Continuum Mechanical Modeling and Simulation of Self-Cleaning Surface Mechanics due to Microstructural Surface Effects


Self-cleaning mechanisms are observed in artificial as well as biological surfaces such as lotus leaves and bird feathers, which are called hydrophobic surfaces. The microstructure of such surfaces allows water to form small droplets which easily roll-off, sweeping dirt or germ particles away from the surface. The major goal of this research is the development of a detailed computational multi-scale model for self-cleaning surface mechanisms that is based on a continuum mechanical description. The model should be able to describe the interaction between the water droplet, surface asperities, and pollutant particles. Three modelling levels are considered, ranging from the millimeter scale of the droplet down to the nanometer scale of the finest surface asperities. This approach is also seen as a preparation for a future extension by a fourth modelling level that describes the interactions at the atomic level. In order to develop the multiscale model, three intermediate steps are taken: Firstly, an improved finite element membrane formulation is required. Secondly, a refined computational contact formulation needs to be developed for the membrane that can account for the rotational discontinuities that are induced within the membrane surface. Thirdly, also the description of the pollutant particles needs to be refined.