Boston Dynamics has given Atlas a new 4-finger hand built to use human tools, not just grab boxes.

- Production target: 100K hands a year

- 13 degrees of freedom, up from 7 on the old 3-finger hand, so Atlas can now move objects inside its hand instead of only gripping them

- No pinky: a 5th finger would cost 3 more actuators and add another part that can break, and engineers agreed after taping their own pinky and ring fingers together for a day

- A 4-DOF opposable thumb can slide along every finger and pinch against any of them, which enables in-hand reorientation and catching a slipping grasp

- Fingers splay sideways, so the hand can hold a tool handle while working its trigger, covering drills, grinders, nail guns and welding torches

- It's still strong enough to carry a loaded minifridge weighing 100lb+

- Every joint uses the same sealed, direct-drive motor with no cables crossing joints, and each actuator pack swaps out as a single unit, so repairs stay quick and cheap

- It feels contact 2 ways: backdrivable motors sense force through the joints, while tactile pressure sensors cover the fingertips and palm

- The hand behaves predictably enough to simulate accurately, so RL can train it virtually, since human-wearable gloves record motion but miss the fast force control dexterity needs

- Early policies trained only in simulation already run on the real hand using motor feedback alone, though Boston Dynamics calls these initial results

https://x.com/BostonDynamics/status/2105659276425298012/video/1