Unitree G1 Dex3-1 Force Control Three Finger Dexterity Hand

Unitree G1 Dex3-1 Force Control Three Finger Dexterity Hand

In Unitree’s ecosystem, Dex3-1 is positioned as an advanced optional hand for G1 configurations that require more than basic grippers. The design emphasizes multi-joint articulation, force control, and optional tactile sensing, enabling the robot to interact with objects using controlled grip forces and more human-like finger coordination.

Dexterous hands are especially important in humanoid robotics because they convert locomotion-focused robots into practical mobile manipulators. For the G1 platform, the Dex3-1 hand supports tasks that involve variable object geometries (tools, bottles, handles, test pieces), delicate placement, and controlled contact—useful in academic labs, demonstrations, and industrial prototyping.

Design and Features

Three-finger architecture optimized for humanoid manipulation

Dex3-1 uses a three-finger layout—typically described as a thumb, index finger, and middle finger—to provide a balance between dexterity and mechanical simplicity. Unitree’s published parameters specify that the thumb has 3 active degrees of freedom, while the index finger has 2, and the middle finger has 2, for a total of 7 degrees of freedom (DOF) per hand.

This arrangement supports common manipulation patterns such as pinching (thumb-index), tripod grasps (thumb-index-middle), and stable enclosure grasps for small-to-medium objects.

Force-controlled joint design for stable gripping

A key differentiator of the Dex3-1 is its force-control capability, which enables controlled gripping pressure rather than purely position-based finger motion. Unitree describes the hand as using micro brushless force-control joints, combining both direct-drive and geared actuation methods: 6 micro brushless force-control joints with direct drive and 1 micro brushless force-control joint with gear drive.

Force control improves handling stability and reduces the risk of dropping objects or crushing fragile items, which is especially beneficial for research demonstrations and repetitive grasp cycles.

Optional tactile sensor arrays for contact awareness

Dex3-1 is commonly described as supporting optional tactile sensing, with public listings and product summaries stating that one hand can be configured with 33 tactile sensors for multi-point contact feedback.

Tactile feedback allows more advanced interaction behaviors such as detecting initial contact, adjusting grip force dynamically, and improving robustness when object positions vary. In practical robotics use, tactile sensing can also improve dataset quality for manipulation learning experiments and contact-rich tasks.

Industrial-grade bearing structure for precision and load handling

Unitree’s G1 product materials reference industrial-grade crossed roller bearings for hand joints, highlighting precision movement and load capacity as part of the mechanical design approach.
Crossed roller bearings are frequently used in robotics where compact packaging, high stiffness, and repeatable joint positioning are required.

Compact form factor suited for humanoid wrists

Dex3-1 is designed to be lightweight and portable for humanoid integration. Unitree’s published body parameters list:

• Weight: 710 g

• Size: 175 × 88 × 77 mm

This compact geometry supports practical operation without overly increasing arm inertia, which can affect balance and motion smoothness on humanoid platforms.

Technology and Specifications

Core kinematic specifications (Degrees of Freedom)

The Dex3-1 hand is specified as 7 DOF total, distributed across the three fingers:

• Thumb: 3 DOF

• Index finger: 2 DOF

• Middle finger: 2 DOF

This DOF allocation is designed to support grasp shaping and finger alignment rather than full five-finger anthropomorphic replication, which typically increases mechanical complexity.

Actuation and transmission

Dex3-1 uses a mixed transmission architecture:

• 6 motors driving directly (direct drive)

• 1 motor using gear drive

Direct-drive joints are often favored for force control and compliance behavior because they reduce backlash and can improve responsiveness in torque/force regulation.

Tactile sensing (optional)

Public specifications frequently reference 33 tactile sensors per hand in tactile-enabled versions.
Some vendor catalogs also distinguish between variants “with tactile sensing” and “without tactile sensing” in complete robot packages.

Physical characteristics

Unitree’s published Dex3-1 body parameters include:

• Weight: 710 g

• Dimensions: 175 × 88 × 77 mm

These characteristics are important for integration planning, especially for labs evaluating payload limits and wrist dynamics on humanoid arms.

Compatibility context: Unitree G1 modular configurations

The Unitree G1 platform is presented as modular, and official documentation references optional force-control three-finger hands as part of expanded configurations. In the Unitree G1 SDK developer documentation, the “single hand degrees of freedom” section references 7 DOF optional force-controlled three-finger hand as a supported configuration element.

Applications and Use Cases

1) Research manipulation and grasping experiments

Dex3-1 is well-suited to robotics research tasks that require repeatable grasps and controlled contact force. Typical lab applications include:

• object pick-and-place with orientation control

• grasp stability evaluation under motion

• dataset generation for imitation learning or reinforcement learning

• force-sensitive manipulation experiments (squeeze, hold, release)

Because it is force-controlled by design, it can support contact-rich trials where position-only hands often struggle.

2) Education and humanoid robotics training

In university programs and training labs, Dex3-1 enables demonstrations of key concepts such as:

• finger kinematics and joint coordination

• force control fundamentals (grip force regulation)

• tactile/contact sensing (with tactile variants)

• grasp planning and motion execution

These capabilities make it suitable for robotics curricula that move beyond walking and balance into practical manipulation.

3) Industrial prototyping and tool interaction pilots

For industrial prototyping, the ability to grasp irregular objects and handle tools is a major value driver. Dex3-1 can be used in controlled pilots for:

• handling small industrial components

• turning knobs or pulling handles (scenario-dependent)

• positioning sensors or measuring devices

• sorting objects in a lab mockup environment

While production-grade automation may require specialized end-effectors, a three-finger dexterous hand provides a flexible baseline for testing workflows quickly.

4) Demos, exhibits, and human-like interaction scenarios

Dex3-1 supports gestures and object interactions that are visually compelling in demonstrations:

• handing over objects

• controlled grasp-and-lift sequences

• fine placement into marked positions

• stable holding during humanoid motion

For humanoid platforms, expressive and stable hand behavior can significantly improve perceived capability and the clarity of technical demos.

Advantages / Benefits

Force control for improved grasp stability

A force-controlled hand can regulate grip pressure during contact, improving reliability when object weight, shape, or friction varies. Dex3-1’s force-control design and micro brushless joint approach are positioned to support such handling improvements.

Practical dexterity without five-finger complexity

By using a three-finger layout with 7 DOF, Dex3-1 targets common real-world grasp patterns (pinch and tripod grasps) while avoiding the added complexity of five-finger, high-DOF anthropomorphic hands.

Optional tactile sensing for advanced manipulation workflows

With up to 33 tactile sensors per hand in tactile-enabled versions, Dex3-1 supports contact-aware behaviors that can be difficult to achieve with vision-only grasping.

Lightweight form factor for humanoid integration

With a listed weight of 710 g and compact dimensions, the Dex3-1 hand is well-sized for wrist-mounted integration without excessively increasing inertial load on humanoid arms.

FAQ Section

What is the Unitree G1 Dex3-1 Three-Finger Dexterous Hand?

The Unitree Dex3-1 is a force-controlled, three-finger dexterous robotic hand designed for the Unitree G1 humanoid robot, providing 7 degrees of freedom for more precise and adaptable manipulation.

How does the G1-DEX3-3FINGERHAND work?

Dex3-1 uses micro brushless force-control joints, combining direct-drive actuation and gear-driven actuation to move finger joints while enabling controlled gripping force during contact.

Why is the Dex3-1 dexterous hand important?

Dexterous hands allow humanoids to grasp real objects reliably. Dex3-1 adds multi-joint finger control and optional tactile sensing, enabling more stable grasps, better object alignment, and more practical manipulation research workflows.

What are the benefits of the Unitree Dex3-1 hand?

Key benefits include force-controlled gripping, 7-DOF dexterity, compact size and low weight, and optional 33-point tactile sensing for contact-aware manipulation.

Summary

The Unitree G1 Dex3-1 Force Control Three-Finger Dexterous Hand (G1-DEX3-3FINGERHAND) is a compact, research-oriented humanoid end-effector designed to deliver practical manipulation capability through 7 degrees of freedom, force-controlled micro brushless joints, and optional tactile sensing (commonly referenced as 33 tactile sensors per hand). With a lightweight 710 g design and modular compatibility within the Unitree G1 platform, Dex3-1 is widely used to enable stable grasping, precise placement, and advanced contact-aware manipulation in education, research labs, and industrial prototyping workflows.