Surface Design Research Articles

Fluid-Solid Interfacial Properties and Drag-Reducing Characterization of the Flexible Conical Microstructured Film Inspired by the Streamlined Body Surface of the Pufferfish.

Given the challenges in accurately replicating the surface of the pufferfish, this study employed three-dimensional (3D) printing to create a model based on inverse modeling. The morphology of the pufferfish exhibits a streamlined configuration, characterized by a gradual widening from the anterior oral region to the central ocular area, followed by a progressive narrowing from the midabdominal region toward the caudal extremity. The RNG k-ε turbulence simulation results demonstrate that the streamlined body surface of the pufferfish diminishes differential pressure resistance. This enhancement promotes laminar flow formation, delays fluid separation, minimizes turbulence-induced vortices, and reduces frictional resistance. Moreover, the pufferfish's supple and uneven outer epidermis was simplified into a flexible, nonsmooth planar film to conduct fluid-solid coupling simulations. These revealed that the pufferfish's unique skin can absorb turbulent energy and minimize momentum transfer between the fluid and the solid film, lowering the fluid resistance during swimming. In summary, The high-efficiency swimming capacity of pufferfish stems not only from their streamlined body surface but also significantly from the unique structural characteristics and mechanical properties of their flexible skin. This research provides critical theoretical underpinnings for the design of functional bionic surfaces aimed at drag reduction.

Aceite esencial de hojas de Minthostachys mollis[HBK] Griseb. del Ecuador: Extracción, composición química, capacidad antioxidante y actividad antimicrobiana

The aim of this study was to optimize by response surface design, the extraction of the leafessential oil (EO) from Minthostachys mollis [HBK] Griseb., grown in Ecuador, using steam distillation. The factors used were extraction time (XTIE) of 60, 105 and 150 min and plant material/water ratio (XRMA) of 1:3, 1:4 and 1:5. The optimal combination was reached with XRMA 1:5 and XTIE 150 min, obtaining a process yield of 0.67%. The chemical composition of the EO analyzed by GC-MS was determined, where the main compounds were carvacryl acetate (44.01%), carvacrol (16.51%) and menthone (8.20%). The antioxidant capacity of EO was evaluated using the FRAP and ABTS methodologies, with an IC50243.21 μmol Fe2+/g and 0.12 mg/mL, respectively. In addition, the antimicrobial activity of EO was found against Pseudomonas aeruginosa, Salmonella enterica, Escherichia coliand Staphylococcus aureus.

CREATIVITY AND BIOINSPIRATION AS A BASIS FOR INNOVATION IN SURFACE DESIGN

Currently, the use of varied methods for Teaching Design and for projecting has gained breadth, and as a result, there are more and more methods and variations in methods for teaching design and for designing products and services on the market. The union of methods is also widely used as a basis for ideating design concepts, thus adding more access to innovation and emotion to objects. The objective of this review is to survey and at the same time make a connection about Creativity, Innovation, Bioinspiration and Surface Design. This review work is the first phase of a broad post-doctoral research on Bioinspiration and the creative phase of Product development.

Thermo-rheological behaviour of styrene-butadiene-styrene, hard plastics with or without graphene oxide modified bitumens

With the increase in traffic volume and heavy vehicles, as the changes in climatic conditions, in recent years the design of the road surface has completely changed because it has to guarantee the suitable performance of the pavement. To this end, in recent decades, modifiers have been introduced into the bitumen and, currently, the most performing modifier is SBS (styrene-butadiene-styrene) polymer, but in recent years the investigation on the so-called green additives, obtained from recycled materials or of natural origin is growing. The study intends to investigate, from a rheological point of view, the possibility of using waste hard plastics also in combination with graphene oxide because considered a promising material for new binder generation. For this purpose, the influence that hard plastics, with or without graphene oxide addition, have on the bitumen performance compared to standard SBS-modified bitumens has been studied. The comparison has shown that the plastomeric additive can improve the rheological properties, in the intermediate and high in-service temperature region, while the graphene oxide addition acts on the transitions from viscoelastic to viscous material at high temperature; nevertheless, the aging reduces the effect. In addition, it was found that 4 %w/w of hard plastics improve the performance of bitumen and the rheological properties are not affected by the influence of aging.

Advancing LED technology: the FDCSP element’s breakthrough in mini and micro-LED packaging and backlight module enhancement

In this research, we introduce an advanced methodology for the calculation of bulk light sources tailored for free-form surface design, focusing on the principle of energy conservation. This method is especially relevant for the evolving needs of micro-LED packaging, highlighting its potential in this burgeoning field. Our work includes the development of an algorithm for creating freeform-designed chip-scale package (FDCSP) components. These components seamlessly integrate LEDs and lenses, underscoring our commitment to advancing free-form surface design in chip-level packaging. By adhering to the principle of energy conservation, our approach facilitates a meticulous comparison of simulation outcomes with predefined target functions. This enables the iterative correction of discrepancies, employing layering techniques to refine the design until the simulated results closely align with our goals, as demonstrated by an appropriate difference curve. The practical application of these simulations leads to the innovative design of FDCSP devices. Notably, these devices are not just suitable for traditional applications in backlight modules but are explicitly optimized for the emerging sector of micro-LED packaging. Our successful demonstration of these FDCSP devices within backlight modules represents a significant achievement. It underscores the effectiveness of our design strategy and its expansive potential to transform micro-LED packaging solutions. This research not only contributes to the theoretical understanding of energy conservation in lighting design but also paves the way for groundbreaking applications in micro-LED and backlight module technologies.

Theoretical Modeling and Surface Roughness Prediction of Microtextured Surfaces in Ultrasonic Vibration-Assisted Milling

Textured surfaces with certain micro/nano structures have been proven to possess some advanced functions, such as reducing friction, improving wear and increasing wettability. Accurate prediction of micro/nano surface textures is of great significance for the design, fabrication and application of functional textured surfaces. In this paper, based on the kinematic analysis of cutter teeth, the discretization of ultrasonic machining process, transformation method of coordinate systems and the cubic spline data interpolation, an integrated theoretical model was established to characterize the distribution and geometric features of micro textures on the surfaces machined by different types of ultrasonic vibration-assisted milling (UVAM). Based on the theoretical model, the effect of key process parameters (vibration directions, vibration dimensions, cutting parameters and vibration parameters) on tool trajectories and microtextured surface morphology in UVAM is investigated. Besides, the effect of phase difference on the elliptical shape in 2D/3D ultrasonic elliptical vibration-assisted milling (UEVAM) was analyzed. Compared to conventional numerical models, the method of the cubic spline data interpolation is applied to the simulation of microtextured surface morphology in UVAM, which is more suitable for characterizing the morphological features of microtextured surfaces than traditional methods due to the presence of numerous micro textures. The prediction of surface roughness indicates that the magnitude of ultrasonic amplitude in z-direction should be strictly limited in 1D rotary UVAM, 2D and 3D UEVAM due to the unfavorable effect of axial ultrasonic vibration on the surface quality. This study can provide theoretical guidance for the design and fabrication of microtextured surfaces in UVAM.

Novel Palladium Hydride Surface Enabling Simultaneous Bacterial Killing and Osteogenic Formation through Proton Capturing and Activation of Antioxidant System in Immune Microenvironments.

Achieving bacterial killing and osteogenic formation on an implant surface rarely occurs. In this study, a novel surface design-a palladium hydride (PdHx) film that enables these two distinct features to coexist is introduced. The PdHx lattice captures protons in the extracellular microenvironment of bacteria, disrupting their normal metabolic activities, such as ATP synthesis, nutrient co-transport, and oxidative stress. This disruption leads to significant bacterial death, as evidenced by RNA sequence analysis. Additionally, the unique enzymatic activity and hydrogen-loading properties of PdHx activate the human antioxidant system, resulting in the rapid clearance of reactive oxygen species. This process reshapes the osteogenic immune microenvironment, promoting accelerated osteogenesis. These findings reveal that the downregulation of the NOD-like receptor signaling pathway is critical for activating immune cells toward M2 phenotype polarization. This novel surface design provides new strategies for modifying implant coatings to simultaneously prevent bacterial infection, reduce inflammation, and enhance tissue regeneration, making it a noteworthy contribution to the field of advanced materials.

Advanced Anti-Icing Strategies and Technologies by Macrostructured Photothermal Storage Superhydrophobic Surfaces.

Water is the source of life and civilization, but water icing causes catastrophic damage to human life and diverse industrial processes. Currently, superhydrophobic surfaces (inspired by the lotus effect) aided anti-icing attracts intensive attention due to their energy-free property. Here, recent advances in anti-icing by design and functionalization of superhydrophobic surfaces are reviewed. The mechanisms and advantages of conventional, macrostructured, and photothermal superhydrophobic surfaces are introduced in turn. Conventional superhydrophobic surfaces, as well as macrostructured ones, easily lose the icephobic property under extreme conditions, while photothermal superhydrophobic surfaces strongly rely on solar illumination. To address the above issues, a potentially smart strategy is found by developing macrostructured photothermal storage superhydrophobic (MPSS) surfaces, which integrate the functions of macrostructured superhydrophobic materials, photothermal materials, and phase change materials (PCMs), and are expected to achieve all-day anti-icing in various fields. Finally, the latest achievements in developing MPSS surfaces, showcasing their immense potential, are highlighted. Besides, the perspectives on the future development of MPSS surfaces are provided and the problems that need to be solved in their practical applications are proposed.

Excellent hydrophobicity and high mobility of condensate droplets on hierarchical nanostructured surfaces: Insights from MD simulations

Comprehending the fundamental physical mechanisms behind condensation and the formation of suspended droplets on hierarchical structured surfaces is of paramount importance in the design of anti-frosting surfaces. In this study, we characterize the nucleation, growth and dynamic wetting behaviors of condensate droplets on hierarchical nanostructured surfaces by molecular dynamics simulation, and reveal that hierarchical structures facilitate the rapid formation and high mobility of suspended droplet during condensation. The mechanism underlying the formation of suspended droplets on hierarchical surfaces is unveiled, which can be attributed to the spontaneous dewetting transition induced by confined growth of individual droplets. Additionally, the impact of solid fraction and secondary structure distribution on condensation and dynamic wetting is systematically discussed. The results indicate that an increase in solid fraction or the number of secondary structures enhances the stability of suspended droplets and improves the droplet mobility. In particular, the presence of bottom secondary structures on sidewalls plays a crucial role in the formation of suspended droplets on hierarchical surface. It is expected that the above findings could provide valuable guidance for optimizing the design of functionalized surfaces with anti-frosting and self-cleaning performance.

Design and Fabrication of Nature-Inspired Surfaces for Anti-Fouling: A Review

Design and Fabrication of Nature-Inspired Surfaces for Anti-Fouling: A Review

Breaking of Lateral Symmetry in Two-Dimensional Crystallization-Driven Self-Assembly on a Surface.

Symmetry breaking is prevalent in nature and provides distinctive access to hierarchical structures for artificial materials. However, it is rarely explored in two-dimensional (2D) entities, especially for lateral asymmetry. Herein, we describe a unique symmetry breaking process in surface-initiated 2D living crystallization-driven self-assembly. The 2D epitaxial growth occurs only at one lateral side of the immobilized cylindrical micelle seeds, accessing unilateral platelets with the yield increasing with the seed length, the growth temperature, and poly(2-vinylpyridine) corona length (maximum = 92%). Generally, the tilted immobilization of seeds blocks one lateral side and triggers the lateral symmetry breaking, where the intensity and spatial arrangement of seed-surface interactions dictate the regulation. Segmented unilateral platelets with segmented corona regions are further fabricated with the addition of different blended unimers. Remarkably, discrete slope-like and dense blade-like platelet arrays grow off the surface when seeds are compactly aligned either with spherical micelles or themselves. This strategy provides nanoscale insights into the symmetry breaking in long-range self-assembly and would be promising for the design of innovative colloids and smart surfaces.

Причины трещинообразования и признаки деформации угольного пласта в зоне вибрационного воздействия

The use of vibration effects for the effective preparation of a low–permeability coal seam is a fairly promising and constantly improving process. The main difficulty of theoretical research is the fact that coal seams are very diverse in their properties and represent a complex environment. Under the influence of vibration, the capacitive and filtration characteristics of the coal massif change. This leads to a change in the structure and capacity of the porous-fissured space of coal. This reaction finds a good explanation: each act of vibration action causes a rapid change in the coal mass in accordance with the operating stresses during vibration. This point of view was used as the basis for theoretical reasoning, in order to justify the rational impact of directional vibration on the coal seam, to change fracturing and further intensify methane recovery. This is confirmed by both laboratory and industrial experiments on vibration effects. Changes in the environment after strong earthquakes are of a similar nature, even at great distances from the source of the impact. Therefore, the simplest in terms of constructive implementation and less costly in terms of energy and material consumption is a directed oscillatory process on a low-permeability coal seam, which is performed using vibration installations of both surface and underground design.

“It would work for me too”: How Online Communities Shape Software Developers’ Trust in AI-Powered Code Generation Tools

While revolutionary AI-powered code generation tools have been rising rapidly, we know little about how and how to help software developers form appropriate trust in those AI tools. Through a two-phase formative study, we investigate how online communities shape developers’ trust in AI tools and how we can leverage community features to facilitate appropriate user trust. Through interviewing 17 developers, we find that developers collectively make sense of AI tools using the experiences shared by community members and leverage community signals to evaluate AI suggestions. We then surface design opportunities and conduct 11 design probe sessions to explore the design space of using community features to support user trust in AI code generation systems. We synthesize our findings and extend an existing model of user trust in AI technologies with sociotechnical factors. We map out the design considerations for integrating user community into the AI code generation experience.

Theoretical Perspective on the Design of Surface Frustrated Lewis Pairs for Small-Molecule Activation.

The excellent reactivity of frustrated Lewis pairs (FLP) to activate small molecules has gained increasing attention in recent decades. Though the development of surface FLP (SFLP) is prompting the application of FLP in the chemical industry, the design of SFLP with superior activity, high density, and excellent stability for small-molecule activation is still challenging. Herein, we review the progress of designing SFLP by surface engineering, screening natural SFLP, and the dynamic formation of SFLP from theoretical perspectives. We highlight the breakthrough in fine-tuning the activity, density, and stability of the designed SFLP studied by using computational methods. We also discuss future challenges and directions in designing SFLP with outstanding capabilities for small-molecule activation.

Exploiting intermediate wetting on superhydrophobic surfaces for efficient icing prevention

HypothesisSuperhydrophobic surfaces can effectively prevent the freezing of supercooled droplets in technological systems. Droplets on superhydrophobic surfaces commonly not only wet the top asperities (Cassie State), but also partially penetrate into microstructure due to surface properties, environment, and droplet impact occurring in real-world applications. Implications on ice nucleation can be expected and are little explored. It remains elusive how anti-icing surfaces can be designed to exploit intermediate wetting phenomena. ExperimentsWe utilized engineered micro-/nanostructures, specifically micropillars, to modulate the wetting fraction in the microstructure. The behavior of intermediate wetting with supercooling and resulting implications on ice nucleation delay when potential nucleation sites are formed in the microcavities were investigated using experimental, theoretical, and simulation components. FindingsThe temperature-dependent wetting fraction in the microstructure increased at supercooled temperatures, partly activated by condensation in the microcavities. At −10/−20 °C, a critical wetting fraction led to maximum ice nucleation delays, with experimental results consistent with theoretical predictions. This critical wetting fraction minimized the effective contact area solid-to-liquid along the partially wetted microstructure. The study establishes physical relations between ice nucleation delays, geometrical surface parameters and wettability properties in the intermediate wetting regime, providing guidance for the design of ice resistant microstructured surfaces.

Optimization, Production, and characterization of cottonseed methyl ester based on Box-Behnken in response surface design and gas Chromatography-Mass spectrum analysis

Renewable energy sources have a significant approach to eco-friendly systems with economically cost-effective and efficient use of biodiesel. The creation of innovative catalysts is attracting the attention and concern of the chemical and manufacturing sectors to be used in the production of biodiesel. The main objective of this work is to produce the optimum biodiesel yield using BBD design and the base-catalyzed method. The production of biodiesel was achieved through experimental investigation (alkali-catalyzed transesterification) and optimized using the BBD design method.The most important parameters such as methanol to oil ratios, KOH as catalysts, and reaction times were provided with variable conditions. The variation of methanol to oil ratios has significant relationships and is highly correlated in findings. The physicochemical properties of cottonseed biodiesel were carried out according to ASTM and EN standards. The maximum yield was achieved at 96.708 at a molar ratio of 6:1, reaction time of 60 min, and catalyst concentration of 1 wt%. The strong correlation between actual and predicted values of COSME was analyzed using ANOVA variances. The F-value and P-value validated the outcomes of produced biodiesel having a model value of 43.68 and 0.00, respectively. The coefficient of determinations and adjusted R2 of CSOME were achieved at 98.7% and 98.6%, respectively. The gas chromatogram mass spectrum analysis was also obtained to identify the acid profile present in COSME. The major percentage of ester available in COSME has been determined using GC–MS analysis and presented by its weight percentages. The main esters have been including myristic acid methyl ester (1.7%), palmitic acid methyl ester (26.65%), methyl 9-cis,11-trans-octadecadienoate(44.05%), ethyl 9. Cis.11.trans octadecadienoate(9.67%), methyl 20-methyl-heneicosanoate(6.83%), 9,12-Octadecadienoic acid (Z,Z)-, 2-hydroxy-1-(hydroxymethyl)ethyl ester(1.93%), and Pentacosanoic acid, methyl ester(7.14%).

Controlled synthesis of defective MOF-808 and its application in levulinic acid esterification

Defective MOF-808 (Def. MOF-808) plays a pivotal role in catalysis, offering the potential for optimizing catalytic reactions and enhancing reactivity. Through precise control of MOF-808 synthesis conditions, including time, temperature, zirconium (Zr) source, ligand ratio, defect agent type, and content, we systematically studied their effect on material properties. The results showed that by adjusting these conditions, we synthesized a series of MOF-808 materials with varying defect concentrations, referred to as Def. MOF-808. Shorter synthesis times, lower temperatures, defect agents with stronger coordination capabilities, and increased defect agent concentration or reduced organic ligand concentration effectively enhance Def. MOF-808’s defect concentration. The presence of defect sites facilitates the effective binding of the sulfate group, thereby amplifying the level of sulfation and augmenting its acid catalytic potential. Furthermore, this study unveiled a direct link between defect concentration and the catalytic activity observed in the levulinic acid esterification reaction. The Defect-engineered MOF-808 optimized through response surface design demonstrates exceptional heterogeneous acid catalysis performance, achieving impressive conversion rates of 97.5% and selectivity of 96.2%, coupled with remarkable catalytic stability. This study highlights defect engineering as a successful strategy to improve MOF-808 catalyst performance, offering insights for future enhancements.

Bouncing Dynamics of Drops' Successive Off-Center Impact.

Bouncing dynamics of a trailing drop off-center impacting a leading drop with varying time intervals and Weber numbers are investigated experimentally. Whether the trailing drop impacts during the spreading or receding process of the leading drop is determined by the time interval. For a short time interval of 0.15 ≤ Δt* ≤ 0.66, the trailing drop impacts during the spreading of the leading drop, and the drops completely coalesce and rebound; for a large time interval of 0.66 < Δt* ≤ 2.21, the trailing drop impacts during the receding process, and the drops partially coalesce and rebound. Whether the trailing drop directly impacts the surface or the liquid film of the leading drop is determined by the Weber number. The trailing drop impacts the surface directly at moderate Weber numbers of 16.22 ≤ We ≤ 45.42, while it impacts the liquid film at large Weber numbers of 45.42 < We ≤ 64.88. Intriguingly, when the trailing drop impacts the surface directly or the receding liquid film, the contact time increases linearly with the time interval but independent of the Weber number; when the trailing drop impacts the spreading liquid film, the contact time suddenly increases, showing that the force of the liquid film of the leading drop inhibits the receding of the trailing drop. Finally, a theoretical model of the contact time for the drops is established, which is suitable for different impact scenarios of the successive off-center impact. This study provides a quantitative relationship to calculate the contact time of drops successively impacting a superhydrophobic surface, facilitating the design of anti-icing surfaces.

Effective Underwater Drag Reduction: A Butterfly Wing Scale-Inspired Superhydrophobic Surface.

The microstructured superhydrophobic surface serves as an alternative strategy to decrease resistance of underwater vehicles, but the sustainment of an entrapped air layer and the stability of the corresponding gas-liquid interface within textures in flow shear or high pressure are still a great challenge. Inspired by the scales of Parantica melaneus wings, we propose a biomimetic surface with a hierarchical structure featuring longitudinal ridges and regular cavities that firmly pin the gas-liquid interface. The drag reduction rate of the Butterfly Wing Scale-Like Surface (BWSLS) demonstrates a noticeable rise over the single-scale textured mainstream biomimetic surfaces at moderate Reynolds numbers. The superior drag reduction mechanism is revealed as the synergistic effect of a thicker gas film and a more pronounced secondary vortex within the hierarchical textures. The former reduces the velocity gradient near the surface, while the latter decreases the vorticity and energy dissipation. In a high hydrostatic pressure environment, the proposed surface also demonstrates significant stability of the gas-liquid interface, with a gas coverage rate of over 67% during the cyclic loading, surpassing single-structured surfaces. Our study suggests promising surface designs for optimal drag reduction by mimicking and leveraging diverse surfaces of organisms adapted to oceanic climates.

Machine-Learning-Aided Understanding of Protein Adsorption on Zwitterionic Polymer Brushes.

Constructing antifouling surfaces is a crucial technique for optimizing the performance of devices such as water treatment membranes and medical devices in practical environments. These surfaces are achieved by modification with hydrophilic polymers. Notably, zwitterionic (ZI) polymers have attracted considerable interest because of their ability to form a robust hydration layer and inhibit the adsorption of foulants. However, the importance of the molecular weight and density of the ZI polymer on the antifouling property is partially understood, and the surface design still retains an empirical flavor. Herein, we individually assessed the influence of the molecular weight and density of the ZI polymer on protein adsorption through machine learning. The results corroborated that protein adsorption is more strongly influenced by density than by molecular weight. Furthermore, the distribution of predicted protein adsorption against molecular weight and polymer density enabled us to determine conditions that enhanced (or weaken) antifouling. The relevance of this prediction method was also demonstrated by estimating the protein adsorption over a wide range of ionic strengths. Overall, this machine-learning-based approach is expected to contribute as a tool for the optimized functionalization of materials, extending beyond the applications of ZI polymer brushes.