Design Of Structural Materials Research Articles

Magnetic Nanoparticles: A Review on Synthesis, Characterization, Functionalization, and Biomedical Applications.

Nowadays, magnetic nanoparticles (MNPs)are applied in numerous fields, especially in biomedical applications. Since biofluidic samples and biological tissues are nonmagnetic, negligible background signals can interfere with the magnetic signals from MNPs in magnetic biosensing and imaging applications. In addition, the MNPs can be remotely controlled by magnetic fields, which make it possible for magnetic separation and targeted drug delivery. Furthermore, due to the unique dynamic magnetizations of MNPs when subjected to alternating magnetic fields, MNPs are also proposed as a key tool in cancer treatment, an example is magnetic hyperthermia therapy. Due to their distinct surface chemistry, good biocompatibility, and inducible magnetic moments, the material and morphological structure design of MNPs has attracted enormous interest from a variety of scientific domains. Herein, a thorough review of the chemical synthesis strategies of MNPs, the methodologies to modify the MNPs surface for better biocompatibility, the physicochemical characterization techniques for MNPs, as well as some representative applications of MNPs in disease diagnosis and treatment are provided. Further portions of the review go into the diagnostic and therapeutic uses of composite MNPs with core/shell structures as well as a deeper analysis of MNP properties to learn about potential biomedical applications.

Effects of Alloying Elements and Mechanical Alloying on Characteristics of WVTaTiCr Refractory High-Entropy Alloys.

Refractory high-entropy alloys (RHEAs) are among the promising candidates for the design of structural materials in advanced nuclear energy systems. The effects of Cr, V, Ta, and Ti elements and ball milling on the microstructural evolution and mechanical properties of model RHEAs were investigated. The results show that W-rich BCC1 and Ta-rich BCC2 solid solution phases were generated after a long milling duration. After high-temperature sintering, the (Cr, Ta)-rich phase associated with the Laves phase was observed in the Cr-containing model RHEAs. In addition, a high level of Ti, Ta, and V contents promoted the in situ formation of oxide particles in the alloys. Complex TiTa2O7 and Ta2VO6 oxide phases were identified by TEM, which suggests a solid-state reaction of Ti-O, Ta-O, and V-O subjected to high-energy ball milling. The oxide particles are uniformly dispersed in the BCC matrix, which can result in dispersion strengthening and the enhancement of mechanical properties.

Photonic jet generated by symmetric four Airy beams illumination

Photonic jet (PJ) is generated by illuminating a dielectric scatterer with symmetric four Airy beams (SFAiB). The PJ properties have been systematically studied as a function of characteristic parameters of both the SFAiB and the scatterer, including the geometric parameter D that controls lateral position of each Airy beam component, decay factor, focal point position of the SFAiB, as well as the refractive index of the scatterer. The results show that the PJ performance can be optimized by all of these parameters as a result that the diffraction and self-focusing effects of the SFAiB itself, and the scatterer’s focusing function simultaneously play roles in the PJ generation in case of SFAiB illumination. The illumination by SFAiB has advantages over that by plane wave or Gaussian beam in flexibility of tailoring the PJ performance and in possibility of generating a photonic hook with asymmetric illumination caused by transverse offset of focal point of incident SFAiB. In addition, the SFAiB illumination makes it possible to generate a PJ outside a scatterer in case that the scatterer has a higher refractive index of ns > 2.0, increasing the flexibility in both material choice and structural design of scatterer for generation of a PJ for some potential applications.

Dynamic Feature Identification of Carbon-Fiber-Reinforced Polymer Laminates Based on Fiber Bragg Grating Sensing Technology

Carbon-fiber-reinforced polymer (CFRP) composites have many advantages, and have been widely used in aerospace structures, buildings, bridges, etc. The analysis of dynamic response characteristics of CFRP composite structures is of great significance for promoting the development of smart composite structures. For this reason, vibration experiments of CFRP laminates with surface-attached fiber Bragg grating (FBG) sensors under various dynamic loading conditions were carried out. Time- and frequency-domain analyses were conducted on the FBG testing signals to check the dynamic characteristics of the CFRP structure and the sensing performance of the installed sensors. The results show that the FBG sensors attached to the surface of the CFRP laminates can accurately measure the dynamic response and determine the excited position of the CFRP laminates, as well as invert the strain distribution of the CFRP laminates through the FBG sensors at different positions. By performing Fourier transform, short-time Fourier transform, and frequency domain decomposition (FDD) on the FBG sensing signals, the time–frequency information and the first eight modal frequencies of the excited CFRP structure can be obtained. The modal frequencies obtained by different excitation types are similar, which can be used for structural damage identification. The research in this paper clarifies the effectiveness and accuracy of FBG sensors in sensing the dynamic characteristics of CFRP structures, which can be used for performance evaluation of CFRP structures and will effectively promote the design and development of intelligent composite material structures.

Going below and beyond the surface: Microneedle structure, materials, drugs, fabrication, and applications for wound healing and tissue regeneration

Microneedle, as a novel drug delivery system, has attracted widespread attention due to its non-invasiveness, painless and simple administration, controllable drug delivery, and diverse cargo loading capacity. Although microneedles are initially designed to penetrate stratum corneum of skin for transdermal drug delivery, they, recently, have been used to promote wound healing and regeneration of diverse tissues and organs and the results are promising. Despite there are reviews about microneedles, few of them focus on wound healing and tissue regeneration. Here, we review the recent advances of microneedles in this field. We first give an overview of microneedle system in terms of its potential cargos (e.g., small molecules, macromolecules, nucleic acids, nanoparticles, extracellular vesicle, cells), structural designs (e.g., multidrug structures, adhesive structures), material selection, and drug release mechanisms. Then we briefly summarize different microneedle fabrication methods, including their advantages and limitations. We finally summarize the recent progress of microneedle-assisted wound healing and tissue regeneration (e.g., skin, cardiac, bone, tendon, ocular, vascular, oral, hair, spinal cord, and uterine tissues). We expect that our article would serve as a guideline for readers to design their microneedle systems according to different applications, including material selection, drug selection, and structure design, for achieving better healing and regeneration efficacy.

Beyond electrode materials structure design: Binders play a vital role for battery application of micro-size electroactive materials

Micrometre-sized electroactive particles with high tapping density show significant potential for commercial application since they effectively alleviate low Coulombic efficiency and excessive solid electrolyte interphase (SEI) issues brought by nanostructures. Furthermore, optimizing the electrode architecture using novel design concepts can improve the energy density. Beyond the electrode material structure design strategy, binder plays a vital role in providing the mechanical stability and regulating the charge transport. This highlight presents the latest development to design high-capacity batteries by optimizing the binder structures in electrodes and emphasizes the significance of binder design for further commercial application.

A cellulose-based membrane with temperature regulation and water transportation for thermal management applications

Thermal management materials are widely employed in the construction and textile industries due to their non-energy input and the ability to precisely adjust the temperature. However, the application of thermal management technique toward sustainable agriculture is still challenging due to the complex environment. Herein, a coupled insulation system with highly asymmetric thermal conductivity and unidirectional water penetration is developed by using the integration of thermal management and water diodes technologies. The hierarchical membrane shows asymmetric thermal conductivity of carbonized cellulose layer (CCL, 0.64 W m−1 K−1) and Al2O3/cellulose layer (ACL, 0.16 W m−1 K−1), and good moisture permeability owing to the anisotropic wettability of the material and hierarchical structure design. Thermal management performance revealed that compared with PET and cellulose membrane, the membrane temperature increased by 4.1 °C and 1.3 °C, respectively, resulting in a decrease in greenhouse heat dissipation. Besides, benefitting from the efficient photothermal conversion performance of carbonized cellulose, the outside can rapidly warm up to 42 °C under 120 W/m2 sun radiation, providing a suitable growth temperature for crops. Meanwhile, unidirectional water penetration achieved in the 60 s not only enables the membrane to maintain long-term and effective insulation, but also ensures the demand of crops for water during drought conditions. Furthermore, the anti-flaming property broadens the range of applications, reducing damage in an emergency such as a fire. The demonstrated membrane can potentially replace the commercial plastic-based greenhouse materials, and the gradient and bilayer design open a new avenue for sustainable thermal management application.

Review of imaging test phantoms.

Photoacoustic tomography has emerged as a prominent medical imaging technique that leverages its hybrid nature to provide deep penetration, high resolution, and exceptional optical contrast with notable applications in early cancer detection, functional brain imaging, drug delivery monitoring, and guiding interventional procedures. Test phantoms are pivotal in accelerating technology development and commercialization, specifically in photoacoustic (PA) imaging, and can be optimized to achieve significant advancements in PA imaging capabilities. The analysis of material properties, structural characteristics, and manufacturing methodologies of test phantoms from existing imaging technologies provides valuable insights into their applicability to PA imaging. This investigation enables a deeper understanding of how phantoms can be effectively employed in the context of PA imaging. Three primary categories of test phantoms (simple, intermediate, and advanced) have been developed to differentiate complexity and manufacturing requirements. In addition, four sub-categories (tube/channel, block, test target, and naturally occurring phantoms) have been identified to encompass the structural variations within these categories, resulting in a comprehensive classification system for test phantoms. Based on a thorough examination of literature and studies on phantoms in various imaging modalities, proposals have been put forth for the development of multiple PA-capable phantoms, encompassing considerations related to the material composition, structural design, and specific applications within each sub-category. The advancement of novel and sophisticated test phantoms within each sub-category is poised to foster substantial progress in both the commercialization and development of PA imaging. Moreover, the continued refinement of test phantoms will enable the exploration of new applications and use cases for PA imaging.

Computer numerical simulations for accelerated design of rare earth permanent magnet motors in renewable energy applications: A review

Rare earth permanent magnet (REPM) motors underpin various emerging fields in electronic and mechanical industries. The rapid growth of renewable energy industries requires the higher performance of the REPM motors, such as the high output torque (≥ 350 N·m), high power (≥ 200 kW), and low ripple torque (< ±5%). To achieve these performances, the fine design for the materials and structures of the REPM motor is required. Computer numerical simulations play important roles in shortening the period and reducing the cost of REPM motor design. Finite difference method (FDM) and finite element method (FEM) are common methods for motor design. Boundary element method (BEM) exhibits advantage in accuracy and efficiency but its commercialization is slower. These three methods have their own advantages and applications. This review discusses the principles and present applications of the FDM, FEM and BEM in details. At present, the electromagnetic and structural simulations are mainly realized by FDM and FEM, while the acoustics simulation is carried out by BEM or combined FEM-BEM. The advantages and limits of various simulation methods in different parts of motor design are comprehensively compared. The recent progress of computer numerical simulations in REPM motor design is summarized, including the simulations in permanent magnets, electromagnetics properties, structure and acoustics characteristics in REPM rotor. In particular, the design of material and electromagnetic structure for the cutting-edge Nd-Fe-B rotor is highlighted. The opportunity and future directions of computational simulations in REPM motor design are also discussed in this review.

Design and optimization of Miura-Origami-inspired structure for high-performance self-charging hybrid nanogenerator

A hybrid piezoelectric-triboelectric-electromagnetic nanogenerator (HPTENG-EMG) has been designed meticulously by focusing on material selection, structural design, and performance evaluation. The module can operate using three parts; piezoelectric, triboelectric and an electromagnetic mechanism. The hybrid concept of triboelectric and piezoelectric is achieved by fabricating triboelectric-piezoelectric composite materials working through the TENG mechanism. In the material design part, the composite film between bacterial cellulose (BC) and BaTiO3 nanoparticles (BT-NPs) fabricates and optimizes its properties with a suitable number of BT-NPs. The unique Miura-Origami (MO) hexagonal multilayer shape is applied within the structural design to increase the contact surface area, which enhances the electrical output signal. The third part of the hybrid system incorporates an electromagnetic generator (EMG) by designing a structure of compact and lightweight cylindrical tubes with magnetic levitation structures. The hexagonal multilayer shape of MO composite TENG (MO-CTENG) generates an open-circuit output voltage (VOC) of ∼414 V and short-circuit output current (ISC) of ∼48.3 μA with maximum output power (P) of about ∼6.94 mW. The highest ISC value of ∼38 mA can be promoted in the optimized EMG, which is higher than the MO-CTENG by ∼786 times. The practical application of this technology is demonstrated by human shaking motion for battery charging in the wireless Global Positioning System (GPS). The maximum direct current output voltage (VDC) saturation of 30 V can be achieved within 19 s. This work provides a potential methodology for increasing electrical output performance by capturing more mechanical energy through the conjunction of three phenomena into a single device, which exhibits a promising way of addressing an energy crisis.

Flexible pressure and temperature sensors towards e-skin: material, mechanism, structure and fabrication

Electronic skin (E-skin) has gained significant attention due to its potential applications in the Internet of Things (IoT), artificial intelligence (AI), and flexible multi-sensing systems. Mimicking human skin, e-skin sensing devices can be employed in various scenarios. Among the most important sensing elements for tactile e-skin sensors are pressure and temperature sensors, which have increasingly garnered research interest over the past few decades. However, the design and fabrication of advanced pressure and temperature sensors can be challenging owing to complications such as signal interference, complex mechanism integration, and structural design issues. This review provides an overview of flexible pressure and temperature sensors used in e-skin, covering four main perspectives: material selection, mechanism integration, structural design, and manufacturing methods. The materials of different elements in the entire sensing system are comprehensively discussed, along with single and compound mechanisms of pressure and temperature sensing. Pressure and temperature sensors are divided into two types based on their electric output signals, which are exemplified in detail. The manufacturing methods used to fabricate these sensors, including printing methods, are outlined. Lastly, a summary of the future challenges faced by flexible pressure and temperature sensors used in e-skin is presented.

Analysis of the stress field in the reactor vessel of the China Initiative Accelerator Driven System during postulated ULOF and UTOP transients

The China Initiative Accelerator Driven System (CiADS) was proposed by China Academy of Science since 2015. The subcritical reactor in CiADS is a liquid Lead Bismuth Eutectic (LBE) cooled fast reactor. When the reactor core is in operation, the LBE coolant will directly contact and corrode the inner surface of reactor vessel. Due to the high temperature, the corrosion will be more severe. If the stress on the reactor vessel exceeds the limit, the plastic deformation will occur, leading to the generation and expansion of defects and cracks, and the safety of the reactor will be affected. Therefore, evaluating the stress field of the reactor vessel under different operating conditions is a very important research project. In this paper, the finite element analysis software ADINA was applied to analyze the reactor vessel in CiADS, and the ASME Code was used as stress assessment standards. We can preliminarily prove that the stress assessments of the vessel during the postulated Unprotected Loss of Flow (ULOF) accidents satisfy the requirements of ASME Code. The limit reactivity insertion to protect the vessel from plastic deformation is 0.58$ in the postulated Unprotected Transient over Power (UTOP) accidents based on our current results. Therefore, we can preliminarily conclude that the current material selection and structural design of the reactor vessel in CiADS could survive most of the postulated transient accidents considering the stress effect.

Development of soft dry electrodes: from materials to structure design

Bioelectric signals reflect our daily physiological activities, which can be recorded in the form of electroencephalography, electrocardiography, electromyography, etc. The traditional Ag/AgCl wet electrode is the gold standard for clinical monitoring of bioelectrical signals at present, while complicated preparation and gel evaporation limit its long-term application. Therefore, it is meaningful to research dry electrodes without conductive paste or additional adhesives. Unfortunately, the high interface impedance between electrodes and skin is a fatal defect of dry electrodes, which leads to excessive noise levels and poor signal quality. Consequently, more efforts are required to achieve conformal contact between dry electrodes and skin to reduce the contact impedance. From this perspective, we review the recent progress in capacitive electrodes, invasive microneedle electrodes, and common-contact dry electrodes. Material selection and structural design to obtain conformal contact are highlighted. Finally, we propose the future development direction of dry electrodes.

Hydrogen bonds determine the nonbonding adhesion at HMX-based PBX interface

Polymer bonded explosives (PBXs) are kind of composite materials consisting of multi-layers structures, where the interfacial interactions can significantly affect their structures, properties and performance. To investigate the determinant factors affecting the interfacial interactions, in this work, the adhesion works at different interfaces are studied by molecular dynamics simulations. A key observation is that the hydrogen bonds are found to be a decisive factor that directly affects the interfacial interactions. When the fluoropolymers change from F2321 to F2319, the adhesion works with the HMX and coupling agent layer present a monotonous decrease and increase, respectively, corresponding to the changes in the number of weak hydrogen bonds. Thus the hydrogen bonds can be utilized to benchmark the nonvalent interfacial interactions. Moreover, the coupling agent layer as an intermediary enhances the adsorption between the explosive crystal and the binder, whose thickness significantly impacts the interfacial interactions. Its interactions with the HMX and fluoropolymers both show a similar increase with respect to its thickness and then stabilize at the thickness above 2.5 nm, corresponding to a surface density of six KH550 chains per nm2. This study provides a basic understanding of the nonbonding adhesion mechanisms in the PBXs and is helpful for the material selection and structure design.

Mathematical Calculation of Material Reliability Using Surface Roughness Feature Based on Plasma Material Interaction Experiment Results

The choice of reactor structural material design must take into account the TOKAMAK fusion reactors' structural reliability. Due to their high levels of heat and energy, fusion reactions have significant deformation effects, which reduce the efficiency of energy production in reactors. Material selection, erosion and damage, heat and stress management, reliability analysis, maintenance, and inspection are crucial elements in determining how reliable fusion reactors are. The focus of this work is on material selection and reliability analysis based on these parameters. The most common wall materials used in fusion reactors are tungsten, beryllium, steel, or graphite. It is advised to utilize aluminum because harmful Beryllium dust limits the study of this element. For this purpose, a target of aluminum samples is established with a plasma of He ions created by glow discharge. The dependability of the samples is determined by calculating the Weibull Distribution and measuring the roughness of the sample surfaces following exposure.

Progress and Opportunities in Computational Modeling of Localized Corrosion

Corrosion can lead to mechanical damage near the material surface and reduce the material’s strength. It is essential to understand and simulate corrosion damage evolution for predicting the residual service life of engineering structure, reliability analysis, and corrosion-resistant design of materials. Several major novel corrosion simulation methods in the past 10 y are mainly introduced: cellular automata method, finite element method, phase field model, and peridynamics model. The computational modeling of localized corrosion is discussed and the advantages and disadvantages are compared. Finally, some difficulties in practical engineering applications such as dynamic interface tracking, multiscale and multiphysical field corrosion simulation, and standardization of corrosion simulation are proposed, and the future investigation direction is explored. With the rapid development of software science and computer technology, the operation speed and accuracy of numerical simulation will be greatly improved. The application advantages of numerical simulation in the field of corrosion will be more prominent.

Hierarchical ternary Zn-Ni-Co sulfide/oxide heterostructure for high specific energy hybrid supercapacitor

The structure design and composite of electrode materials have positive effect on supercapacitors (SCs) and have become a research hotpot. In this work, a ternary Zn-Ni-Co-S (ZNCS)/Zn-Ni-Co-O (ZNCO) composite is prepared by hydrothermal vulcanization ZNCO for SCs. Especially, a dissolution and recrystallinity process of ZNCO controlled by appropriate vulcanization has a critical role in obtaining such unique structure. The obtained hierarchical ZNCS/ZNCO microsphere with flower-like shape presents large specific area, uniform mesoporous distribution and good conductivity. Moreover, the potential synergistic effect of multi metal ions can provide abundant sites for reversible redox reactions. As expect, the resultant ZNCS/ZNCO composite presents a battery like energy storage kinetics with a specific capacity of 1445 C/g at 1 A/g. For practical purpose, the assembled ZNCS/ZNCO//AC HSC device achieves long lifespan of 93.3% for 20,000 cycles at 7 A/g with a specific energy of 67.05 Wh/kg at 850 W/kg.

Design and Performance Analysis of a Torsional Soft Actuator Based on Hyperelastic Materials

Conducting research on soft robots is crucial as there are still many problems that need to be resolved in the areas of material selection, structure design and manufacture, and drive control. Soft manipulators, a subset of soft robots, are now a popular area of study for many researchers. In comparison to typical manipulators, soft manipulators feature a high degree of gripping flexibility and a basic morphological structure. They are composed of flexible materials. They have a wide range of potential applications in healthcare, rehabilitation, bionics, and detection, and they can compensate for the drawbacks of rigid manipulators in some use scenarios. A modular soft-body torsional gripping system is developed after a torsional and gripping actuator is conceived and constructed, and its performance examined. The torsion actuator and the grasping actuator can be combined in the system in a modular fashion. With the help of RGB-D vision algorithms, this multi-modular setup makes it possible to combine soft actuators with various twisting degrees and achieve exact gripping. Through pneumatic control, the target object is precisely grasped and rotated at various angles, enabling the rotation of the target object in three dimensions.

Oriented Porous NASICON 3D Framework via Freeze-Casting for Sodium-Metal Batteries.

Sodium-metal batteries are promising candidates for low-cost, large-format energy storage systems. However, sodium-metal batteries suffer from high interfacial resistance between the electrodes and the solid electrolyte, leading to poor electrochemical performance. We demonstrate a sodium superionic conductor (NASICON) with an oriented porous framework of sodium aluminum titanium phosphate (NATP) fabricated by the freeze-casting technique, which shows excellent properties as a solid electrolyte. Using X-ray computed tomography, we confirm the uniform low-tortuosity channels present along the thickness of the scaffold. We infiltrated the porous NATP scaffolds with sodium vanadium phosphate (NVP) cathode nanoparticles achieving mass loadings of ∼3-4 mg cm-2, which enables short sodium ion diffusion path lengths. For the resulting hybrid cell, we achieved a capacity of ∼90 mAh g-1 at a specific current of 50 mA g-1 (∼300 Wh kg-1) for over 100 cycles with ∼94% capacity retention. Our study offers valuable insights for the design of hybrid solid electrolyte-cathode active material structures to achieve improved electrochemical performance through low-tortuosity ion transport networks.

Construction of hierarchical MOF-derived CoS2 microsheet arrays@NiMo2S4 nanoflakes on Ni foam as a high-performance supercapacitor electrode

The reasonable design of electrode material composition and structure is an effective way to solve the low energy density of supercapacitors. In this paper, hierarchical MOF-derived CoS2 microsheet arrays@NiMo2S4 nanoflakes on Ni foam (CoS2@NiMo2S4/NF) was prepared by the co-precipitation, electrodeposition and sulfurization process. MOF-derived CoS2 microsheet arrays on NF are used as ideal backbones to provide fast transport channels, and NiMo2S4 nanoflakes with a network-like distribution on the CoS2 microsheet arrays can improve the accessible active sites and promote the penetration and transfer of electrolyte ions. Due to the synergistic effects between the multi components, CoS2@NiMo2S4 exhibits excellent electrochemical properties. The specific capacity of CoS2@NiMo2S4 is 802 C g−1 at 1 A g−1. Hybrid supercapacitor assembled by CoS2@NiMo2S4 and activated carbon exhibits an energy density of 32.1 Wh kg−1 at a power density of 1130.3 W kg−1 and a cycle stability of 87.2% after 10, 000 cycles. This confirms the great potential of CoS2@NiMo2S4 as a supercapacitor electrode material.