Year: 2006
Type: report
Abstract: This SAND report describes progress made during a Sandia National Laboratories sponsored graduate fellowship.The fellowship was funded through an LDRD proposal.The goal of this project is development and characterization of mixing strategies for polymeric microfluidic devices.The mixing strategies under investigation include electroosmotic flow focusing, hydrodynamic focusing, physical constrictions and porous polymer monoliths.For electroosmotic flow focusing, simulations were performed to determine the effect of electroosmotic flow in a microchannel with heterogeneous surface potential.The heterogeneous surface potential caused recirculations to form within the microchannel.These recirculations could then be used to restrict two mixing streams and reduce the characteristic diffusion length.Maximum mixing occurred when the ratio of the mixing region surface potential to the average channel surface potential was made large in magnitude and negative in sign, and when the ratio of the characteristic convection time to the characteristic diffusion time was minimized.Based on these results, experiments were performed to evaluate the manipulation of surface potential using living-radical photopolymerization.The material chosen to manipulate typically exhibits a negative surface potential.Using living-radical surface grafting, a positive surface potential was produced using 2-(Dimethylamino)ethyl methacrylate and a neutral surface was
DOI: 10.2172/893155
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4230402829