Electroosmosis-Driven Nanofluidic Diodes
Electroosmosis-Driven Nanofluidic Diodes
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DOI：
10.1021/acs.jpcb.0c04677
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发表时间：
2020-08-13
影响因子：
3.3
通讯作者：
Taniguchi, Masateru
中科院分区：
文献类型：
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作者：
Leong, Iat Wai;Tsutsui, Makusu;Taniguchi, Masateru
离子在流体通道中传输的基本理解对于实现离子电子学是至关重要的。在这里，我们报告了低厚度与直径纵横比纳米孔中的不对称离子传输。在均匀盐浓度条件下，跨孔离子电流呈现欧姆特性，不依赖于偏压极性。与此形成鲜明对比的是，尽管所采用的相对大的纳米孔预期的离子选择性较弱，但当在薄膜上施加盐梯度时，我们观察到了二极管样行为。该意想不到的结果归因于电渗流，电渗流用于通过将凝聚的离子拖入或拖出纳米孔孔口来调节进入阻力。还揭示了简单的机制在从微米到纳米级的各种尺寸的流体通道中是有效的，使得能够通过孔几何形状来校正性质工程。本发明的发现允许人工离子通道构建块的新颖设计。
Fundamental understanding of ion transport in a fluidic channel is of critical importance for realizing iontronics. Here we report on asymmetric ion transport in a low thickness-to-diameter aspect ratio nanopore. Under uniform salt concentration conditions, the cross-pore ionic current showed ohmic characteristics with no bias polarity dependence. In stark contrast, despite the weak ion selectivity expected for the relatively large nanopores employed, we observed diode-like behavior when a salt gradient was imposed across the thin membrane. This unexpected result was attributed to the electroosmotic flow that served to modulate the access resistance through dragging the condensed ions into or out of the nanopore orifices. The simple mechanism was also revealed to be effective in fluidic channels of various size from micro- to nanoscale enabling rectification of the property engineering by the pore geometries. The present findings allow for novel designs of artificial ion channel building blocks.