A robotic hand comprises a base having fingers and a palm. The fingers
define a working volume. The hand is able to grasp objects between the
fingers and the palm by varying a distance from the palm to the working
volume. Varying this distance can be achieved by either moving the palm
towards the working volume or by moving the working volume towards the
palm. Robotic hands that move the palm comprise an actuator that extends
the palm from the base towards the working volume. Robotic hands that
move the working volume relative to the palm have the fingers mounted to
a common finger support unit that is configured to translate relative to
the base.