Elasto-capillary phenomena, involving finite deformation of elastomer and elasto-capillary effect of droplet/film, widely exist in biological and micro-electro-mechanical systems. To quantitatively analyze the influence of surface tension and to accurately predict the deformation of elastomer, we develop a finite strain model of hyperelastic materials, and then solve it by the explicit dynamics employing the combined finite-discrete element method (FDEM). Based on our model, we investigate the expansion of a small cavity in elastomer and examine the relation between radius and pressure of cavity. Besides, we explore the deformation of an elastic rod that is immersed in liquid and subjected to surface tension. Results show that when the elasto-capillary effect is neglected, edges of the rod would be unrealistically roughened, while the surface is actually smoothed as the surface tension increases. Moreover, we explore the elasto-capillary effect on advanced multiple-period wrinkling patterns in both planar and curved film–substrate systems, showing that the rough wavy surface can be smoothed by increasing surface tension. Our results not only provide fundamental insights into a variety of elasto-capillary phenomena, but also offer a platform to quantitatively guide rational designs of flexible smart devices actuated by surface tension.

弹性毛细管现象涉及弹性体的有限变形和液滴/薄膜的弹性毛细管效应，广泛存在于生物和微机电系统中。为了定量分析表面张力的影响并准确预测弹性体的变形，我们开发了超弹性材料的有限应变模型，然后采用有限离散元组合法 (FDEM) 通过显式动力学对其进行求解。基于我们的模型，我们研究了弹性体中小空腔的膨胀，并检查了空腔半径和压力之间的关系。此外，我们探索了浸入液体并受到表面张力作用的弹性杆的变形。结果表明，当忽略弹性毛细管效应时，杆的边缘会变得不切实际地粗糙，而表面实际上随着表面张力的增加而变得光滑。此外，我们探索了弹性毛细管效应对平面和曲面薄膜-基底系统中高级多周期起皱模式的影响，表明可以通过增加表面张力来平滑粗糙的波浪表面。我们的结果不仅提供了对各种弹性毛细管现象的基本见解，而且还提供了一个平台来定量指导由表面张力驱动的柔性智能设备的合理设计。