title: Effect of fingerprints orientation on skin vibrations during tactile exploration of textured surfaces.
abstract: In humans, the tactile perception of fine textures is mediated by skin vibrations when scanning the surface with the fingertip. These vibrations are encoded by specific mechanoreceptors, Pacinian corpuscules (PCs), located about 2 mm below the skin surface. In a recent article, we performed experiments using a biomimetic sensor which suggest that fingerprints (epidermal ridges) may play an important role in shaping the subcutaneous stress vibrations in a way which facilitates their processing by the PC channel. Here we further test this hypothesis by directly recording the modulations of the fingerpad/substrate friction force induced by scanning an actual fingertip across a textured surface. When the fingerprints are oriented perpendicular to the scanning direction, the spectrum of these modulations shows a pronounced maximum around the frequency v/lambda, where v is the scanning velocity and lambda the fingerprints period. This simple biomechanical result confirms the relevance of our previous finding for human touch.
authors.affiliation: Laboratoire de Physique Statistique; ENS, Universités Paris 6 & Paris 7, CNRS, Paris, France. alexis.prevost@lps.ens.fr
authors.forename: Alexis
authors.initials: A
authors.lastname: Prevost
authors.forename: Julien
authors.initials: J
authors.lastname: Scheibert
authors.forename: Georges
authors.initials: G
authors.lastname: Debrégeas