25 joints, tendon-driven: a hand for the humanoid robot 1X that can truly “touch the world,” delivering an impressive demonstration

1X introduced a new-generation robotic gripper for its NEO humanoid robot, featuring 25 degrees of freedom and tendon-driven actuation, claiming it has near-human dexterity and strength, and can also sense force and slips and react instantly.
(Background: Musk predicted that in 5 years, there will be at least 100 million humanoid robots worldwide, even 1 billion.)
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Most humanoid robots’ hands can basically do three things: grasp, release, and push. How much force they apply, and whether the item slips off, is not easy for them to sense quickly. But on the 9th, 1X unveiled the new-generation hand for its NEO humanoid robot: 25 degrees of freedom, tendon-driven, with official claims that it is approaching human-level dexterity, strength, and reliability. In the actual videos released by the company, you can see that the robot’s finger agility really has reached a new level, sparking discussion in the community.

From two-finger pinch grippers to 25 joints

Most humanoid robots use two-finger pinch grippers, while NEO’s new hand has 25 degrees of freedom—22 in the fingers and palm, and 3 in the wrist— all natively capable of force control and can be backdriven.

Put simply, if you push a single finger, it will yield according to the force you apply while also reporting back how much you pushed it. Behind this is “1X tendon drive”: replacing a traditional gearbox with a tendon system featuring a low gear ratio, roughly 5:1 to 15:1, far lower than the 100:1 to 200:1 gear ratios common in the industry. The lower the ratio, the less of the force gets “eaten up” by friction before it reaches the fingertips, so the hand actually feels what it’s touching.

In terms of specs, peak torque at the thumb base (CMC joint) is 3.5 Nm, the knuckle joint (MCP) is 2.6 Nm, the maximum flexion force at the fingertips is 45 N, the wrist torque is 17.75 Nm, and the positioning accuracy is ±0.2 mm. The entire hand is also built to IP68 for waterproofing and uses food-grade materials. In the official demo video, NEO can even wash its own hands.

The distribution of the 25 degrees of freedom also follows human anatomical proportions, with a particular emphasis on the thumb—so it can truly generate gripping force when opposing the other four fingers, rather than just having the thumb positioned symbolically as a prop.

The hand is the sensor itself

1X’s framing is: cameras are passive observers, but the hand is an active experiment—it uses its strength to ask questions, then reads the answers from the same set of joints. Most robotic hands are “write-only” devices: you issue commands, the hand moves into place, and then there’s no meaningful feedback signal sent back.

NEO, by contrast, is “read and write”: each joint is closed-loop, which creates proprioception—without needing to look, the hand itself knows what posture it is in. Achieving this relies on a direct-drive design: the motors pull the tendons almost directly, with no layered gearboxes in the middle that chew up the signal. In simple terms, with that layer of gearbox removed, the hand can “hear” the sound of what it’s touching.

Combined with high-resolution tactile sensors distributed across the fingertips and palm, it outputs normal force, contact location, and shear force. The company calls this “force transparency.” This allows NEO to instantly detect when an object is starting to slip in the hand and react accordingly—especially critical for objects that are small, transparent, easy to deform, or occluded, where vision alone can’t identify them.

According to the official demo video, NEO assembles LEGO bricks, picks up a single coin or screw from a wallet, twists a light bulb, uses a screwdriver, helps zip up a jacket, sorts grapes by color, pours tea, catches a soft ball, plugs in a USB-C charging cable, wipes down a tabletop, and even communicates using sign language.

On reliability, 1X states that zero components and the entire set of fingers have already gone through tens of millions of test cycles, and the wrist joints have been verified to exceed 2 million times under high loads. With the extremely low gear ratio plus tendon-driven actuation, external impacts can safely “backdrive” the fingers—getting slapped, struck with a hammer, or even trapped in a drawer—so the hand yields and moves aside instead of hard-colliding and breaking.