Nanofluidic Devices for AC Electrokinetic Trapping and Separation

分析和表面化学计划支持印第安纳州大学的Stephen Jacobson教授通过将纳米级导管与AC电动力学相结合来生产可调谐过滤器，用于传输，捕获，浓缩和反应颗粒和分子。 纳米多孔元件提供物理屏障，并且所施加的AC场增强选择性。 在纳米孔结构附近产生的高场强和场梯度引起电泳效应和介电泳效应两者，使得能够基于尺寸、电荷和极化率分级颗粒。 具有捕获元件（例如，与微流体结构集成的纳米孔）允许分离单个纳米孔，改善向纳米孔的质量传递，并允许以阵列形式寻址孔。 Jacobson博士和他的学生研究了运输，捕获和分离如何受到所施加波形的形状和振幅的影响;纳米管道的尺寸，几何形状和密度;管道的表面特性;周围介质的组成;以及颗粒形状和组成。该项目适合更广泛的液相分离竞技场，这是分析科学的核心。 有一个基本的了解发生了什么事时，纳米结构的材料与交流电动力学相结合，提供了一个框架，从更具有挑战性的分离问题，可以进行。 这项研究为代表性不足的群体和本科生提供了一个独特的机会，可以使用最先进的分离技术，并为研究生和本科生提供了一个刺激的研究环境。

The Analytical and Surface Chemistry Program supports Prof. Stephen Jacobson at Indiana University to produce tunable filters for transporting, trapping, concentrating, and reacting particles and molecules by combining nanoscale conduits with AC electrokinetics. The nanoporous elements provide a physical barrier and the applied AC field enhances selectivity. High field strengths and field gradients generated in the vicinity of the nanopore structures give rise to both electrophoretic and dielectrophoretic effects, enabling fractionation of particles based on size, charge, and polarizability. Having the trapping elements (e.g., nanopores) integrated with microfluidic structures permits isolation of single nanopores, improves the mass transfer to the nanopores, and allows the pores to be addressed in an array format. Dr. Jacobson and his students study how transport, trapping, and separation are influenced by the shape and amplitude of the applied waveform; dimensions, geometry, and density of the nanoscale conduit; surface properties of the conduit; composition of the surrounding medium; and particle shape and composition. This project fits into the broader arena of liquid phase separations, which are central to analytical sciences. Having a fundamental understanding of what happens when nanostructured materials are combined with AC electrokinetics provides a framework from which more challenging separation problems can be undertaken. The research provides a unique opportunity for underrepresented groups and undergraduate students to work with state-of-the-art separation techniques and provides a stimulating research environment for both graduate and undergraduate students.