Abstract
The tactile sensation of hair depends on its shape and mechanical properties. However, scientific analysis of hair bundles during the combing process is not a lot. This study explored hand movements and mechanical stimuli using an in-situ tactile sensing system to uncover the physical origin of tactile sensation and the attractiveness of three hair bundle types: straight, curly, and wavy. The straight hair type received the highest attractiveness score (6.9 ± 2.5), closely associated with the sensations of smoothness and slipperiness. While a higher smoothness score correlated with a smaller vertical force F(z), with a value exceeding eight at F(z) < 1.2 N, a higher slippery sensation score correlated with a smaller moment M(x), with a value surpassing eight at M(x) < 0.15 N m. Smooth and slippery sensations were implicated as the dominant factors of hair attractiveness. The smooth sensation arises when fingers glide through the hair during hand-combing without encountering resistance, while the slippery sensation is perceived as fingers pass through the ends of the hair with minimal force.