Measurement of the viscoelastic mechanical properties of the skin tissue under uniaxial loading

Skin as an external membrane has a key asset in the human body, i.e. heat balance and protection from the peripheral mechanical loads. The mechanical properties of the skin tissue are almost intricate under various loading conditions that may also differ according to the anatomical locations of a body. Although the mechanical properties of the skin tissue have been largely studied using different testing methods as well as different material models, the time-dependent viscoelastic mechanical behavior of the skin in different anatomical regions has not been quantified via the Quasi-linear viscoelastic model. In this study, the quasi-linear viscoelastic mechanical properties of the rat back and abdomen skins were computed under uniaxial loading. The relaxation test was carried out on the back and abdomen of eight rats and afterward the quasi-linear viscoelastic coefficients were calculated by fitting the quasi-linear viscoelastic model to the experimental stress–relaxation data. The results revealed that the peak stress in the abdomen skin samples is slightly higher than that of the back ones. Besides, the stress reached to a balance in 100 s for both the back and abdomen skin tissues in tension. The findings of this study may have implications not only for understanding the viscoelastic time-dependent mechanical behavior of the back and abdomen skin tissues but also to give a biomechanical awareness in a variety of areas such as tissue engineering, dermatology, and cosmetics industry.