The Power of Small Liquid Droplets

It has long been known that water has the ability to erode some of the hardest materials on earth given enough time but the mechanics of how this occurs has only recently been studied. At the University of Minnesota Twin Cities, researchers have discovered why small liquid droplets cause the erosion of solid surfaces. Using a new analysis technique called high-speed stress microscopy that measures the force and pressure exerted on a surface as a drop contact it, the researchers have discovered that the force of a droplet spreads out as the drop deforms itself on impact. This deformation happens faster than the speed of sound, unleashing a shockwave along the surface of the solid object: “Each droplet behaves like a small bomb, releasing its impact energy explosively and giving it the force necessary to erode surfaces over time”. This discovery is expected to help material developers and engineers create better erosion-resistant coatings and materials that weather the elements better than current systems.

University of Minnesota. “New study solves mystery of how soft liquid droplets erode hard surfaces.” ScienceDaily. ScienceDaily, 31 March 2022.