Session: Rising Stars of Mechanical Engineering Celebration & Showcase

Paper Number: 149978

149978 - Alternating Current Electrophoresis in Spatially Non-Uniform Electric Fields 

Electrolytes are charged ions and molecules such as sodium, lithium, and potassium hydroxide that conduct electricity. Applying an alternating current (AC) electric field to electrolytes in a solution causes them to migrate because of their charge properties. This phenomenon is used in many important applications, including supercapacitors, high-rate batteries, and cellular and biomolecular manipulation like cell sorting. AC electric fields can be regular waves of alternating voltage (spatially uniform) or less predictable, irregular waves (spatially non-uniform). Scientists have assumed that applying AC voltages to an electrolyte solution encourages the electrolytes to migrate in a way that does not affect the overall bulk solution properties. However, recent research studies revealed that electrolyte bulk solution properties change when a spatially non-uniform AC electric field is applied. Effects such as flow reversal, pH shifts, solution osmotic pressure change, and the generation of ion concentration gradients were observed. This project?s objective is to understand how electrolytes and other charged particles respond to spatially non-uniform AC electric fields in bulk solutions over extended periods. This fundamental knowledge can be applied to develop novel technologies for molecular biosensing, water desalination, and high-throughput drug screening assays. The project will also support STEM outreach and educational activities. It aims to develop industrially relevant skillsets for graduate and undergraduate students through interactions with industrial leaders and industry-informed student projects. The investigator also aims to cultivate interest in STEM education and technology-driven solutions to enhance healthcare and societal well-being among high school students from underserved communities.This project will test the hypothesis that the biased AC electromigration under spatially non-uniform AC electric fields facilitates the directed enrichment and generation of concentration gradients of biochemically relevant charged species in bulk aqueous phase and biofluids. The specific research objectives are to (A) engineer a new system for isolating confounding variables from biased AC electromigration, (B) interrogate the influence of spatially non-uniform AC electric field properties on biased AC electromigration behaviors of designated charged species, and (C) elucidate the influence of charged species? intrinsic properties on their biased AC electromigration behavior under designated spatially non-uniform AC electric fields. This project will provide a fundamental understanding of the behaviors of charged species under spatially non-uniform AC electric fields in the bulk solution beyond the electric double layer and at longer times than previously studied (>60 seconds). This fundamental understanding of biased AC electromigration is broadly relevant to many scientific communities; it can be applied to develop technologies that (1) selectively enrich or deplete biomolecules, which will improve the sensitivity and accuracy of biosensing by allowing the detection of concentrations of target molecules that are otherwise below detection limits and (2) generate spatially and temporally controllable and quantifiable two- and three-dimensional gradients.

Presenting Author: Ran An University of Houston

Presenting Author Biography: Dr. Ran An is an assistant professor in the Department of Biomedical Engineering at the University of Houston. He also serves as joint faculty in the Department of Biomedical Sciences at the UH Tilman J. Fertitta Family College of Medicine. His current research focuses on the development, clinical translation, and potentially commercialization of: 1) electrokinetic- and electrochemical-driven microfluidic biosensors for rapid and affordable point-of-care disease diagnostics and monitoring; 2) organ-on-chip functional assays to facilitate fundamental understanding of disease pathophysiology, drug testing, and personalized healthcare, with a specific interest in human microcirculatory health. Dr. An has won the NSF CAREER award, NIH K25 Career Development Award, and NIH Technology Accelerator Challenge Award for Global Disease Diagnostics.

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