Reed leaf-inspired anisotropic slippery lubricant-infused surface for water collection and bubble transportation

Abstract

Anisotropic slippery lubricant-infused surfaces with favorable sliding behaviors are highly desirable for water collection and directional bubble transportation. Inspired by natural reed leaves with anisotropic wettability along two directions of groove geometry, a soft lithographic approach of replica molding was implemented to successfully replicate the surface microstructures of reed leaves using polydimethylsiloxane (PDMS). Subsequently, various lubricants were infused to fabricate anisotropic hydrophobic or hydrophilic slippery surfaces. The as-prepared anisotropic hydrophilic lubricant-infused surface (A-HH-LIS) exhibited remarkable droplet nucleation and removal during water collection. The results demonstrated that the surfaces maintained stable water collection rate even under high shear force rate up to 7000 rpm and exhibited favorable liquid repellency at lower or higher temperature. Furthermore, the directional transportations of water (in air) and air bubbles (underwater) on anisotropic hydrophobic lubricant-infused surface (A-HB-LIS) were achieved with outstanding performance. Moreover, the effects of tilted angle β (the angle between sample and plumb line) and rotational angle α (the angle between groove direction and horizontal line) on sliding behavior were explored. The reported anisotropic slippery lubricant-infused surfaces have great potential in water condensation, bubble transportation and marine anti-fouling.