Development of a Multi-Use Modular Microfluidic Platform Using 3D Printing

Authors

Carson Emeigh, University of Nebraska-LincolnFollow

First Advisor

Sangjin Ryu

Date of this Version

5-2024

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Mechanical Engineering and Applied Mechanics

Under the supervision of Professor Sangjin Ryu

Lincoln, Nebraska, May 2024

Comments

Copyright 2024, Carson Emeigh. Used by permission

Abstract

Microfluidic lab-on-a-chip (LoC) technology has driven numerous innovations due to their ability to perform laboratory-scale experiments on a single chip using microchannels. Although LoC technology has been innovative, it still suffers from limitations related to its fabrication and design flexibility. Typical LoC fabrication, with photolithography, is time consuming, expensive, and inflexible. To overcome the limitations of LoC devices, modular microfluidic platforms have been developed where multiple microfluidic modules, each with a specific function or group of functions, can be combined on a single platform. Modular microfluidics have overcome some of the limitations of LoC devices, but currently, their fabrication is complex, and they remain relatively inaccessible. This study attempts to address the limitations of both LoC microfluidics and modular microfluidic platforms by implementing stereolithography 3D printing for ease of fabrication, design flexibility, and increased accessibility. A modular platform with reversible connections was developed that could accommodate two microfluidic modules in series. The optimal printing parameters and fabrication procedure for printing both microfluidic molds and microfluidic devices was found. The base to a modular platform was designed and 3D printed with integrated O-ring module attachments and luer-lock mechanisms for connection to external flow sources. To demonstrate the capability of the developed platform, a microfluidic device previously used to compress cells by inflating a thin PDMS membrane, like a balloon, was reconfigured to serve as an active mixing microfluidic module. Next, the height response of the balloons of the active mixer was characterized in response to an applied pressure to ensure the performance of the mixer fabricated with 3D printing was comparable to that of the previous study. Separately, a straight-channel microfluidic module was fabricated. The flow through the straight-channel microfluidic was measured using particle tracking velocimetry because many studies require shear stress application. Finally, the modular platform, mixing module, and straight-channel module was combined, and a mixing experiment was performed by dynamically actuating the balloons of the mixing module at varying frequencies. The fabricated mixing module could mix two samples before they flowed into the second module, and the platform was capable of quick, reversible, and leak-free connections.

Advisor: Sangjin Ryu