Jachowicz J, McMullen R, Prettypaul D
International Specialty Products, Wayne, NJ, USA.
Skin Res Technol. 2007 Aug;13(3):299-309. doi: 10.1111/j.1600-0846.2007.00229.x.
BACKGROUND/PURPOSE: The mechanical properties of the skin have been previously analyzed by a number of different techniques including torsional analysis, cutometery, gas-bearing electrodynamometry, etc. The objective of this work is to present quantitative analysis of skin rheology by a technique termed indentometry.
The instrument used was a texture analyzer, which is a mechanical tensiometer simulating the process of touch. The experiments were carried out on human subjects as well as on artificial skin models. They included indentometry tests performed by using spherical probes with various geometrical dimensions as well as stress relaxation and creep experiments. The experimental data were interpreted by using the Hertz theory of contact mechanics and by calculation of fundamental parameters such as the modulus of elasticity.
The calculated Young's modulae for skin models ranged from 5.5 x 10(4) to 17.7 x 10(4) N/m(2), while the corresponding values for forearm and facial skin of ten panelists were found to be in the range of 0.7 x 10(4) -3.3 x 10(4) N/m(2). In addition, stress relaxation and creep experiments were conducted, which permitted the assessment of the viscoelastic properties of skin. The results of these measurements were interpreted within the framework of the Kelvin-Voigt model of delayed elasticity leading to the calculation of viscosities and relaxation times. Indentomeric data, obtained by varying the diameter of the indentor and the indentation depth, are also discussed.
The indentometric analysis for both in vivo skin and artificial skin models could be interpreted by using the Hertz theory of contact mechanics. The loading and unloading indentometric curves could be used to assess the viscoelasticity of the investigated materials while creep and stress relaxation processes were analyzed quantitatively by the Kelvin-Voigt model with one relaxation time.
背景/目的：先前已通过多种不同技术分析皮肤的力学性能，包括扭转分析、皮肤角质层测定法、气浮电动测功法等。本研究的目的是通过一种称为压痕测定法的技术对皮肤流变学进行定量分析。
所使用的仪器是一台质地分析仪，它是一种模拟触摸过程的机械张力计。实验在人体受试者以及人工皮肤模型上进行。实验包括使用具有不同几何尺寸的球形探头进行的压痕测定测试以及应力松弛和蠕变实验。通过使用接触力学的赫兹理论并计算诸如弹性模量等基本参数来解释实验数据。
计算得出的皮肤模型的杨氏模量范围为5.5×10⁴至17.7×10⁴N/m²，而十名小组成员的前臂和面部皮肤的相应值在0.7×10⁴ - 3.3×10⁴N/m²范围内。此外，还进行了应力松弛和蠕变实验，这使得能够评估皮肤的粘弹性。这些测量结果在延迟弹性的开尔文 - 沃伊特模型框架内进行解释，从而计算出粘度和松弛时间。还讨论了通过改变压头直径和压痕深度获得的压痕测定数据。
体内皮肤和人工皮肤模型的压痕测定分析均可通过使用接触力学的赫兹理论进行解释。加载和卸载压痕测定曲线可用于评估所研究材料的粘弹性，而蠕变和应力松弛过程则通过具有一个松弛时间的开尔文 - 沃伊特模型进行定量分析。
