Heterogeneously flagellated microswimmer behavior in viscous fluids
Heterogeneously flagellated microswimmer behavior in viscous fluids
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DOI：
10.1063/1.5137743
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发表时间：
2020-03-01
期刊：
影响因子：
3.2
通讯作者：
Kim, Min Jun
中科院分区：
文献类型：
--
作者：
Rogowski, Louis William;Oxner, Micah;Kim, Min Jun
本文分析了粘性流体中的非均匀鞭毛微泳者。从鼠伤寒沙门氏菌收获的鞭毛被分离、重聚合并官能化以在其末端具有生物素，从而允许沿着抗生物素蛋白包被的微粒的表面沿着。组装的microswimmer旋转下递增的磁场频率，在盐水和甲基纤维素溶液中，基线的速度响应。均方位移分析表明，旋转microswimmer表现出异常的扩散行为，在小的时间尺度在每种流体，并增加了扩散率相比，非旋转的情况下。鞭状微泳者有较低的扩散率相比，非鞭状微粒在布朗条件。微型游泳者被证明在比例反馈控制下以合理的精度执行选定的轨迹。最后，microswimmer推进被证明在很大程度上受到旋转磁场的手性的影响，顺时针旋转下观察到的频率诱导的游泳方向的逆转，这种效果被确定为鞭毛捆绑和解开的结果。
An analysis of heterogeneously flagellated microswimmers inside viscous fluids is presented. Flagella harvested from Salmonella typhimurium were isolated, repolymerized, and functionalized to have biotin at their ends, allowing for chemical attachment along the surfaces of avidin-coated microparticles. Assembled microswimmers were rotated under incremental magnetic field frequencies, in saline and methylcellulose solutions, to baseline their velocity responses. A mean square displacement analysis revealed that rotating microswimmers exhibited anomalous diffusive behavior at small time scales in each fluid and had increased diffusivity compared with the non-rotating cases. Flagellated microswimmers had decreased diffusivity when compared with non-flagellated microparticles in Brownian conditions. Microswimmers were demonstrated to perform selected trajectories under proportional feedback control with reasonable accuracy. Finally, microswimmer propulsion was shown to be heavily influenced by the handedness of the rotating magnetic fields, with frequency induced reversals of swimming direction observed under clockwise rotation; this effect was determined to be the result of flagellar bundling and unbundling.