An underactuated mechanical hand: A first prototype

In the present paper a model of an underactuated tendon driven mechanical hand is proposed. The aim of the activity was to study the possibility of realization of a mechanical hand five fingers, the movement of which is realized by the use of one only actuator. The mechanism is conceived as an hand prosthesis. The main particularity of the device essentially consist in that it is based on an adaptive scheme. In this way it is possible to obtain that the three phalanxes of each of the fingers adapt their rotation to the grasped object shape. This will be obtained by non-extendible tendons. So each finger will grasp the object surface independently on the configuration of the finger itself and independently on the configuration of the other fingers.