Our sense of fine touch deteriorates as we age, a phenomenon typically associated with neurological changes to the skin. However, geometric and material changes to the skin may also play an important role on tactile perception and have not been studied in detail. Here, a finite element model is utilised to assess the extent to which age-related structural changes to the skin influence the tactile stimuli experienced by the mechanoreceptors. A numerical, hyperelastic, four-layered skin model was developed to simulate sliding of the finger against a rigid surface. The strain, deviatoric stress and strain energy density were recorded at the sites of the Merkel and Meissner receptors, whilst parameters of the model were systematically varied to simulate age-related geometric and material skin changes. The simulations comprise changes in skin layer stiffness, flattening of the dermal-epidermal junction and thinning of the dermis. It was found that the stiffness of the skin layers has a substantial effect on the stimulus magnitudes recorded at mechanoreceptors. Additionally, reducing the thickness of the dermis has a substantial effect on the Merkel disc whilst the Meissner corpuscle is particularly affected by flattening of the dermal epidermal junction. In order to represent aged skin, a model comprising a combination of ageing manifestations revealed a decrease in stimulus magnitudes at both mechanoreceptor sites. The result from the combined model differed from the sum of effects of the individually tested ageing manifestations, indicating that the individual effects of ageing cannot be linearly superimposed. Each manifestation of ageing results in a decreased stimulation intensity at the Meissner Corpuscle site, suggesting that ageing reduces the proportion of stimuli meeting the receptor amplitude detection threshold. This model therefore offers an additional biomechanical explanation for tactile perceptive degradation amongst the elderly. Applications of the developed model are in the evaluation of cosmetics products aimed at mitigating the effects of ageing, e.g. through skin hydration and administration of antioxidants, as well as in the design of products with improved tactile sensation, e.g. through the optimisation of materials and surface textures.

随着年龄的增长，我们的精细触感会下降，这种现象通常与皮肤的神经系统变化有关。但是，皮肤的几何形状和材料变化也可能在触觉感知中发挥重要作用，因此尚未进行详细研究。在这里，利用有限元模型来评估与年龄相关的皮肤结构变化影响机械感受器所经历的触觉刺激的程度。开发了一个数字化的，超弹性的四层皮肤模型来模拟手指在刚性表面上的滑动。在默克尔和迈斯纳受体的位置记录了应变，偏应力和应变能密度，同时系统地改变了模型的参数以模拟与年龄有关的几何和物质皮肤变化。模拟包括皮肤层刚度的变化，真皮-表皮连接处的变平以及真皮的变薄。已经发现，皮肤层的刚度对在机械感受器处记录的刺激幅度具有实质性影响。另外，减小真皮的厚度对默克尔椎间盘有实质性影响，而迈斯纳小体尤其受皮肤表皮连接处变平的影响。为了表示老化的皮肤，包含多个老化表现的模型揭示了在两个机械感受器位点刺激幅度的降低。组合模型的结果与单独测试的衰老表现的影响之和不同，表明衰老的个体影响无法线性叠加。衰老的每种表现都会导致Meissner小体部位的刺激强度降低，这表明衰老会降低满足受体幅度检测阈值的刺激比例。因此，该模型为老年人的触觉感知退化提供了额外的生物力学解释。所开发模型的应用在评估旨在减轻衰老影响的化妆品产品中，例如通过皮肤水合和抗氧化剂的使用，以及在设计具有改善触感的产品中（例如通过优化材料和表面）纹理。因此，该模型为老年人的触觉感知退化提供了额外的生物力学解释。所开发模型的应用在评估旨在减轻衰老影响的化妆品产品中，例如通过皮肤水合和抗氧化剂的使用，以及在设计具有改善触感的产品中（例如通过优化材料和表面）纹理。因此，该模型为老年人的触觉感知退化提供了额外的生物力学解释。所开发模型的应用在评估旨在减轻衰老影响的化妆品产品中，例如通过皮肤水合和抗氧化剂的使用，以及在设计具有改善触感的产品中（例如通过优化材料和表面）纹理。