Tribology in the Hair Surface and Tactile Perception

Abstract

The alteration of hair surface properties due to hair damage results in a coarse texture for tactile feeling. The relationship between the surface properties of hair and the recognition of hair damage was investigated using unique artificial hair surface model plates engraved with an excimer laser. Four model plates that specifically represent normal and damaged states of hair were utilized for these experiments. The relative tactile feeling for the degree of hair damage of the 4 plates was evaluated by volunteers (n=10) who touched and rubbed the plates with their fingers. Simultaneously, the coefficient of dynamic friction of their fingers against the plates was measured by recording the normal and frictional forces which indicated that the plate with a wider area of artificial cuticle structure was recognized as damaged hair. Further, an irregular pattern of height and width in the cuticle structure influenced the perception of hair damage. As the friction of the fingers against the plates increased, the tactile feeling of each plate became more coarse in texture. In contrast, not all the tests of friction measured corresponded exactly with the results mentioned above. These results show that the recognition of hair damage depends on a wider cuticle and on an irregular order of cuticle structure (both in width and in height).

Keywords

• tactile feeling
• hair cuticle
• finger
• coefficient of dynamic friction
• excimer laser