Effects of surface energy landscape on shear resistant biofilm structures in high shear flows*

Biofilm consisting of structured bacterial communities protected cells from environmental insults such as antibiotics, biocides, and mechanical abrasions.  Recent studies on near surface bacterial motility and biofilm responses to flow shear leads to hypothesis that substrate landscape (e.g. surface hydrophobicity, roughness, and chemistry) and hydrodynamic conditions (e.g. flow and shear) substantially affect the fundamental formation processes and cause the film to evolve to diametrically different mature biofilms. In this study, we apply our newly developed Ecology-on-a-chip (eChip) microfluidic microcosm platform and surface-patterning technique with OTS self-assembled monolayer micro-patches to study the role of surficial energy landscape and flow shear on 3D biofilm structures. Pseudomonas biofilms are be formed in-situ in eChip platform with a SMA patterned bottom surface. The formation processes (e.g. attachment, proliferation, dispersal, regrowth) and the evolution of 3D film structures are measured in the real-time as well as their capability of resisting shear will also be assessed and quantified. Results show that direct correlations of length and time scale between energy landscape and near wall flow.