Fabrication of microfluidic devices for generating and controlling non-linear chemical gradients
Location
Session 1 (Room 1300)
Session Format
Oral Presentation
Your Campus
Statesboro Campus- Henderson Library, April 20th
Academic Unit
Department of Mathematical Sciences
Research Area Topic:
Natural & Physical Sciences - Physics
Co-Presenters and Faculty Mentors or Advisors
Elijah Waters
Elizabeth Hutton
Dragos Amarie
Abstract
My project is focused on the fabrication of microfluidic devices as well as expanding upon the existing processing protocols. The fabrication of a microfluidic device requires glass covalently bonded to a fluidic housing that accommodates input and output connecting tubing. To make the fluidic housing, master molds are first needed. The master mold is made out of SU-8, a UV-activated photoresist epoxy that hardens when irradiated. SU-8 is spin-coated to previously cleaned glass slides and then exposed through a photomask that has our device design imprinted on it. From such mold we replicate the pattern that yields the fluidic housing in poly-dimethyl-siloxane, an optically clear, inert, biocompatible elastomer. The PDMS housing is plasma activated and bonds to a glass making a leak-free device. The gradient-generating structures are designed in levels using a series of bifurcations, trifurcations, and mixers to merge the input chemical concentrations of 100% and 0% to generate a chemical gradient both along and across the flow chamber. Gradient profile analysis will be run on a number of biased-mixer designs, starting with a linear profile across the chamber in the 1:1 mixing design, followed by nonlinear profile alterations as the mixing ratio becomes 2:1, 3:1, 4:1, and 5:1. To test for proper mixing and gradient profiles, both across and along the chamber, Fluorescein will be used to track the mixing of 100% and 0% solutions into the 2D concentration space of the flow chamber. As the mixing ratio increases, the gradient linearity degenerates and the end-chamber concentration drops from a 50% average to a 25% average. The gradient along the chamber thus gains more slope, e.g., from 100% to 25%. Each design variant's biasing structure will allow us to study which design generates the most well-defined gradient in the flow chamber.
Program Description
Building devices to generate and study non-linear chemical gradient formation. Expanding upon existing protocol for the production and testing of the devices for future cell studies.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Presentation Type and Release Option
Presentation (Open Access)
Start Date
4-20-2022 11:00 AM
End Date
4-20-2022 12:00 PM
Recommended Citation
Hutton, Alex J.; Hutton, Elizabeth M.; and Waters, Elijah L., "Fabrication of microfluidic devices for generating and controlling non-linear chemical gradients" (2022). GS4 Georgia Southern Student Scholars Symposium. 68.
https://digitalcommons.georgiasouthern.edu/research_symposium/2022/2022/68
Fabrication of microfluidic devices for generating and controlling non-linear chemical gradients
Session 1 (Room 1300)
My project is focused on the fabrication of microfluidic devices as well as expanding upon the existing processing protocols. The fabrication of a microfluidic device requires glass covalently bonded to a fluidic housing that accommodates input and output connecting tubing. To make the fluidic housing, master molds are first needed. The master mold is made out of SU-8, a UV-activated photoresist epoxy that hardens when irradiated. SU-8 is spin-coated to previously cleaned glass slides and then exposed through a photomask that has our device design imprinted on it. From such mold we replicate the pattern that yields the fluidic housing in poly-dimethyl-siloxane, an optically clear, inert, biocompatible elastomer. The PDMS housing is plasma activated and bonds to a glass making a leak-free device. The gradient-generating structures are designed in levels using a series of bifurcations, trifurcations, and mixers to merge the input chemical concentrations of 100% and 0% to generate a chemical gradient both along and across the flow chamber. Gradient profile analysis will be run on a number of biased-mixer designs, starting with a linear profile across the chamber in the 1:1 mixing design, followed by nonlinear profile alterations as the mixing ratio becomes 2:1, 3:1, 4:1, and 5:1. To test for proper mixing and gradient profiles, both across and along the chamber, Fluorescein will be used to track the mixing of 100% and 0% solutions into the 2D concentration space of the flow chamber. As the mixing ratio increases, the gradient linearity degenerates and the end-chamber concentration drops from a 50% average to a 25% average. The gradient along the chamber thus gains more slope, e.g., from 100% to 25%. Each design variant's biasing structure will allow us to study which design generates the most well-defined gradient in the flow chamber.
