On the fundamentals of microfoulant adhesion and dynamics on microengineered soft materials in water shear flow environments

The interfacial interaction between tenacious microfoulants, water, and surfaces plays an important role in various technologies including, water treatment, desalination, and energy conversion processes. Efforts to create sustainable surfaces with inherent resistance to microfouling have been ongoing, but success has been challenging to achieve. This is primarily because there is still a lack of fundamental understanding regarding the deposition, adhesion, and removal mechanisms of microfoulants in dynamic shear flow environments. Here, we investigate experimentally the intertwined effects of shear flow, substrate compliance, and surface texture on microfoulant adhesion and detachment. To elucidate the effects, we use a micro-scanning fluid dynamic gauge (µ-sFDG) system which allows us to observe the interfacial dynamics in-situ in a laminar shear flow environment. Guided by fluidic and adhesion theories we explore guidelines for the design of microfouling resistant surfaces and demonstrate an engineered surface that can passively remove 98% of tenacious microfoulants under natural flow conditions.