Structural Materials Research Articles

Molecular Engineering in the Semiconductor Industry: Progress and Prospects

Abstract. Along with population growth and economic development, human demand for energy and information will be more than ever, and humans need to rely on semiconductor devices to achieve energy storage, signal and other conversions. So how to design and prepare semiconductor materials with better performance, and industrialise and commercialise the materials has become a new hot topic. Typically, semiconductor materials are nanomaterials, and the current mainstream industrial processing is a top-down process, which raises the cost of production and leads to a waste of resources. Because of this, scientists are starting to believe that molecular engineeringa bottom-up strategy based on molecule self-assembly can save resources, energy, and production costs by constructing semiconductor material structures. This paper examines the bottom-up conceptual approach of molecular engineering and discusses the potential challenges in applying molecular self-assembly technology, which is a crucial method in molecular engineering, to the semiconductor industry. It ultimately concludes that molecular engineering plays a significant role in the semiconductor production process due to its advantages and vast potential for development.

Supplemental Material for Cultural Spanish Adaptation, Factor Structure, and Reliability of Implementation Science Instruments for Suicide Prevention

Supplemental Material for Cultural Spanish Adaptation, Factor Structure, and Reliability of Implementation Science Instruments for Suicide Prevention

Planar Tetracoordinate Silicon in Si3Cu3 - Cluster.

Photoelectron spectroscopy and theoretical calculations have identified the global minimum structure of the 16-valence electron Si3Cu3 - cluster, which features a planar tetracoordinate silicon (ptSi) in a rhombic arrangement. The Si3 and Cu3 triangles are interconnected by a Si2/Cu2 edge, forming an ordered chain-like structure. Besides the conventional 2c-2e σ-bond connecting Si3 and Cu3, the stability of this cluster is reinforced by a delocalized 3c-2e σ-bond in Cu3 and a π-bond in Si3. Our study provides experimental confirmation of a planar hypercoordinate heavier Group 14 element, opening possibilities for exploring similar structures in two-dimensional materials.

Energy storaging multifunctional carbon fiber composites based on Nano‐SiO2 reinforced epoxy matrix structural electrolytes

AbstractMultifunctional carbon fiber composite materials capable of storing energy and carrying structural loads have advantages for aerospace structures. In this paper, a structural supercapacitor that consists of an epoxy‐based solid polymer electrolytes (E‐SPEs) and carbon fiber was proposed. To develop an E‐SPEs with better mechanical properties and ionic conductivity, Nano‐SiO2 was introduced into the solid polymer electrolytes. Nano‐SiO2 reinforced E‐SPEs (Nano‐SiO2/E‐SPEs) show improved mechanical properties (Young's modulus [E] = 0.85 GPa) and ionic conductivity (4.99 × 10−4 S cm−1), compared to E‐SPEs without Nano‐SiO2. Structural supercapacitors were further prepared by combining E‐SPEs with carbon fibers. The structural supercapacitor prepared with Nano‐SiO2/E‐SPEs exhibits the higher power and energy density (261.93 W kg−1 and 2.11 Wh kg−1) compared to the structural supercapacitor prepared with E‐SPEs without Nano‐SiO2 (51 W kg−1 and 0.34 Wh kg−1), indicating improved mechanical and energy storage properties for structural supercapacitors after incorporation of Nano‐SiO2. This strategy has great potential in enhancing performance of structural energy storage composite materials for application in next‐generation aerospace vehicles.

Hydrophobic and Elastic Structural Triboelectric Materials Enabled by Template Method toward Real-Time Material Recognition.

Since each material has a unique ability to lose or obtain electrons, specific triboelectric signals are produced when triboelectric materials are in contact with different objects. Triboelectric nanogenerator (TENG) devices show great potential for use as tactile sensors; nevertheless, analyzing the structure-function relationship of functionalized triboelectric sensing interfaces under environmental conditions and improving the sensing stability and accuracy through the design of hydrophobic structure on the triboelectric material surface remain major challenges in the development of intelligent sensing networks. Compared with the traditional rigid micronanostructure, the elastic micronanostructure strategy is applied to achieve both hydrophobicity and stability of triboelectric materials based on the template method in this work. The corresponding surface roughness and contact angle are 89.9 nm and 117.9°, respectively. As expected, the output voltage and charge density are enhanced by almost 65.8 and 33.4%, respectively, with the establishment of an elastic micronanostructure on the triboelectric material surface. More importantly, the triboelectric signal waveforms also present acceptable durability for subsequent recognition after immersion in water or ethanol for 12 days and metal impact for 12 000 cycles. Hence, combined with deep machine learning and triboelectric effect, a material perception system integrated with a moisture-resistant TENG-based sensor after fatigue testing, data processing, and display modules is also developed for real-time monitoring with approximately 100% (mask), 76% (plank), 93% (plastic), and 89% (rubber) identification accuracies in the natural environment. Finally, the proposed hydrophobic and elastic triboelectric materials show broad potential for application in the field of human-computer interaction.

Playgrounds as Residual Areas—Case Study of a Playground Regeneration Proposal in Târgu-Mureș, Romania

Playgrounds are envisaged as spaces designed to provide a safe and enjoyable environment that facilitates physical activity among children and adolescents. However, in various instances within cities formerly under socialist governance, these playgrounds have suffered neglect and lacked maintenance, coherent conceptual frameworks, professional oversight, suitable materials for playground structures, and attention to vegetation or potentially toxic elements. They became residual areas in the city’s built environment. Presently, the evaluation and the regeneration of playgrounds in cities have emerged as a significant task. Amidst the densely populated urban fabric, these spaces hold considerable importance for outdoor activities, social interaction, recreational pursuits, and the healthy development of future generations. Simultaneously, these places can play a crucial role in a city’s green infrastructure, local landscapes, and the challenges of sustainability prompted by climate change. The landscape analysis of 22 playgrounds classified them based on land use characteristics, location, functions, equipment, quality, and accessibility. A case study in Târgu-Mureș, scrutinized in detail within this analysis due to its proximity to the city center, within a densely populated urban area, and its multifaceted functionalities, underscores the need for a comprehensive approach encompassing diverse disciplines to address its manifold usage requirements.

Dipolar Recoupling in Rotating Solids.

Magic angle spinning (MAS) nuclear magnetic resonance (NMR) has evolved significantly over the past three decades and established itself as a vital tool for the structural analysis of biological macromolecules and materials. This review delves into the development and application of dipolar recoupling techniques in MAS NMR, which are crucial for obtaining detailed structural and dynamic information. We discuss a variety of homonuclear and heteronuclear recoupling methods which are essential for measuring spatial restraints and explain in detail the spin dynamics that these sequences generate. We also explore recent developments in high spinning frequency MAS, proton detection, and dynamic nuclear polarization, underscoring their importance in advancing biomolecular NMR. Our aim is to provide a comprehensive account of contemporary dipolar recoupling methods, their principles, and their application to structural biology and materials, highlighting significant contributions to the field and emerging techniques that enhance resolution and sensitivity in MAS NMR spectroscopy.

Flexible Inverse Opal Structural Color Films with High Strength and Harsh Environment Stability.

Flexible photonic crystals (PCs) constructed by PCs and special polymers are very promising to achieve a combination of vivid structural colors, mechanical robustness, and environment stability. However, PCs that incorporate polymer binders are still susceptible to destruction and subsequent loss of structural color when subjected to significant external forces or harsh environments. Besides, because most of these polymers are highly flammable, crucial fire safety is difficult to be guaranteed in the application of these materials. In this study, we report a poly(m-phenyleneisophthalamide) inverse opal (PMIA IO) structural color film through a SiO2 PC template sacrificing method. Benefiting from the high rigid PMIA molecular structural configuration, the PMIA IO films are able to maintain their structural colors even in harsh conditions, such as large tensile stress, high and low temperatures, potent acids and bases, and ultraviolet radiation. More attractively, the PMIA IO films demonstrate excellent flame retardancy, with the limiting oxygen index (LOI) and flame retardant rating reaching 28 vol % and V0, respectively. We believe that the flexible structural color films with high strength, harsh environment stability, and flame retardancy, which are difficult for other structural color materials to possess simultaneously, have great potential for special applications in fire protection, national defense, aviation, marine, and aerospace fields.

Recent Advances in Near‐β Titanium Alloys: Microstructure Control, Deformation Mechanisms, and Oxidation Behavior

Near‐β titanium alloys are used as promising structural materials for aerospace, biomedical, and other advanced applications due to their excellent combination of high specific strength and superior corrosion resistance. Precise control of the microstructure and mechanical properties through thermomechanical processing and heat treatment is paramount for exploiting the full potential of these alloys. This review article provides a comprehensive and critical assessment of the state‐of‐the‐art research on the microstructure evolution, deformation mechanisms, and oxidation behavior of near‐β titanium alloys. Furthermore, the challenges and emerging opportunities in the development of near‐β titanium alloys have also been identified, ranging from alloy design and processing optimization to multiscale characterization and integrated computational materials engineering. This review article provides a timely and comprehensive roadmap for the research and development of near‐β titanium alloys, paving the way for unlocking their full potential in critical industries.

Discussion on Human-induced Vibration of Glulam Pedestrian Arch Bridge

In the process of urban modernization, with the wide application of lightweight and high-strength structural materials and the constant pursuit of structural aesthetics, footbridges tend to develop in the direction of long span, slender and gentle. However, the problem of human-induced vibration comfort caused by such bridges is becoming increasingly prominent. Especially the wooden footbridge, although its static performance (such as bearing capacity and deflection) can well meet the structural design and use standards, its dynamic performance, especially the excessive vibration under the excitation of crowds, has become the core consideration to control the design of modern wooden footbridges.

Exploration of Pristine ZnO and Cobalt Doped ZnO for the Solar Photocatalytic Degradation of Methylene Blue Dye

The ZnO and Co-doped ZnO were prepared by eco-friendly and modest route, including thermal disintegration of zinc oxalate (ZnOx) and cobalt-zinc oxalate (CoZnOx) powders, respectively, from a mechano-chemical method. The process of conversion of metal/s oxalate dihydrate to the pristine ZnO and cobalt-doped ZnO was studied with TG-DTG and FTIR spectroscopy. ZnO and Co-doped ZnO crystallites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), UV–visible and photoluminescence (PL) spectroscopies. Hexagonal Wurtzite crystallite structures of the aforementioned materials were illustrated from XRD data. The surface morphological investigation was done with SEM. EDX study confirms the elemental purity of materials. Chemical bonding information was obtained from FTIR spectra. Optical properties were studied from UV-visible and photoluminescence spectroscopy. Exploration of pristine ZnO and cobalt-doped ZnO for the solar photocatalytic degradation (PCD) of methylene blue dye has been done in a batch photoreactor. The various related parameters such as photocatalyst amount, initial concentration of dye and pH were also examined for maximum degradation efficiency for mentioned dye.

Analysis of Vibration Characteristics for Rotating Braided Fiber-Reinforced Composite Annular Plates with Perforations

In the current study, a comprehensive numerical model for analyzing the vibrational characteristics of braided fiber-reinforced composite (BFRC) rotating annular plate with perforations under diverse boundary constraints was introduced. This model employs the differential quadrature finite element method (DQFEM), which was developed based on the first-order shear deformation theory (FSDT) and coordinate transformation approach. The BFRC material, specifically a two-dimensional biaxial orthogonal fabric, was utilized to fabricate the annular plate with two distinct types of holes: circular and sector-shaped. The model’s convergence, accuracy, numerical stability, and reliability were confirmed through comparative assessments utilizing data from the literature, from ABAQUS software, and from experimental findings. The analysis focuses on studying the influences of structural properties, material parameters, and boundary restraints on the frequencies of vibration for BFRC rotating annular plates with holes. This theoretical model helps provide scientific basis and technical guidance for the stability and lightweight design of rotating annular plates, such as rotor structures in aircraft engines.

Machine learning driven design of high-performance Al alloys

Aluminum (Al) alloys with both high strength and thermal conductivity (TC) are promising structural materials for wide application across different industries. Yet, design of such alloys is challenging, since strength and TC often share a trade-off. In this paper, we build prediction models for TC and ultimate tensile strength (UTS) of Al alloys using eXtreme gradient boosting (XGBoost) and support vector machine (SVM) algorithms, respectively. The models take physical descriptors from the alloy composition into account. Lasso and Gini Impurity algorithms were adopted for feature engineering. Guided by the models, an Al-2.64Si-0.43Mg-0.10Zn-0.03Cu alloy with TC over 190 W·m-1·K-1 and UTS over 220 MPa was designed. The alloy was fabricated and tested by experiment, and its UTS and TC are close to the model prediction. Microstructure characterization suggests that the fragmented and spherical Si phase, along with a few non-spherical Si phases, may be a key reason for the improved properties.

Free Vibration and Buckling Analyses of Functionally Graded Plates With Graphene Platelets Reinforcement

Abstract While existing research has focused on using graphene platelets (GPLs) as reinforcement for homogeneous matrices, this study proposes a new nanocomposite for plate structures consisting of GPLs incorporated into a conventional functionally graded matrix with the aim of enhancing their overall stiffness. The performance of such plates is evaluated via free vibration and buckling analyses in the present study. Note that the matrix phase is graded continuously with the power law distribution across the plate's thickness, whereas various GPL dispersion patterns along the thickness are studied. The material properties of the typical functionally graded matrix are determined by the rule of mixture, and then those of the composite are estimated by the modified Halpin–Tsai model as well as the rule of mixture. Based on Hamilton's principle and the novel four-unknown refined plate theory (RPT4), the governing equations of the plate are developed. The Navier-type solution scheme is then adopted to get the critical buckling load and natural frequency of the nanocomposite plate. Numerical findings are examined to evaluate the novel nanocomposite plate model, and a parametric study is also conducted. In addition, high-accurate results are provided via the Navier-type solution here as benchmark solutions for further studies on functionally graded material structures reinforced by GPLs.

Self-Reporting Multiple Microscopic Stresses Through Tunable Microcapsule Arrays.

Self-reporting materials have emerged as a promising tool for real-time monitoring of stress and damage in structural materials. When critical stress is applied to these materials, an optical response is triggered - for example by dye release, or molecular cleavage. A key challenge is to extend these systems to respond to multiple different stress levels. To achieve this, a novel microcapsule-based assembly strategy is presented. Microfluidic synthesis is used to create microcapsules that release dye at a precise level of applied force. Subsequently, capillary assembly is used to combine microcapsules with different stress-responsiveness and different fluorescent dyes into chains, which are uniformly patterned into regular arrays, and embed these into the self-reporting materials. Through indentation experiments, it is shown that these materials can distinguish and record spatially resolved local stresses based on the fluorescence emitted upon microcapsule rupture. Crucially, the technique's accuracy is significantly improved when microcapsules are spatially organized within the material. This versatile technique can be applied to a range of different materials, via the use of thin coatings containing the regularly patterned microcapsule chains.

The role of structural and insulating material in the structure-borne noise propagation of superyachts

The insulation and noise and vibration damping characteristics of complex systems used by humans, such as automobiles, airplanes and ships are becoming increasingly important from the early design stages to ensure an adequate level of comfort. Especially in the naval fields, the design of insulation plans is crucial to prevent the propagation of noise and vibrations on board of megayachts. Since it is quite complex to identify and correctly model the sources due to their deterministic and random nature, during the early design stage, the focus is on insulation rather than reducing the acoustic levels of the sources themselves. In this article, a method for analyzing sea trials on a superyacht will be proposed with the aim of analyzing how much the insulation materials can limit the levels of vibrational energy on board during the path between sources and receivers. A new a descriptor based on harmonic transmission energy through the structure is proposed for path insertion loss experimental identification. In particular, by using spectral analyses and synchronous averaging of sound levels in various areas of the superyacht, it will be possible to study the vibroacoustic insulation of structural materials and their damping coefficient.

Pre-Planning and Post-Evaluation Approaches to Sustainable Vernacular Architectural Practice: A Research-by-Design Study to Building Renovation in Shangri-La’s Shanpian House, China

The renovation and revitalization of vernacular architecture are pivotal in sustainable rural development. In regions like Shangri-La, traditional structures not only safeguard cultural heritage but also provide a foundation for enhancing local communities’ living conditions. However, these villages face growing challenges, including infrastructure decay, cultural erosion, and inadequate adaptation to modern living standards. Addressing these issues requires innovative research approaches that combine heritage preservation with the integration of contemporary functionality. This study employs a research-by-design approach, focusing on the Shanpian House as a case study, to explore how pre-planning and post-evaluation methods can revitalize traditional vernacular architecture. The pre-planning phase utilizes field surveys and archival research to assess spatial, cultural, and environmental conditions, framing a design strategy informed by field theory. In doing so, it evaluates how traditional architectural elements can be preserved while introducing modern construction techniques that meet current living standards. The post-evaluation phase, conducted through questionnaires and semi-structured interviews, assesses user satisfaction, focusing on the impact of architectural esthetics, structural stability, and material choices. Key findings from an OLS regression highlight the strong positive correlation between architectural style, structural choices, and cultural relevance with resident satisfaction. The research emphasizes that design elements such as structural details, materials, and infrastructure upgrades are critical in shaping perceptions of both functionality and cultural identity. Interestingly, the model reveals that improving architectural esthetics, alongside modern indoor features such as network connectivity, has a significant impact on enhancing overall resident satisfaction (significance level: 0.181). This study contributes to the broader discourse on sustainable building renovation by demonstrating how traditional architecture can be thoughtfully adapted for contemporary use and also proposes a paradigm shift in the renovation of historic buildings, advocating for a balance between preservation and modernization. The application of sustainable materials, digital modeling, and innovative construction techniques further ensures that these traditional structures meet the demands of modern civilization while maintaining their cultural integrity.

Mechanical characterization of a 3D printed lattice core sandwich structure

AbstractSandwich structures have garnered interest as versatile structures for applications in advanced engineering structures. To fabricate sandwich structures, plastics have replaced conventional materials; however, most of these plastics remain in the environment beyond their functional lifespan. This study describes the fabrication of sustainable hybrid sandwich structures with 3D printed poly‐lactic acid (PLA) cores and self‐reinforced polyethylene terephthalate (srPET) face sheets. The mechanical responses of the hybrid sandwich structures with three types of lattice cores, S‐90, S‐45, and S‐V, were compared with those of the parent material sandwich structures after performing bending and impact tests. The face sheet in the hybrid sandwich structure transferred the load to the core without failure. The hybrid sandwich structure containing the S‐90 core exhibited a higher fracture strength (52.4 MPa) and tangent modulus of elasticity (2860 MPa) than those of the other structures. S‐V exhibited the highest fracture strains of 3.3% and 5% for parent material and hybrid sandwich structures, respectively. This study highlights the sandwich structures with excellent mechanical properties for structural applications.Highlights Novel sandwich structures with 3D printed PLA cores are fabricated. Three‐point bending and low‐velocity impact tests are performed. Failure occurred in the core, but the Sr‐PET face sheets did not deform. Hybrid sandwich structures significantly improve mechanical performance.

Extracting Thin Film Structures of Energy Materials Using Transformers

Extracting Thin Film Structures of Energy Materials Using Transformers

Memcapacitors and Memristor Characteristics of ISGE-SOT and SHE-SOT Gain-Driven MoS2:Er Ferromagnets.

The enhancement of the spin-orbit torque (SOT) effect through the integration of intrinsic inverse spin galvanic effect spin-orbit torque and spin Hall effect spin-orbit torque is fundamentally dependent on the structural and material properties of the ferromagnets. Consequently, the synthesis of ferromagnets with superior structural integrity and material characteristics is of paramount importance. In this study, a gas-liquid chemical reaction, in conjunction with ultrasonic crushing, was employed to synthesize few-layer MoS2:Er nanosheets. X-ray diffraction, X-ray photoelectron spectroscopy, and energy-dispersive spectroscopy analyses confirm the successful substitution of Mo4+ by Er3+ through doping within the MoS2 lattice. Vibrating sample magnetometry and MT measurements indicate that MoS2:Er exhibits room-temperature ferromagnetism (RTFM), with the underlying mechanism elucidated through first-principles calculations. Furthermore, the unique electron density of states at the Fermi level suggests the presence of ferromagnetism in MoS2:Er. A wedge-shaped Pt/MoS2:Er/Au structure was fabricated and subsequently evaluated for current-induced SOT switching, as well as for its memcapacitor and memristor characteristics. The precession of a magnetic moment in three-dimensional space was successfully simulated by solving the Landau-Lifshitz-Gilbert-Slonczewski equation using the Mumax.