title: Optimizing micromixer design for enhancing dielectrophoretic microconcentrator performance.
abstract: We present an investigation into optimizing micromixer design for enhancing dielectrophoretic (DEP) microconcentrator performance. DEP-based microconcentrators use the dielectrophoretic force to collect particles on electrodes. Because the DEP force generated by electrodes decays rapidly away from the electrodes, DEP-based microconcentrators are only effective at capturing particles from a limited cross section of the input liquid stream. Adding a mixer can circulate the input liquid, increasing the probability that particles will drift near the electrodes for capture. Because mixers for DEP-based microconcentrators aim to circulate particles, rather than mix two species, design specifications for such mixers may be significantly different from that for conventional mixers. Here we investigated the performance of patterned-groove micromixers on particle trapping efficiency in DEP-based microconcentrators numerically and experimentally. We used modeling software to simulate the particle motion due to various forces on the particle (DEP, hydrodynamic, etc.), allowing us to predict trapping efficiency. We also conducted trapping experiments and measured the capture efficiency of different micromixer configurations, including the slanted groove, staggered herringbone, and herringbone mixers. Finally, we used these analyses to illustrate the design principles of mixers for DEP-based concentrators.
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 50 Vassar Street, Room 36-824, Cambridge, Massachusetts 02139, USA.
authors.forename: Hsu-Yi
authors.initials: HY
authors.lastname: Lee
authors.forename: Joel
authors.initials: J
authors.lastname: Voldman
mesh_terms: D003198:Computer Simulation; D004586:Electrophoresis / Q000379:methods*; D004867:Equipment Design; D008828:Microbiological Techniques / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D012984:Software