Solar-driven water evaporation represents an environmentally benign method of water purification/desalination. However, the efficiency is limited by increased salt concentration and accumulation. Here, we propose an energy reutilizing strategy based on a bio-mimetic 3D structure. The spontaneously formed water film, with thickness inhomogeneity and temperature gradient, fully utilizes the input energy through Marangoni effect and results in localized salt crystallization. Solar-driven water evaporation rate of 2.63 kg m−2 h−1, with energy efficiency of >96% under one sun illumination and under high salinity (25 wt% NaCl), and water collecting rate of 1.72 kg m−2 h−1 are achieved in purifying natural seawater in a closed system. The crystalized salt freely stands on the 3D evaporator and can be easily removed. Additionally, energy efficiency and water evaporation are not influenced by salt accumulation thanks to an expanded water film inside the salt, indicating the potential for sustainable and practical applications.

Solar‐driven water evaporation has been considered a sustainable method to obtain clean water through desalination. However, its further application is limited by the complicated preparation strategy, poor salt rejection, and durability. Herein, inspired by superfast water transportation of the Nepenthes alata peristome surface and continuous bridge‐arch design in architecture, a biomimetic 3D bridge‐arch solar evaporator is proposed to induce Marangoni flow for long‐term salt rejection. The formed double‐layer 3D liquid film on the evaporator is composed of a confined water film for water supplementation and a free‐flowing water film with ultrafast directional Marangoni convection for salt rejection, which functions cooperatively to endow the 3D evaporator with all‐in‐one function including superior solar‐driven water evaporation (1.64 kg m‐2 h‐1, 91% efficiency for pure water), efficient solar desalination, and long‐term salt‐rejecting property (continuous 200 h in 10 wt% saline water) without any post‐cleaning treatment. The design principle of the 3D structures is provided for extending the application of Marangoni‐driven salt rejection and the investigation of structure‐design‐induced liquid film control in the solar desalination field. Furthermore, excellent mechanical and chemical stability is proved, where a self‐sustainable and solar‐powered desalination–cultivation platform is developed, indicating promising application for agricultural cultivation.

Various creatures, such as spider silk and cacti, have harnessed their surface structures to collect fog for survival. These surfaces typically stay dry and have a large contact hysteresis enabling them to move a condensed water droplet, resulting in an intermittent transport state and a relatively reduced speed. In contrast to these creatures, here we demonstrate that Nepenthes alata offers a remarkably integrated system on its peristome surface to harvest water continuously in a humid environment. Multicurvature structures are equipped on the peristome to collect and transport water continuously in three steps: nucleation of droplets on the ratchet teeth, self-pumping of water collection that steadily increases by the concavity, and transport of the acquired water to overflow the whole arch channel of the peristome. The water-wetted peristome surface can further enhance the water transport speed by ∼300 times. The biomimetic design expands the application fields in water and organic fogs gathering to the evaporation tower, laboratory, kitchen, and chemical industry.

Nowadays, oily wastewater and spilled oil have caused great threats on both ecosystem and human life. To address these severe problems, considerable efforts have been possessed on developing novel oil/water separation materials. The porous oil‐absorbent materials, especially the porous polydimethylsiloxane (PDMS) with excellent properties of easy fabrication and inherent hydrophobicity, have attracted tremendous attentions from worldwide. The conventional methods using salt or sugar as sacrificial template and water as solvent have been widely adopted to fabricate the porous PDMS sponge. Due to the inherent hydrophobicity of PDMS, the solvent of water hardly penetrates into the inside of PDMS, which results in the difficult and incomplete remove of the hard template. In this contribution, the 3D interconnected porous PDMS sponge is facilely prepared by utilizing a modified technique with the citric acid monohydrate as hard template and ethanol as solvent. The proposed approach is capable of removing the hard template efficiently and thoroughly, which demonstrates promising utilizations in practical applications.

The ballistic ejection of liquid drops by electrostatic manipulating has both fundamental and practical implications, from raindrops in thunderclouds to self-cleaning, anti-icing, condensation, and heat transfer enhancements. In this paper, the ballistic jumping behavior of liquid drops from a superhydrophobic surface is investigated. Powered by the repulsion of the same kind of charges, water drops can jump from the surface. The electrostatic acting time for the jumping of a microliter supercooled drop only takes several milliseconds, even shorter than the time for icing. In addition, one can control the ballistic jumping direction precisely by the relative position above the electrostatic field. The approach offers a facile method that can be used to manipulate the ballistic drop jumping via an electrostatic field, opening the possibility of energy efficient drop detaching techniques in various applications.

Separation of micro-scaled water-in-oil droplets is important in environmental protection, bioassays, and saving functional inks. So far, bulk oil-water separation has been achieved by membrane separation and sponge absorption, but micro-drop separation still remains a challenge. Herein we report that instead of the "plug-and-go" separation model, tiny water-in-oil droplets can be separated into pure water and oil droplets through "go-in-opposite ways" on curved peristome-mimetic surfaces, in milliseconds, without energy input. More importantly, this overflow controlled method can be applied to handle oil-in-oil droplets with surface tension differences as low as 14.7 mN m and viscous liquids with viscosities as high as hundreds centipoises, which markedly increases the range of applicable liquids for micro-scaled separation. Furthermore, the curved peristome-mimetic surface guides the separated drops in different directions with high efficiency.

Liquid drops impacting on a solid surface is a familiar phenomenon. On rainy days, it is quite important for leaves to drain off impacting raindrops. Water can bounce off or flow down a water-repellent leaf easily, but with difficulty on a hydrophilic leaf. Here, we show an interesting phenomenon in which impacting drops on the hydrophilic pitcher rim of Nepenthes alata can spread outward to prohibit water filling the pitcher tank. We mimic the peristome surface through a designed 3D printing and replicating way and report a time-dependently switchable liquid transport based on biomimetic topological structures, where surface curvature can work synergistically with the surface microtextures to manipulate the switchable spreading performance. Motived by this strange behavior, we construct a large-scaled peristome-mimetic surface in a 3D profile, demonstrating the ability to reduce the need to mop or to squeegee drops that form during the drop impacting process on pipes or other curved surfaces in food processing, moisture transfer, heat management, etc.

self-cleaning and antifouling ability for repelling the deposition of other materials and liquid confining properties for enhancing printing resolution and avoiding coffee-ring effects. [13] However, inertial water drops impacting superhydrophobic surfaces can bounce off quickly or splash violently. [14][15][16][17][18][19][20][21][22][23] Undesired rebound and splash cause material waste [24] and weaken the related performance and efficiency. Many attempts have been conducted to promote water drop spreading on hydrophobic surfaces by using polymers [1,23,[25][26][27][28] or surfactants. [22,[29][30][31][32] However, these two methods still have drawbacks for achieving drop deposition, not to mention uniform spreading: 1) Polymer additives can delay drop retraction but leave drops with hemispherical shape and nonuniform material distribution on the hydrophobic substrate.2) The poor wettability and large mole cular weight of polymer additives restrict the ejecting process during inkjet printing. 3) Surfactant additives can promote drop spreading in a static state owing to the reduced surface tension (γ); [33] however, the low surface tension increases the instability of the impacting drop and leads to drop splashing with satellite droplets, according to the Kelvin-Helmholtz instability, [34] k max ∼ 2ρ a U r 2 /3γ (ρ a is the air density). It is therefore a great challenge for uniform shape spreading on superhydrophobic surfaces without any loss of the drops. Here, we show a new and simple strategy for uniform round-shape drop spreading on superhydrophobic surfaces after high-speed impact, up to 5.0 m s −1 , by utilizing live-oligomeric surfactant jamming, diethylenetriamine/sodium dodecyl sulfate (triamine/SDS). The live-oligomeric surfactant, which noncovalently constructed by SDS and triamine through electrostatic interaction, has a dynamic equilibrium between monomer surfactant and oligomeric surfactant. Figure 1 shows the contrast spread dynamics of a liveoligomeric surfactant drop and other drops impacting superhydrophobic surfaces at an impacting velocity (U ) of 2.42 m s −1 from side and bottom views (Movie S1, Supporting Information). The diameter (D 0 ) of pure water and the surfactant drops is ≈2.25 and 1.90-2.00 mm, respectively (Figure S1, Supporting Information for experimental setup). The Weber number (We), We = ρDV 2 /γ, of water, SDS, N2C3/SDS, triamine/SDS, and 12-3-12-3-12 is 182. 68, 295.29, 358.29, 383.00, and 292.29, respectively. The superhydrophobic surface [35] composed of random micro-nanostructures of typical size and spacing of Inkjet printing of water-based inks on superhydrophobic surfaces is important in high-resolution bioarray detection, chemical analysis, and highperformance electronic circuits and devices. Obtaining uniform spreading of a drop on a superhydrophobic surface is still a challenge. Uniform round drop spreading and high-resolution inkjet printing patterns are demonstrated on superhydrophobic surfaces without splash or rebound after high-speed impacting by introducing...