Since the discovery of the mechanism of adhesion in geckos, many synthetic dry adhesives have been developed with desirable gecko-like properties such as reusability, directionality, self-cleaning ability, rough surface adhesion and high adhesive stress. However, fully exploiting these adhesives in practical applications at different length scales requires efficient scaling (i.e. with little loss in adhesion as area grows). Just as natural gecko adhesives have been used as a benchmark for synthetic materials, so can gecko adhesion systems provide a baseline for scaling efficiency. In the tokay gecko (Gekko gecko), a scaling power law has been reported relating the maximum shear stress σmax to the area A: σmax ∝ A−1/4. We present a mechanical concept which improves upon the gecko's non-uniform load-sharing and results in a nearly even load distribution over multiple patches of gecko-inspired adhesive. We created a synthetic adhesion system incorporating this concept which shows efficient scaling across four orders of magnitude of area, yielding an improved scaling power law: σmax ∝ A−1/50. Furthermore, we found that the synthetic adhesion system does not fail catastrophically when a simulated failure is induced on a portion of the adhesive. In a practical demonstration, the synthetic adhesion system enabled a 70 kg human to climb vertical glass with 140 cm2 of adhesive per hand.
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机译：自从发现壁虎的粘附机理以来，已经开发出许多合成的干粘合剂，它们具有理想的壁虎性质，例如可重复使用性，方向性，自清洁能力，粗糙的表面粘附力和高粘附力。但是，在实际应用中以不同的长度比例充分利用这些粘合剂需要有效的缩放比例（即随着面积的增加粘合损失很小）。正如天然壁虎粘合剂已被用作合成材料的基准一样，壁虎粘合系统也可以为定标效率提供基准。在tokay壁虎（Gekko壁虎）中，已经报道了将最大剪切应力σmax与面积A相关的定标幂定律：σmax∝A -1/4 。我们提出了一种机械概念，可以改善壁虎的不均匀负载分配，并在壁虎启发的粘合剂的多个贴片上产生几乎均匀的负载分布。我们创建了一个包含此概念的合成粘合系统，该系统显示了四个数量级面积上的有效缩放，从而产生了改进的缩放幂律：σmax∝ A -1/50 。此外，我们发现，当在一部分粘合剂上引发模拟失效时，合成粘合系统不会发生灾难性的失效。在实际演示中，合成粘合系统使70公斤重的人能够以每只手140 cm 2 的粘合剂爬上垂直玻璃。
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