Analysis of a Novel Underactuated Robotic Finger

In this article, a unique underactuated robotic finger is designed, which is composed of an underactuated planar linkage and a spherical four-bar linkage. The robotic finger can imitate the motion of a human index finger to grasp different objects. The kinematic model of robotic finger is established, and its workspace is analyzed. The relationship between the instantaneous kinematic of the internal four-bar mechanism and the first spring is derived using the screw theory. A prototype is designed, and its self-adaptability is evaluated through the experiment of grasping some daily objects.