Study on tactile illusion of stiffness feeling by surface roughness

Abstract

In this study, we focus on the tactile illusion of stiffness feeling by surface roughness. Human factors on tactile illusion is analyzed from the viewpoint of the fingertip stiffness and finger motion. Specifically, five types of samples with different surface roughness are fabricated. Sensory evaluations for the stiffness feeling and the roughness feeling are conducted. Also, the fingertip stiffness and fingertip force when the panelists touch the samples are measured. As a result, it is confirmed that tactile illusion on stiffness due to surface roughness occurs to some panelists. And it is shown that the tactile illusion is less likely to occur in panelists with hard fingertips. Moreover, the panelists with tactile illusion are classified into two groups based on the relationship between the surface roughness and the stiffness feeling. And it is suggested that each group has characteristics in the relationship between the touch motion and fingertip stiffness.