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High-throughput experiments involving isolated droplets based on patterned superwettable surfaces are important for various applications related to biology, chemistry, and medicine, and they have attracted a large amount of interest. This paper provides a directional anchoring liquid-infused superamphiphobic surface (DAS), via combining concepts based on the droplet-anchoring behavior of beetle backs with patterned wettability, the directional adhesion of butterfly wings, and the slippery liquid-infused surfaces (SLISs) of pitcher plants. Regularly arranged ">"-shaped SLIS patterns were created on a superamphiphobic (SAM) background through ultrafast-laser-based technology. Improved directional anchoring abilities with a sliding angle difference of 77° were achieved; this is the largest sliding angle difference in a one-dimensional direction achieved using an artificial surface, to the best of the authors' knowledge. Thanks to the directional anchoring abilities, the DAS coupled droplet 'anchoring' and 'releasing' abilities. Furthermore, a high-throughput droplet manipulation device was designed, on which a micro-droplet array with a large number of droplets can be 'captured', 'transferred', or 'released' in a single step. With the addition of lubricant, the DAS can work continuously for even more than 30 cycles without cross-contamination between different droplets. The DAS also shows good stability under an ambient atmosphere and can maintain its functionality when manipulating corrosive droplets. The DAS and corresponding high-throughput droplet manipulation method are excellent candidates for practical applications. [ABSTRACT FROM AUTHOR]

• A hybrid fabrication method combining ultrafast lasers ablations and rotational homogenization process was developed to construct uniform PDMS micro-nanostructures systematically. • The novel rotational homogenization process utilized centrifugal forces to confront surface tensions, achieving uniform distribution of PDMS on various microstructures. • Multiple tests were applied on the superhydrophobic surfaces, showing their comprehensive durability against mechanical and chemical damages, especially their recovery in freezing-melting cycles and resistance to supercooled droplet intrusion in −20 °C environment. Superhydrophobic surface is one of the most promising materials for the prevention and elimination of ice in daily lives but its durability remains a tremendous problem. Inevitable deterioration on the low-free-energy coating caused by harsh environment restrains their potential applications. Icephobic polymers are more durable than mostly used fluorosilanes for their higher thickness and cohesive strength but difficult to be uniformly modified on rugged micro-nanostructures. In this study, a nanostructured tungsten carbide doped PDMS layer was uniformly covered on aluminum microcones via a hybrid fabrication process combining nanosecond and femtosecond laser ablations and a rotational homogenization process. The prepared superhydrophobic surfaces exhibited excellent water repellency and anti-icing properties in icing-deicing cycles, water flow impacting and freezing-melting cycles. Multiple mechanical/chemical damage tests were performed to test their durability comprehensively. In mechanical tests, the surfaces could withstand linear abrasion length of 240 cm under 5.2 kPa pressure, impacting sand amount of at least 80 g or tape peeling for at least 200 cycles. The chemical durability was elucidated in −40 to 200 °C cycles, 2-day ultraviolet exposure and immersion in different liquids. The proposed hybrid method to form homogenous, ductile and durable superhydrophobic coatings could yield a prospective candidate for applications in anti-fouling and anti-icing. [ABSTRACT FROM AUTHOR]

W/Cu joining is key for the fabrication of plasma facing components of fusion reactors, which however is very challenging due to the low bonding strength and high W/Cu interface thermal stress as a result of the immiscible nature of W-Cu binary system and thermal expansion coefficient mismatch between W and Cu. In this paper, we proposed a method for comprehensive enhancement of the mechanical and thermo-mechanical properties of W/Cu joints based on femtosecond (fs) laser fabricated micro/nano interface structures. Four kinds of surface structures, namely pristine structure, nano ripples, micro-cubes and micro-pits were fabricated on W by fs laser ablation and introduced into W/Cu joining interface by hot pressing joining at 1000 °C, 80 MPa. The micro/nano interface structures contribute to significant enhancement of the tensile strength, shearing strength and thermal fatigue life of the W/Cu joints, which reach 101.58 MPa, 186.47 MPa and >800 thermal cycles, increased by about 150%, 320% and 400% compared with W/Cu joints with pristine interface structure. This research provides an approach for enhanced joining between dissimilar materials, including but not limited to W and Cu. [ABSTRACT FROM AUTHOR]

W/Cu joining is key for the fabrication of plasma facing components for fusion reactors, which however is very challenging due to the immiscible nature of Cu-W binary system and the mismatch of thermal expansion coefficient between W and Cu. In this research, we proposed a method for comprehensive enhancement of the bonding strength and heat transfer capability of W/Cu joining based on femtosecond (fs) laser fabricated micro/nano interface structures. Four kinds of surface structures, namely pristine structure, nano ripples, micro-cubes array and micro-pits array were designed and fabricated on W by fs laser ablation, which were then introduced into W/Cu interfaces by hot pressing joining at 1000 °C, 80 MPa. The micro/nano interface structures lead to significant enhancement of W/Cu bonding strength, which reaches 101.58 MPa for W/Cu direct joining and 120.43 MPa for W/Cu joining with Cu interlayer, increased by about 150% and 190% compared with W/Cu joining with a flat interface. The thermal diffusivity and thermal stress resistance of W/Cu joining are also improved. The strengthening mechanism is recognized to be the combined effects of micro/nano interface structures related interdiffusion between W and Cu and increased resistance against W/Cu interfacial debonding. Our research provides a method for enhanced joining between W and Cu, as well as a vast range of dissimilar materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A unique SERS substrate processed by one-step femtosecond laser ablation in Argon. • S-Ag-Ar can detect 10-8mol/L R6G with enhancement factor up to 5.3 × 106. • S-Ag-Ar has high uniformity with relative standard deviation less than 11.97%. • S-Ag-Ar can be stored for more than seven months and shows good universality. • This unique SERS substrate demonstrates good potentials for food safety evaluation. Surface Enhanced Raman Scattering (SERS) is a reliable tool for detection of food additives due to its advantages including rapid detection, non-destructive and excellent sensitivity. Currently, the commercial SERS substrates are not yet satisfactory referring to cost, sensitivity, uniformity and stability. Herein, we report a unique SERS substrate processed by one-step femtosecond laser ablation in Argon. The substrate shows high sensitivity with limit of detection up to 10-8mol/L for Rhodamine 6G (R6G) and enhancement factor up to 5.3 × 106 due to laser induced more plentiful nanostructures and less oxidation in Argon, in addition to high uniformity with relative standard deviation less than 11.97% and long storage time more than seven months. This SERS substrate is capable of detecting the common food additives including malachite green (1 ppm), crystal violet (10-7mol/L), Sudan I (1 ppm), melamin (1 ppm), brilliant blue (1 ppm) and tartrazine (1 ppm). This unique Ag SERS substrate demonstrates good potentials for food safety evaluation. [ABSTRACT FROM AUTHOR]

• We developed a patterned superhydrophilic-superhydrophobic SERS substrate. • This platform can locate analyte molecules on-demand via evaporation enrichment. • This SERS substrate can realize ultra-sensitive Raman detection (1 aM). • This SERS substrate can be used as a disease early diagnosis platform. The detection of molecules in ultra-low concentration solution is essential in numerous fields including pollutant monitoring, explosive detection and disease early diagnosis. Recently, studies indicated that surface-enhanced Raman scattering (SERS) combining with superhydrophobic surfaces were capable of breaking diffusion limit, realizing detection in femto/atto-molar range. However, the complicated and costly fabrication methods limited larger-scale practical application. In this regard, patterned superhydrophilic-superhydrophobic platform fabricated by ultrafast laser, which could simplify the preparation process and fix the droplet, attracted attention. Nevertheless, the related works reported cannot realize atto-molar detection. Therefore, the SERS platform with abilities of simplified fabrication processes, on-demand locating analyte and ultra-high sensitivity (1 aM) is needed. In this paper, we processed a new patterned SERS platform via femtosecond laser, achieving atto-molar detection with an enhancement factor of 1.09 × 1014. After evaporation enrichment, the target molecules were deposited on the superhydrophilic area of ∼0.01 mm2. We further optimized the SERS substrates by comparing three types of colloids: Ag nano-particles, Au nano-particles and Au nano-stars, finding Au nano-stars exhibited the best. Meanwhile, this platform showed good uniformity: the relative standard deviation (RSD) was 11.7 % at 10−14mol/L. The results offer valuable information and potentials on the ultra-low concentration molecular detection in biosensors. [ABSTRACT FROM AUTHOR]

• Composite structures consisting of nano-ripples and grooves are fabricated. • The adhesion of E. coli was limited on nano-ripples and micro-grooves. • Deep grooves are conducive to the deformation and rupture of bacteria. • All types of nano-ripples surfaces present good biocompatibility. Structured surfaces with both anti-bacterial capability and biocompatibility are essential to medical devices including orthopedic implants. Over the past few years, numerous studies indicated that nanostructures such as nanotubes, nanowires, nano-pillars and nano-ripples were capable of repelling or killing bacteria, while the morphology and dimensions of the nanostructures showed essential influence on the adhesion and proliferation of cells. The long-term functionalities of implants depend on their reliable anti-bacterial performance at the same time enhanced biocompatibility. However, researches covering both these two aspects are still very limited. In this paper, we applied one-step femtosecond laser irradiation to produce three types of nano-ripples, and to investigate their anti-bacterial behavior and their biocompatibility. Our results demonstrate that all the three types of nano-ripples are capable of preventing bacterial colonization and biofilm formation, with their anti-bacteria rates towards E. coli respectively 43%, 49% and 56%. Meanwhile, the femtosecond laser induced nano-ripples exhibit good rat mesenchymal stem cells (MSCs) proliferation capacity and spreading performance, and the nano-ripples affect significantly the orientation of MSCs. The results offer valuable information and potentials on the anti-bacteria and biocompatibility of nanostructures. [ABSTRACT FROM AUTHOR]