Hasil untuk "Materials of engineering and construction. Mechanics of materials"

Ning Sheng, Yirui Wang, Xu Luo et al.

Abstract Musculoskeletal, neural, and skin injuries present significant clinical challenges due to limited regenerative capacity and complex physiological interactions. Ferroelectric biomaterials—including PVDF, P(VDF-TrFE), BaTiO₃, BiFeO₃, KNN, and PLLA—have emerged as promising candidates for tissue repair owing to their electromechanical responsiveness and biocompatibility. Extensive research has focused on their cross-coupling effects to develop high-performance biomaterials. However, progress in ferroelectric materials for tissue repair remains comparatively fragmented, primarily due to the poorly understood and multifaceted interplay between material performance and biological responses. This review systematically examines the role of ferroelectric biomaterials in modulating biological processes, with emphasis on their cross-coupling effects in cellular behavior and tissue regeneration. We further analyze how key fabrication techniques influence material properties and therapeutic outcomes. By integrating design principles, material science, and biological efficacy, this work provides a comprehensive framework for developing ferroelectric biomaterials as self-powered, adaptive, and clinically viable solutions for regenerative medicine.

Naman Sharma, Kirti Mishra, Nirankar Singh et al.

Abstract Recently, research all over the world is being carried out to develop eco‐friendly supercapacitors (SCs) using biopolymeric materials like proteins or polysaccharides. These polymers offer these innovative energy storage devices' sustainability and recyclability, flexibility, lightweight, and steady cycling performance—all crucial for utilizations involving wearable electronics and others. Given its abundance and extensive recycling behavior, cellulose is one of the most sustainable natural polymers requiring special attention. The paper discusses the various types of cellulose‐based materials (CBMs), including nanocellulose, cellulose derivatives, and composites, as well as their synthesis methods and electrochemical properties. The review also highlights the performance of CBMs in SC applications, including their capacitance, cycling stability, and rate capability, along with recent advances in modifying the materials, such as surface modification and hybrid materials. Finally, the proposed topic is concluded with the current challenges and future prospects of CBMs for SC applications.

Zhiqiang Dai, Rungroj Chanajaree, Chengwu Yang et al.

Traditional aqueous electrolyte systems in zinc-ion batteries (ZIBs) often face challenges such as sluggish ion transfer kinetics, dendrite formation, and sudden battery failures in harsh temperature environments. Herein, we introduce a pioneering approach by integrating a bifunctional additive composed of ethylene glycol (EG) and sodium gluconate (Ga) into ZnSO4 (ZSO) electrolyte to overcome these obstacles. The polyhydroxy structures of EG and Ga can reconstruct the hydrogen bond network of H2O to improve its liquid stability, and also adjust the coordination environment around hydrated Zn2+. Additionally, Ga in the H2O–EG mixture leads to the formation of a robust protective layer that promotes uniform deposition of Zn2+ ions and minimizes unwanted side reactions. Therefore, Zn anodes with 40% ZSO–Ga electrolyte can cycle for more than 3,000 h at 25 °C and 800 h at 50 °C. Furthermore, Zn||NH4V4O10 (NVO) full batteries demonstrate remarkable cycle stability, lasting up to 10,000 cycles at 1 A g−1 with a capacity retention of 79.1%. The multifunctional electrolyte additive employed in this study emerges as a promising candidate for enabling highly stable zinc anodes under diverse temperature conditions.

Valerii Kidalov, Lukas Hertling, Roman Redko et al.

Silicon carbide films on porous-Si/Si substrates have attracted considerable attention due to their potential use in modern high-power electronic devices. Here, SiC/porous-Si/Si heterostructures fabricated by an atomic substitution method are investigated. Scanning electron microscopy shows the formation of a continuous about 40 nm thick film of SiC, with a sharp interface to the porous Si sublayer. Energy-dispersive x-ray spectroscopy confirmed that Si, C, and O are the only constituents of the SiC film and the porous-Si underlayer. Raman spectroscopy indicated 3C and 6H polytypes in the SiC film. Spectroscopic ellipsometry in the range of 0.6–5.1 eV was performed in order to determine the refractive index (n), extinction coefficient (k), and bandgap (Eg) of the SiC layer. Macro-FTIR transmission spectra showed the expected absorption features of SiC. IR reflectance maps measured with nano-resolution reveal lateral inhomogeneities of the intensity, which we attribute to the morphology of the porous silicon sublayer. Numerical simulations of the local near-field response were performed for regions, where the SiC layer lay directly on silicon and for regions where it is free-standing over pores. The simulation results are in close agreement with the experimental observations obtained by nanoFTIR and confirm that the porous substrate plays a decisive role in determining the local optical and structural properties of the SiC/porous-Si/Si heterostructures.

Farhin Tabassum, M. R. Asekin, M. Salim Kaiser et al.

The mechanical and frictional behaviors of jute-textile-reinforced polymer composites have been investigated experimentally under the influence of matrix modification and postprocessing thermal treatments. Three different matrix modifiers, namely, carbon, silicon, and aluminum powders are considered for the modification of polymeric material used in the sandwich structured biodegradable jute-textile-reinforced composites. The modified composites are then subjected to post-processing thermal treatments isochronally at temperatures within the range of 0–250°C. Inclusion of carbon, silicon, and aluminum powders into the polyester resin leads to significant changes in the performance of the composite materials in terms of hardness, tensile, as well as wear and frictional properties. More specifically, the aluminum powders show the most promising potential to improve the properties of polyester-jute composites compared with those of silicon and carbon powders. Moreover, at the postprocessing temperature of 125°C, all the modified composite samples show their best performances in terms of hardness, strength, modulus, wear rate, and friction coefficient, which is eventually verified to be the optimum postprocessing temperature for the composites of the present type. The pin-on-disc wear study shows that under constant and varying load conditions, the coefficient of friction of the composite is found to be relatively higher for the case of aluminum-powder modifier compared with those of silicon and carbon power modifiers. The results of optical microstructures, scanning electron microscopic (SEM) images, and energy dispersive x-ray (EDX) spectra are found to be in support of the results observed through direct measurements. A quantitative comparison of the measured results verifies the relative improvement of the major mechanical and frictional properties of the composites, which, in turn, verifies the effectiveness of the selective matrix modifiers in conjunction with post-thermal treatments.

Somayajulu Dhulipala, Carlos M. Portela

Additively manufactured (AM) architected materials have enabled unprecedented control over mechanical properties of engineered materials. While lattice architectures have played a key role in these advances, they suffer from stress concentrations at sharp joints and bending-dominated behavior at high relative densities, limiting their mechanical efficiency. Additionally, high-resolution AM techniques often result in low-throughput or costly fabrication, restricting manufacturing scalability of these materials. Aperiodic spinodal architected materials offer a promising alternative by leveraging low-curvature architectures that can be fabricated through techniques beyond AM. Enabled by phase separation processes, these architectures exhibit tunable mechanical properties and enhanced defect tolerance by tailoring their curvature distributions. However, the relation between curvature and their anisotropic mechanical behavior remains poorly understood. In this work, we develop a theoretical framework to quantify the role of curvature in governing the anisotropic stiffness and strength of shell-based spinodal architected materials. We introduce geometric metrics that predict the distribution of stretching and bending energies under different loading conditions, bridging the gap between curvature in doubly curved shell-based morphologies and their mechanical anisotropy. We validate our framework through finite element simulations and microscale experiments, demonstrating its utility in designing mechanically robust spinodal architectures. This study provides fundamental insights into curvature-driven mechanics, guiding the optimization of next-generation architected materials for engineering applications.

Mohammad Alaghemandi, Morgan Alamandi

Understanding heat transfer in composite materials is essential for optimizing their performance in critical applications across industries such as aerospace, automotive, renewable energy, and construction. This review offers a comprehensive examination of the various heat transfer mechanisms within composite materials and explores how these processes, spanning different length and time scales, are influenced by the materials' composition and structure. Both traditional and advanced analytical and numerical modeling techniques are explored, emphasizing their importance in predicting and optimizing thermal behavior across these scales. Furthermore, the review evaluates current experimental methods for measuring thermal properties, discussing their limitations and potential areas for enhancement. Significant attention is devoted to the practical applications of composite materials, from thermal management in electronic devices to heat-resistant components in aerospace engineering. Recent innovations, such as the integration of phase change materials and the development of nano-enhanced composites, are assessed for their potential to transform heat transfer capabilities. Ongoing challenges are addressed, and future research directions are outlined, highlighting the need for advancements in material science and engineering to meet emerging demands. This review aims to bridge the gap between fundamental research and practical applications, providing a comprehensive understanding of heat transfer in composite materials that is both rooted in current science and driven by future possibilities.

Xin He, Xun Zhou, Ting Shang et al.

Sacrificial metallic coatings are an effective strategy for mitigating corrosion in steel operating in industrial environments. This review article focuses on examining the protection mechanism of zinc-aluminum-magnesium (Zn-Al-Mg) coatings on steel substrates. Specifically, it investigates the effects of various elements and their corrosion products on the corrosion resistance of Zn-Al-Mg coatings. Furthermore, this review summarizes the formation mechanisms of various specialized corrosion modes that occur following the corrosion of Zn-Al-Mg coatings, based on previous experimental findings. It also includes suggestions for further research areas that could contribute to the development of highly corrosion-resistant and long-lasting coatings. These suggestions are based on published laboratory and field test results available in literature.

Karthik Nuthalapati, Raviraj Vankayala, Munusamy Shanmugam et al.

Glioblastoma multiforme (GBM) is one of the most aggressive, incurable, and difficult‐to‐treat malignant brain tumor with very poor survival rates. The gold standard in treating GBMs includes neurosurgical resection of the tumor, followed by the chemotherapy and radiotherapy. However, these strategies remain ineffective in treating patients with GBMs, as tumor recurrence always occur in most cases. Therefore, it remains a grand challenge to develop an effective strategy to combat orthotopic glioblastoma with simultaneous imaging capabilities to monitor the therapeutic outcomes. To tackle this challenge, this study demonstrates, for the first time, that a tumor‐specific europium hexaboride (EuB6)‐based nanomedicine surface‐modified with RGD‐K peptide to target αvβ3 integrin receptors overexpressed on the glioblastoma cells. Further, EuB6@RGD‐K NPs are able to exert theranostic capabilities to effectively diagnose and combat difficult‐to‐treat orthotopic glioblastoma tumors using NIR‐II 1064 nm and NIR‐III 1550 nm photodynamic therapy (NIR PDT) effects. In the in vivo experiments, the average half‐life of 55 d for mice treated with EuB6@RGD‐K NPs and exposed to NIR‐III 1550 nm light irradiation is far higher than that of EuB6@RGD‐K NPs exposed to NIR‐II 1064 nm light irradiation (25 d), PBS‐treated mice (20 d) and EuB6@RGD‐K NPs‐treated mice (no light irradiation, 18 d). To the best of our knowledge, this work represents the first example for destructing murine brain tumors via multi‐functional tumor‐specific europium hexaboride‐based nanotheranostic agent to mediate MR imaging‐guided NIR‐II/‐III photodynamic therapy.

Jotaro Honda, Kosuke Sugawa, Koki Honma et al.

Abstract We designed an external stimulus-responsive anti-Stokes emission switching using dual-annihilator-based triplet–triplet annihilation upconversion systems. This system, which was constructed by incorporating a palladium porphyrin derivative as a sensitizer and 9,10-diphenylanthracene (DPA) and 9,10-bis(triisopropylsilyl)ethynylanthracene (TIPS) as annihilators into polymer thin films, produced TIPS- and DPA-based anti-Stokes emission under low and high excitation powers, respectively. The mechanism involves the following: under low excitation power, triplet energy transfer from triplet-excited PdOEP to DPA is induced, followed by relay to TIPS. This results in the generation of triplet-excited TIPS, and the subsequent triplet–triplet annihilation between them produces TIPS-based anti-Stokes emission. Conversely, under high excitation power, the high-density triplet-excited DPA, generated through triplet energy transfer from PdOEP, undergoes triplet–triplet annihilation among themselves, resulting in the generation of DPA-based anti-Stokes emission. Additionally, we achieved energy savings by reducing the required excitation power for switching through the utilization of plasmonic metal nanoparticles. The strong local electromagnetic fields associated with the localized surface plasmon resonance of metal nanoparticles enhance the photoexcitation efficiency of PdOEP, subsequently increasing the density of triplet-excited DPA. As a result, anti-Stokes emission switching becomes feasible at lower excitation powers.

Marcelo Rodrigues, Maurício Maia Ribeiro, Robson Luis Baleeiro Cardoso et al.

The Digital Image Correlation (DIC) technique is an important method of evaluating material strain fields. Composite materials have inherently heterogeneous elastic properties, in the function of the different phases present in the composition, whereat the traditional techniques of deformation evaluation may not be sufficient to determine the mechanisms that eventually contribute to the failure of the material. The present work were evaluated, the tensile mechanical properties of polyester matrix composites loaded with an industrial residue of red mud, with a mass fraction of 20%. The properties were surveyed using the conventional technique of strain gauge and compared with the data obtained through DIC. The results showed that the DIC technique was accurate in monitoring the displacements and determining the average deformation of the tested specimens, in addition to providing ample deformation fields, for the evaluation of failure mechanisms throughout the sample request process.

Daniel T. Yimam, Minpeng Liang, Jianting Ye et al.

In the past few years, phase-change materials have become increasingly important in nano-photonics and optoelectronics. The advantages of sizeable optical contrast between phases and the additional degree of freedom from phase switching have been the driving force. From multilevel reflectance to dynamic nanoprinting and structural colors, phase-change materials have achieved outstanding results with prospects for real-world applications. The local crystallization/amorphization of phase-change materials and the corresponding reflectance tunning by the crystallized/amorphized region size have potential applications for future dynamic display devices. Although the resolution is much higher than current display devices, the pixel sizes in those devices are limited by the locally switchable structure size. Here, we reduce the spot sizes further by using ion beams instead of laser beams and dramatically increase the pixel density, demonstrating the capability of having superior resolution. In addition, the power to sputter away materials can be utilized in creating nanostructures with relative height differences and local contrast. Our experiment focuses on one archetypal phase-change material, Sb$_2$Se$_3$, prepared by pulsed-laser deposition on a reflective gold substrate. We demonstrate that we can produce structural colors and achieve reflectance tunning by focused ion beam milling/sputtering of phase change materials at the nanoscale. Furthermore, we show that the local structuring of phase-change materials by focused ion beam can be used to produce high pixel density display devices with superior resolutions.

Daniel Schwalbe-Koda

Advances in high-throughput simulation (HTS) software enabled computational databases and big data to become common resources in materials science. However, while computational power is increasingly larger, software packages orchestrating complex workflows in heterogeneous environments are scarce. This paper introduces mkite, a Python package for performing HTS in distributed computing environments. The mkite toolkit is built with the server-client pattern, decoupling production databases from client runners. When used in combination with message brokers, mkite enables any available client to perform calculations without prior hardware specification on the server side. Furthermore, the software enables the creation of complex workflows with multiple inputs and branches, facilitating the exploration of combinatorial chemical spaces. Software design principles are discussed in detail, highlighting the usefulness of decoupling simulations and data management tasks to diversify simulation environments. To exemplify how mkite handles simulation workflows of combinatorial systems, case studies on zeolite synthesis and surface catalyst discovery are provided. Finally, key differences with other atomistic simulation workflows are outlined. The mkite suite can enable HTS in distributed computing environments, simplifying workflows with heterogeneous hardware and software, and helping deployment of calculations at scale.

King Yau Yip, Siu Tung Lam, Kai Ham Yu et al.

Type-II Weyl semimetal candidate MoTe$_2$, which superconducts at T_c~0.1 K, is one of the promising candidates for realizing topological superconductivity. However, the exceedingly low $T_c$ is associated with a small upper critical field ($H_{c2}$), implying a fragile superconducting phase that only exists on a small region of the $H$-$T$ phase diagram. Here, we describe a simple and versatile approach based on the differential thermal expansion between dissimilar materials to subject a thin single crystalline MoTe$_2$ to biaxial strain. With this approach, we successfully enhance the $T_c$ of MoTe$_2$ five-fold and consequently expand the superconducting region on the $H$-$T$ phase diagram significantly. To demonstrate the relative ease of studying the superconductivity in the biaxially strained MoTe$_2$, we further present the magnetotransport data, enabling the study of the temperature-dependent $H_{c2}$ and the anisotropy of the superconducting state which would otherwise be difficult to obtain in a free-standing MoTe$_2$. Our work shows that biaxial strain is an effective knob to tune the electronic properties of MoTe$_2$. Due to the simplicity of our methodology to apply biaxial strain, we anticipate its direct applicability to a wider class of quantum materials.

Seyyedfaridoddin Fattahpour, Sara Kadkhodaei

Saddle point search schemes are widely used to identify the transition state of different processes, like chemical reactions, surface and bulk diffusion, surface adsorption, and many more. In solid-state materials with relatively large numbers of atoms, the minimum mode following schemes such as dimer are commonly used because they alleviate the calculation of the Hessian on the high-dimensional potential energy surface. Here, we show that the dimer search can be further accelerated by leveraging Gaussian process regression (GPR). The GPR serves as a surrogate model to feed the dimer with the required energy and force input. We test the GPR- accelerated dimer method for predicting the diffusion coefficient of vacancy-mediated self-diffusion in bcc molybdenum and sulfur diffusion in hexagonal molybdenum disulfide. We use a multi-task learning approach that utilizes a shared covariance function between energy and force input, and we show that the multi-task learning significantly improves the performance of the GPR surrogate model compared to previously used learning approaches. Additionally, we demonstrate that a translation-hop sampling approach is necessary to avoid over-fitting the GPR surrogate model to the minimum-mode-following pathway and thus succeeding in locating the saddle point. We show that our method reduces the number of evaluations to a fraction of what a conventional dimer requires.

Kang Wang, Yangyang Zhang, Hankun Li et al.

The rapid development of internet technology and artificial intelligence drives the demand for flexible sensors. Compared with vacuum technology and solution method, the fabrication of flexible sensors by pencil writing directly has advantages such as low cost, simple operation, low temperature, and no pollution. However, they are based on paper and rely on rigid fibers on the surface of it. The polymer is comfortable, portable and has excellent tensile properties, making it more suitable than paper as flexible substrates for wearable devices. In this paper, flexible pressure sensors and arrays are prepared by friction on polymers (Eco-flex、PDMS and bionic skin). The sensitivity of the prepared pressure sensor was 0.78 kPa−1 in the range of 20 kPa, and the response time was 400 ms, while the pressure detection ranged up to 160 kPa. Finally, it can be reused for 1000 cycles. As a wearable device, it can be applied to object grasping, muscle movement and respiratory monitoring. Furthermore, by combining the friction process with the transfer printing process, the stretchable flexible pressure sensor can be prepared on 3D cylindrical and curved hemispherical surfaces. Moreover, patterned sensors can also be prepared. It should be noted that the sensor can be cleaned after being discarded and has no pollution to the environment due to the mild type of materials, which is of certain significance for the development of flexible sensors towards green and low-cost development trends.

S.-R. Bae, D.Y. Heo, S.Y. Kim

Metal halide perovskites have been studied in semiconductor fields such as light-emitting diodes (LEDs) and solar cells owing to their simple manufacturing, high optoelectronic performance, and low manufacturing cost. In this regard, spin-coating method facilitates the fabrication of perovskite devices. However, the spin-coating method for perovskite film deposition is difficult to finely control the thickness and form a uniform surface. Thus. the thermal evaporation method was proposed to overcome these shortcomings. This method provides better reproducibility and film quality than the spin-coating method. In this review, the spin-coating method and thermal evaporation method used to manufacture perovskite thin films will be explained. Moreover, the basic principles of perovskite devices (LEDs, solar cells, memory, X-ray detectors) are explained, and research on perovskite devices developed using thermal evaporation is summarized.

Onur Çakıroğlu, Joshua O. Island, Yong Xie et al.

This work presents an automated three-point bending apparatus that can be used to study strain engineering and straintronics in two-dimensional materials. We benchmark the system by reporting reproducible strain tuned micro-reflectance, Raman, and photoluminescence spectra for monolayer molybdenum disulfide (MoS2). These results are in good agreement with reported literature using conventional bending apparatus. We further utilize the system to automate strain investigations of straintronic devices by measuring the piezoresistive effect and the strain effect on photoresponse in an MoS2 electrical device. The details of the construction of the straightforward system are given and we anticipate it can be easily implemented for study of strain engineering and straintronics in a wide variety of 2D material systems.

Woo Seung Ham, Abdul-Muizz Pradipto, Kay Yakushiji et al.

Abstract Dzyaloshinskii–Moriya interaction (DMI) is considered as one of the most important energies for specific chiral textures such as magnetic skyrmions. The keys of generating DMI are the absence of structural inversion symmetry and exchange energy with spin–orbit coupling. Therefore, a vast majority of research activities about DMI are mainly limited to heavy metal/ferromagnet bilayer systems, only focusing on their interfaces. Here, we report an asymmetric band formation in a superlattices (SL) which arises from inversion symmetry breaking in stacking order of atomic layers, implying the role of bulk-like contribution. Such bulk DMI is more than 300% larger than simple sum of interfacial contribution. Moreover, the asymmetric band is largely affected by strong spin–orbit coupling, showing crucial role of a heavy metal even in the non-interfacial origin of DMI. Our work provides more degrees of freedom to design chiral magnets for spintronics applications.