Alexandra Homsy

Prof. Alexandra Homsy

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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 February 2005 in Lab on a Chip
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Journal Article
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AHAlexandra Homsy
Alexandra Homsy
SKSander Koster
Sander Koster
JEJan C. T. Eijkel
Jan C. T. Eijkel
ABAlbert van Den Berg
Albert van Den Berg
FLFrieder Lucklum
Frieder Lucklum
NRNico F. de Rooij
Nico F. de Rooij
This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-µm-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a micromachined frit-like structure that connects the pumping channel to side reservoirs, where platinum electrodes are located. Current densities up to 4000 A m−2 could be obtained without noticeable Joule heating in the system. The pump performance was studied as a function of current density and magnetic field intensity, as well as buffer ionic strength and pH. Bead velocities of up to 1 mm s−1 (0.5 µL min−1) were observed in buffered solutions using a 0.4 T NdFeB permanent magnet, at an applied current density of 4000 A m−2. This pump is intended for transport of electrolyte solutions having a relatively high ionic strength (0.5–1 M) in a DC magnetic field environment. The application of this pump for the study of biological samples in a miniaturized total analysis system (µTAS) with integrated NMR detection is foreseen. In the 7 T NMR environment, a minimum 16-fold increase in volumetric flow rate for a given applied current density is expected.