Search Results (842)

Two-Photon Polymerization (2PP) has been established in recent decades as one of the most promising additive manufacturing processes for the fabrication of freeform 3D micro- and nanostructures. In 2PP, the photochemical reaction, induced by the absorption of the energy of two photons, is confined to a small and well-defined region of the space known as voxel, enabling the manufacture of 3D features with high accuracy and resolutions in the submicrometric range. Unfortunately, 2PP shows some drawbacks, among which its low productivity appears as one of its main limitations nowadays. In this regard, different approaches have recently been explored aiming at increasing 2PP throughput, like the use of Spatial Light Modulators (SLMs), which allows dynamically adjusting the shape of the laser beam into different geometries, patterns or even complex images. In this work an experimental 2PP setup comprising a femtosecond visible laser in combination with high accuracy linear stages and different optical solutions including an SLM has been used to explore the improvement achieved in productivity and additional advantages for the manufacturing of different 2.5 and 3D microstructures. A commercial photoresist has been used as base for these experiments, adjusting its photoinitiator content to obtain the optimal sensitivity to the wavelength provided by the laser. Full article

Drag-reducing coating technology is a core approach to enhancing the performance of ice and snow sports equipment. By regulating the interfacial characteristics between the equipment surface and the ice or snow medium, it significantly reduces frictional resistance during motion, thereby optimizing athletes’ speed performance and control precision. This paper aims to review the current research status and challenges in this technological field. The review first elaborates on the fundamental principles of applying drag-reducing coatings to key equipment such as skis, sleds, and ice skates, covering current mainstream coating material systems, key preparation processes, and comprehensive performance evaluation methods. Furthermore, integrating multidisciplinary advances in surface engineering, fluid dynamics, and materials science, this review specifically examines how these disciplines can be harnessed to address the unique tribological challenges of snow/ice interfaces. It focuses on cutting-edge research directions such as micro-nano-structured coatings driven by biomimetic design concepts and smart coatings with environmental responsiveness. By synthesizing existing research achievements and potential technological bottlenecks, this paper aims to provide a systematic, theoretical basis and innovative ideas for the future development of a new generation of high-performance, intelligent ice and snow sports equipment. Full article

Micro- and nanoplastic (MNP) pollution has emerged as a global environmental and health concern, driving the rapid development of sensor technologies for faster, more sensitive, and field-deployable detection. This review synthesizes recent advances in optical, electrochemical, and biosensor platforms for MNP analysis and compares their analytical performance and practical feasibility. Optical sensors, including plasmonic, spectroscopic, and colorimetric systems, enable label-free and often rapid detection with material discrimination capability, and are well-suited for screening applications, though they commonly exhibit higher detection limits and matrix interference. Electrochemical sensors demonstrate the highest analytical sensitivity overall, frequently reaching low µg L⁻¹ to ng mL⁻¹ levels, with strong potential for miniaturization and on-site deployment; performance is further enhanced by nanostructured electrodes, photoelectrochemical designs, and signal amplification strategies. Biosensors incorporating peptides, aptamers, enzymes, or engineered proteins provide improved polymer selectivity and enable targeted detection, but face challenges related to stability, cross-reactivity, and reproducibility in complex samples. Practically, portable electrochemical and simple optical colorimetric platforms are currently the most feasible for field use, while hybrid bio-electrochemical systems show the highest performance potential. Future research should prioritize robust selective recognition elements, antifouling interfaces, standardized validation protocols, mixed-polymer quantification models, and integration with machine learning to enable reliable, real-world MNP monitoring. Full article

Cancer therapy is increasingly shaped by the need for agents that are both mechanistically precise and clinically tolerable. Sulforaphane (SFN), a dietary isothiocyanate enriched in cabbage-family vegetables such as cauliflower and Brussels sprouts, has emerged as a pleiotropic modulator of tumor biology. This review synthesizes current evidence that SFN regulates diverse cancer-relevant processes, including redox homeostasis, cell-cycle progression, apoptosis, autophagy and epigenetic remodeling, largely through coordinated effects on transcriptional (for example, Nrf2, MAPK, NF-κB and AP-1), post-transcriptional (microRNAs and messenger RNAs) and epigenetic (DNA methyltransferases and histone deacetylases) networks. We then examine how functional nucleic acids, including aptamers, small interfering RNAs, microRNAs and tetrahedral DNA nanostructures, can be engineered to guide SFN to tumor cells, amplify pathway-specific effects and overcome resistance. Particular emphasis is placed on nanotechnology-enabled delivery platforms that enhance SFN stability, bioavailability and tumor selectivity. Finally, we outline key challenges, such as context-dependent Nrf2 activity, inter-individual variability in metabolism and incomplete clinical validation, and propose priorities for translating SFN-based functional nucleic acid systems into rational, combination-ready strategies for precision oncology. Full article

This study investigates the effect of complex nanomodification combined with the simultaneous application of magnetic fields and mechanical vibration on the structure formation and performance properties of medium-alloy steel 40CrNi3MoV. Improving the structural homogeneity and operational characteristics of such steels remains an important task due to their widespread use in components operating under severe loading and wear conditions. The introduction of the nanostructured modifier InSteel-7 at a concentration of 0.03%, together with simultaneous magnetic and vibrational treatment of the melt, resulted in pronounced structural homogenization and grain refinement. Quantitative metallographic analysis using Thixomet Pro image analyzer revealed a significant refinement of the dendritic structure, with the secondary dendrite arm spacing decreasing from 73.9 μm to 27.9 μm. X-ray phase analysis confirmed the preservation of phase composition while indicating increased structural uniformity of the BCC matrix. Energy-dispersive spectroscopy and elemental micro-mapping demonstrated high chemical purity of the alloy and a uniform distribution of the modifier components. The combined treatment significantly improved the mechanical and tribological characteristics of the material. The average hardness increased from 390 HV to 510 HV, while tribological tests showed a reduction in wear track depth from 5.16 μm to 0.87 μm and a decrease in surface roughness from Ra 2.13 μm to 0.20 μm, indicating enhanced wear resistance. Full article

Superhydrophobic coatings are regarded as a promising passive anti-icing strategy; however, their practical engineering application, particularly in electrical insulation, is severely hindered by the performance deterioration caused by mechanical damage and a lack of theoretical understanding of microscopic ice adhesion mechanisms. In this study, a layered polymer composite coating was designed to resolve the trade-off between abrasion resistance and low ice adhesion. The chemistry of the coating relies on a synergistic “primer–topcoat” design: the primer consists of an epoxy resin matrix chemically modified by amino silicone oil to lower its surface energy and improve toughness, while the topcoat features hierarchical SiO₂ clusters functionalized with hexamethyldisilazane (HMDS) and silane coupling agents. This architecture was fabricated via a controllable layer-by-layer spraying method. Systematic investigations revealed that the hierarchical micro/nanostructure, composed of microscale protrusions and nanoscale SiO₂ clusters, provides excellent superhydrophobicity (contact angle of 155.2°, sliding angle of 2°). Crucially, the crosslinked polymer network and stable siloxane (Si-O-Si) covalent bonding ensure that the coating maintains its functionality after a cumulative sand impact of 3 kg, demonstrating superior mechanical durability. Furthermore, differentiated theoretical models for ice adhesion in Cassie–Baxter and Wenzel states were established based on intermolecular interactions, identifying that maintaining a stable Cassie–Baxter state is key to reducing adhesion. This study offers a robust approach to balancing functionality and durability in polymer composites through synergistic structural design, providing both a scalable fabrication strategy and a quantitative theoretical framework for understanding interfacial ice adhesion. Full article

Access to clean water remains a critical global challenge, particularly in arid and fog-rich regions where conventional resources are limited. Fog water harvesting has emerged as a low-energy alternative; however, the performance of traditional collectors (typically 3–10 L m⁻² day⁻¹) remains constrained by inefficient droplet capture and transport. This review provides a systematic and critical analysis of recent advances in membrane-based fog harvesting technologies, focusing on material design, surface engineering, and structural optimization. The analysis shows that nanostructured and electrospun membrane systems can enhance water collection rates to ~20–60 L m⁻² day⁻¹, representing up to a 5–6 times improvement over conventional meshes. Furthermore, biomimetic and Janus wettability designs significantly improve droplet nucleation and directional transport, while hierarchical micro/nanostructures accelerate coalescence and runoff dynamics. At the structural level, optimized collector geometries (vertical harp designs) demonstrate ~3–4 times higher collection efficiency compared to traditional Raschel mesh due to reduced clogging and enhanced drainage. Despite these advances, key challenges remain, including material durability, fouling resistance, lack of standardized testing protocols, and limited large-scale validation. This review identifies critical design–performance relationships and proposes a framework linking surface wettability, morphology, and environmental parameters to harvesting efficiency. Future directions emphasize the development of durable, scalable membrane systems and the integration of fog harvesting with hybrid water supply technologies. Full article

The gut microbiota takes charge in a pivotal role in metabolic equilibrium, immune response, and modulating gut lining stability and has become the main focus of nutrition and functional food research. In this regard, the definition of prebiotics has progressed past the traditional approach limited to indigestible dietary fibers, embracing more targeted, biologically active, and functional delivery systems. In recent years, plant-derived exosomes (PDEs), a subclass of exosomes defined as extracellular vesicles (EVs) in the 30–150 nm size range, have emerged as an innovative class of nanostructures supporting this transformation. Plant-derived exosome-like nanoparticles (PELNs) have been taken into account as natural nanocarriers which are suitable for the gastrointestinal system with the help of their high biocompatibility, low immunogenicity profiles and rich bioactive cargo contents. This review discusses structural features of PELNs, molecular cargo content, and biological roles comprehensively and focuses especially on gut microbiota interactions. MicroRNAs, proteins, lipids, polyphenols, and glycans which PELNs contain are discussed with regard to shaping the microbial composition, regulating microbial metabolic activity, and modulating host-microbe communication. Findings derived from in vitro, in vivo, and limited translational studies indicate that PELNs can modulate specific microbial taxa, increase short-chain fatty acid (SCFA) yield, strengthen mucosal immune homeostasis, and induce source-dependent responses in the gut microbiota. In their traditional definition, prebiotics are taken into account as food components which selectively support proliferation and metabolism of helpful microbes, especially Bifidobacteria and Lactobacilli. Within this framework, PELNs are not only passive carriers of functional components but also evaluated as active systems which can directly affect microbiota composition and metabolic functions. Thus, they are repositioned as “prebiotic nanocarriers.” Also this review evaluates the potential of functional food and integration of major edible PELNs into synbiotic formulations by discussing their isolation and characterization methods and stabilities in the gastrointestinal environment. Limitations of clinical applications and lack of research from a prebiotic nanocarrier perspective of PELNs show that this field still contains important research gaps. The novelty of the study lies in its integration of PELN research with nutrition-based approaches to microbiota modulation and innovative functional food strategies under a single multidisciplinary conceptual framework. Full article

The corrosion protection of copper in acidic urban rain environments was studied using self-assembled hydrophobic layers (SAHLs) based on stearic acid (SA), with and without rosehip seed oil (RH). The limited durability of fatty acid-based self-assembled layers under acidic conditions was addressed by correlating surface wettability, morphology, and electrochemical behaviour. Contact angle and SEM analyses showed that SA alone forms a moderately hydrophobic but structurally irregular layer, whereas the addition of 2.0 wt.% RH produces a hierarchical micro/nanostructure with near-superhydrophobic characteristics (CA ≈ 149°). Electrochemical measurements in simulated acid rain solutions (pH 5, 3, and 1) revealed a strong pH dependence of protective performance. While SA-derived layers provided effective protection at pH 5, they deteriorated at lower pH due to protonation of carboxylate anchoring groups and electrolyte ingress. In contrast, SAHLs containing 2.0 wt.% RH maintained polarisation resistance in the MΩ cm² range and inhibition efficiencies above 99% at pH 3, and remained effective even at pH 1. Long-term EIS results indicate a predominantly diffusion-controlled, barrier-type inhibition mechanism associated with defects sealing and interfacial reorganisation. Notably, the rosehip seed oil used is a commercially available, bio-based material with expired shelf life, highlighting the potential of waste-derived resources for sustainable corrosion protection. Full article

This study investigates the femtosecond laser surface texturing approach to tune the wetting properties of glass substrates applied for photovoltaic panels. Two types of microstructured LIPSS-containing motifs—parallel channels and intersecting (crossing) patterns—were fabricated and evaluated through comprehensive durability tests, including thermal cycling, UV exposure, chemical immersion, mechanical abrasion, and dust retention assessment. Wettability measurements showed that both textures exhibit stable hydrophilicity behavior, with the intersecting patterns exhibiting the fastest wetting dynamics; in many cases, complete surface wetting occurred within the first few minutes, preventing a measurable contact angle at later stages. The durability tests caused only minor smoothing of the textured features, and the overall micro- and nanostructures remained intact. Optical characterization revealed that the laser-induced textures maintained high transmittance with no significant degradation after environmental exposure. Overall, the results demonstrate that femtosecond laser texturing provides a robust, coating-free method for producing stable and tunable wetting behavior on glass, offering a promising pathway for the future creation of durable, highly hydrophilic self-cleaning surfaces in photovoltaic systems. Full article

To address the drag reduction requirements of superhydrophobic surface coatings for underwater vehicle hulls, this study designed a synthesis method based on resin substrate modification and filler modification according to superhydrophobic coating synthesis techniques. Three types of superhydrophobic microstructured surface coatings were prepared: polyurethane resin, silicone resin, and fluororesin. The coatings were fabricated by incorporating fluorine-modified SiO₂ nanoparticles into the modified resin matrices to construct hierarchical micro/nanostructures. The main components and synthesis processes for each coating were determined. Performance tests were conducted to evaluate mechanical properties (thickness, hardness, adhesion, wear resistance), functional characteristics (surface morphology, static/dynamic hydrophobic angles), and environmental resistance (seawater immersion, salt spray stability, thermal stability). Five surface coating test plans for underwater vehicle hull models were proposed, and drag reduction experiments were carried out to compare total drag, drag coefficient, and drag reduction rate across coating plans. Experimental results indicated that the silicone resin superhydrophobic coating with F660 + 8% SiO₂ exhibited the best comprehensive performance, while the PU + 6% SiO₂ superhydrophobic coating achieved optimal drag reduction at speeds below 9 m/s, meeting the performance criteria for underwater vehicle hull applications. Full article

Superhydrophobic surfaces are typically achieved through the synergistic integration of appropriate nanostructures and low-surface-energy chemical compositions. This study presents a novel and facile method for constructing a superhydrophobic hierarchical structure directly on a pristine selective laser melting (SLM) titanium surface. The intrinsic partially melted Ti particles, which are inherent to the SLM fabrication process, were strategically utilized as a natural microscale template for the in situ growth of TiO₂ nanotubes via electrochemical anodization. Three distinct micro/nano-topographies were successfully fabricated, integrating the spherical microparticles with either conventional TiO₂ nanotube arrays or separated nanotube arrays. The results demonstrate that the resulting superhydrophobic behavior can be effectively regulated by two key factors: the liquid–solid contact mode at the microscale and the strength of capillary action within the nanostructures. Notably, these characteristics can be tailored by controlling the nanotube diameter and intertubular spacing. These findings contribute to a deeper understanding of the role of micro–nano hierarchical structures in engineering superhydrophobic surfaces, thereby opening new avenues for advanced applications. Full article

Many termite species initiate colonization flights during or shortly after periods of rain, employing two different flight strategies: flying during the day in the rain and flying at night in a dry environment. As noted in previous studies, it appears easier for a species to become adapted to a wet environment by changing the contour/shape rather than the composition of the cuticle surface. We utilized differential interference contrast and scanning electron microscopy to observe the micro-nanostructure of the wing cuticles of 54 termite species from 16 families/subfamilies. Twenty-four species of higher termites possessed wings with anti-wetting structures of setae and a micraster array. The majority of lower termite wings had smoother cuticle surfaces. Based on the hierarchical design of termite wings, we conclude that various species are adapted to flying in the rain. Full article

Photothermal superhydrophobic surfaces represent a promising solution for passive anti-icing; however, the persistent high solar absorption of static black coatings often leads to undesirable overheating under non-icing conditions. To address this limitation, we developed a smart superhydrophobic polydimethylsiloxane (PDMS) surface embedded with thermochromic capsules (TC) (S-PDMS/TC) featuring reversible thermochromic capability via a facile combination of spin-coating and femtosecond laser ablation. The resulting hierarchical micro-grid structure acts as a sacrificial layer, shielding fragile nanostructures against mechanical abrasion, while endowing the surface with robust superhydrophobicity (contact angle > 155°). Uniquely, S-PDMS/TC exhibits an adaptive color transition from pale yellow to deep black when the temperature drops below 5 °C. This response enables on-demand photothermal enhancement, significantly boosting solar absorption in freezing environments while minimizing heat absorption at room temperature. Consequently, S-PDMS/TC demonstrates superior anti-icing performance, extending the freezing time to 310 s and reducing ice adhesion strength to 40.4 kPa. Notably, during photothermal de-icing, the meltwater exhibits spontaneous dewetting behavior driven by the replenishment of the air cushion, effectively preventing secondary icing. This work presents a mechanically durable and intelligent strategy for ice protection, successfully balancing efficient de-icing with thermal management. Full article

Epoxy resin (E-51) exhibits excellent adhesion and is widely used in the preparation of functional composite coatings. However, its smooth surface lacking micro/nano composite structures limits its self-cleaning capability and optical properties. Direct incorporation of organic silicone or inorganic fillers often faces severe phase separation and filler agglomeration issues, resulting in defects in coating durability and weather resistance. To address these challenges, this study developed a synergistic modification strategy integrating surface energy modulation with the architectural design of micro/nano-structures. Amino-terminated PDMS undergoes ring-opening addition reactions with epoxy groups in the epoxy resin, while functionalized barium sulfate nanoparticles modified with dual silane coupling agents are incorporated to enhance optical properties. This synergistic approach not only resolved interfacial compatibility but also endowed the PDMS@EP-BaSO₄ coating with outstanding comprehensive properties; the water contact angle increased to 123.5°, demonstrating an easy-to-clean benefit. Visible light reflectance reached 95%, and emissivity rose to 90%. Furthermore, when applied to metal surfaces, the coating exhibited excellent stability against acid–alkali–salt corrosion, extreme temperatures, and ultrasonic agitation. This work provided a novel approach for developing protective coatings that integrated high reflectance, high emissivity, and long-term anti-soiling properties. Full article