A Novel 3RRS Wearable Fingertip Cutaneous Device for Virtual Interaction

We present a novel 3RRS wearable fingertip device. It is composed of a static upper body and a mobile end-effector. The upper body is located on the nail side of the finger, supporting three small servo motors, and the mobile end-effector is in contact with the finger pulp. The two parts are connected by three articulated legs, actuated by the motors. The end-effector can move toward the users fingertip and rotate it to simulate contacts with arbitrarily-oriented surfaces. Moreover, a vibrotactile motor placed below the end-effector conveys vibrations to the fingertip. The axes of the two revolute joints of each leg are parallel, so that it constitutes a 2-DoF planar articulated mechanism, constraining the motion of the center of each spherical joint on a plane fixed with respect to the upper body. The mobile end-effector has therefore 3-DoF with respect to the body. The proposed device weights 25 g for 355048 mm dimensions.