Effect of Fiber Type, Water Content, and Velocity on Wetness Perception by the Volar Forearm Test: Threshold Detection Test

Abstract

Two kinds of evaluation methods were applied to gain insight into how fabrics affect the perception of wetness under dynamic skin contact at different velocities. In a previous study, the stimulus intensity rating was tested by applying a fixed amount of water to fabric samples to determine the quantitative ratings for the intensity of the perception of wetness. In this study, the perceived threshold was determined by supplying water continually until the level of wetness was just-detectable. The results indicated positive correlations between the fabric coefficient of friction, the water spreading speed, and the wetness perception threshold, and there were negative correlations between fabric wetting time, skin cooling rate, and wetness perception threshold. However, no correlation between wetness threshold and maximum transient thermal flow (Qmax) was found in this study. The wetness threshold can be predicted by wetting time and coefficient of friction (R2 = .70, p < .001). The threshold detection was qualified to evaluate the sensitivity to wetness at the initial detection of moisture on the skin, while the stimulus intensity rating would give a better prediction at the moisture absorption stage. This study provided the evaluation technology for designing sportswear, leisurewear, and health-care products with desirable wetness levels.

Comparison of reality and illusion of wetness on soft materials and the multisensory perceptual space of wetness illusion

“…All the experiments were conducted in a climate-controlled chamber with the temperature at 20 ± 2°C, the relative humidity at 65% ± 5%, and the air velocity below 0.4 m/s, to enable the participants to maintain a thermoneutral state. 14,15…”

“…According to previous studies, 3,15,16 the surface temperatures were set at 8°C, 13°C and 18°C in experiment 1 and 10°C and 15°C in experiment 2. To avoid perceptual differences due to individual initial skin temperature variation, participants’ finger temperature was adjusted to 30°C by heating (Figure 2(j)) or cooling (Figure 2(a)) before each touch.…”

“…Experiment 2: Effect of material properties on wetness illusion. According to experiment 1, the main characteristics of the wetness illusion by touching soft materials lie in the coldness, softness, and surface roughness, according to previous studies, 14,15,20 which are essentially influenced by surface temperature, thickness, and dynamic friction of the material. Thus, experiment 2 (Figure 3(c)) aimed to investigate the effect of these three parameters on wetness illusion.…”

“…All the experiments were conducted in a climatecontrolled chamber with the temperature at 20 AE 2 C, the relative humidity at 65% AE 5%, and the air velocity below 0.4 m/s, to enable the participants to maintain a thermoneutral state. 14,15 According to previous studies, 3,15,16 the surface temperatures were set at 8 C, 13 C and 18 C in experiment 1 and 10 C and 15 C in experiment 2. To avoid perceptual differences due to individual initial skin temperature variation, participants' finger temperature was adjusted to 30 C by heating (Figure 2(j)) or cooling (Figure 2(a)) before each touch.…”

A review of advances in tribology in 2020–2021

“…The effect of sliding direction was shown to influence finger tactile perception, friction, and dynamics [750]. A wide range of applications were made, including in cosmetics [751], textile industry [752], virtual reality [753], and sports [754,755]. The role of friction was examined in a brain-computer interface, for people with visual impairments [756] and limb reconstruction and comfort [757].…”