microfluidics – Page 14 – TechConnect Briefs

Mixing and Impulse Extremization in Microscale Vortex Formation

Mohseni K., University of Colorado, US

A key idea in microscale mixing, where the conventional turbulent mixing is not applicable, is to increase the area of the interface between two fluids. Significant entrainment and consequently mixing during vortex formation works based [...]

Dispersion Modeling in Microfluidic Channels for System-level Optimization

Baidya B., Mukherjee T., Hoburg J.F., Carnegie Mellon University, US

Chip-based microfluidic separation systems often use serpentine channels to achieve long separation lengths in minimal area. Such designs suffer from the ‘racetrack’ effect due to the bends in the microchannel. In addition, the skew produced [...]

Viscous Dissipation Effects For Liquid Flow In Microchannels

Xu B., Ooi K.T., Mavriplis C., Zaghloul M.E., Nanyang Technological University, SG

Different phenomena have been observed in various works indicating that the mechanisms of flow and heat transfer in microchannels are still not understood clearly. There is little experimental data and theoretical analysis in the literature [...]

Separation of Long Polyelectrolytes in a Microfuluidic Channel with Constrictions: A Monte Carlo Study

Tessier F., Slater G.W., University of Ottawa, CA

We present Monte Carlo simulation results for the motion of long linear polyelectrolytes inside a microchannel of molecular dimensions, structured as a periodic array of wells linked by narrow constrictions. Molecules are driven in the [...]

Analysis of Physico-Chemical Processes in an Amperometric Oxygen Biosensor

Krishnamoorthy S., Feng J.J., Makhijani V.B., Gao C., Choi J.W., Ahn C., CFD Research Corporation, US

Amperometric techniques are commonly used in lab-on-a-chip systems to sense various blood gas analytes such as H+, CO2, O2, etc. In the present study, a microchip-based amperometric biosensor, being developed as a part of plastic-based [...]

Three-Dimensional Single Step Flow Sheathing in Micro Cell Sorters

Goranovic G., Perch-Nielsen I., Larsen U.D., Wolff A., Kutter J., Telleman P., Bio/Chemical MicroSystems, DK

We present a novel microstructure that enables 3 dimensional hydrodynamic focusing of cells in a pressure driven micro cell sorter. This so-called "chimney" structure for single step coaxial sheathing was designed and optimized through simulation, [...]

Application of the Direct Simulation Monte Carlo Method to Modeling of Microfluidics

Sharipov F., Universidade Federal do Parana, BR

For mathematical modeling of microfluidics it is necessary to calculate a rarefied gas flow through micropumps, microvalves and other elements with high accuracy. Since the size of microfluidics is close to the molecular mean free [...]

Inverted Method for Simulation of Electrokinetic Transport in Microchannel Devices

Nilson R.H., Griffiths S.K., Sandia National Laboratories, US

An inverted method of solution is used to numerically solve the equations governing electrokinetic fluid flow and species transport in microscale turns, junctions and curved channels. Rather than solving for the electric potential and fluid [...]

Analysis of Sample Transport in Capillary Electrophoresis Microchip Using Full-Scale Numerical Analysis

Krishnamoorthy S., Feng J.J., Makhijani V.B., CFD Research Corporation, US

An implicit finite-volume numerical scheme has been developed to solve the three-dimensional transport equations along with fully-coupled ionization equilibria in acid/base systems. The scheme solves conservation equations for mass and momentum while satisfying the electroneutrality [...]

Mixed-Dimensionality, Multi-Physics Simulation Tools for Design Analysis of Microfluidic Devices and Integrated Systems

Przekwas A.J., Makhijani V.B., CFD Research Corporation, US

Computational design of microfluidic devices and integrated microsystems involves several strongly coupled physical disciplines, including fluid mechanics, heat transfer, stress/deformation dynam-ics, electrokinetics, biochemistry and others. CFDRC is dev