title: Dynamics of fingertip contact during the onset of tangential slip.
abstract: Through highly precise perceptual and sensorimotor activities, the human tactile system continuously acquires information about the environment. Mechanical interactions between the skin at the point of contact and a touched surface serve as the source of this tactile information. Using a dedicated custom robotic platform, we imaged skin deformation at the contact area between the finger and a flat surface during the onset of tangential sliding movements in four different directions (proximal, distal, radial and ulnar) and with varying normal force and tangential speeds. This simple tactile event evidenced complex mechanics. We observed a reduction of the contact area while increasing the tangential force and proposed to explain this phenomenon by nonlinear stiffening of the skin. The deformation's shape and amplitude were highly dependent on stimulation direction. We conclude that the complex, but highly patterned and reproducible, deformations measured in this study are a potential source of information for the central nervous system and that further mechanical measurement are needed to better understand tactile perceptual and motor performances.
authors.affiliation: Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Benoit
authors.initials: B
authors.lastname: Delhaye
authors.affiliation: Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lefèvre
authors.affiliation: Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium Cliniques Universitaires Saint-Luc, Physical and Rehabilitation Medicine Department, Université catholique de Louvain, Brussels, Belgium jean-louis.thonnard@uclouvain.be.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Thonnard
mesh_terms: D005260:Female; D005385:Fingers; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D014110:Touch / Q000502:physiology*
keywords: friction; skin mechanics; tactile perception; touch