Chemotaxis and autochemotaxis of self-propelling droplet swimmers
Chemotaxis and autochemotaxis of self-propelling droplet swimmers
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DOI：
10.1073/pnas.1619783114
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发表时间：
2017-05-16
影响因子：
11.1
通讯作者：
Maass, Corinna C.
中科院分区：
文献类型：
--
作者：
Jin, Chenyu;Krueger, Carsten;Maass, Corinna C.
趋化作用和自身趋化作用在许多重要的生物学过程中发挥着重要作用。我们提出了一种自动推进的人工游泳系统，它既表现出趋化作用，也表现出负的自趋化作用。表面活性剂水溶液中的油滴是由油相的胶束增溶引起的界面Marangoni流驱动的。我们证明，沿胶束表面活性物质梯度的趋化性可以引导这些游泳者通过微流体迷宫。同样，在水滴游泳者之后，空胶束的耗尽会导致负的自趋化性，从而避免拖尾。我们在分叉通道的微流控装置中定量地研究了自趋化作用：连续游泳者的分支选择是反相关的，这种影响会随着时间的推移而因踪迹分散而衰减。我们用一个简单的一维扩散过程和随机朗之万动力学来模拟这个过程。我们的结果与线性表面活性剂梯度力和适合胶束扩散的扩散常数是一致的，并提供了自趋化反馈强度与随机力的量度。该方法适用于人工和生物自身趋化系统的定量研究。
Chemotaxis and autochemotaxis play an important role in many essential biological processes. We present a self-propelling artificial swimmer system that exhibits chemotaxis as well as negative autochemotaxis. Oil droplets in an aqueous surfactant solution are driven by interfacial Marangoni flows induced by micellar solubilization of the oil phase. We demonstrate that chemotaxis along micellar surfactant gradients can guide these swimmers through a microfluidic maze. Similarly, a depletion of empty micelles in the wake of a droplet swimmer causes negative autochemotaxis and thereby trail avoidance. We studied autochemotaxis quantitatively in a microfluidic device of bifurcating channels: Branch choices of consecutive swimmers are anticorrelated, an effect decaying over time due to trail dispersion. We modeled this process by a simple one-dimensional diffusion process and stochastic Langevin dynamics. Our results are consistent with a linear surfactant gradient force and diffusion constants appropriate for micellar diffusion and provide a measure of autochemotactic feedback strength vs. stochastic forces. This assay is readily adaptable for quantitative studies of both artificial and biological autochemotactic systems.