TY - JOUR
T1 - Dipolar assembly of ferromagnetic nanoparticles into magnetically driven artificial cilia
AU - Benkoski, Jason J.
AU - Deacon, Ryan M.
AU - Land, H. Bruce
AU - Baird, Lance M.
AU - Breidenich, Jennifer L.
AU - Srinivasan, Rengaswamy
AU - Clatterbaugh, Guy V.
AU - Keng, Pei Yuin
AU - Pyun, Jeffrey
PY - 2010
Y1 - 2010
N2 - Taking inspiration from eukaryotic cilia, we report a method for growing dense arrays of magnetically actuated microscopic filaments. Fabricated from the bottom-up assembly of polymer-coated cobalt nanoparticles, each segmented filament measures approximately 5-15 μm in length and 23.5 nm in diameter, which was commensurate with the width of a single nanoparticle. A custom microscope stage actuates the filaments through orthogonal permanent and alternating magnetic fields. We implemented design of experiments (DOE) to efficiently screen the effects of cobalt nanoparticle concentration, crosslinker concentration, and surface chemistry. The results indicated that the formation of dense, cilia-mimetic arrays could be explained by physical, non-covalent interactions (i.e. dipolar association forces) rather than chemistry. The experiments also determined an optimal Co nanoparticle concentration of approximately 500 μg ml-1 for forming dense arrays near the ends of the permanent magnets, and a critical concentration of approximately 0.3 μg ml-1, below which particle assembly into chains was not observed.
AB - Taking inspiration from eukaryotic cilia, we report a method for growing dense arrays of magnetically actuated microscopic filaments. Fabricated from the bottom-up assembly of polymer-coated cobalt nanoparticles, each segmented filament measures approximately 5-15 μm in length and 23.5 nm in diameter, which was commensurate with the width of a single nanoparticle. A custom microscope stage actuates the filaments through orthogonal permanent and alternating magnetic fields. We implemented design of experiments (DOE) to efficiently screen the effects of cobalt nanoparticle concentration, crosslinker concentration, and surface chemistry. The results indicated that the formation of dense, cilia-mimetic arrays could be explained by physical, non-covalent interactions (i.e. dipolar association forces) rather than chemistry. The experiments also determined an optimal Co nanoparticle concentration of approximately 500 μg ml-1 for forming dense arrays near the ends of the permanent magnets, and a critical concentration of approximately 0.3 μg ml-1, below which particle assembly into chains was not observed.
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U2 - 10.1039/b918215b
DO - 10.1039/b918215b
M3 - Article
AN - SCOPUS:75949116502
SN - 1744-683X
VL - 6
SP - 602
EP - 609
JO - Soft Matter
JF - Soft Matter
IS - 3
ER -