Design of Bio-Inspired Robot Hand Using Multiple Types of Actuators

Many prosthetic hands are focused on appearance and grip strength, however, gestures are also one of the performances that users need for communicating with others as body language to express their feeling and intention. For this paper, the initial prototype of the gesturing robotics hand is presented by using multiple types of actuators concept to maintain its appearance while the number of degrees of freedom (DOFs) is increased. The gesture performance of this robotic hand is improved by designing 2 DOFs in each finger; therefore, the entire hand has 15 joints, 10 DOFs, and one controllable wrist joint. In the detail of the design, all actuating mechanisms of 3 joints for each finger are specifically designed to maintain the human limb appearance. The Distal Phalange joint (DIP) used a linkage mechanism to acquire the Proximal Phalange joint’s (PIP) movement by a 1:0.961 ratio due to appearance designed. The PIP joint is built with a cable-drive mechanism powered by a digital servo motor installed in the forearm. The Metacarpal joint (MCP) is driven by a micro linear actuator in the hand palm. A micro linear actuator was also selected to drive the wrist of the robot. The hand can perform 10 hand gestures follow common emoji hand gestures and holding 12 objects in the hand. The design of this bio inspired robot hand can be downloaded for educational purpose.