Publication Date

2023

Document Type

Dissertation/Thesis

First Advisor

Korampally, Venumadhav

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Electrical Engineering

Abstract

In this thesis, we explore the rapidly evolving landscape of healthcare and diagnostics, shaped by the transformative impact of the COVID-19 pandemic. The focus of Point-of-care showcases innovative breakthroughs in microfluidics, capillary action, and lateral flow technology that are revolutionizing medical diagnostics. We delve into the mechanics of current assays, particularly in resource-limited settings. We then unveiled the introduction of a novel fluidic diode valve, designed to enhance lateral flow assays (LFAs) for point-of-care diagnostics. This diode design boasts a unidirectional flow mechanism, and our proof-of-concept experiments validate its potential for scalability, precise flow control, and applications in complex lateral flow assays. Proof of concept designs for cascaded diodes demonstrate their ability to prevent backflow and the potential to improve sensitivity and specificity. The subsequent design focuses on introducing tunable time delays within the fluidic diode to regulate fluid movement. This innovative approach allows for precise reagent timing, providing versatility for complex tests and utilizes materials like laser jet ink and double-sided tape. Our design has achieved time delays of two minutes in a single fluidic diode. Finally, we explore electrowetting-based fluid control, emphasizing its potential and application in customizable fluid control devices with electronically controlled burst valves. We boast the robustness of our diodes, with a 100% success rate in all tested devices, and a forward pin time of over 45 minutes in all cases. The documented release time for the fluid after the voltage application averaged 3 seconds. The scalable design can be seamlessly integrated into existing lateral flow assays, promising significant advancements in the field of point-of-care diagnostics. This document includes a folder of supplementary materials, comprising: 1. PDF: "Fluidic Diode Channel Pinning Delays (Printed Stripes)" - Illustrating the initial tunable delay trials and setup leading to the final version. 2. PDF: "Fluidic Diode Channel Pinning Delays (Tape and White Out)" - An update focusing on inlet-based flow delay methods. 3. PDF: "Inverse Fluidic Diode All Electrowetting Silver Devices" - Displaying the development process of all inverse fluidic diodes with silver, leading to the final version. 4. Various proof-of-concept videos starting with "Video Proof," including: 1. "Cascaded Diodes Proof of Concept" - Demonstrating the working concept of cascaded diode design. 2. "Diode Robustness Test" - Showing diode performance over time. 3. "Electrowetting Proof of Concept" - Displaying the functionality of version seven of the electrowetting device. 4. "Tunable Time Delays Single Diode Fluid Flow at Inlet" - Depicting the cross-section of the final version of the tunable time delay. And finally, 5. “Inverse Fluidic Diode All Electrowetting Material testing" delivers an indepth analysis of each trial, including the data and observations, presented on a trial-by-trial basis. It details how these individual trials contribute to the ultimate selection of silver as the final choice.

Extent

212 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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Available for download on Friday, January 23, 2026

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