The Anthro-Thumb: A Biomimetic Soft Robotic CarpoMetaCarpal (CMC) Saddle Joint for the Thumb

Abstract Robotic hand design is multifaceted, with the design of robotic thumbs often oversimplified for ease of manufacture, control, and reliability. While soft robotics presents a plethora of design possibilities, this paper delves into the conception, evolution, and evaluation of a unique bio-inspired soft thumb. By harnessing the biologically accurate mechanisms of the CMC joint, this research seeks to enhance the functionality of tendon-driven robotic hands. The introduced Anthro-Thumb is a biomimetic soft robotic thumb, providing a comprehensive range of motion at the thumb’s base, all the while ensuring cost-efficiency and reduced mechanical intricacy. A holistic overview of thumb bio-mechanics is presented, extracting relevant biological data and juxtaposing it with the prevailing trends in robotic thumb systems. When subjected to the Kapandji physiotherapy test, the design secured a commendable score of 9. The findings affirm that employing biomimetic soft structured robotic CMC saddle joints is a promising strategy to navigate the intricacies associated with robotic thumb development in robotic hands.