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层的微米级和纳米级结构，可以进行定向水传输。在这里，我们报告了一个瓶子草毛状体表面的超快速水传输过程，其传输速度比在仙人掌脊柱和蜘蛛丝中测得的传输速度快三个数量级。水运输的高速度归因于毛状体的独特的分层微通道组织。两种不同高度的肋骨经常分布在三角毛锥周围，其中两个相邻的高肋骨形成一个大通道，其中包含1-5个低肋骨，这些肋骨定义了较小的基本通道。这导致了两种连续但截然不同的水运输方式。最初，基本通道内部会形成一层快速的水薄膜（模式I），然后是超快水在该薄膜的顶部滑动（模式II）。在生物启发的微通道中对这种两步式超快水传输机制进行了建模和实验测试，证明了这种分层设计在微流体应用中的潜力。