Design of a highly biomimetic and fully-actuated robotic finger

Abstract

During design a mechanical structure such as a robotic finger, modeling parts and designing joints are two timeconsuming steps. This paper presents a method for design and fabrication of a humanoid robotic finger that intends to mimic the human finger in terms of tendon, bones, ligaments and the pulley systems which aims to generate a mechanism rapidly. The method is inspired by the anatomy and biomechanics of human hand, and focuses on bones, joints and actuation systems, with the aim of creating a customised finger that has the similar degrees of freedom and ranges of motion of a human finger. Specifically, we propose to create the personalised 3D models of finger's bones by adapting a template to the data acquired by scanning the real hand, which are then fabricated by 3D printing. Low cost and easy-to-get materials such as Nylon cables and silicon rubber are used to build the tendon sheaths and the joints. We design a 3 layer cascade cable driven system built upon eight driven cables and four servo motors for simulating all possible four Degree of Freedom (DOF) of the finger. As a result, we present a highly biomimetic and fully-actuated robotic finger, which can achieve more DOFs and larger ranges of motion compared to existing humanoid robotic hands. Particularly, the experiments validate that our robotic finger is capable of achieving all 11 standard finger gestures as a human fìnger.