Nanofluidic Devices for AC Electrokinetic Trapping and Separation

Indiana University, Bloomington IN

Investigators

Abstract

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.