CRAFT: A Tendon-Driven Hand with Hybrid Hard-Soft Compliance

2026-03-12

AI Summary

This work addresses the imbalance between rigidity and compliance in dexterous hands during contact-intensive manipulation, which often leads to poor impact resistance and limited load-bearing capacity. To overcome these limitations, the authors propose a tendon-driven anthropomorphic hand that innovatively integrates a hybrid hard–soft compliant structure: soft materials are embedded at the joints to absorb impacts, while rigid linkages are retained to ensure high payload capability and motion accuracy. The design further incorporates rolling-contact joints and a 15-motor fingertip actuation layout. Integrated with an open-source vision-based teleoperation and simulation platform, the hand demonstrates high repeatability, robustness, and exceptional durability in experiments, successfully achieving stable grasps of fragile and low-friction objects across all 33 Feix grasp types, with a total hardware cost under $600.

Technology Category

• Intelligent Robots: Manipulation
• Humans and AI: Interaction Techniques and Devices
• Computer Vision: Biometrics, Face, Gesture & Pose

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Economics, Online Markets and Human Computation: The sharing economy
• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications

Abstract

We introduce CRAFT hand, a tendon-driven anthropomorphic hand with hybrid hard-soft compliance for contact-rich manipulation. The design is based on a simple idea: contact is not uniform across the hand. Impacts concentrate at joints, while links carry most of the load. CRAFT places soft material at joints and keeps links rigid, and uses rollingcontact joint surfaces to keep flexion on repeatable motion paths. Fifteen motors mounted on the fingers drive the hand through tendons, keeping the form factor compact and the fingers light. In structural tests, CRAFT improves strength and endurance while maintaining comparable repeatability. In teleoperation, CRAFT improves handling of fragile and low-friction items, and the hand covers 33/33 grasps in the Feix taxonomy. The full design costs under $600 and will be released open-source with visionbased teleoperation and simulation integration. Project page: http://craft-hand.github.io/

Problem

• tendon-driven hand
• hybrid compliance
• contact-rich manipulation
• anthropomorphic hand
• grasping fragile objects

Innovation

• hybrid hard-soft compliance
• tendon-driven hand
• rolling-contact joints
• anthropomorphic manipulation
• open-source robotic hand