Medical & Biotech – Page 136 – TechConnect Briefs

Capillary filling speed in silicon dioxide nano-channels

Jarlgaard S.E., Mikkelsen M.B.L., Skafte-Pedersen P., Bruus H., Kristensen A., Technical University of Denmark, DK

We present a simple silicon-based fabrication technique for nanocapillaries based on controlled growth of silicon-dioxide, UV lithography, etching with etch-stop, and glass wafer bonding. Our approach improves state-of-the-art with respect to the obtained cross-wafer homogeneity [...]

Macromodeling for Microfluidic Channels

Kuo C-W, Chein C-M, Yang Y-J, National Taiwan University, TW

In this paper, we present a methodology of generating microfluidic macromodels (reduced-order models) for 3-D non-linear microchannels. Compared with the full-meshed simulations, the generated macromodels not only provide accuracy results, but also give three-orders-of-magnitude speed-ups. [...]

Electric Field Driven Motion of Flexible Polyelectrolytes – A Molecular Dynamics Study

Lo T.S., Khusid B., Acrivos A., Koplik J., New Jersey Institute of Technology, US

Our work aims to develop multi-scale computational procedures for simulating the dielectrophoretic behavior of biomolecules in micro- and nano-electrofluidics, which combine electrohydrodynamics with molecular theories for the macromolecule polarization caused by the distortion of the [...]

Infinitely fast reactions in micromixers

Gleeson J.P., University College Cork, Ireland, IE

Efficient mixing to promote chemical reactions is extremely desirable in lab-on-a-chip microfluidic devices, but is difficult to achieve in the typical low Reynolds-number flows. Numerical simulation of the high Peclet-number case common in microfluidics is [...]

Simulation of Electrokinetic Flow and Analyte Transport in Nano Channels

Feng J.J., Krishnamoorthy S., Wang G.W., Sundaram S., CFD Research Corporation, US

This paper demonstrates the electrokinetic flow and transport of charged and neutral analytes in nanochannels by solving full system of governing Poisson-Nernst-Planck equations without any assumptions. The issues related to the spatial and time scales [...]

Superhydrophobic Nanowire Surfaces for Drop Movement Using Magnetic Fields

Egatz-Gomez A., Melle S., García A.A., Lindsay S., Rubio M.A., Domínguez P., Picraux T., Taraci J., Clement T., Hayes M., Gust D., Arizona State University, US

We present a novel method to control water drop movement on superhydrophobic surfaces through magnetic fields. Water drops with paramagnetic particles can be moved on fractal Si-nanowire superhydrophobic surfaces at high speeds by displacing a [...]

On the Motion of a Bubble through Microchannel Contractions

Chio H., Jensen M.J., Wang X., Bruus H., Attinger D., Columbia University, US

We present the first transient pressure measurements and high-speed visualizations of a gas bubble passing through liquid-filled microchannel contractions. Results are compared with a simple theoretical model taking into account the Young-Laplace pressure drop, the [...]

Simulation of filling of microfluidic devices using a coarse-grained continuum contact angle model

Narayanan C., Lakehal D., ASCOMP, CH

We present a new dynamic contact angle model applied to the fillingproblem in microfluidic devices. The level-set method is used forinterface capture. Several attempts have been made in the past decades to model contact--line dynamics [...]

Blood dynamics in microfabricated vessel networks

Mulivor A.W., Shevkoplyas S., Sun C., Bitensky M.W., Munn L.L., Massachusetts General Hospital, US

Blood displays interesting behavior when flowing through channels with dimensions similar to the blood cells. Two well-known examples include the decrease in flow resistance with tube size (Fahraeus-Lindqvist effect) and the enhancement of leukocyte (WBC) [...]

Combination Ultrasonic- Dielectrophoretic Particle Traps for Particle Trapping and Sample Purification in a Microfluidic Channel

Marina O., Ward M.D., Kaduchak G., Los Alamos National Laboratory, US

Ultrasonic and dielectrophoretic particle manipulation has been studied for particle trajectory modification and particle trapping in microfluidic channels. We report a new approach of a combination of dielectrophoresis (DEP) and ultrasonic fields to trap and [...]