The preferred lifestyle of microorganisms in the aquatic environment isthe organization in biofilms. Thus, they can be found in nature as well as in the technosphere. They cultivate almost any surface and at even harsh environmental conditions (e.g., extreme pH values, high temperature). Biofilms are highly dynamic and their interaction with the surrounding fluid depends on the structure and vice versa. This is referred to as “fluid-structure-interaction”. To visualize and to understand the biofilm structure at micro-, meso- and macroscale will gain further understanding of the fluid-structure-interaction and related mass transport and transfer processes. The visualization of the biofilm structure by means of various imaging techniques as well as the characterization by suitable structural parameters is the focus of my research.