Droplet depinning on superhydrophobic surfaces is pervasive in nature and critical to many applications and hence has been studied extensively over the past few decades. A consensus has been reached that the droplet depinning force mainly stems from the synergistic dynamics of the three-phase contact line and the liquid–vapor interface. Nevertheless, the aforementioned conclusions were made using simple (pure water) droplets depinning on rigid superhydrophobic surfaces, denoted as simple rigid wetting, where the main influencing factors are liquid–vapor interfacial tension, surface texture geometry and material wettability. In recent years, an increasing amount of attention has been paid to complex soft wetting, where liquid physiochemical properties (e.g. viscoelasticity) and solid surface rigidity play an important role. To encourage the investigation of complex soft wetting, in this perspective, depinning of simple droplets on soft surfaces and depinning of viscoelastic droplets on rigid surfaces are briefly introduced. Then, possible factors that affect viscoelastic droplet depinning on soft superhydrophobic surfaces are discussed. Moreover, applications that are highly relevant to complex soft wetting are introduced.

中文翻译：

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超疏水表面上的液滴脱钉：从简单的刚性润湿到复杂的软润湿

超疏水表面上的液滴脱钉在自然界中普遍存在，对许多应用至关重要，因此在过去几十年中得到了广泛的研究。已达成共识，液滴脱钉力主要源于三相接触线和液-气界面的协同动力学。尽管如此，上述结论是使用简单（纯水）液滴在刚性超疏水表面上脱钉得到的，称为简单刚性润湿，其中主要影响因素是液-气界面张力、表面纹理几何形状和材料润湿性。近年来，复杂的软润湿受到越来越多的关注，其中液体的物理化学性质（例如粘弹性）和固体表面刚度起着重要作用。为了鼓励研究复杂的软润湿，从这个角度来看，简单的液滴在软表面上的脱钉和粘弹性液滴在刚性表面上的脱钉被简要介绍。然后，讨论了影响粘弹性液滴在软超疏水表面上脱钉的可能因素。此外，还介绍了与复杂的软润湿高度相关的应用。