标题： 蒸发的相互连接液滴的动力学 显示英文标题

标题： Dynamics of evaporating, interconnected droplets

摘要： 我们报告了由微通道连接的两个附着液滴的动力学情况，但它们开放于大气中，因此可以自由蒸发。 我们的结果表明，液滴之间的流体交换是通过由两个液滴之间静压和拉普拉斯压差驱动的泵浦流实现的。 蒸发导致液滴逐渐失去体积并改变形状，这随后影响它们之间的流体传输。 我们观察到，在接触面积相等的情况下，较大的液滴通常在蒸发过程中向较小的液滴供液，连接通道中的流动是单向的。 然而，在接触面积不等的情况下，随着蒸发过程中液滴形状的突然变化，连接通道中的流动可以发生反转。 稳定性分析表明，交换流的动力学是由超临界叉式分岔所支撑的。 蒸发引起的体积损失使得液滴对能够通过由系统瞬时体积决定的一系列准稳态状态逐步变化。 强制使接触面积不等展开分岔，使得液滴形状变化和相关的流动反转可以理解为从分岔的断开分支跳转到连接分支。 这确立了对称性破缺作为在连接液滴中诱导蒸发驱动流动反转的机制。 显示英文摘要

摘要： We report on the dynamics of a pair of sessile droplets that are connected by a microchannel, yet open to the atmosphere and hence free to evaporate. Our results reveal that fluid exchange between droplets occurs via a pumping flow driven by differences in hydrostatic and Laplace pressure between the two droplets. Evaporation causes the droplets to slowly lose volume and change shape, which subsequently affects the fluid transport between them. We observe that, for equal contact areas, a larger droplet typically feeds a smaller droplet during evaporation and the flow in the connecting channel is unidirectional. However, for unequal contact areas, the flow can reverse in the connecting channel following a sudden switch in dropletshape that occurs during evaporation. A stability,analysis reveals that the dynamics of the exchange flow are underpinned by a supercritical pitchfork bifurcation. Evaporative volume loss permits the droplet pair to step through a sequence of quasi-stationary states determined by the instantaneous volume of the system. Enforcing unequal contact area unfolds the bifurcation such that droplet-shape switching and the associated flow reversal can be understood in terms of a jump from the disconnected to the connected branch of the bifurcation. This establishes symmetry breaking as a mechanism to induce evaporation-driven flow reversal in connected droplets.