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Mixing within Confined Spaces


Professor Paul E. Laibinis (Chemical Engineering) is developing strategies using magnetic nanoparticles to provide internal mixing within microfluidic devices.  A particular focus is the thin film geometry present in many high- throughput microarray-type experiments used today in areas of genomics and proteomics. 

"Many of these so-called gene and protein chips require interrogating the contents of a few microliters of sample against printed arrays that cover the surface of a typical microscope slide,” Laibinis says.  “The thickness of the solution on the array chip is a few tens of microns, and contact between the molecules in the sample liquid and the microarrayed features on the chip surface occurs by slow diffusional processes.  As a result, typical microarray experiments require lengthy incubation times." 

To solve this problem, Professor Laibinis and members of his research group use magnetite nanoparticles to induce mixing within this restricted geometry.   The particle surfaces are tailored to be non-interacting with the microarray surface and the adsorbing molecules in solution.  The nanoparticles respond to an externally applied magnetic field, freely move about the confined space, and provide active mixing to the contacting solution.

Vanderbilt University