Biomimetic water-collecting materials inspired by nature

Abstract

Nowadays, water shortage is a severe issue all over the world, especially in some arid and undeveloped areas. Interestingly, a variety of natural creatures can collect water from fog, which can provide a source of inspiration to develop novel and functional water-collecting materials. Recently, as an increasingly hot research topic, bioinspired materials with the water collection ability have captured vast scientific attention in both practical applications and fundamental research studies. In this review, we summarize the mechanisms of water collection in various natural creatures and present the fabrications, functions, applications, and new developments of bioinspired materials in recent years. The theoretical basis related to the phenomenon of water collection containing wetting behaviors and water droplet transportations is described in the beginning, i.e., the Young's equation, Wenzel model, Cassie model, surface energy gradient model and Laplace pressure equation. Then, the water collection mechanisms of three typical and widely researched natural animals and plants are discussed and their corresponding bioinspired materials are simultaneously detailed, which are cactus, spider, and desert beetles, respectively. This is followed by introducing another eight animals and plants (butterfly, shore birds, wheat awns, green bristlegrass, the Cotula fallax plant, Namib grass, green tree frogs and Australian desert lizards) that are rarely reported, exhibiting water collection properties or similar water droplet transportation. Finally, conclusions and outlook concerning the future development of bioinspired fog-collecting materials are presented.

Bioinspired Special Wettability Surfaces: From Fundamental Research to Water Harvesting Applications

“…Animals and plants, over the past hundreds of million years, have evolved and survived in extreme conditions. For example in the Namib desert, beetles, spider, cactus, Nepenthes alata have adopted water harvesting features as shown in Figure . To develop man‐made materials for water‐harvesting, it is essential to first understand the water‐harvesting mechanisms, before the biomimetic materials are developed.…”

Direct Measurements of Adhesion Forces for Water Droplets in Contact with Smooth and Patterned Polymers

“…[1][2][3] In addition, many engineering inventions rely on liquid-solid interactions, including inkjet printing, 4 biosurfactant transport in agricultural soil, 5 froth flotation of particles 6,7 and many other applications. [8][9][10][11] By grasping the mechanism that governs liquid-solid interactions, solid surfaces can be designed and fabricated to meet demands in industrial applications, such as slippery superhydrophobic surfaces for self-cleaning, 12,13 anti-icing, [14][15][16] drag reduction 13 and enhanced condensation, 17 sticky superhydrophobic surfaces for liquid capturing, [18][19][20] superhydrophobic fabric for water and dirt resistance, 21 superhydrophilic surfaces for boiling 22 and water collection 23 and other surfaces.…”

Bioinspired Dynamic Wetting on Multiple Fibers

“…Therefore, multiscale structured membranes could successfully improve the water collection efficiency, as proven by additional experiments. [22] Recently, a smart hydrogel-based, wet-responsive switch for directional droplet transport was developed. [23] In this system, the state of the droplet could alternate between moving and not moving by opening and closing two parallel copper fibers via varying the humidity.…”