Bioinspired Hierarchical Surfaces Fabricated by Femtosecond Laser and Hydrothermal Method for Water Harvesting

Abstract

The world is facing a global issue of water scarcity where two-thirds of the population does not have access to safe drinking water. Water harvesting from the ambient environment has a potential equivalent to ∼10% of the fresh water available on the earth’s surface, but its efficiency requires a special control of surface morphology. We report a novel facile physicochemical hybrid method that combines femtosecond laser structuring with hydrothermal treatment to create a surface with a well-arranged hierarchical nanoneedle structures. Polydimethylsiloxane treatment of the thus-produced hierarchical structures nurtured superhydrophobic functionality with a very low water sliding angle (∼3°) and a high water adhesion ability. About 2.2 times higher water-collection efficiency was achieved using hierarchical structures over untreated flat Ti surfaces of the same area under a given experimental condition. The comparison of water-collection behavior with other samples showed that the improved efficiency is due to the structure, and wettability induced superior water attraction and removal ability. Moreover, a uniform water condensation under low humidity (28%) is achieved, which has potential applications in harvesting water from arid environments and in high-precision drop control.

Lubricant self-replenishing slippery surface with prolonged service life for fog harvesting

“…| https://mc03.manuscriptcentral.com/friction are generally recognized as the three stages of fog harvesting [22,59]. First, the fog-capture process based on a humidifier is captured by small droplets from a mist flow by a surface, in which the oil-infused slippery surfaces have a higher droplet nucleation density than HBSs [37].…”

“…In these fields, harvesting water from fog is an effective solution for the shortage of fresh water, which has drawn wide attention [16][17][18][19][20]. Fog capture, water condensation, and water removal are generally recognized as the three stages of fog harvesting [21][22][23][24]. The wettability of artificial surfaces, including hydrophobic surfaces (HBSs), hydrophilic surfaces (HHSs), and slippery liquid-infused porous surfaces (SLIPs), can be controlled by adjusting the surface morphology and surface chemical composition [25,26].…”

Which Is the Motion State of a Droplet on an Inclined Hydrophilic Rough Surface in Gravity: Pinned or Sliding?

“…Droplets on surfaces are a phenomenon observed in everyday life, as well as in many environmental or industrial applications: coating processes [1][2][3], combustion processes [4][5][6], printing [7,8], self-cleaning surfaces [9][10][11], self-catchment surfaces [12][13][14], protein adsorption chips, etc. [15][16][17].…”

Bioinspired materials for water-harvesting: focusing on microstructure designs and the improvement of sustainability

“…Inspired by nature, the research on bioinspired materials came into being and became a hot topic. [30][31][32][33][34][35][36][37][38][39][40][41][42] In the past ten years, it has made great achievements. 43 According to the previous literature, by imitating the micro-nano structure, morphology, and wettability of organisms such as spider silk, cactus, and desert beetles, a variety of design and preparation methods of bioinspired water collection materials have been produced.…”