title: A unified scaling model for flow through a lattice of microfabricated posts.
abstract: A scaling model is presented for low Reynolds number viscous flow within an array of microfabricated posts. Such posts are widely used in several lab-on-a-chip applications such as heat pipes, antibody arrays and biomolecule separation columns. Finite element simulations are used to develop a predictive model for pressure driven viscous flow through posts. The results indicate that the flow rate per unit width scales as approximately h1.17g1.33/d0.5 where h is the post height, d post diameter and g is the spacing between the posts. These results compare favorably to theoretical limits. The scaling is extended to capillary pressure driven viscous flows. This unified model is the first report of a scaling that incorporates both viscous and capillary forces in the microfabricated post geometry. The model is consistent with Washburn dynamics and was experimentally validated to within 8% using wetting on microfabricated silicon posts.
authors.affiliation: Department of Mechanical Engineering, University of California Santa Barbara, CA 93106, USA.
authors.forename: Nimisha
authors.initials: N
authors.lastname: Srivastava
authors.forename: Changsong
authors.initials: C
authors.lastname: Din
authors.forename: Andrew
authors.initials: A
authors.lastname: Judson
authors.forename: Noel C
authors.initials: NC
authors.lastname: MacDonald
authors.forename: Carl D
authors.initials: CD
authors.lastname: Meinhart
mesh_terms: D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D008904:Miniaturization; D008956:Models, Chemical; D012996:Solutions / Q000737:chemistry*
chemical_list: D012996:Solutions