Biofouling control: a microfluidic assessment of patterned surfaces

Abstract

Biofouling, by the sessile growth of microorganisms onto submerged surfaces, presents a serious problem for underwater structures. While biofouling can be controlled to various degrees with different patterned surfaces, the underlying mechanisms are still imprecise. Since long researchers are speculating that microtopographies might influence surface-near microfluidic conditions and thus micro-hydrodynamically preventing microorganism settlement. It is therefore very important to identify the microfluidic environment developed on patterned surfaces and its relation with antifouling behavior of those surfaces. This study considered the wall shear stress distribution pattern of microtopographies as a significant aspect of this microfluidic environment. Though the requirement of effective shear stress is quite low for removing microorganisms at their early stage of attachment, still the development of this critical shear stress is limited due to inadequate inertial forces in the viscous dominated sublayer. So in this study, patterned surfaces were analyzed in the perspective of developing critical microfluidic shear stress with specific distribution pattern to inhibit the gregariousness of microorganisms. A shape comparison of patterned surfaces with equivalent roughness geometries was carried out using CFD simulations. Finally, the study pointed out some geometrical features of a patterned surface and related fluid flow conditions to be considered while selecting the surface for biofouling control.