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
Category: Robotic Hands
| 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 | | Dupont Jumper Wires | 1 kit | $7 | Wiring (inferred) |