Abstract:

Objective Wetness perception is an important sensation to evaluate whether the human body is comfortable or not. In recent years, in order to clarify the factors affecting wetness perception, scholars have mostly analyzed from two aspects, temperature and mechanical stimulation, while ignoring the influence of sensory modality on wetness perception. Therefore, in order to clarify the relationship between sensory modality and wetness perception, this paper conducts wetness perception evaluation experiments by selecting fabrics with different properties based on dynamic contact between skin and fabric.

Method For the experiment, three fabrics with comparable thickness but distinct moisture transfer properties were selected: fabric 1^#, a 100% cotton sweatband with a weft flat knit construction, exhibiting excellent moisture-wicking properties; fabric 2^#, 100% Coolmax^®, featuring a double jacquard construction and a modified polyester with a radial 6-groove structure, renowned for its superior moisture transfer capability; Fabric 3^#, a polyester-ammonia blend sweatband with a weft flat knit construction, characterized by poor moisture-wicking performance. The samples were subjected to three levels of wetness: low (L), representing 20% of the saturated water content; medium (M), at 50% of the saturated water content; and high (H), reaching 80% of the saturated water content. Among them, the experimental fabric with the level of L was used as the standard stimulus. In a subjective evaluation experiment, 21 female participants with a mean age of approximately 22 years dynamically interacted with fabrics through touch under three sensory modalities (tactile unimodal, visual-tactile bimodal, and audio-visual-tactile trimodal), and the assessments of the perceived magnitude of wetness sensation were obtained.

Results According to three-way repeated measures ANOVA, there were no significant effect of sensory modality [F (2,40) =2.463,p =0.098]and fabric type [F (2,40) =2.989,p = 0.062]on wetness perception, while a significant effect of water content [F (1.217,24.335) =109.627,p <0.001]or interactions between fabric and water content[F (2.697,53.942) =4.276,p =0.011]was found. Bonferroni's post hoc analysis displayed significant difference between the two water contents (p <0.001), with the humidity levels increasing with increasing water content in the knitted fabrics. At low level of water content, there was no significant difference on wetness perception score among fabrics; at medium level of water content, the wetness perception score of fabric 3^# (polyester) was significantly lower than other fabrics; at high level of water content, the wetness perception score of fabric 2^# (Coolmax^®) was significantly lower than fabric 3^#, while no significant difference between other fabrics. The wetness perception scores in the different sensory modalities were as follows: tactile unimodal: (4.767 ± 0.070); visual-tactile bimodal: (4.730 ± 0.052); and audiovisual-tactile trimodality: (4.941 ± 0.053). The multisensory modalities (visual-haptic bimodal and audiovisual-tactile trimodality) of moisture discrimination were greater than the tactile unimodality. Furthermore, the moisture discrimination was greater at low level than at high level humidification capacity. In addition, applying multiple regression analysis, regression equations with sensory modality, water content, and fabric type as independent variables and moisture discrimination (d') as the dependent variable is established. The results show that water content had the highest influence weight, followed by fabric type, and finally sensory modality. Together, the three independent variables explained 34% of the total variance, which was statistically significant (p = 0.032).

Conclusion This article analyzes the effects of sensory (three levels), fabric (three levels) and water addition (three levels) on skin wetting. Studies have shown that fabric and water addition have an interactive effect on skin wetness, and wettability classes increase with increasing moisture content. The audiovisual-tactile trimodality was higher on wetness perception score compared to other modalities (tactile unimodality and visual-haptic bimodal), but not statistically difference. The multisensory modalities of wetness sensitivity were greater than the tactile unimodality. By evaluating the effect of sensory modality on skin wetness sensation, the theoretical basis of multisensory genesis was enriched. In addition, the study of the effect of different interaction methods on wetness sensation can provide a reference for the comfort design of human-computer interaction. It can also be applied to fields such as sports and medicine to improve the wetness sensation experience of clothing comfort.

Key words: wetness perception, sensory modality, fabric property, theory of signal detection, dynamic contact