Arrays of high aspect ratio magnetic microstructures for large trapping throughput in lab-on-chip systems

Abstract

Here we report a novel technology that requires simple fabrication process, to obtain highly efficient magnetic micro-traps. Developed micro-traps consist in chains of iron particles diluted in PolyDiMethylSiloxane (PDMS). X-ray tomography was used to analyze the microstructure of particle ordering in the PDMS membrane and revealed the predominance of chain-like agglomerates. Largest formed traps, with diameter ranging from 4 to 11 µm are found to be the most efficient. The self-organized trap arrays are characterized by a density of 1300 magnetic microtraps/mm 2 , with an average nearest neighbour distance, center-to-center, of 21 µm. Implemented in a microfluidic channel operating at a flow rate of 3 mL/h-a fluid flow of 8,3 mm/s-we measured trapping throughputs up to 7100 beads/min with an average distribution of 750 beads/mm 2. At fluid velocity up to 9,7 mm/s a trapping efficiency of 99,99% were measured. This novel technology allows to trap thousands of beads with throughputs that permit to compete with hydrodynamic trapping functions, while requiring simple fabrication process, and handling. Manuscript Click here to download Manuscript Arrays of high aspect ratio magnetic microstructures .pdf

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