Dexterous Hand

A robotic hand with multiple independently moving fingers, capable of fine manipulation.

A dexterous hand is a multi-fingered end effector mounted on a robot arm, built to mimic the structure of a human hand, typically with 3 to 5 fingers and a dozen to two dozen joints. Compared with a gripper, which can only open and close, it can pinch, grip, twirl a pen, twist open a bottle cap, and reposition an object within the hand itself (in-hand manipulation) — making it a key component for general-purpose manipulation on humanoid robots. The hard part is packing many degrees of freedom into very little space: motors, gearboxes, and sensors all have to fit inside the palm and fingers, usually driven through tendons, linkages, or miniature lead screws; controlling it is also harder because its action space has many dimensions, and collecting training data for it is difficult. Dexterous hands are usually specified by “active degrees of freedom” (the joints actually driven by a motor), which is often fewer than the total number of joints.

ExampleOpenAI's Dactyl project in 2019 used a Shadow Dexterous Hand to solve a Rubik's Cube one-handed.

Also called

Multi-fingered Hand, Five-fingered Hand

Related

Dexterous Manipulation · In-hand Manipulation · End Effector · Active DoF / Passive DoF · Shadow Dexterous Hand · Tendon-Driven Actuation

Sources

Shadow Hand - Wikipedia
OpenAI 2019: Solving Rubik's Cube with a Robot Hand (arXiv 1910.07113)