BAbout this program
BiDexHand is a 16-DOF biomimetic dexterous robotic hand that mimics the kinematic structure of a human hand — complete with independent adduction/abduction for each finger and a 4-DOF opposable thumb.
The design uses a cable-and-pulley tendon system with 15 Feetech SCS0009 servos arranged in an N-configuration within the palm housing, plus a dedicated four-bar linkage for the DIP joint of each finger. The thumb has all four biomimetic degrees of freedom: CMC abduction/adduction, CMC flexion/extension, MCP abduction/adduction, and MCP flexion/extension.
Key specs:
- DOF: 16 total — 3 DOF per finger (MCP ab/ad, MCP flex/ext, PIP flex/ext + coupled DIP) × 4 fingers, plus 4-DOF thumb
- Actuation: Cable-and-pulley tendon system, 15× Feetech SCS0009 servos + servo2040 controller
- Grasps: Power grasp, pinch grasp, precision manipulation, VR teleoperation
- VR control: Meta Quest motion shadowing via WebXR (separate VR teleop repo)
- Franka integration: Full-arm VR teleoperation with BiDexHand as the end effector
- ROS 2: Full ROS 2 Jazzy packages included (motion shadowing, servo streaming, CLI)
- Design: Open CAD on OnShape, STEP + STL files in repository
V4 improvements over prior versions:
- Updated single-shear phalanx design (more durable under high-frequency grasping)
- Servo calibration modules for accurate joint position mapping
- Unified Feetech servo ecosystem throughout (SCS0009 everywhere)
- servo2040 PWM controller option alongside traditional SCS bus
MIT License. Original design by Zhengyang Kris Weng — https://github.com/wengmister/BiDexHand
🖨 Print Files (46)
plx, base.STL
plx, distal.STL
plx, support.STL
sleeve, base.STL
sleeve, servo carriage.STL
palm, coupler.STL
Required Hardware
| Item | Qty | Unit Cost | Notes |
|---|---|---|---|
| Feetech SCS0009 Serial Bus Servo | 16 | $14 | Primary actuators (V4 unified) |
| FT90M / FT90B 9g Servo (alt PWM build) | 16 | $9 | Alternative for PWM build |
| Pimoroni Servo2040 (RP2040 servo controller) | 1 | $25 | Used for PWM variant |
| ESP32 DevKit | 1 | $10 | Main MCU |
| FE-URT-1 USB to TTL adapter | 1 | $8 | Programs Feetech servos |
| SCS Signal Distribute Board | 5 | $5 | Servo bus distribution |
| Intel RealSense D405 Wrist Camera | 1 | $440 | Vision sensor (optional) |
| 6V 5A Power Supply (5.5x2.1mm) | 1 | $20 | Servo bus power |
| DuraBraid 40lb Fishing Wire | 1 spool | $12 | Tendon cables |
| 3mm OD PTFE Tube | 1m | $8 | Cable routing |
| 2mm Cable Zipties | 100 | $5 | Cable management (inferred) |
| McMaster Shoulder Screws (90323A605/A608/A604/A612) | ~24 | varies | Pivots |
| McMaster Slotted Shoulder Screws 97307A111 | 10 | varies | Pivots |
| McMaster Alloy Socket Head Screws (91290 series) | 114 | varies | Fastening |
| McMaster Sleeve Bearings (2705T112) | 26 | varies | Joint bearings |
| McMaster Stainless Round Shims (98089A201) | 16 | varies | Joint spacing |
| McMaster Compression Springs (2006N111) | 10 | varies | Return springs |
| McMaster Brass Threaded Inserts (94510A370) | 10 | varies | 3D-print inserts |