The hair of mammals varies in diameter across species from ∼60 μm in humans to over ∼400 μm in giraffes and elephants. Here, we establish that the tensile strength of hair generally decreases with increasing diameter. Although there is a commonality in the morphology of the hair in such differing species as they all possess a cortex surrounded by cuticles, there are also significant differences in the hierarchical structure that contribute to the observed differences in strength. In this work, the internal structure of the hair from different species is examined, with some unique peculiarities in javelina and capybara hair uncovered. The dimensional dependence of hair strength is compared using Weibull predictions. The good correlation of the strength of hair using such Weibull analysis suggests that the failure strength is dictated by the probability distribution of flaws within the cortex.

哺乳动物的毛发直径各不相同，从人类的约60μm到长颈鹿和大象的约400μm以上。在这里，我们确定头发的拉伸强度通常随着直径的增加而降低。尽管在这些不同的物种中，头发的形态具有共同点，因为它们都具有被表皮包围的皮层，但是在层次结构上也存在明显的差异，这有助于观察到强度的差异。在这项工作中，检查了来自不同物种的头发的内部结构，并发现了标枪和水豚头发的一些独特特征。使用Weibull预测比较头发强度的尺寸依赖性。