Fingertip skin friction plays a critical role during object manipulation. We will describe a simple and reliable method to estimate the fingertip static coefficient of friction (CF) continuously and quickly during object manipulation, and we will describe a global expression of the CF as a function of the normal force and fingertip moisture. Then we will show how skin hydration modifies the skin deformation dynamics during grip-like contacts. Certain motor behaviours observed during object manipulation could be explained by the effects of skin hydration. Then the biomechanics of the partial slip phenomenon will be described, and we will examine how this partial slip phenomenon is related to the subjective perception of fingertip slip.
Biography: Prof. Thonnard is an accomplished expert in the field of fingertip biomechanics and dexterous manipulation of objects. His main research interests are tactile spatial resolution and tactile roughness discrimination, mechanical properties of fingertip-object contact, dynamics of precision grip during object manipulation, dexterous manipulation in microgravity. He is Professor at the Institute of Neuroscience of UCLouvain in Belgium. He has more than 140 refereed scientific papers (total number of citations in September 2019: 5400; h-index: 41; Source: Google Scholar).