Skin: Thermomechanical BehaviorBEBC1111111Hydrothermaltensile system
Hydrothermal tensile system Skin: Thermomechanical Behavior
Skin: Thermomechanical BehaviorBEBCAtypicaluniaxialtensile behaviour of pig ear skin sampleUniaxial tensilebehaviour,y=12.5%/s2.0-Pigearskin(Exp.)BHumanchestskin[Dunnetal.1985]Catbackskin[Veronda&Westmann1970]1.5(BdN)01.00.50.0400206080(%)Pigearskinis selectedpurposelyfortensiletestsduetoitshighsimilaritywithhuman skintissueDunn et al.,TheJ.Invest.Derm.,1985;Veronda &Westmann,J.Biomech.,1970,Meyer etal.,Ann.Anat.,2007
0 20 40 60 80 0.0 0.5 1.0 1.5 2.0 Uniaxial tensile behaviour, = 12.5%/s (MPa) (%) Pig ear skin (Exp.) Human chest skin [Dunn et al. 1985] Cat back skin [Veronda & Westmann 1970] Dunn et al., The J. Invest. Derm., 1985; Veronda & Westmann, J. Biomech., 1970; Meyer et al., Ann. Anat., 2007 A typical uniaxial tensile behaviour of pig ear skin sample Pig ear skin is selected purposely for tensile tests due to its high similarity with human skin tissue Skin: Thermomechanical Behavior
Skin: Thermomechanical BehaviorBEBCPigearskin,y=12.5%/sPigearskin,y=12.5%/s1.010°T(℃)370.8102-4550---60(ean)0.610470T(℃)80sd3760.410%4550-600.210870.-8010-l00.025050751002575501000ε(%)(%)
0 25 50 75 100 0.0 0.2 0.4 0.6 0.8 1.0 T ( OC) 37 45 50 60 70 80 (MPa) (%) Pig ear skin, = 12.5%/s 0 25 50 75 100 10-10 10-8 10-6 10-4 10-2 100 T ( OC) 37 45 50 60 70 80 Deg (%) Pig ear skin, = 12.5%/s Skin: Thermomechanical Behavior
Thermomechanics: MicrostructureBEBCThermal damage induced change inmechanical behavior of the skin(a)The stress-strain2.0(a)3.5(b)37°℃R°0.973.0relationship under(edN,o1)a45℃1.5R-0.942.5..50℃R0.88(ed)uniaxial tensile loading60°℃R0.892.070℃1.0R20.87S1.00.5(b)Changesinmodulus70.5afterthermaltreatment0.00.05152510203037045506070T('C)6(%)under different(c)(d)temperatures;(c)-(d) The changes ofmicrostructures of skinbefore (c)and after (d)stretch at 37° C.CollagenFiberNucleusScale bar: 10 μm
Thermomechanics: Microstructure (a) The stress-strain relationship under uniaxial tensile loading; (b) Changes in modulus after thermal treatment under different temperatures; (c)-(d) The changes of microstructures of skin before (c) and after (d) stretch at 37°C. Scale bar: 10 μm Thermal damage induced change in mechanical behavior of the skin
Thermomechanics: MicrostructureBEBCT=37 °CC1T=50°CT=45 °CThe H&E staining resultsofthermaldamageinduced microstructurechanges in skin>Longer time (i.e., 10 min)T=70 °CT=60 °C(d)(e)is need for obtainingcomparablethermal effecton the molten of the fibersScalebar:5um
➢ The H&E staining results of thermal damage induced microstructure changes in skin ➢ Longer time (i.e., 10 min) is need for obtaining comparable thermal effect on the molten of the fibers Scale bar: 5μm T=37 oC T=45 oC T=50 oC T=60 oC T=70 oC Thermomechanics: Microstructure