A new mechanical hand: Theoretical studies and first prototyping

mechanical underactuated hand is proposed. The hand can be used as robot grasping end-effector and, mainly, as human prosthesis. The peculiarity of the underactuated mechanism permits to move five fingers with an only actuator, so that each of the tendons will move the phalanxes of each of the fingers adjusting themselves to self-adapting their mechanical configuration to the surface shape of the grasped object. The tendon are un-extendible, so that each finger will grasp the object ever with the same force, independently of the surface shape. The force will be controlled just by the only actuator force. Preliminary kinematic and dynamic studies are presented together with early tests on a prototype