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 two contexts: composites and adhesive contacts. In both of these examples, we find that surface tension dominates over elasticity on length scales determined by material properties, requiring us to rethink solid mechanics for soft materials. Our findings potentially impact the design of any system that relies on compliant materials with interfaces, including soft robotics, functional soft medical implants, and commercial adhesives.
Dr. Katharine Jensen is a postdoctoral associate at Yale University in the Department of Mechanical Engineering and Materials Science, where her research focuses on the mechanics of soft materials. She earned her A.B. in Physics at Princeton in 2004 and her Ph.D. in Physics at Harvard in 2013. Between college and graduate school, she was a researcher at MIT Lincoln Laboratory, where she worked on the optoelectronic properties of III-V semiconductors. Her dissertation explored structure formation and deformation dynamics of hard-sphere colloidal materials, with particular emphasis on the mechanisms of plastic deformation in amorphous materials. More broadly, her research focuses on the relationship between the microscopic structure and the macroscopic mechanics of materials.