An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their environments: some 10 million living prototypes (i.e., estimated number of existing plants and animals) for engineers. The complexity of the hierarchical structures and their functionality in biological organisms surpasses all abiotic natural surfaces: even superhydrophobicity is restricted in nature to living organisms and was probably a key evolutionary step with the invasion of terrestrial habitats some 350-450 million years ago in plants and insects. Special attention should be paid to the fact that global environmental change implies a dramatic loss of species and with it the biological role models. Plants, the dominating group of organisms on our planet, are sessile organisms with large multifunctional surfaces and thus exhibit particular intriguing features. Superhydrophilicity and superhydrophobicity are focal points in this work. We estimate that superhydrophobic plant leaves (e.g., grasses) comprise in total an area of around 250 million km2, which is about 50% of the total surface of our planet. A survey of structures and functions based on own examinations of almost 20,000 species is provided, for further references we refer to Barthlott et al. (Philos. Trans. R. Soc. A 374: 20160191, 1). A basic difference exists between aquatic non-vascular and land-living vascular plants; the latter exhibit a particular intriguing surface chemistry and architecture. The diversity of features is described in detail according to their hierarchical structural order. The first underlying and essential feature is the polymer cuticle superimposed by epicuticular wax and the curvature of single cells up to complex multicellular structures. A descriptive terminology for this diversity is provided. Simplified, the functions of plant surface characteristics may be grouped into six categories: (1) mechanical properties, (2) influence on reflection and absorption of spectral radiation, (3) reduction of water loss or increase of water uptake, moisture harvesting, (4) adhesion and non-adhesion (lotus effect, insect trapping), (5) drag and turbulence increase, or (6) air retention under water for drag reduction or gas exchange (Salvinia effect). This list is far from complete. A short overview of the history of bionics and the impressive spectrum of existing and anticipated biomimetic applications are provided. The major challenge for engineers and materials scientists, the durability of the fragile nanocoatings, is also discussed.

中文翻译：

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植物表面：仿生创新的结构和功能。

介绍了植物表面结构及其演变的概况。它结合了表面化学和结构及其功能，并涉及可能的仿生应用。在大约35亿年内，生物物种进化出了高度复杂的多功能表面以与环境相互作用：工程师可以使用大约1000万个活体原型（即现有动植物的估计数量）。层次结构及其在生物有机体中的功能的复杂性超过了所有非生物自然表面：甚至超疏水性在自然界也仅限于生物体，并且可能是大约350-4.5亿年前入侵植物和植物的陆地栖息地的重要进化步骤。昆虫。应该特别注意这样一个事实，即全球环境变化意味着物种的急剧丧失以及随之而来的生物学榜样。植物是地球上占主导地位的生物群，是具有大型多功能表面的无柄生物，因此具有特殊的吸引力。超亲水性和超疏水性是这项工作的重点。我们估计超疏水性植物叶子（例如草）的总面积约为2.5亿平方公里，约占地球总表面积的50％。根据自己对近20,000种物种的检查，对结构和功能进行了调查，有关更多参考，请参考Barthlott等。（Philos.Trans.R.Soc.A 374：20160191，1）。水生非维管植物和陆地维管植物之间存在基本差异。后者表现出特别有趣的表面化学和结构。根据特征的层次结构顺序详细描述其多样性。第一个基本且必不可少的特征是聚合物表皮被表皮蜡叠加，单细胞的弯曲直至复杂的多细胞结构。提供了这种多样性的描述性术语。简而言之，植物表面特征的功能可以分为六类：（1）机械性能，（2）对光谱辐射的反射和吸收的影响，（3）减少水分流失或增加吸水率，收获水分，（ 4）附着力和不附着力（莲花效应，昆虫诱捕），（5）阻力和湍流增加，或（6）在水下的空气滞留以减少阻力或交换气体（Salvinia效应）。此列表远非完整。提供了仿生学历史的简短概述以及现有和预期的仿生应用的令人印象深刻的范围。还讨论了工程师和材料科学家面临的主要挑战，即易碎纳米涂层的耐用性。