Modular, underactuated anthropomorphic robot hand with flexible fingers and twisted string actuators

Abstract

For general grasping, a strong lightweight and compact robot hand needs to be designed as a robot end effector. This paper describes the design of a 3D printed anthropomorphic robot hand that actuates flexible fingers using Twisted String Actuators (TSAs). A total of 6 of these actuators were fitted within a limited confined space, the palm of the hand. This gives the hand 6 Degrees of Freedom (DOFs) 2 in the thumb and 1 in each of the other fingers. A simple modular design was used which allows for rapid prototyping of different finger designs with respect to different requirements at low cost. In this paper, only power grasping is considered for simplicity. The hand is capable of performing both spherical and cylindrical grasps whereby the flexible nature of the fingers allows for forming around the geometry of a target object. The maximum holding load of the hand was found to be 10 kg in performance tests.