Sticking with Soft Solids
Surface tension is usually neglected in solid mechanics because elasticity dominates the mechanical response of stiff materials. However, for very compliant solids, the surface tension can compete with and even dominate over the elastic response. This results in counterintuitive phenomena that sometimes directly contradict the predictions of classic elastic theory. Here, I will describe solid surface tension at work in the specific context of soft adhesive contact. In this and other examples, we find that surface tension dominates over elasticity on length scales determined by material properties, requiring us to rethink solid mechanics for soft solids. Our findings potentially impact the design of any system that relies on compliant materials with interfaces, including soft robotics, flexible and wearable electronics, functional soft medical implants, and commercial adhesives.