Evaluation of Tactile Sensation using Periodic Si Micro-bump Arrayed Surface with Various Bump Sizes

Abstract

In this paper, we fabricated periodic Si micro-bump structure, and sensory evaluation of tactile feeling of roughness and frictional resistance with human finger was conducted with paired comparison method. In addition, friction coefficient between the micro-bump array and an artificial urethane finger model that mimics human fingertip was evaluated. The samples had various bump sizes with width of 20∼600 µm and space of 20 µm. The space between the bumps (20 µm) was decided so that finger skin cannot enter the grooves. The result of sensory evaluation showed that rough feeling was increased with decreasing the micro bump size from 600 µm to 50 µm due to the edge effects of micro bump. The friction resistance feeling was influenced by contact area between the skin and bump surface. In addition, the friction resistance feeling was strong when the micro bump size was 50 µm. Also, the stick-slip phenomenon was strongly observed in the frictional measurement using artificial finger model.