EgoThumb adds a robotic thumb that helps grasp and hold objects
EgoThumb: A Vision-Driven Supernumerary Robotic Thumb for Autonomous Grasp and Holding Assistance
Robotics
Summary
People sometimes need a third thumb to help hold and use objects better with one hand. The authors created EgoThumb, a small extra robotic thumb controlled by a camera on the hand. The system watches the hand and object to guess what you want to do and moves the thumb automatically. It works well with different people and objects and is openly available for others to build or improve.
What this means in practice
- •For prosthetics manufacturers: Integrate EgoThumb technology to create lightweight, vision-based robotic thumbs that assist users in complex single-hand tasks.$Commercial implications: Enables marketable robotic thumb products enhancing hand dexterity for users needing extra grasping support.
- •For assistive device developers: Develop assistive robotic devices that autonomously support holding and manipulating objects by decoding user intent visually.
Authors
Jianyu Hou, Jiawei Fu, Weikang Wan, Minghui Jiang, Jiajun Li, Hao Su
Abstract
Supernumerary robotic fingers augment human dexterity by enabling a single hand to perform complex "hold-and-manipulate" tasks that typically require bimanual coordination. However, existing devices are often hindered by bulky hardware that limits interaction to large objects and rely on explicit hand motion triggers that lack environmental context. To address these challenges, we present EgoThumb, a fully open-source, vision-driven supernumerary robotic thumb. EgoThumb features a compact, dual tendon-driven finger whose actuation is relocated to the forearm, reducing distal weight while enabling precise active joint control. The system utilizes a visual imitation learning policy that maps egocentric images from a palm-facing camera directly to continuous joint positions. By implicitly decoding human intent from visual cues capturing both the hand and the object of interest, EgoThumb achieves robust autonomous manipulation and strong generalization across diverse users and environments. All hardware designs and software implementations are fully open-sourced at https://ego-thumb.github.io.