Friction modifications induced by the variation of the finger angular position when touching microtextured surfaces - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2023

Friction modifications induced by the variation of the finger angular position when touching microtextured surfaces

Résumé

Tactile tribology arouses many interests in the recent years, leading to numerous experimental investigations through in vivo friction testing of the fingerpad rubbing on various surfaces. Among them, many studies have been conducted with dedicated tribometers and measurement protocols allowing to reproduce more or less accurately the contact conditions of natural touch. It frequently leads to “active” friction tests in which the finger positioning, the sliding speed, and the normal load strongly differ from one experiment to another, resulting in uncertainties in the characterization of the friction behaviour. The present study aims to investigate the impact of the angular position of the finger on the friction coefficient when a subject touches micro-textured surfaces. These finely-defined textures were produced by photolithography and plasma etching in clean room. Friction tests were performed with two different “active” tribometers. Depending on the setup, the subject either tried to maintain a finger sliding speed of approximately 30 mm/s, or the surface moved under the finger at this exact speed. The subject was also asked to apply a 0.4 N normal load and was expected to maintain the angle of the finger on the surface at either 20°, 35° or 50°. The exact contact angle and sliding speed were measured afterwards through the analysis of images from video recording of each test, and both friction and normal forces signals were also acquired. Results exhibit a significant decrease of the friction coefficient (COF) when the contact angle of the finger increases. Another important finding is the strong connection between the variation of the COF as a function of the angle with the surface the finger was slid on: the extent to which the COF varies differs strongly depending on the texture characteristics. These results are also supported by an innovative method allowing to characterize the contact area and the pressure distribution into the contact. This method comprises both simulations with a Boundary Element Method (BEM) model and in vivo characterisation of the fingerpad’s elasticity, geometry, and surface topography.
Fichier non déposé

Dates et versions

hal-04530500 , version 1 (03-04-2024)

Identifiants

  • HAL Id : hal-04530500 , version 1

Citer

Louyot Etienne, Luc Carpentier, E. Chatelet, Francesco Massi, Pierre-Henri Cornuault. Friction modifications induced by the variation of the finger angular position when touching microtextured surfaces. 9th International Tribology Conference (ITC), The Japanese Society of Tribologists, Sep 2023, Fukuoka (Japan), Japan. ⟨hal-04530500⟩
5 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More