Wandering spiders climb vertically and walk upside‐down on rough and smooth surfaces using a nanostructured attachment system on their feet. The spiders are assumed to adhere by intermolecular van der Waals forces between the adhesive structures and the substrate. The adhesive elements are arranged highly ordered on the hierarchically structured attachment hair (setae). While walking, it has been suggested that the spiders apply a shear force on their legs to increase friction. However, the detailed mechanical behavior of the hair's structures during attachment and detachment remains unknown. Here, gradients of the mechanical properties of the attachment hair on different length scales that have evolved to support attachment, stabilize adhesion in contact, and withstand high stress at detachment, examined by in situ experiments, are shown. Shearing helps to self‐align the adhesive elements with the substrate. The study is anticipated to contribute to the development of optimized artificial dry adhesives.

中文翻译：

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多个机械梯度负责蜘蛛附着头发的强粘附力。

流浪蜘蛛通过脚上的纳米结构附着系统垂直爬升并在粗糙和光滑的表面上上下颠倒行走。假设蜘蛛网是通过粘合剂结构和基底之间的分子间范德华力而粘附的。粘合元件在层次结构化的附着头发（刚毛）上排列有序。有人在行走时建议蜘蛛在腿上施加剪切力以增加摩擦。然而，在附着和分离过程中头发结构的详细机械行为仍然未知。在此，显示了通过原位实验检验的附着长度在不同长度尺度上的机械特性的梯度，这些梯度已演变为可支持附着，稳定接触中的附着力并承受分离时的高应力。剪切有助于使粘合元件与基材自对准。预期该研究将有助于优化人工干胶的开发。