A mechanical finger has a base adapted to be connected to an actuator for being displaced in at least one degree of actuation, and has two or more phalanges. A first phalanx is rotationally connected at a proximal end to the base, and a second phalanx is rotationally connected at a proximal end to a distal end of the first phalanx. A transmission linkage providing at least one rotational degree of freedom (DOF) between the base and a distal-most one of the phalanges. Passive rotational DOF joints are between the phalanges, between the base and the first phalanx, and in the transmission linkage, whereby the mechanical finger has a passive state of actuation in which the base, the at least two phalanges and the transmission linkage remain in a constant orientation relative to one another through displacement of the base caused by the actuator absent a contact of one of the phalanges with an object, and a grasping state of actuation in which a contact of at least one of the phalanges with an object causes a variation of the orientation of at least one of the phalanges relative to the base through displacement of the base caused by the actuator.