RUKA

RUKA is an open-source humanoid hand from Lerrel Pinto's group at New York University, presented at RSS 2025. Its distinctive idea is to do without joint sensors altogether: five fingers with 15 underactuated degrees of freedom are pulled by tendons from forearm motors, and the mapping from motor position to joint angle and fingertip position is learned from data recorded with a MANUS glove.

That keeps the hardware down to 3D-printed parts and off-the-shelf servos, with parts costing under USD 1,300 and assembly taking under seven hours. The authors ran the hand for 20 hours continuously without overheating. Weight, load, grip force and motor type are stated neither on the project page nor in the abstract.

The repository is MIT-licensed, the paper CC BY-NC-SA 4.0. Nobody sells RUKA; anyone who wants one prints and assembles it, so there is no price. MM-Hand 1.0 takes the opposite approach with a sensor on every joint, and LEAP Hand is the other widely used open hand built from hobby servos.