The skin properties, structure, and performance can be influenced by many internal and external factors, such as age, gender, lifestyle, skin diseases, and a hydration level that can vary in relation to the environment. The aim of this work was to demonstrate the multifaceted influence of water on human skin through a combination of in vivo confocal Raman spectroscopy and images of volar–forearm skin captured with the laser scanning confocal microscopy. By means of this pilot study, the authors have both qualitatively and quantitatively studied the influence of changing the depth-dependent hydration level of the stratum corneum (SC) on the real contact area, surface roughness, and the dimensions of the primary lines and presented a new method for characterizing the contact area for different states of the skin. The hydration level of the skin and the thickness of the SC increased significantly due to uptake of moisture derived from liquid water or, to a much lesser extent, from humidity present in the environment. Hydrated skin was smoother and exhibited higher real contact area values. The highest rates of water uptake were observed for the upper few micrometers of skin and for short exposure times.

No abstract

No abstract

Summary To simulate temperature rise of human skin and to predict burn injury during radiant heat exposure, the traditional method is to use a sensor to simulate skin surface and use a numerical model to simulate heat transfer in inner skin. However, the numerical models of skin burns are based on few experimental data of nude skin and some simplifications of human skin characteristics. In this study, a new multi‐layered skin simulant is presented for low radiant heat exposures up to 15 kW/m2. The skin simulant has implanted thermocouples into layered polydimethylsiloxane (PDMS) materials with controlled thermal properties and thicknesses of the skin layers. The multi‐layered skin simulant developed in this study has a good reproducibility for temperature measurements with similar temperature rise profiles compared with human skin except at skin surface. For burn injury prediction, the results of our PDMS skin model can be linearly corrected using ASTM model as a reference. Our developed skin simulant provides an advanced method to directly simulate the heat transfer inside human skin in a multi‐layered structure rather than using the combined physical sensor‐numerical model in the traditional way.