Xiaomi 21-DoF Bionic Hand

Overview

Xiaomi's robotics team built this five-finger hand for flexible manufacturing work in its car factories. The team recorded video and motion capture of 1,827 of the 2,579 SOPs (standard operating procedures, the written steps for each manual job) across 16 workstation types. That came from the pilot center of Xiaomi Auto's intelligent manufacturing department, and the set covers over 70.8% of manual operations there. In simulation, hands with 17 to 21 DOF grasped factory parts 15% to 38% more reliably than hands with 6 to 15. Gains flattened at 23 or more, so the team settled on 21. Xiaomi first shared a tactile hand design in March 2026 and put it to work in its car factory in July.

The hand uses 26 motors. Most sit in the forearm and pull tendons, and five direct-drive joints handle low-load motions. This keeps the palm at 324 g, which lowers inertia at the wrist. Tendon tension sensors correct for tendon creep (cables slowly stretching under load), which helps fine force control. A replaceable tactile glove carries 1,500 sensing points. Worst-case power can pass 100 W per hand, so a thermal model predicts temperatures 5 to 10 minutes ahead within 3 °C. It can then reschedule tasks, lower joint torque or speed up fans. Xiaomi gives no grip force, speed or full arm weight, and it calls the hand a technical exploration with no sale plans.