Tough Reversible Adhesion Properties of a Dry Self-Cleaning Biomimetic Surface.

Abstract

Geckos have one of the world's most efficient reversible adhesion systems. Even walking in dusty conditions, geckos can dislodge up to 80% of contaminants and recover their adhesion capability after walking as few as four steps. Thus far, artificial dry self-cleaning materials inspired by the geckos' hierarchical fibrillar structure have been only able to remove 55% of collected large particle contaminants with 30 steps. Challenges, including low mechanical strength, low stiffness, and short fatigue time keep these materials from being used in practical applications. This study involves the novel fabrication of dry self-cleaning surfaces with a high mechanical performance and an outstanding dry self-cleaning property. Imposing a load-drag-pull process similar to a gecko's foot adhesion process, our biomimetic surfaces could dislodge up to 59% of microparticles (∼8 μm) with as few as five steps. Furthermore, the surface had an excellent screening ability at low temperatures regardless of the surface roughness similarity. The surfaces were also proven to be scratch resistant. The biomimetic surfaces exhibit enhanced dry self-cleaning and mechanical properties and could be promising in applications such as reusable adhesives, biochips, aerospace satellite waste collection, and screening equipment.