A biomimetic hand employing a dual actuation scheme

This paper presents a biomimetic hand that employs a hybrid actuation scheme that provides large grasping forces and swift motion. This hybrid hand is made up of a red muscle actuator used for grasping and a white muscle actuator used for fast and accurate movement. A parallel structure utilizing fully back-drivable linear motors has been adopted for the white muscle actuators. The red muscle actuators employ a Micro Hydraulic Compressor Converter (MHCC), hydraulic cylinder, and a tendon. The tendon structure enables a passive shape adaptation during the act of grasping an object. Safety in regards to impact is achieved through the back-drivability. The hybrid hand is comprised of two fingers and a thumb. The fingers and the thumb all have 2 degrees of freedom. The hybrid actuation is only applied to the fingers. The experiment results indicate that a grasping force of 94N is generated through the red muscle actuator and a 3 Hz sinusoidal motion is obtained from the white muscle actuator.