Biomedical Engineering and Bioengineering Commons^™

An Analysis Of Eliminating Electroosmotic Flow In A Microfluidic Pdms Chip, Cecile D. Redington

Master's Theses

The goal of this project is to eliminate electroosmotic flow (EOF) in a microfluidic chip. EOF is a naturally occurring phenomenon at the fluid-surface interface in microfluidic chips when an electric field is applied across the fluid. When isoelectric focusing (IEF) is carried out to separate proteins based on their surface charge, the analytes must remain in the separation chamber, and not migrate to adjacent features in the microfluidic chip, which happens with EOF.

For this project, a microfluidic chip was designed and commissioned to be photolithographically transferred onto a Si wafer. A PDMS component was then casted on the …

The Fabrication & Characterization Of An Electrokinetic Microfluidic Pump From Su-8, A Negative Epoxy-Based Photoresist, Nash Anderson

Master's Theses

Microfluidics refers to manipulation, precise control, and behavior of fluids at the micro and nanoliter scales. It has entered the realm of science as a way to precisely measure or mix small amounts of fluid to perform highly controlled reactions. Glass and polydimethylsiloxane (PDMS) are common materials used to create microfluidic devices; however, glass is difficult to process and PDMS is relatively hydrophobic. In this study, SU-8, an epoxy based (negative) photoresist was used to create various electrokinetic microfluidic chips. SU-8 is commonly used in microelectromechanical design. Spin coating of various SU-8 formulations allows for 1 μm to 100 μm …

A Microfluidic Pretreatment Isoelectric Focusing Dc-Field Assisted H-Filter For The Separation Of Charged Particles, Cameron Sean Carroll

Biomedical Engineering

Microfluidic devices are small portable diagnostic chips that allow for analysis of a biologic sample at relatively low cost. This makes them ideal for settings where a hospital is unavailable. The microfluidic pretreatment isoelectric focusing DC-field assisted H-filter is a device that allows for the separation of differently charged particles in a biologic sample. It does this by employing the concepts of diffusion, electrophoresis, and isoelectric focusing. This is perfect for isolation of a desired analyte or separation of waste from a sample in order to achieve better diagnostic results. The device was first modeled mathematically and visually using Comsol. …

An Acoustic-Based Microfluidic Platform For Active Separation And Mixing, Myeong Chan Jo

USF Tampa Graduate Theses and Dissertations

Particle separation is of great interest to many biological and biomedical applications. Flow-based methods have been used to sort particles and cells. However, the main challenge with flow based particle separation systems is the need for a sheath flow for successful operation. Existence of the sheath liquid dilutes the analyte, necessitates precise flow control between sample and sheath flow, requires a complicated design to create sheath flow and separation efficiency depends on the sheath liquid composition. In addition, current gold standard active separation techniques are only capable of separation based on particle size; hence, separation cannot be achieved for same-size …

Microfluidic Devices Applied On Enriching Post –Translational Modified Proteins For Proteomics, Hui Xia

Doctoral Dissertations

In this work, microfluidic devices were developed for enriching post-translational modified proteins. Post-translational modifications (PTM) of proteins play essential roles in cellular physiology and disease. The identification of protein substrates and detection of modification site helps understand PTM-mediated regulation in essential biological pathways and functions in various diseases. However, PTM proteins are typically present only at trace levels, making them difficult to identify in mass spectrometry based proteomics. This work study is about the design, fabrication and testing of the microfluidic device for the enrichment of abundant amount of PTMs. Carbonylated protein is used as a representative PTM to illustrate …