(366e) Colloid Aggregation and Concentration Through Double Layer Polarization

Electrokinetic mechanisms like electrophoresis, dielectrophoresis, and electro-osmotic flow have revolutionized lab-on-a-chip systems. Their advantages are numerous and have been utilized to precisely control biological media and enhance particle separation. This presentation demonstrates a novel AC electrokinetic method that can rapidly and continuously accumulate and sort micro- and nanoparticles. The mechanisms responsible for this technique are founded upon the polarization and relaxation of the colloids’ electric double layer. Previously the author has demonstrated this technique, termed rapid electrokinetic patterning (REP), through optically controlled methods. Here, an improved, portable REP device is demonstrated capable of massively parallel colloid concentration and sorting. Unlike dielectrophoresis which is based on interfacial polarization, REP utilizes the polarization of the colloids’ electric double layer to trap and sort particles, enabling a new electrokinetic manipulation methodology. The ability to concentrate and sort particles suspended in a fluid sample directly impacts biological lab-on-a-chip and national security efforts.