TL;DR: New patents reveal the upcoming Optimus V3 hand ditches bulky finger motors for a slick, tendon-driven system housed in the forearm.
Hands are notoriously the hardest part of a humanoid robot to build. Tesla just revealed exactly how they plan to pull it off. Newly published patents show the Optimus V3 hand uses a tendon-driven system that mimics human biology.
Instead of stuffing motors directly into the fingers, Tesla shifted the actuators up into the forearm. From there, thin cables act like tendons. They run straight through the wrist and pull the fingers into position. Each finger gets four degrees of freedom. The wrist gets two.
This solves a massive engineering headache. Packing motors into hands makes them heavy and clumsy. Tesla’s new design uses a clever transition zone in the wrist to stop the cables from rubbing or stretching. They also ditched old-school pin hinges for flexible, layered joints that bend naturally.
Elon Musk has repeatedly said the hand is the trickiest part of the Optimus project. These patents prove they are optimizing for mass production. We caught a tiny glimpse of this hand back at the Cybercab event in October 2024. Now we know exactly what is inside.