This project is developing predictive models for dielectrophoretic separations. Dielectrophoresis is a type of force whereby charged and non-charged species undergo separation in the presence of a non-uniform electric field. Current models that explain these separations do not align with experimental observations by up to two orders of magnitude. To reconcile this discrepancy, a new model that incorporates properties of the solution is being developed. Key to this is acquiring and correlating local solution property data and field strength using a continuum model. Four objectives are sought. First, the continuum model of dielectrophoretic transport is being validated for colloidal particle solutions. Second, the validity of this model is being extended to the molecular scale. Next, an understanding between separations throughput and efficiency is sought so that the final objective, which focuses on understanding and quantifying the sensitivity of dielectrophoretic separations by observing several challenging separations such as the rare earth series and chiral solutions, is achieved. The completion of these objectives is enabled by a unique experimental approach that permits real time, spatially resolved spectroscopy measurements of solution composition between and around electrodes while controlling initial concentrations, field strengths and gradients, and flow rates. In so doing, advancements in and expansion of this non-thermal separation mechanism are likely.

This research was selected for funding by the Office of Basic Energy Sciences.