Dipolar assembly of ferromagnetic nanoparticles into magnetically driven artificial cilia
Dipolar assembly of ferromagnetic nanoparticles into magnetically driven artificial cilia
复制标题
DOI：
10.1039/b918215b
复制
发表时间：
2010-01-01
期刊：
影响因子：
3.4
通讯作者：
Pyun, Jeffrey
中科院分区：
文献类型：
--
作者：
Benkoski, Jason J.;Deacon, Ryan M.;Pyun, Jeffrey
受真核纤毛的启发，我们报告了一种生长密集的磁驱动微观丝阵列的方法。由聚合物涂覆的钴纳米颗粒自下而上组装而成，每个分段细丝的长度约为 5-15 毫米，直径为 23.5 纳米，与单个纳米颗粒的宽度相当。定制的显微镜载物台通过正交永久和交变磁场驱动细丝。我们实施了实验设计 (DOE)，以有效筛选钴纳米粒子浓度、交联剂浓度和表面化学的影响。结果表明，密集的纤毛模拟阵列的形成可以通过物理、非共价相互作用（即偶极缔合力）而不是化学来解释。实验还确定了在永磁体末端附近形成致密阵列的最佳Co纳米颗粒浓度约为500μgml(-1)，以及大约0.3μgml(-1)的临界浓度，低于该浓度则不会观察到颗粒组装成链。
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 mm 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 mu g ml(-1) for forming dense arrays near the ends of the permanent magnets, and a critical concentration of approximately 0.3 mu g ml(-1), below which particle assembly into chains was not observed.