A microfluidic pump is described that uses magnetic actuation to push fluid through a microchannel. Operation relies on the use of magnetically-actuated plugs of ferrofluid, a suspension of nanosize ferromagnetic particles. The ferrofluid contacts but is immiscible with the pumped fluid. The prototype circular design demonstrates continuous pumping by regenerating a translating ferrofluidic plu...

An analytical solution for the time periodic electroosmotic flow (EOF) of the generalized Maxwell model through a circular microtube is presented by solving the linearized Poisson-Boltzmann equation, together with Cauchy momentum equation and General Maxwell constitutive equation. By numerical calculations, we find that for lower Ω and smaller De, classical plug-like profile of Newtonian fluids...

Self-regulating fluidic components are critical to the advancement of micro/nanofluidic circuitry for chemical and biological applications, including sample preparation on chip and point-of-care (POC) molecular diagnostics. Previously, a variety of diodic components have been developed to enable flow rectification in fluidic technologies (e.g., microscale drug delivery systems in which backflow...

A transform method for determining the flow generated by the singularities of Stokes flow in a two-dimensional channel is presented. The analysis is based on a general approach to biharmonic boundary value problems in a simply connected polygon formulated by Crowdy & Fokas in this journal. The method differs from a traditional Fourier transform approach in entailing a simultaneous spectral anal...

Automotive HVAC systems manufacturers were the first to introduce microchannel condensers in the comfort airconditioning market. HVAC&R original equipment manufacturers have followed their lead and recently started using microchannel condensers in residential and commercial cooling and heat pump applications. These applications began less than a decade back and their number has been increasing ...

Polydimethylsiloxane has been dominantly employed as the substrate material for microchip capillary electrophoresis. The poor surface chemistry, however, generates inconsistent electroosmotic flow under the electrophoretic condition, limiting its broader applications. In this work, different polyelectrolytes, including polydiallyldimethylammonium chloride, polyvinyl sulfate, and dextran sulfa...

In this study, a numerical approach was carried out to analyze the effects of different geometries microchannel heat sinks on forced convective transfer in single-phase flow. The simulations were performed using commercially available software COMSOLMultiphysics 5.6® (Burlington, MA, USA) and its results compared with those obtained from experimental tests polydimethylsiloxane (PDMS). Distilled...

the paper numerically presents laminar forced convection of a nanofluid flowing in a duct at microscale. results were compared with both analytical and experimental data and observed good concordance with previous studies available in the literature. influences of brinkman and reynolds number on thermal and hydrodynamic indexes have been investigated. for a given nanofluid, no change in efficie...

The alternating current electroosmotic flow of a non-Newtonian power-law fluid is studied in a circular microchannel. A numerical method is employed to solve the non-linear Poisson-Boltzmann and the momentum equations. The main parameters which affect the flow field are the flow behavior index, the dimensionless zeta potential and the dimensionless frequency. At very low dimensionless frequenci...

A microfluidic device known to mix bulk solutions, the herringbone microchannel, was incorporated into a surface-binding assay to determine if the recirculation of solution altered the binding of a model protein (streptavidin) to the surface. Streptavidin solutions were pumped over surfaces functionalized with its ligand, biotin, and the binding of streptavidin to those surfaces was monitored u...