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Frost formation is a normal phase transition phenomenon in cold climates, while it usually brings certain troubles to human lives and production. Therefore, it is of great significance to develop frost resistant materials and key technologies. Here, a salt-philic and superhydrophobic surface is designed on a PDMS substrate by femtosecond laser direct writing technology in combination with salt–ethanol–water mixtures droplet treatment. The laser-treated PDMS embedded salt (LTP-S) surface exhibits superhydrophobicity, which alone is a property that can resist the formation of frost and enables a self-cleaning effect. Meanwhile, the salt coating further enhances the frost resistance of the surface by reducing the freezing point temperature. The LTP-S surface is revealed to perform well in frosting-defrosting cycles, washing resistance, chemical corrosion resistance, heating resistance, and long-term air exposure tests as a highly efficient and stable anti-frosting surface. This work demonstrates a facile strategy to fabricate a salt-philic and superhydrophobic surface for efficient anti-frosting. [ABSTRACT FROM AUTHOR]

Liquid droplets on superheated surfaces produce the Leidenfrost effect. This phenomenon might lead to droplet manipulation and control strategies in microfluidics and thermal management. However, Leidenfrost droplets move randomly and irregularly on superheated surfaces and the manufacturing of special surfaces to control Leidenfrost droplet movement poses great challenges. Here, we propose a simple and environment-friendly method to create heterogeneously wetting surface structures to control the spin motion of droplets on superheated brass using femtosecond laser patterning. The water contact angle of the superhydrophobic area on the surface was ∼160°, and the superhydrophilic area showed ∼7°. A z-shaped pattern was fabricated, which segmented the vapor film and influenced gas flow, and it resulted in the spinning of oval-shaped droplets analogous to a spinning egg. We used simulation to explain this phenomenon and also expanded the application of this droplet control in accelerating dissolution of solids and mechanical driving. This study provides the basis for a creative control method using the Leidenfrost droplet phenomenon, which has broad implications in steam-driven droplet motion and future fluid manipulation. [ABSTRACT FROM AUTHOR]

Marine oil spills have become a major global environmental challenge, yet there remains a lack of effective and environmentally friendly strategies for the remediation of water contaminated with high-viscosity oil. In this study, we introduce a superhydrophobic oleophilic material with photothermal properties for efficient absorption of viscous oil. Femtosecond laser treatment methodology is applied to cork (FSLA-cork), which exhibits not only superior hydrophobic and oleophilic properties but also the exceptional ability to be rapidly heated from ambient conditions to 58 °C in 10 s under 1.8 solar irradiation. Under solar irradiance, the FSLA-cork adsorbent functions synergistically by capillary absorption and centrifugal pumping. At one-sun intensity, an oil absorption rate of 4.02 g cm−2 within 200 s was observed. The high adsorption rates of FSLA-cork combined with the high availability of the raw material and its eco-friendly fabrication methods indicate that such methods and materials can be utilized for large-scale clean up of aqueous environments contaminated with high-viscosity oils. [ABSTRACT FROM AUTHOR]

Modulating the thermal emission of a material in the infrared (IR) range can be essential for various practical applications such as smart textiles, camouflage, and anti-counterfeiting. Although many different materials or structures have been proposed, the complex manufacturing processes are still hindering their widespread use. Herein, a facile femtosecond laser processing technology and a drop-coating method are introduced to form a patternable low emissivity film. Laser-treated polyimide films resulted in superhydrophilic structured surfaces that are uniformly coated with silver-nanowires (AgNWs) in aqueous solutions for low emissivity surfaces. Furthermore, the emissivity of the samples is as low as ∼0.2 without deterioration over 800 bending-releasing cycles. The as-prepared films also display good thermal camouflage properties, namely, the films reduced the thermal radiation temperature of an object by 35.8 °C when the object temperature was ∼69.1 °C. Additionally, this IR camouflage effect of the AgNWs coated samples shows excellent stability even in harsh environments such as immersion in water, acid, alkali, and salt solution and applied voltage. We also show that information encryption was possible by adjusting the amount of AgNWs. The design of this programmable patterned low emissivity film indicates an idea for the thermal camouflage and anti-counterfeiting technology, which can carry more abundant application scenario and disguise them more complex and sophisticated. [ABSTRACT FROM AUTHOR]

Laser-induced graphene (LIG) is an innovative material that can be used in the construction of smart wood houses due to its high electrical and thermal conductivity. However, potential practical challenges such as fire hazards, and the complexity of daily cleaning are limitations in such an application. In this study, we utilized femtosecond laser direct writing technology to create femtosecond laser-induced graphene (FLIG) on flame retardant cork. The FLIG surface was then coated with multi-scale candle soot particles to incorporate carbon black (CB-FLIG) superhydrophobic surface properties. Here we demonstrate CB-FLIG as a raw material for electronic components in multifunctional wooden houses. The infrared emissivity of the CB-FLIG surface was as high as 97.2 % and the electric heating performance was good. As such, it can be used as an electric heater in the winter, and we achieved room temperature control at a comfortable 24.9 °C with 4 V voltage in a model house. Also, the water contact angle was 151.2°, giving CB-FLIG self-cleaning properties. Ultimately, we demonstrate the application of CB-FLIG in the field of smart home components such as electrical wiring, electric heaters, fire protection, and self-cleaning, increasing functionality while reducing the need for routine maintenance. This study lays a robust foundation for state-of-the-art devices within smart timber houses and significantly propels the development of versatile, interconnected wooden dwellings. [Display omitted] • CB-FLIG has conductivity, electrothermal properties, and superhydrophobic properties. • CB-FLIG exhibited exceptional Joule heating capabilities, achieving high surface temperatures at low voltages. • The introduction of candle soot nanoparticles creates a superhydrophobic surface, offering self-cleaning properties. • The CB-FLIG's unique properties are utilized to envision a multifunctional wooden house model, integrating heating systems, electrical wiring, and intelligent control mechanisms. [ABSTRACT FROM AUTHOR]

Multifunctional materials with photothermal and electrothermal effects have garnered considerable attention for solving the icing problem. Although great progress has been made in the field of anti-icing/deicing, the low electrothermal performance, complicated fabrication methods, and low durability restrict their widespread application. Here, we fabricate multiscale hybrid-structured femtosecond laser-induced graphene (FsLIG) on polyimide (PI) substrates using femtosecond laser direct writing technology in ambient air, and apply the FsLIG to all-day anti-icing/deicing. With the optimized laser scanning speed, the as-fabricated surface exhibits high light absorption rate (∼98.5%) in the range of 220–1400 nm and low sheet resistance (∼18.2 Ω sq−1), which bestows outstanding photo-electro-thermal effects on the FsLIG surface. Under 1.0 sun illumination or an applied voltage of 4 V, the average surface temperature can rise to ∼69.3 °C or ∼193.1 °C within 30 s. As a result, the FsLIG is successfully applied in anti-icing/deicing. The FsLIG surface realizes anti-icing and deicing when exposed to a sunlight intensity or an applied voltage of 1.0 sun or 2 V. The photo-electro-thermal material developed in this work, along with its simple preparation method, might have broad application prospects in the field of anti-icing/deicing. [Display omitted] • Femtosecond laser-induced graphene (FsLIG) is formed on polyimide film. • Multiscale hybrid-structures provide a high average light absorption rate of 98.5%. • High degree of graphitization of FsLIG delivers a low sheet resistance of 18.2 Ω sq−1. • Anti-Icing/deicing tests are conducted using photothermal and electrothermal effects. • A conceptual schematic of all-day efficient anti-icing/deicing system is proposed. [ABSTRACT FROM AUTHOR]

• A triple property surface is fabricated by femtosecond laser. • Efficient water boiling evaporation is achieved on this multifunctional surface. • The multifunctional surface demonstrates excellent stability and repeatability. • This research may provide a viable source for efficient energy utilization. Water boiling evaporation is crucial for diverse applications ranging from thermal management to power generation. However, current strategies for water boiling evaporation interfaces are restricted to complicated fabrication methods, single function, and low availability. Here, a superhydrophilic (a water contact angle of ∼ 0°), underwater superaerophobic (a bubble contact angle of ∼ 161.5°), and high infrared emissivity (up to 0.9) interface is fabricated via femtosecond laser direct writing technology. The extreme surface wettability and underwater superaerophobicity combined with its high infrared emissivity result in greatly enhanced water temperature ascending speeds and water boiling evaporation efficiency. At the optimum scanning speed, with a heater set at 190 °C and ∼ 0.2 mL volume water, the water on the laser-treated stainless steel surface exhibits the shortest time (∼20 s) required for water boiling evaporation, which is significantly shorter than that of on the pristine stainless steel surface (∼71 s). Moreover, the laser-treated surfaces demonstrate fast water boiling in a heating kettle and rapid water evaporation on an electrical heating element. The temperature of water in the laser-treated stainless steel cup rises faster than that in the pristine stainless steel cup, reaching boiling 1 min earlier and stabilizing ∼ 2 °C higher. Femtosecond laser treatment improves the highest water evaporation efficiency of the electrical heating rod by ∼ 49.1%. Understanding the design parameters for efficient water boiling evaporation using laser-treated surfaces can lead to the development of highly effective technology. [ABSTRACT FROM AUTHOR]