Available at: http://digitalcommons.calpoly.edu/theses/694
Date of Award
MS in Biomedical Engineering
Biomedical and General Engineering
David Clague, Ph.D.
Filtration processes, whether on the microfluidic, clinical treatment systems, or industrial scale (e.g., point-of-care diagnostics, dialysis, and biopharmaceutical manufacturing, respectively), are often inseparable from membrane clogging (fouling). As a consequence, most, if not all, filtration systems require frequent maintenance to maintain functionality and efficiency. The thesis of this project hypothesizes that Dielectrophoresis can be combined with standard filtration to reduce filter fouling, extending membrane life, and enabling continuous operation. This project investigates a method to reduce fouling, add specificity and efficiency, and decrease the cost and challenge of filtration based biofluid separations.
To substantiate this thesis, we designed, fabricated, and tested a filtration system to filter micron diameter particles in suspension using Millipore™ membranes together with fabricated electrodes in a cross-flow filtration system. This prototype device elicits a repulsive dielectrophoretic (DEP) force via the application of a direct current (5-20 volts) sourced from a computer controlled voltage sequencer, designed to levitate and remove larger particles (> 6 µm) before particulate-membrane interaction. Analysis of the results shows a sufficient decrease in particles adhered to the filtration membrane, as compared to control, suggesting DC DEP may be a valid effector in this device. We are convinced that further research will augment the results validating the proof-of-concept thesis presented herein.