Electrokinetically-Driven Microfluidic Devices for Biomedical and Biological Applications

The advancement of microfluidics has led to the recognition of micro/nano-scale electrokinetic phenomena as a promising and increasingly area of study in Lab on a Chip (LOC) applications. These phenomena, resulting from the interaction between electric fields and fluids or particles in microfluidic systems, have presented researchers with interesting physical observations. These observations present promising capabilities in manipulating cells, fluids, and particles, thereby providing effective opportunities for a wide range of biological and biomedical applications. The overall research objective of this dissertation is to investigate the applications of electrokinetically-driven microfluidics for biological and biomedical applications. Within this dissertation, we present literature review and research findings on self-power, electroosmotic flow and dielectrophoresis in microfluidics. These findings shed light on their diverse utility in various biological and biomedical applications, such as fluid manipulation, blood clots generation, cell manipulation, cancer cell sorting. By utilizing both numerical simulations and experimental approaches, we investigate the utilization of electroosmotic flow for fluid control and the manipulation of fluid patterns at localized levels. With Xurography microfluidics and thin film electrode microfabrication techniques, we design and construct several electrokinetically-driven microfluidics devices for the thrombosis generation study. These devices are specifically designed for the study of thrombosis generation. We introduce a controllable micro mixing method within microchannels to examine the localized flow patterns of electroosmosis, with a focus on generating blood clots in fluids that mimic flow conditions and biological samples. Our findings showcase the potential real-world applications of this approach in thrombosis research. Furthermore, we have made significant advancements in the field by developing a microfluidic platform based on dielectrophoresis, enabling the manipulation of cells using a nonuniform electric field. Through thorough numerical calculations and simulations, we have successfully designed and fabricated a cost-effective thin film lab-on-a-foil microfluidic system, specifically aimed at separating cancer cells from blood flow. By exerting precise control over dielectrophoretic phenomena within microfluidics, we effectively managed to control and quantitatively study the displacement of cells within a multilayer microfluidic device. Lastly, we utilized an electrokinetically-driven microfluidic device to sort cancer cells, presenting a highly effective approach with promising implications for future biological applications. The work presented in this dissertation offers a cost-effective, rapid, biocompatible, and simple method for manipulating cells and fluids related to health care. Through further advancements in both theory and experimentation, we anticipate that electrokinetically-driven microfluidic devices will play increasingly significant roles in biomedical and biological applications. These devices hold the potential to address complex challenges across various scientific and engineering domains, providing innovative solutions with broad implications.