Fabrication and properties of dual-level hierarchical structures mimicking gecko foot hairs.
Fabrication and properties of dual-level hierarchical structures mimicking gecko foot hairs.
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DOI：
10.1166/jnn.2013.6013
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发表时间：
2013-02
影响因子：
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通讯作者：
Peng Zhang;Shiyuan Liu;Hao Lv
中科院分区：
文献类型：
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作者：
Peng Zhang;Shiyuan Liu;Hao Lv
在自然界中，壁虎具有非凡的粘附能力。壁虎足毛的多尺度层次结构，特别是微米级刚毛和纳米级刮刀的高纵横比结构，是壁虎能够以强大的粘附力适应和粘附于任何不同表面的关键因素。在本文中，我们提出了一种简单而有效的方法来制造模仿壁虎足毛的双层层次结构。聚二甲基硅氧烷（PDMS）的分层阵列的制造脱模从一个双堆叠模具，该模具是由SU-8模具通过厚膜光刻和硅模具通过电感耦合等离子体（ICP）蚀刻。制造的结构的顶柱具有3微米直径和18微米高度，而底柱具有25微米直径和40微米高度。水滴接触角测试表明，与单级阵列和非结构化聚合物相比，分级结构显著增加了疏水性能，表现出与Tokay壁虎（160.9度）相似的超疏水性（154.2度）。剪切力测试表明，顶柱通过约0.25 N/cm 2的值的侧接触进行附着，并且此外，分级结构被证明更适合于与粗糙表面接触。
In nature, geckos have extraordinary adhesive capabilities. The multi-scale hierarchical structure of the gecko foot hairs, especially the high-aspect-ratio structure of its micro-scale seta and nano-scale spatulae is the critical factor of the gecko's ability to adopt and stick to any different surface with powerful adhesion force. In this paper, we present a simple and effective approach to fabricate dual-level hierarchical structures mimicking gecko foot hairs. Polydimethyl-siloxane (PDMS) hierarchical arrays were fabricated by demolding from a double stack mold that was composed of an SU-8 mold by thick film photolithography and a silicon mold by inductively coupled plasma (ICP) etching. Top pillars of the fabricated structures have 3 micom diameter and 18 microm in height, while base pillars have 25 microm diameter and 40 microm in height. The water droplet contact angle tests indicate that the hierarchical structures increase the hydrophobic property significantly compared with the single-level arrays and the unstructured polymers, exhibiting superhydrophobicity (154.2 degrees) like the Tokay gecko's (160.9 degrees). The shear force tests show that the top pillars make attachment through side contact with a value of about 0.25 N/cm2, and moreover, the hierarchical structures are demonstrated to be more suitable for contacting with rough surfaces.