标题： 液滴在软固体上滑动时形成弹性毛细轨道 显示英文标题

标题： Droplets sliding on soft solids shed elastocapillary rails

摘要： 部分润湿液滴的表面张力会变形柔软基底。 这些变形通常局限于接触线附近的狭窄区域，形成所谓的“弹性毛细脊”。 当液滴沿基底滑动时，弹性毛细脊的运动会在基底中耗散能量并减缓液滴的运动。 先前的研究分析了各向同性扩展的液滴，并发现前进的接触线“沿着”弹性毛细脊移动，其速度由毛细力和整体流变学的局部平衡决定。 在这里，我们通过实验研究了液滴在柔软基底上滑动的动力学行为。 在低速下，接触线几乎是圆形的，耗散能量随速度对数增加。 在较高液滴速度下，接触线呈现出子弹状形状，耗散能量趋于稳定。 同时，液滴会脱落一对“弹性毛细轨道”，这些轨道缓慢消失在后面。 这些结果表明，液滴更倾向于沿静止的脊滑动，而不是在移动的脊上“冲浪”。 显示英文摘要

摘要： The surface tension of partially wetting droplets deforms soft substrates. These deformations are usually localized to a narrow region near the contact line, forming a so-called `elastocapillary ridge.' When a droplet slides along a substrate, the movement of the elastocapillary ridge dissipates energy in the substrate and slows the droplet down. Previous studies have analyzed isotropically spreading droplets and found that the advancing contact line `surfs' the elastocapillary ridge, with a velocity determined by a local balance of capillary forces and bulk rheology. Here, we experimentally explore the dynamics of a droplet sliding across soft substrates. At low velocities, the contact line is nearly circular, and dissipation increases logarithmically with speed. At higher droplet velocities, the contact line adopts a bullet-like shape, and the dissipation levels off. At the same time, droplets shed a pair of `elastocapillary rails' that fade away slowly behind it. These results suggest that droplets favor sliding along a stationary ridge over surfing atop a translating one.