Bio-Inspired Active Self-Cleaning Surfaces via Filament-Like Sweepers Array

Hydrodynamic forces from moving fluids can be utilized to remove contaminants which is an ideal fouling-release strategy for underwater surfaces. However, the hydrodynamic forces in the viscous sublayer are greatly reduced owing to the no-slip condition, which restricts their practical applications. Here, inspired by sweeper tentacles of corals, an active self-cleaning surface with flexible filament-like sweepers are reported. The sweepers can penetrate the viscous sublayer by utilizing energy from outer turbulent flows and remove contaminants with adhesion strength of >30 kPa. Under an oscillating flow, the removal rate of the single sweeper can reach up to 99.5% due to dynamic buckling movements. In addition, the sweepers array can completely clean its coverage area within 10 s through coordinated movements as symplectic waves. The active self-cleaning surface depends on the fluid-structure coupling between sweepers and flows, which breaks the concept of conventional self-cleaning.

Automated summary

Hydrodynamic forces can be used to remove contaminants from underwater surfaces, but their practical applications are limited due to the no-slip condition in the viscous sublayer. Inspired by corals, an active self-cleaning surface with flexible filament-like sweepers is developed. These sweepers can penetrate the viscous sublayer and remove contaminants with high adhesion strength using energy from outer turbulent flows. Under oscillating flow, the single sweeper achieves a removal rate of up to 99.5% through dynamic buckling movements, and the coordinated movements of the sweepers array can completely clean the coverage area within 10 s as symplectic waves. This active self-cleaning surface breaks the concept of conventional self-cleaning by relying on fluid-structure coupling between sweepers and flows.