Physical properties and tactile sensory perception of microtextured molded plastics

We developed molded plastic samples with microscale textured features, and investigated the relationship between the tactile sensory response and the physical properties of the surfaces. Samples with various pitch features, and features with various height protrusions were prepared. Changes in the tactile sensory perception of the surfaces were correlated with the magnitude of the fluctuation in the coefficients of friction that occurred as a fingerprint moved across the surface, caused by the intrusion of the features of the textured surface into the grooves of the fingerprint. This occurred when the pitch of the features on the textured surface approached that of the pattern of the fingerprint; the height of the features was not significant. A change in the tactile perception of the surfaces occurred when the pitch of the features at the surface was approximately 100 μm.