Anthropomorphic robotic hand grasps objects from both sides
Design and Validation of an Antagonistic Tendon-Driven Dexterous Robotic Hand with Bidirectional Operation
Robotics
Summary
Robotic hands often mimic human hands but can only grasp objects from one side, limiting how they interact with things. The authors created a human-sized, lightweight robot hand that can flex and move its fingers in two directions, allowing it to grasp things from both the palm and back sides. This new design uses special tendon routing to actively control finger movements without needing extra springs to return them. Tests show it moves precisely, applies strong fingertip force, and can perform many types of grips on both sides, making it a flexible, dexterous robotic hand.
What this means in practice
- •For prosthetic device engineers: Build advanced prosthetic hands that can grasp objects from both palm and dorsal sides, improving user functionality.$Commercial implications: Enables development of bimanual grasp-capable prosthetic hands with realistic human scale and dexterity for amputees.
- •For robotic manipulation developers: Develop robotic hands for versatile grasping tasks in cluttered environments by enabling bidirectional finger movement in a compact design.
Authors
Chunghyeon Lee, Hyukjun Kwon, Sungeon Kim, Saehyun Moon, Seokhwan Jeong
Abstract
Dexterous robotic hands typically reproduce human hand morphology but inherit its one-sided grasping workspace, requiring wrist or arm reorientation to grasp from the opposite side. Existing reversible hands generally rely on non-anthropomorphic, soft, or task-specific finger arrangements, whereas conventional five-digit anthropomorphic hands remain designed primarily for palmar-side grasping. This paper presents an anthropomorphic, human-scale (200 mm length), lightweight (220 g), 3D-printed, 17-DoF robotic hand built on a bidirectional antagonistic tendon-routing mechanism, in which flexion/extension (except the coupled joint) and abduction/adduction at joints are actively driven without passive return springs. The proposed routing mechanism allows all degrees of freedom to cross their neutral configuration and form grasp closures on either the palmar or dorsal side. Experimental evaluation demonstrates an average motor-to-joint transmission error of 3.0%, an average joint transmission bandwidth of 13.2 Hz, a maximum fingertip force of 29 N, and a positioning repeatability up to 0.15 mm. The hand further achieves a Kapandji score of 8, successfully performs all 33 GRASP Taxonomy grasp types, and performs palmar- and dorsal-side grasping tasks, validating bidirectional operation in a compact, human-scale platform.