Résumé
A good gripper can adapt itself on any grasped object and ensure contact pressure as homogenous as possible. A gripper that provides a uniform contact pressure is said to be isotropic. Another feature of a gripper is its dexterity, which can be improved by under-actuation. This paper presents the design of a three-phalanx pseudo-isotropic under-actuated finger with anthropomorphic dimensions. Contact forces depend on the gripper folding angles and the transmission torque ratio between unactuated joints. In order to ensure a grasping as isotropic as possible two cams were used. The isotropy is checked up by recalculation of the contact forces.