Tactile Features of Human Finger Contact Motor Primitives

The human hand interacts with the environment via physical contact, and tactile information is closely associated with finger movement patterns. Studying the relationship between motor primitives of the finger and the corresponding tactile feedback provides valuable insight into the nature of touch and informs the simulation of humanoid tactile. This research decomposed finger contact into three fundamental motor primitives: contact-on, stick-to-slip, and full slip, then examined the tactile features associated with each motor primitive, including the center of mass (COM) and the centroid of the contact pressure distribution matrix and the total contact area. The change in fingertip contact area during contact-on was in accordance with a first-order kinetic model. In the stick-to-slip, there was a generalized linear relationship between the fingertip skin stretch and the magnitude of the tangential force. Moreover, the skin stretch of the fingertip mirrored the direction of the motion. During the full slip, the COM's movement effectively represented the direction of the tangential force, with an error margin of no more than five degrees. Experiments showed that certain fingertip motions can be portrayed, transmitted, and replicated using tactile information. This research opens potential avenues for remote immersive physical communication in robotics and other related fields.