A quadruple biomimetic hydrophilic/hydrophobic Janus composite material integrating Cu(OH)2 micro-needles and embedded bead-on-string nanofiber membrane for efficient fog harvesting

Bioinspired topological design with unidirectional water transfer for efficient atmospheric water harvesting

“…Unlike the asymmetrical wettability for water transfer (surface energy gradient), 30 unidirectional water transfer in conical channels is driven by the Laplace differential pressure. 30–32 The asymmetry Laplace pressure for droplets on the surface of a conical shaped object can be explained using eqn (1): 32 where R is the local radius of a water droplet on a cone-like surface ( R 1 and R 2 are the local radii of opposite sides of the droplet), R 0 is the contact droplet radius of the three-phase contact line ( R 0 = (3 V /4π) 1/3 , V is the volume of the droplet), β is the semi-apex angle of the conical structure, and z is the integrating variable that extends along the diameter of the conical shapes. The negative sign of Δ P indicates that there is smaller Laplace pressure at the side with a larger curvature radius R 2 , which causes the droplet to move towards the side with higher curvature (shown in Fig.…”

“…Unlike the asymmetrical wettability for water transfer (surface energy gradient), 30 unidirectional water transfer in conical channels is driven by the Laplace differential pressure. [30][31][32] The asymmetry Laplace pressure for droplets on the surface of a conical shaped object can be explained using eqn (1): 32 Journal of Materials Chemistry A Paper…”

Liquid-Assisted Bionic Conical Needle for In-Air and In-Oil–Water Droplet Ultrafast Unidirectional Transportation and Efficient Fog Harvesting

“…As shown in Figure S6a–d, the density of formed nanowires on the copper needle without acid-etching pretreatment is much lower than that of the copper needle with acid-etching pretreatment at the same chemical oxidation time (2 h). This is because after the copper needle was acid-etched by HNO3, the oxide film on the copper needle surface was removed, which resulted in more Cu 2+ in the later chemical oxidation process, so more nanowires could be formed . As a consequence, the water droplet can hardly self-transport on the obtained NCCN without acid-etching pretreatment (Figure S6e).…”

Bionic Surfaces for Fog Collection: A Comprehensive Review of Natural Organisms and Bioinspired Strategies

“…The material achieved an excellent fog collection efficiency of 80.57 mg min −1 cm −2 through effective fog capture and unidirectional droplet transport. 108 The unique asymmetric structure and gradient wettability of cactus thorns can promote the continuous transmission of water droplets and reduce evaporation. It is an important reason cactus has efficient fog collection ability, which provides inspiration for the design and preparation of fog collection materials and structures.…”