Chen Huawei, Ran Tong, Gan Yang, Zhou Jiajia, Zhang Yi, Zhang Liwen, Zhang Deyuan, Jiang Lei
School of Mechanical Engineering and Automation, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China.
School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China.
Nat Mater. 2018 Oct;17(10):935-942. doi: 10.1038/s41563-018-0171-9. Epub 2018 Sep 24.
Various natural materials have hierarchical microscale and nanoscale structures that allow for directional water transport. Here we report an ultrafast water transport process in the surface of a Sarracenia trichome, whose transport velocity is about three orders of magnitude faster than those measured in cactus spine and spider silk. The high velocity of water transport is attributed to the unique hierarchical microchannel organization of the trichome. Two types of ribs with different height regularly distribute around the trichome cone, where two neighbouring high ribs form a large channel that contains 1-5 low ribs that define smaller base channels. This results in two successive but distinct modes of water transport. Initially, a rapid thin film of water is formed inside the base channels (Mode I), which is followed by ultrafast water sliding on top of that thin film (Mode II). This two-step ultrafast water transport mechanism is modelled and experimentally tested in bio-inspired microchannels, which demonstrates the potential of this hierarchal design for microfluidic applications.
各种天然材料具有分级的微观和纳米尺度结构，这些结构允许水进行定向传输。在此，我们报道了瓶子草腺毛表面的一种超快水传输过程，其传输速度比在仙人掌刺和蜘蛛丝中测得的速度快约三个数量级。水传输的高速归因于腺毛独特的分级微通道结构。两种不同高度的肋条围绕腺毛圆锥体规则分布，相邻的两条高肋条形成一个大通道，该大通道包含1 - 5条定义较小底部通道的低肋条。这导致了两种连续但不同的水传输模式。最初，在底部通道内形成快速的水薄膜（模式I），随后在该薄膜顶部发生超快的水滑动（模式II）。这种两步超快水传输机制在受生物启发的微通道中进行了建模和实验测试，这证明了这种分级设计在微流体应用中的潜力。
