Enhanced locomotion, effective diffusion and trapping of undulatory micro-swimmers in heterogeneous environments
Enhanced locomotion, effective diffusion and trapping of undulatory micro-swimmers in heterogeneous environments
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DOI：
10.1098/rsif.2018.0592
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发表时间：
2018-11-01
影响因子：
3.9
通讯作者：
Keaveny, Eric E.
中科院分区：
文献类型：
--
作者：
Kamal, Arshad;Keaveny, Eric E.
游泳细胞和微生物必须经常通过复杂的流体，其中包含浸没的微观结构，如聚合物分子或细丝。在许多重要的生物过程中，如哺乳动物繁殖和细菌感染，浸没的微结构的大小与游泳细胞的大小相当。这导致离散的游泳者微观结构的相互作用，改变游泳者的路径和速度。在本文中，我们使用详细的模拟和数据驱动的随机模型相结合，以检查运动的平面波动游泳者在球形障碍物的环境中，通过线性弹簧拴在运动平面中的随机点的运动。我们发现，根据环境参数，与障碍物的相互作用可以提高游泳速度或阻止游泳者移动。我们还展示了离散的相互作用如何产生平移和角速度波动，随着时间的推移导致扩散行为，主要是由于游泳和旋转扩散的耦合。我们的研究结果表明，直接的游泳者微结构的相互作用可以产生游泳者运动的变化，可能有重要的影响，细胞群的传播或捕获的有害病原体的复杂流体。
Swimming cells and microorganisms must often move through complex fluids that contain an immersed microstructure such as polymer molecules or filaments. In many important biological processes, such as mammalian reproduction and bacterial infection, the size of the immersed microstructure is comparable to that of the swimming cells. This leads to discrete swimmermicrostructure interactions that alter the swimmer's path and speed. In this paper, we use a combination of detailed simulation and data-driven stochastic models to examine the motion of a planar undulatory swimmer in an environment of spherical obstacles tethered via linear springs to random points in the plane of locomotion. We find that, depending on environmental parameters, the interactions with the obstacles can enhance swimming speeds or prevent the swimmer from moving at all. We also show how the discrete interactions produce translational and angular velocity fluctuations that over time lead to diffusive behaviour primarily due to the coupling of swimming and rotational diffusion. Our results demonstrate that direct swimmer-microstructure interactions can produce changes in swimmer motion that may have important implications for the spreading of cell populations in or the trapping of harmful pathogens by complex fluids.