Dry Under Water: Comparative Morphology and Functional Aspects of Air-Retaining Insect Surfaces
Dry Under Water: Comparative Morphology and Functional Aspects of Air-Retaining Insect Surfaces
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DOI：
10.1002/jmor.10921
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发表时间：
2011-04-01
影响因子：
1.5
通讯作者：
Barthlott, Wilhelm
中科院分区：
文献类型：
--
作者：
Balmert, Alexander;Bohn, Holger Florian;Barthlott, Wilhelm
超疏水表面可以防止半水生和水生昆虫的某些身体部位在浸没在水中时变湿。这些表面上的空气层可以作为昆虫的物理鳃。利用扫描电子显微镜，我们调查了五种不同程度的适应水生栖息地的昆虫的空气保留表面的形态。我们发现表面要么大而稀疏的头发（刚毛），小而密集的头发（microtrichia），或分层结构的表面与两种类型的头发。比较了这些表面的结构参数和气膜持久性。气膜持续时间在甲虫Galerucella nymphaea中为2天，只有稀疏的刚毛，而在昆虫Notonecta glauca和Ilyocoris cimicoides中超过120天，具有密集的微毛（每平方毫米高达6.6 x 10（6）微毛）。从我们的结果，我们得出的结论是，表面结构的密度是影响空气膜的持久性的最重要的因素。刚毛和微毛的组合对于空气膜的整体持久性不是决定性的，但可能在短时间内提供厚的空气储存，并且在长时间内提供薄但机械上更稳定的空气膜。因此，我们假设，一个密集的覆盖microtrichia作为一个“备份系统”，防止润湿的情况下，空气-水界面被压向表面的身体表面。我们的研究结果可能是有益的仿生表面的发展，长期的空气滞留和减阻在水中。此外，还讨论了不同保气能力的生物学功能。J. Morphol. 272：442-451，2011. (C)2011 Wiley-Liss，Inc.
Superhydrophobic surfaces prevent certain body parts of semiaquatic and aquatic insects from getting wet while submerged in water. The air layer on these surfaces can serve the insects as a physical gill. Using scanning electron microscopy, we investigated the morphology of air-retaining surfaces in five insect species with different levels of adaptation to aquatic habitats. We found surfaces with either large and sparse hairs (setae), small and dense hairs (microtrichia), or hierarchically structured surfaces with both types of hairs. The structural parameters and air-film persistence of these surfaces were compared. Air-film persistence varied between 2 days in the beetle Galerucella nymphaea possessing only sparse setae and more than 120 days in the bugs Notonecta glauca and Ilyocoris cimicoides possessing dense microtrichia (up to 6.6 x 10(6) microtrichia per millimeter square). From our results, we conclude that the density of the surface structures is the most important factor that affects the persistence of air films. Combinations of setae and microtrichia are not decisive for the overall persistence of the air film but might provide a thick air store for a short time and a thin but mechanically more stable air film for a long time. Thus, we assume that a dense cover of microtrichia acts as a "backup system'' preventing wetting of the body surface in case the air-water interface is pressed toward the surface. Our findings might be beneficial for the development of biomimetic surfaces for long-term air retention and drag reduction under water. In addition, the biological functions of the different air retention capabilities are discussed. J. Morphol. 272:442-451, 2011. (C) 2011 Wiley-Liss, Inc.