Splash dynamics induced by raindrops impacting textured surfaces

The prevalence of raindrops impacting insects, promoting soil erosion, and impinging outdoor surfaces like leaves and stones ensures enduring interests from fluid mechanicians and biologists. Until now, researchers have not systematically investigated splash dynamics induced by raindrops impacting textured surfaces. In this experimental study, we use high-speed videography to film drop impacts on various surfaces and compare impact behavior with drops striking a hydrophilic and a hydrophobic surface. Generally, free-falling drops impacting homogenous surfaces produce bouncing, spreading or splintering depending on impact velocity and surface texture. Here, we show previously undocumented fluid-structure interactions between drops and surfaces often encountered by terrestrial insects like the fire ant and expect our results to translate to the survival dynamics of small creatures exposed to rain.