Frequency-dependent higher-order Stokes singularities near a planar elastic boundary: Implications for the hydrodynamics of an active microswimmer near an elastic interface.
Frequency-dependent higher-order Stokes singularities near a planar elastic boundary: Implications for the hydrodynamics of an active microswimmer near an elastic interface.
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平面弹性边界附近频率相关的高阶斯托克斯奇点：对弹性界面附近主动微型游泳器的流体动力学的影响
DOI：
10.1103/physreve.100.032610
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
S. Gekle
中科院分区：
文献类型：
--
作者：
A. Daddi-Moussa-Ider;C. Kurzthaler;C. Hoell;A. Zöttl;M. Mirzakhanloo;M. R. Alam;A. M. Menzel;H. öwen;S. Gekle
流体环境中的自驱动活性粒子这一新兴领域最近引起了生物物理学和生物工程界的极大兴趣，因为它们在生物医学和技术应用方面具有广阔的前景。这些微型游泳者在水介质中自主移动，在现实情况下，它们会遇到大量的外部刺激和具有特殊弹性特性的限制表面。基于远场流体动力学模型，我们提出了一种分析理论来描述自驱动式主动微型游泳器与具有抗剪切和抗弯曲能力的弹性界面之间的物理相互作用和流体动力学耦合。我们将活性剂建模为高阶斯托克斯奇点的叠加，并阐明由附近弹性边界引起的相关平移和旋转速度。我们的结果表明，速度可以分解为与剪切和弯曲相关的贡献，这些贡献接近稳定极限下接近无滑移刚性壁的活性剂的速度。瞬态动力学预测，弯曲阻力对微型游泳器速度的贡献通常比剪切阻力更明显。弯曲可以增强（抑制）由高阶奇点产生的速度，而与剪切相关的贡献会降低（增加）速度。最突出的是，我们发现在仅对剪切变形具有能量抵抗的弹性界面附近，例如设计用于药物输送的弹性胶囊的弹性界面，游动的细菌会经历与在无滑移壁附近观察到的相同方向的旋转。与此相反，在仅对弯曲具有能量阻力的界面附近，例如流体囊泡或脂质体的界面，我们发现了反向旋转方向。我们的结果提供了对弹性约束附近人工和合成自推进主动微型游泳器的控制和引导的见解。
The emerging field of self-driven active particles in fluid environments has recently created significant interest in the biophysics and bioengineering communities owing to their promising future for biomedical and technological applications. These microswimmers move autonomously through aqueous media, where under realistic situations they encounter a plethora of external stimuli and confining surfaces with peculiar elastic properties. Based on a far-field hydrodynamic model, we present an analytical theory to describe the physical interaction and hydrodynamic couplings between a self-propelled active microswimmer and an elastic interface that features resistance toward shear and bending. We model the active agent as a superposition of higher-order Stokes singularities and elucidate the associated translational and rotational velocities induced by the nearby elastic boundary. Our results show that the velocities can be decomposed in shear and bending related contributions which approach the velocities of active agents close to a no-slip rigid wall in the steady limit. The transient dynamics predict that contributions to the velocities of the microswimmer due to bending resistance are generally more pronounced than those due to shear resistance. Bending can enhance (suppress) the velocities resulting from higher-order singularities whereas the shear related contribution decreases (increases) the velocities. Most prominently, we find that near an elastic interface of only energetic resistance toward shear deformation, such as that of an elastic capsule designed for drug delivery, a swimming bacterium undergoes rotation of the same sense as observed near a no-slip wall. In contrast to that, near an interface of only energetic resistance toward bending, such as that of a fluid vesicle or liposome, we find a reversed sense of rotation. Our results provide insight into the control and guidance of artificial and synthetic self-propelling active microswimmers near elastic confinements.
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影响因子：
2.7
作者：
Downton, Matthew T.;Stark, Holger
通讯作者：
Stark, Holger
胶体悬浮液中的残存结构从 3D 挤压到 2D。
影响因子：
8.6
作者：
S. Klapp;Yan Zeng;D. Qu;R. von Klitzing
通讯作者：
R. von Klitzing
影响因子：
3.4
作者：
W. Uspal;W. Uspal;M. N. Popescu;M. N. Popescu;S. Dietrich;S. Dietrich;M. Tasinkevych;M. Tasinkevych
通讯作者：
W. Uspal;W. Uspal;M. N. Popescu;M. N. Popescu;S. Dietrich;S. Dietrich;M. Tasinkevych;M. Tasinkevych
DOI：
10.1088/0953-8984/28/25/253001
发表时间：
2016-01
期刊：
Journal of Physics: Condensed Matter
影响因子：
--
作者：
A. Zöttl;H. Stark
通讯作者：
A. Zöttl;H. Stark
影响因子：
8.6
作者：
Hill, Jane;Kalkanci, Ozge;Koser, Hur
通讯作者：
Koser, Hur