinch grasps between the thumb and any other finger, as well as dexterous tripodal grasps.

The hand also supports triggered tool grasps, including drills, power torque drivers, grinders, nail guns, and welding torches.