Master's Thesis Defense - Blood Model Plasma Separation in a Microfabricated PDMS Device Exploiting Capillary Action Driving Forces
Date: May 6, 2008
Time: 2:00 PM
Location: Bossone Research Enterprise Center, Room: 302
Tyler N. Hinkle
Advisor: Elisabeth Papazoglou, Ph.D.
The goal of this thesis was to successfully design and fabricate a point-of-care microfluidic device that effectively separates plasma from a blood model without external pumping or other applied driving forces. There is currently no commercially available or published microfluidic device that accomplishes blood plasma separation without pumping or externally applied driving forces. This pump-free device will decrease size and cost while increasing the number of possible applications. The final separated plasma could be further used for detection of biomarkers linked to specific diseases and conditions through tailored antibody based assays by future researchers. The separation device was fabricated using known lithography masking techniques to create a negative to be molded in PDMS using standardized molding fixtures to ensure device uniformity. Fluid flow through the device was promoted by using a plasma-free hydrophilic surface treatment greatly reducing the contact angle of PDMS from about 90 degrees to about 50 degrees. The effectiveness of this device was tested and validated using water emulsions of polystyrene beads adjusted to a viscosity equivalent to that of blood (4.0 +/- 0.5 cP) to represent a simple blood model. The final device is able to separate the model plasma cells (1-3um diameter) from the red (3-8um diameter) and white (8-12um diameter) blood cells with greater than 85% efficiency with a low filtration dead-volume of less than 100ul.
The Bossone Research Enterprise Center is located at the corner of 32nd and Market Streets.