Objective This paper aims to characterize the tensile and compressive behaviors of skin tissue under different temperatures and to study the effect of temperature and corresponding dermal collagen denaturation on the mechanical properties of skin tissue.Methods The uniaxial tensile and compressive tests of fresh pig ear skin under different temperatures have been performed by using two specifically-designed hydrothermal experimental systems.Results In tensile tests,the skin stiffness decreases with increased temperature,while a contrary trend is observed in compressive tests.Conclusion The results show that temperature has a great influence on both tensile and compressive properties of skin tissue,but the mechanisms are different.The variation of skin tensile properties is caused by the thermal denaturation of skin collagen with increased temperature,while the variation of skin compressive behavior of skin tissue may be due to the hydration change with thermal denaturation.

Objective To test the hypothesis that collagen is a significant determinant of skin viscoelasticity,with particular attention paid to the thermomechanical properties of skin under dynamic loading.Methods Differential scanning calorimetry (DSC) was used to detect the denaturation of dermal collagen and assess its thermal stability.The DSC results obtained with various heating rates were used to derive the Arrhenius parameters in burn damage integration,which were subsequently used to calculate the degree of denatured collagen in the skin.The dynamic mechanical analyzer (DMA) was employed to evaluate the changes in skin viscoelastic properties as a function of temperature and collagen damage.Results The results showed remarkable changes in storage modulus,possibly due to the release of water,whilst there was no significant change in loss factor.Conclusion These results suggest that at a fixed frequency the denaturation of collagen molecules has a large effect on the viscoelastic behavior of skin tissue.