纳米流体系统内离子传输的主动控制
Active control of ion transport within a nanofluidic system
摘要：
诱导与受外部施加的电场影响的选择性渗透膜或纳米通道相邻的高和低离子浓度区域的能力（称为浓度-极化的现象）已经用于从芯片上脱盐、细菌过滤到生物分子预浓缩的广泛应用。但是这些应用受到控制扩散层长度的能力的限制，扩散层的长度通常由纳米流体系统的固定几何和表面性质间接规定。在这里，我们证明了耗尽层可以动态地变化，诱导受控的温度梯度与所施加的电场的相互作用驱动的电流。为此，在微通道的底部嵌入了一系列可以根据需要单独激活的微型加热器，并表征了它们的激活与离子浓度之间的关系。扩散层的这种时空控制可用于通过产生较短的耗尽层来增强芯片上电渗析，以相对于基于纳米通道的（生物）感测的纳米通道的电阻动态地降低微通道电阻，以产生使人联想到二极管样行为的电流整流，并控制分析物的预浓缩塞或盐水和脱盐流的界面的位置。
英文摘要：
The ability to induce regions of high and low ionic concentration adjacent to a permeselective membrane or nanochannel subject to an externally applied electric field (a phenomenon termed concentration-polarization) has been used for a broad spectrum of applications ranging from on-chip desalination, bacteria filtration to biomolecule preconcentration. But these applications have been limited by the ability to control the length of the diffusion layer that is commonly indirectly prescribed by the fixed geometric and surface properties of the nanofluidic system. Here, we demonstrate that the depletion layer can be dynamically varied by inducing controlled electrothermal flow driven by the interaction of temperature gradients with the applied electric field. To this end, a series of microscale heaters, which can be individually activated on demand are embedded at the bottom of the microchannel and the relationship between their activation and ionic concentration is characterized. Such spatio-temporal control of the diffusion layer can be used to enhance on-chip electro-dialysis by producing shorter depletion layers, to dynamically reduce the microchannel resistance relative to that of the nanochannel for nanochannel based (bio)sensing, to generate current rectification reminiscent of a diode like behavior and control the location of the preconcentrated plug of analytes or the interface of brine and desalted streams.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
