Validating a Device for Measuring the Coefficient of Dynamic Friction of the Fingertip Pad Coefficient of Dynamic Friction Measurement

Abstract

This study presents the results of a pilot study that validated a device designed to estimate the coefficient of dynamic friction of the fingertip pad. Coefficients of dynamic friction between the skin of the index finger and test plates of five textures were estimated for six Asian males while exerting 1, 10, 20 Newton normal forces. The test plates were made of polycarbonate with100%, 75%, 50% or 25% skin contact areas. The results showed that the coefficients of dynamic friction increased as the contact area increased, and decreased as the exerted normal force increased. The measured coefficients of dynamic friction were also compared to the results reported by Bobjer et al.’s article appeared in print on 1993. Two-sample t-test statistical analysis was used to evaluate the differences between the mean values of the coefficients of dynamic friction obtained in these two studies. Out of fifteen test plate-normal force combinations, only one test plate-normal force combination showed statistically significant difference in the coefficients of dynamic friction. In conclusion, the device designed and fabricated at the Chaoyang University of Technology (CYUT) Occupational Ergonomics Laboratory can serve the purpose to characterize the coefficient of dynamic friction between the fingertip pad and surface of potential handle materials where more subjects should also be recruited in the near future to further verify the results.