Design and Experiments of a Underactuated Finger

This paper presents the design of a simple underactuated finger mechanism. The finger has 1 degrees of actuation (DOAs) and 3 degrees of freedom (DOFs), and can perform adaptive grasping. The grasping methods of fingers are classified into three-phalanx and single-phalanx contacts. The working spaces of a single finger was analysed. In addition, the principle of virtual work was used to analyse the conditions of θ1 >90° and θ1 <90° in three-phalanx contact and perform static analysis of single-phalanx contact. The under-actuation and self-adaptability of the manipulator were verified through the Grab experiment, and the force in the grasping process was investigated to analyse the establishment of static equilibrium in different cases