We introduce the concept of Flowing Droplet Interface Bilayers (FDIBs) that are made of two droplets maintained in contact due to the presence of an adhesive lipidic surfactant. This system is similar to a flowing dumbbell made of two droplets interconnected by a lipid bilayer and driven by an external flow. Interestingly, such a dumbbell does not show a straight flow trajectory, but it oscillates between the sidewalls while moving along the microchannel. The origin of this unusual motion is hydrodynamic interactions, as demonstrated by analytical calculations and micro particle image velocimentry (µPiV) measurements. The hydrodynamic motion appears to be highly sensitive to the mechanical properties of the lipid bilayer connecting the two droplets (FDIB). Thus, droplet trajectories can be controlled by tuning the lipid bilayer composition, which enables in turn investigating mechanical properties of free-standing lipid bilayers.

中文翻译：

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流动的液滴界面双层：一种微流体工具，可控制液滴轨迹并研究无支撑脂质双层的机械性能。

我们介绍了流动的液滴界面双层（FDIBs）的概念，该层由两个由于粘附性脂质表面活性剂的存在而保持接触的液滴组成。该系统类似于由两个液滴组成的流动哑铃，该两个液滴通过脂质双层相互连接并由外部流驱动。有趣的是，这种哑铃并没有显示出直线的流动轨迹，而是在沿着微通道移动时在侧壁之间振荡。这种异常运动的起源是流体动力相互作用，如分析计算和微粒图像速度（µPiV）测量所证明的。流体动力学运动似乎对连接两个液滴的脂质双层（FDIB）的机械性能高度敏感。因此，可以通过调整脂质双层的组成来控制液滴的轨迹，