Overview
BrainCo Revo 3 is an intelligent biomimetic dexterous hand engineered for industrial automation, scientific research, and advanced robotics applications. Featuring 21 independently driven motors for 21 active degrees of freedom, it delivers extreme dexterity within a compact, lightweight, and highly biomimetic form factor. Equipped with industrial-grade RS-485, CAN FD, and EtherCAT interfaces, Revo 3 ensures reliable operation in demanding electromagnetic environments. Supported by a complete cross-platform C/C++ and Python SDK suite compatible with Linux and Windows, it enables high-frequency, low-latency control and seamless secondary development.
Key Features
- 21-DoF Fully Active Biomimetic Layout: Equipped with 21 independent motors supporting full finger opposition, abduction/adduction, and biomimetic motion. It reproduces human-like dexterity and multi-posture adaptive grasping. Fully direct-driven with back-drivability, low latency, rapid response, and industry-leading channel density.
- High-Resolution Tactile Sensing: Integrated distributed high-sensitivity tactile arrays enable real-time contact state detection and adaptive grasping of fragile, soft, and irregular objects.
- High Reliability & Environmental Durability: Joint bending lifespan exceeds 1,000,000 cycles. Qualified through drop, impact, vibration, load, temperature extremes, and salt spray tests for long-term industrial and outdoor reliability.
- Developer-Friendly & Robotics Ecosystem Ready: Comprehensive C/C++ and Python SDKs alongside ROS support allow seamless integration with mainstream robotics platforms and open-source algorithm demos, accelerating research and engineering workflows.
Product Dimensions
Product Parameters
Standard styles: Bionic Silver (supporting Left/Right hands laterality, customizable in bulk)| Category | Parameter | Revo 3 U21 | Revo 3 U21T | Revo 3 U21VT |
|---|---|---|---|---|
| Degrees of Freedom | Total DoF | 21 (Direct drive & fully back-drivable) | 21 (Direct drive & fully back-drivable) | 21 (Direct drive & fully back-drivable) |
| DoF Distribution | Four fingers 4×4 DoFs, Thumb 5 DoFs | Four fingers 4×4 DoFs, Thumb 5 DoFs | Four fingers 4×4 DoFs, Thumb 5 DoFs | |
| Dimensions | Hand Dimensions | 216 × 108 × 50 mm | 216 × 108 × 50 mm | 216 × 108 × 50 mm |
| Operating Parameters | Supply Voltage | 16–85 V | 16–85 V | 16–85 V |
| Max Current | 10 A (24V) | 10 A (24V) | 10 A (24V) | |
| Max Active Grip Force | ≥100 N | ≥100 N | ≥100 N | |
| Max Fingertip Pinch Force | ≥25 N | ≥25 N | ≥25 N | |
| Total Hand Load | 20 kg | 20 kg | 20 kg | |
| Four-finger Load | 5 kg | 5 kg | 5 kg | |
| Repeatability | 0.1° | 0.1° | 0.1° | |
| Joint Open/Close Speed | 0.33 s | 0.33 s | 0.33 s | |
| Motion Range | Motion Capability | Kapandji opposition test full score Covers 33 grasp types (Feix, GRASP, Taxonomy) | Kapandji opposition test full score Covers 33 grasp types (Feix, GRASP, Taxonomy) | Kapandji opposition test full score Covers 33 grasp types (Feix, GRASP, Taxonomy) |
| Min Grasping Diameter | 10 mm | 10 mm | 10 mm | |
| Max Grasping Diameter | 150 mm | 150 mm | 150 mm | |
| Hardware Configuration | Communication Interface | EtherCAT / CAN FD / RS-485 | EtherCAT / CAN FD / RS-485 | EtherCAT / CAN FD / RS-485 |
| Communication Frequency | 500 Hz | 500 Hz | 500 Hz | |
| Sensors | IMU (Mainboard), Temperature (Mainboard) | IMU (Mainboard), Temperature (Mainboard) | IMU (Mainboard), Temperature (Mainboard) | |
| Control Modes | Position, MIT Force/Position, Current, Admittance, Impedance | Position, MIT Force/Position, Current, Admittance, Impedance | Position, MIT Force/Position, Current, Admittance, Impedance | |
| Tactile Module | Tactile Distribution | / | Full-hand tactile | Full-hand tactile |
| Tactile Type | / | Full-hand piezoresistive array | Full-palm piezoresistive array + Fingertip vision-tactile | |
| Array Elements / Points | / | 416 | 301 (Piezoresistive) + 2000 (Vision-tactile) | |
| Force Range | / | 0–20 N | 0–20 N | |
| Resolution | / | 0.01 N | 0.01 N |
Parameter Description
Degrees of Freedom Distribution
Revo 3 provides 21 fully active independently driven degrees of freedom, faithfully replicating human anatomy with high biomimetic fidelity:
- Thumb: 5 active DoFs—carpometacarpal abduction/adduction (CMC Abd), carpometacarpal axial rotation / opposition (CMC Rot), metacarpophalangeal flexion/extension (MCP Flex), proximal interphalangeal flexion/extension (PIP Flex), and distal interphalangeal flexion/extension (DIP Flex). This layout reproduces human-like thumb opposition, precision pinch, and complex grasping postures.
- Index, Middle, Ring, and Pinky: 4 active DoFs per finger from base to tip—lateral abduction/adduction (Abd), metacarpophalangeal flexion/extension (MCP Flex), proximal interphalangeal flexion/extension (PIP Flex), and distal interphalangeal flexion/extension (DIP Flex). This enables independent finger actuation, coordinated multi-finger grasping, and delicate manipulation aligned with ergonomic principles.
Physical distribution diagram of the 21 fully active independently driven degrees of freedom (motors) of the Revo 3 smart dexterous handJoint Motion Range
The physical achievable joint motion range (corresponding to the physical float parameters in the SDK interface) for each joint is listed in the table below:
| Active Joint | Degree of Freedom (DoF) | Min Angle | Max Angle |
|---|---|---|---|
| Thumb | CMC Abd (Carpometacarpal Abduction/Adduction) | 0° | 110° |
| CMC Rot (Carpometacarpal Axial Rotation) | 0° | 105° | |
| MCP Flex (Metacarpophalangeal Flexion) | 0° | 75° | |
| PIP Flex (Proximal Interphalangeal Flexion) | -10° | 90° | |
| DIP Flex (Distal Interphalangeal Flexion) | -20° | 90° | |
| Index | Abd (Lateral Abduction/Adduction) | -10° | 30° |
| MCP Flex (Metacarpophalangeal Flexion) | -5° | 90° | |
| PIP Flex (Proximal Interphalangeal Flexion) | -10° | 90° | |
| DIP Flex (Distal Interphalangeal Flexion) | -20° | 90° | |
| Middle | Abd (Lateral Abduction/Adduction) | -20° | 25° |
| MCP Flex (Metacarpophalangeal Flexion) | -5° | 90° | |
| PIP Flex (Proximal Interphalangeal Flexion) | -10° | 90° | |
| DIP Flex (Distal Interphalangeal Flexion) | -20° | 90° | |
| Ring | Abd (Lateral Abduction/Adduction) | -25° | 20° |
| MCP Flex (Metacarpophalangeal Flexion) | -5° | 90° | |
| PIP Flex (Proximal Interphalangeal Flexion) | -10° | 90° | |
| DIP Flex (Distal Interphalangeal Flexion) | -20° | 90° | |
| Pinky | Abd (Lateral Abduction/Adduction) | -30° | 10° |
| MCP Flex (Metacarpophalangeal Flexion) | -5° | 90° | |
| PIP Flex (Proximal Interphalangeal Flexion) | -10° | 90° | |
| DIP Flex (Distal Interphalangeal Flexion) | -20° | 90° |
Control Modes
| Control Mode | Target Parameters | Detailed Description |
|---|---|---|
| Current Mode | Target Current | Pure current closed-loop control operating as low-level single-loop torque control. The system regulates motor current directly to deliver fixed torque without position or velocity constraints. Joint compliance allows passive following of external forces without rigid resistance, ideal for compliant interaction, lead-through teaching, zero-resistance dragging, and adaptive surface conforming. |
| Position (Trajectory) Mode | Target Position, Kp, Kd | High-precision position closed-loop control based on trajectory planning. Built-in smooth acceleration/deceleration algorithms generate continuous, jerk-free profiles while Kp/Kd parameters damp oscillations and eliminate overshoots. Ensures accurate point-to-point positioning and smooth gesture transitions for standardized precision tasks. |
| MIT Mode | Target Position, Target Velocity, Feedforward Torque, Kp, Kd | Multi-dimensional hybrid closed-loop control coupling position, velocity, and feedforward torque through configurable stiffness and damping. Delivers dynamic trade-offs between precision and compliance, allowing responsive adaptation to external contact forces. Ideal for embodied AI, dynamic grasping, adaptive manipulation, and reinforcement learning policy transfer. |
💡 More Control Modes Coming Soon
Additional advanced control modes (such as impedance control, admittance control, and intelligent adaptive grasping) will be released in upcoming firmware and SDK updates. Stay tuned.
Device ID Specifications
In the RS485 bus network topology, the default Left Hand ID for both Revo 2 and Revo 3 dexterous hands is 126, the default Right Hand ID is 127, and the Broadcast ID is 0.
In multi-device topologies, developers can configure unique IDs to identify and control the left and right hands separately. Sending instructions to Broadcast ID 0 will control all dexterous hands on the bus simultaneously.
Power-On Reset & Calibration
Power-on self-reset refers to the dexterous hand automatically executing physical position calibration upon power-on. The system will search for the starting position of each finger, and all fingers will open during this period.
⚠️ Critical Safety Notes for Power-On Calibration
- Note 1 (Drop Risk): During the process of position calibration, if the hand is holding any object, there is a potential risk of the object falling.
- Note 2 (Control Prerequisite): After the hand is powered on, a position calibration must be executed once before it can be controlled normally.
Communication Interface
The Revo 3 dexterous hand communicates through RS485, CAN FD, or EtherCAT interfaces.
Physical Connector Specifications
| Interface | Connector Model | Description |
|---|---|---|
| 485 | A1257WV-S-2P-6T | RS485 communication interface |
| CAN FD | A1257WV-S-2P-6T | CAN FD communication interface |
| EtherCAT | A1257WV-S-5P-6T | EtherCAT communication interface |
| VCC | XT30UPB-M | Main power supply interface |
| VBTS | A1257WV-S-10P | Tactile/sensor data transmission expansion interface |
When performing physical wiring and debugging, please pay close attention to the following guidelines:
🔌 Power Supply & Bus Security
- Power Budget: Since the Revo 3 integrates 21 independent motors, instantaneous current can be high under heavy loads or when multiple fingers are gripping. Use a stable 24V DC power supply with a power rating of at least 100W to reduce voltage drop risk.
- Bus Wiring: At 5M baud rate, use shielded twisted pair cables for the RS485 bus and keep the wiring length as short as possible to reduce signal reflection and noise.