Fingertip Friction of a Braille Display and Neural Correlates
Roland Bennewitz, Novaf Özgün, Christiane Petzold, Angelika Gedsun,
René Hensel, Eduard Arzt, and Daniel J. Strauss
INM – Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
Friction plays an important role in the perception of materials by touch. We present results of a study on neural response to sudden changes in fingertip friction. Electroencephalographic (EEG) signals where recorded while a Braille display was sliding along the fingertip of passive participants. Event-related EEG potentials were observed when the dots of the Braille display were raised or lowered. The challenges encountered in the application of tens of identical friction stimuli for statistical analysis of the EEG signals provide interesting insights into fingertip viscoelasticity and friction.
Moving from the Braille display to materials with a well-defined surface microstructure, we present results of a study on friction between fingertips of human subjects and elastomer samples with fibrillar surfaces, which were actively explored by the participants. Systematic differences in friction between samples and between participants are discussed. First results for the perceived similarity of surface microstructures will be presented.