Electrokinetic-Driven Microflows in Axially-Varying Rectangular Geometry- Selected Applications in Biomedicine

Abstract

Microflows driven by electrokinetic forces form a large family of flows with relevant applications in microfluidic devices, biophysical systems in the human body (kidney, lung, etc.), drug delivery and cancer tumor treatment, among others. The geometry of the capillary has been shown to play an important role in predicting the flow rate.  Microflows and electrokinetic-based transport in axially-varying sections of capillaries is far from being complete and in need of further studies. In this project, we perform a fundamental analysis for microflows within a rectangular capillary of a divergent section to gain understanding of the impact of different parameters on the flow rate, electrohydrodynamics, and electrostatic potential. Illustative cases include the possibility that the electrical charges on the capillary walls have different signs, that the applied electric fields could be  constant in time (DC) or periodic (AC) and the microflows could be either constant or transient. The analysis has been performed by following the guidelines of the electrokinetics-hydrodynamic (EKHD) framework and the illustration and justification of assumptions can be made within those typically used within the domain of the continuum mechanics. As shown by the illustrative results, the relevance of the research in impactful and broad areas of applications in clinical diagnostics, cancer detection (by using protein tracers), and electro-treatment of tumors, among others. Preliminary results have been presented in previous TTU Research Days and at the American Institute of Chemical Engineering (AIChE) Annual meeting and documentation is progressing towards the submission of several papers in peer-reviewed journals.