An Underactuated Finger for a Robotic Hand

In the paper a study on an underactuated finger for a robotic hand is presented. The mechanical hand, of which the finger is a part, is an underactuated device made of five fingers, each one having three phalanxes, operated by non-extendible tendons; thus it can be used both as robot grasping end-effector and as human prosthesesis. The mechanical behavior of the finger was studied by means of an energetic or variational approach. The latter model permits an easier computing of the constraint reaction applied to the tendon end when the displacement is imposed. Results are presented obtained both by the proposed model and by a simulation multilink code. Finally an early experimental prototype is also shown.