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Materials with ultra‐fast responsive properties are essential for various applications. Among the responsive materials, poly(N‐isopropylacrylamide) (PNIPAM) stands out due to its well‐studied temperature‐responsive properties. Improving the kinetics of the responsive properties of PNIPAM is, however, still essential for advancing its practical use. Here, the responsive rate of PNIPAM hydrogels is enhanced by first incorporating sub‐micrometer porosity into the material through polymerization‐induced phase separation (PIPS), followed by introducing millimeter scale pores via 3D printing, thereby rendering the material with hierarchical porosity. The 3D‐printed porous PNIPAM structures show accelerated swelling and deswelling, when compared to non‐porous PNIPAM structures, due to enhanced water permeability associated with the continuous network of micrometer to millimeter‐sized pores. Additionally, thinner polymer structures result in faster temperature response rates. At the same time, the mechanical strength of PNIPAM hydrogels with high porosity and thinner polymer walls is not compromised, overcoming the common trade‐off between swelling and mechanical properties. [ABSTRACT FROM AUTHOR]

The development of additive manufacturing (AM) techniques has sparked interest in porous structures that can be customized in terms of size, shape, and arrangement of pores. Porous lattice structure (LS, called also lattice struct) offer superior specific stiffness and strength, making them ideal components for lightweight products with energy absorption and heat transfer capabilities. They find applications in industries such as aerospace, aeronautics, automotive, and bone ingrowth applications. One of the main advantages of additive manufacturing is the freedom of design, control over geometry and architecture, cost and time savings, waste reduction, and product customization. However, the designation of appropriate struct/pore geometry to achieve the desired properties and structure remains a challenge. In this part of the study, five lattice structs with various pore sizes, with two volume fractions for each, and shapes (ellipsoidal, helical, X-shape, trapezoidal, and triangular) were designed and manufactured using selective laser sintering (SLS) additive manufacturing technology. Mechanical properties were tested through uniaxial compression, and the apparent stress-strain curves were analyzed. The results showed that the compression tests revealed both monotonic and non-monotonic stress-strain curves, indicating different compression behaviors among the structures. The helical structure exhibited the highest resistance to compression, while other structures showed similarities in their mechanical properties. In Part II of this study provides a comprehensive analysis of these findings, emphasizing the potential of purpose-designed porous structures for various engineering applications. [ABSTRACT FROM AUTHOR]

Monte Carlo simulation was performed to investigate the effect of sintering on the changes in microstructure, porosity, and pore distribution of thermal barrier coating layers synthesized by electron beam physical vapor deposition. First, the simulation well expressed the characteristic porous structures such as columnar and featherlike structures, which were fabricated under the condition of substrate rotation. Secondly, the sintering of such a porous structure by high-temperature annealing could be demonstrated using the simulation. The microstructure of the layer close to the substrate surface shows fine grains and pores, suggesting ease of sintering and grain growth, which is clearly demonstrated from the experimental results of the yttria-stabilized zirconia layer deposited by electron beam physical vapor deposition. The simulation also reveals the sintering behavior of the porous including heterogeneous structure and pore distribution. By introducing a small sintering step to the deposition process during the simulation, the experimental values of the porosity observed in the layers could be successfully explained. The doubled effects of sintering on porosity during both deposition and exposure to high temperature environment enhanced the heterogeneity of the microstructures of the layers. [ABSTRACT FROM AUTHOR]

The present study examines a microplate with a porous structure and two nanocomposite piezoelectric layers. All the layers' properties are graded functionally, bonded to each other, and supported by an elastic foundation that can withstand both normal and shear loads. Additionally, carbon nanotubes are used to increase the electro-mechanical performance of the piezoelectric patches, which are exposed to an externally applied electric voltage. Using a higher-order trigonometric shear deformation theory and von Karman's assumptions, the kinematic relations are demonstrated. The governing motion equations are derived using Hamilton's principle and variational technique, and the modified couple stress theory is employed to take the scale effect into account. An analytical method based on Fourier series functions is used to solve the differential motion equations, and the impact of diverse factors such as porosity percentage, pore distribution patterns, carbon nanotubes distribution patterns, and other key parameters on the normalized frequencies of the model is analyzed after verifying the accuracy of the results. The findings of this research may aid in the development and production of smart structures and devices with increased efficiency. [ABSTRACT FROM AUTHOR]

With the growing interest in additive manufacturing technology, assessing the biocompatibility of manufactured elements for medical and veterinary applications has become crucial. This study aimed to investigate the corrosion properties and cytotoxicity of porous structures designed to enhance the osseointegration potential of implant surfaces. The structures were fabricated using BJ technology from 316L stainless steel powder, and their surfaces were modified with a DLC coating. The studies carried out on porous metal samples with and without DLC coatings demonstrated low cytotoxicity. However, no significant differences were found between the uncoated and DLC-coated samples, likely due to variations in the thickness of the coating on the porous samples and the occurrence of mechanical damage. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the rapidly developing field of biomedical research, the search for new materials with improved properties is crucial to moving the entire field forward. Double phosphates have generated significant interest in a wide range of applications, ranging from drug delivery systems to catalysts for biomedical reactions, and the fields of biomedicine and tissue engineering are no exception. In this article, we propose a method for finding new double phosphate materials, which is based on machine learning, screening, and applying data from structural databases, and use this methodology combined with chemical knowledge to propose several promising materials for bone tissue engineering. For the selected candidates, we develop a solid-phase synthesis procedure and apply their physical characteristics to confirm the results. In addition, the role of morphology, that is, the porosity of frameworks based on these materials, is discussed from a biomedical point of view, and several synthetic ways to adjust this parameter are proposed and investigated. [ABSTRACT FROM AUTHOR]

The aim of this work was to design, print, and examine elastic properties of porous structures with various parameters and beam distributions. These structures, generated using an algorithm, featured three types of lattices: octet, cubic, and Voronoi diagram-based, with different porosities (40 %, 60 %, 80 %) and beam sizes (0.45 mm, 0.66 mm). They were printed using Direct Light Processing and examined using X-ray computed microtomography. Compression tests were conducted to determine the Young’s modulus. The results were compared with computer simulations performed using Abaqus. The tools used, such as 3D printing and X-ray computed microtomography, were described, and the results and conclusions of the tests were presented. As a result, comparable outcomes were obtained for structures with higher beam diameter, while significantly different results were observed for structures with lower beam diameter.

The field of orthopaedic implants has experienced significant advancements in recent years, transforming the approach to orthopaedic treatments. Amongst these advancements, porous structures have emerged as a promising solution to address the limitations of traditional solid implants. This comprehensive review paper offers a thorough overview of the importance of advanced porous hip implants, focusing on three key areas bone morphology and biomechanical parameters, complications associated with solid implants, and the benefits of porous structures and porous implants.Understanding the intricate interplay between bone morphology and biomechanical parameters is crucial when designing orthopaedic implants. Mimicking the native bone structure ensures optimal osseointegration, load distribution, and long-term success. Porous implants closely resemble natural bone structures, facilitating improved integration and biomechanical compatibility.Complications with solid implants are a significant concern in orthopaedic procedures. Stress shielding, cortical hypertrophy, and micromotion can lead to implant failure or revision surgeries. By contrast, porous structures promise to mitigate these issues by promoting bone ingrowth, reducing stress concentrations, and providing stability at the bone-implant interface.The benefits of porous structures and porous implants go beyond addressing solid implant complications. These structures enhance bone in-growth potential, strengthening integration and long-term stability. The interconnected porosity promotes nutrient diffusion and new blood vessel formation, supporting healing and minimizing infection risk.Furthermore, porous implants exhibit improved mechanical properties, such as lower elastic modulus and higher energy absorption, that better match those of bone. This feature helps alleviate stress shielding and enhances the overall performance and longevity of the implant.In conclusion, advanced porous implants have tremendous potential in orthopaedics. By closely mimicking native bone structure and reducing complications associated with solid implants, they can revolutionize orthopaedic treatments. Further research and development are warranted to fully exploit the potential of these innovative solutions and improve patient outcomes.

Solid titanium alloys are extensively employed in orthopedic applications due to their reliable mechanical strength, but the stress shielding phenomenon caused by its high elastic modulus and the disadvantage of lack of bone integration may lead to clinical complications. The design of porous structure is a feasible approach to reduce the elastic modulus and promote bone and vascular ingrowth. This paper reviewed the application and current challenges of solid titanium implants in orthopedics. To address the drawbacks and explore porous titanium implants that can effectively integrate with bone tissue while possessing sufficient mechanical strength, this review discussed the latest preclinical research from the perspectives of structural design, surface modification, and material composition. The porous structure parameters that affect bone ingrowth and mechanical strength in implants, including porosity, pore size, cellular structure, and gradient structure, were presented. Based on the current research progress, various surface modification techniques aimed at enhancing the performance of porous titanium implants were overviewed. Moreover, a range of titanium alloys including nickel-titanium alloy, β-titanium alloy, high-entropy alloy, and composite alloys are investigated for their prospective applications in orthopedics. Overall, this review provided valuable insights into the current state of research and highlighted the potential of porous titanium alloys in improving clinical outcomes in orthopedics.

For the first time, the S-doped g-C 3 N 4 nanostructures (SCN(x)) were prepared by the reflux method as an aqueous-based method with different weight ratios of Na 2 S (x) and then characterized. The results of S-doped g-C 3 N 4 nanostructures confirmed the presence of sulfur doping in the g-C 3 N 4 structure. Moreover, these nanostructures showed superior photocatalytic efficiency compared to the bulk g-C 3 N 4. Among different SCN(x) nanostructures, SCN(0.2) showed the most remarkable photocatalytic performance. This outcome is attributed to a decrease in the band gap of this sample. The FESEM analysis indicated that the nanoparticles tended to adhere together in SCN(0.2) nanostructure. This phenomenon has led to the reduction of surface roughness, and improving the surface texture quality of this nanostructure. On the other hand, the lowest FWHM and PL peak intensity show an increase in crystallinity and a decrease in the amount of recombination in this nanostructure. Moreover, the evaluation of electrochemical impedance and optical current showed a decrease in the semi-circular pattern and an increase in photocurrent for the optimal sample of SCN (0.2) compared to the bulk g-C 3 N 4. Therefore, the results of investigating the photocatalytic performance of the synthesized nanostructures show that the SCN(x) nanostructures have higher efficiency compared to the bulk g-C 3 N 4. In addition, the SCN(0.2)) sample showed the highest photocatalytic efficiency. Compared to the other conventional deposition methods based on electrostatic or van der Waals forces, this study suggests that using the reflux technique to substitute sulfur in the g-C 3 N 4 can be a successful approach due to the chemical bonding on to host framework. Moreover, this method may provide a facile aqueous-based route for doping in the g-C 3 N 4 layered structure and can offer advantages compared to other common method such as simple, low cost, excellent distribution uniformity, fast reaction kinetics, high levels of purity, and environmentally friendly process. [ABSTRACT FROM AUTHOR]

In this paper, porous single-crystal diamond with boron doping were synthesized by adding TiB 2 to the Fe–Ni–C system at a pressure of 5.6 GPa and a temperature of 1360 °C. The boron and nitrogen impurities were investigated in depth along with the surface defects of the diamonds. The results indicate that when the TiB 2 content was within the range of 0–10 wt%, an increase in the doping concentration of TiB 2 can lead to a decrease in the nitrogen content and an increase in the boron content in the diamond, causing the crystal color to transition from yellow to pale yellow, pale yellow-blue, and black. When the TiB 2 content was within the range of 20–40 wt%, several triangular concave porous structures appeared on the crystal surface. With an increase in the TiB 2 addition, the side length of these triangular pits decreased from 2.85 μm to 1.09 μm, while their depth decreased from 590 nm to 50 nm. The roughness of the crystal surface measured by Rq demonstrated values up to 145.302 nm. The results indicate that the size, depth, and density of the triangular defects can be adjusted by the amount of additive TiB 2. Our findings provide insights into the surface regulation and functionalization of boron-doped diamond single crystals. [ABSTRACT FROM AUTHOR]

Recently, vigorous progress is made in the selective and high‐current reduction of carbon dioxide (CO2) to ethylene (C2H4) by using a flow cell. In most cases, however, the reduction is only achieved in strong alkaline electrolytes, which results in substantial deactivation of electrocatalysts due to the accumulation of precipitates. Here, porous Cu nanowires (NWs) is prepared with abundant atomic defects, which create a synergy with the pore‐induced electric field to comprehensively tune the local microenvironment of the electrode surface, thus enabling efficient and stable C2H4 production from the CO2 reduction reaction (CO2RR) in neutral media. In particular, the enhanced electric field effect increases the local K+ concentration for the generation of *CO intermediates; while the atomic defects stabilize OH− and *CO, leading to high local pH and *CO coverage. Such synergy can provide a favorable local environment and high *CO coverage for significantly decreasing the energy barrier of the C─C coupling step. Consequently, a large partial C2H4 current density of 222.3 mA cm−2 with excellent stability is achieved in a neutral electrolyte. Altogether, this work paves new pathways to promote C2H4 production in the neutral CO2RR through multiple tuning of the local environment. [ABSTRACT FROM AUTHOR]

Low back pain is among the main issues in vertebral orthopaedics. Intervertebral disk degeneration can be severe, up to requiring the replacement of the damaged disk by substitutes to achieve spine fusion. Disk removal results in critical size defects, so fusion does not occur naturally, but synthetic bone grafts are needed. Since the surgical procedure is time‐consuming, high infection rates occur. Hence, in spine fusion, bone regeneration enhancement and infection prevention are needed. Here, a new dual‐component system is proposed, to tackle both issues at one time. To enable spine fusion, 3D extrusion‐based printing is employed to develop coherent custom magnesium phosphate (CaMgP)‐based cages. The 3D‐printed scaffolds are hardened, and the structural properties are evaluated to be within the ranges of physiological bone. To prevent infection, an in‐house ice‐templating device is employed in combination with a 3D‐printed ceramic scaffold, to develop tailored porous alginate structures loaded with vancomycin. Results show that CaMgP can be printed into complex geometries and that the geometry influences the pore orientation during ice‐templating. These structures loaded with vancomycin have antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) strains. [ABSTRACT FROM AUTHOR]

Conducting polymers (CPs) possess the intrinsic attractive properties of conventional polymers, coupled with unique electronic characteristics reminiscent of metals or semiconductors. Nanostructured CPs have recently gained significant interest for their distinct advantages over bulk counterparts. They demonstrate potential applications in energy storage devices, sensors, and catalysts, attributed to their large surface areas and shortened charge transport paths. A crucial structural aspect in this context includes introducing porous morphologies into CPs, and enhancing their functionality through interconnected channels. In this review, various synthetic methods of nanostructured CPs are introduced, emphasizing two‐dimensional (2D) configurations. The primary objective is to achieve high‐performance devices with highly organized stacking of conjugated backbones. Particular attention is placed on integrating 2D structures and porous morphologies into CPs through ice‐assisted methods and interfacial synthesis. The review also highlights successful applications of porous 2D CPs in practical devices and explores insights into future developments in the porous CPs field. [ABSTRACT FROM AUTHOR]

Understanding the transport of point source solutes across the sediment–water interface (SWI) is important for the protection of river environments. Conventional coupled models assume the porous media layer as Darcy's laminar flow and therefore cannot accurately capture the transport processes within the porous media. Furthermore, the effect of the porous structure of the riverbed on the transport process is largely unknown. In this study, we performed pore-scale numerical simulations of point source solutes transport across the SWI to investigate the effects of different porous structures in the riverbed on flow and point source dispersion. By solving the Reynolds-averaged Navier–Stokes equations with the k–ω shear stress transport turbulence closure model, we determine the complex flow field information and the spatial distribution of point source solutes for the coupled model. The results indicate that the presence of porous structures creates recirculation zones in the coupled model, which prevents turbulent structures reaching deeper layers. Random porous structures induce more preferential flow, inhibit the formation of recirculation zones, and exhibit higher solute dispersion, which is directly related to turbulent solute fluxes. Furthermore, our study reveals that the release position of point sources significantly influences the distribution of solute concentrations within the porous bed. HIGHLIGHTS The influence of porous structures on flow and point source dispersion is elucidated within a coupled system of overlying water and porous media.; Random porous structures will induce more preferential flow and accelerate solute transport.; The presence of preferential flow inhibits the formation of recirculation zones.; Turbulent solute flux explains the wider distribution of random porous structures.;

Porous structures by additive manufacturing have fascinating and compelling performance compared with solid structures. The stress‐related porous infill designs which could greatly mitigate the effects of the intrinsic high residual stress in additive manufacturing process have gained increasing attention. In the current work, we propose a promising Isogeometric Topology Optimization (ITO) method for porous infill structures with stress minimization to avoid the occurrence of stress concentrations in additive manufacturing. The IsoGeometric Analysis (IGA) and induced p‐norm aggregation are utilized to develop a stress‐minimization topology description model for infill design, which can remove the mesh dependency and offer benefits for improving numerical accuracy and convergence stability. We also introduced global volume constraints to easily control the usage of material and eliminate the over‐fine structures affecting the printing accuracy. Several numerical examples are performed to demonstrate the effectiveness and advantages of the proposed ITO method on porous infill designs with stress minimization. The laser powder bed fusion (LPBF) technique is employed to fabricate several prototypes, and the performance are evaluated by experiments. The advancements of our work are demonstrated effectively, which is adapted for additive manufacturing and practical application. [ABSTRACT FROM AUTHOR]

Polymer-based (nano)composite foams containing conductive (nano)fillers limit electromagnetic interference (EMI) pollution, and have been shown to act as good shielding materials in electronic devices. However, due to their high (micro)structural complexity, there is still a great deal to learn about the shielding mechanisms in these materials; understanding this is necessary to study the relationship between the properties of the microstructure and the porous structure, especially their EMI shielding efficiency (EMI SE). Targeting and controlling the electrical conductivity through a controlled distribution of conductive nanofillers are two of the main objectives when combining foaming with the addition of nanofillers; to achieve this, both single or combined nanofillers (nanohybrids) are used (as there is a direct relationship between electrical conductivity and EMI SE), as are the main shielding mechanisms working on the foams (which are expected to be absorption-dominated). The present review considers the most significant developments over the last three years concerning polymer-based foams containing conductive nanofillers, especially carbon-based nanofillers, as well as other porous structures created using new technologies such as 3D printing for EMI shielding applications. It starts by detailing the microcellular foaming strategy, which develops polymer foams with enhanced EMI shielding, and it particularly focuses on technologies using supercritical CO2 (sCO2). It also notes the use of polymer foams as templates to prepare carbon foams with high EMI shielding performances for high temperature applications, as well as a recent strategy which combines different functional (nano)fillers to create nanohybrids. This review also explains the control and selective distribution of the nanofillers, which favor an effective conductive network formation, which thus promotes the enhancement of the EMI SE. The recent use of computational approaches to tailor the EMI shielding properties are given, as are new possibilities for creating components with varied porous structures using the abovementioned materials and 3D printing. Finally, future perspectives are discussed. [ABSTRACT FROM AUTHOR]

Lattice and gyroid structures are often subjected to additive technologies to produce various types of products, and the current market has a number of 3D printers that can be used for their production. The quality of the products produced in this way can be assessed on the basis of technical parameters and the filament used. Such an approach, however, is insufficient. In terms of quality, other product parameters need to be assessed, such as the surface texture and the internal structure's porosity. For such an assessment, we can use the industrial tomography method and the method of roughness measurement via an optical microscope. The paper presents research on the assessment of the surface texture and porosity in lattice and gyroid structures. For the research, two types of test specimens—a specimen with a lattice structure and a specimen with a gyroid structure—were prepared. The obtained results proved that the 3D printing technology directly impacted the surface texture and porosity. For experimental specimens produced by SLS technology, we found that it was very important to carefully remove the excess powder, as unremoved powder can significantly affect the porosity results. For specimens produced by FDM technology, the research confirmed that some "gaps" between the layers were not pores but defects created during specimen production. When analyzing the surface using the Alicon Infinite G5 optical microscope, we found that the measured roughness results were directly impacted by the specimen's surface color, the structure's geometry, and the ambient light, which was confirmed by a red lattice experimental specimen, the surface of which could not be scanned. Based on the above, it can be stated that the selection of 3D technology for additive production needs must be given adequate attention regarding the quality of the created structures and textures. [ABSTRACT FROM AUTHOR]

As a waste derivative, glass fiber has drawn a lot of interest from the engineering community. The purpose of this study was to use glass fiber to improve the performance of defective gypsum boards. Single compression experiments, repeated loading experiments, and scanning electron microscopy (SEM) testing were performed on defective gypsum boards. The results showed that the addition of glass fiber can improve the compressive strength of defective gypsum boards. When the fiber concentration is 1.5%, the strength of single-hole gypsum boards increases by 77.1%. Energy evolution and residual strain evaluation after repeated loading showed the significant reinforcement of the dual-hole gypsum board samples with the addition of glass fiber, improving the stress distribution and elasticity, which was confirmed using damage factor analysis. Glass fibers reduce stress concentrations, improve integrity, and prevent brittle failure, especially at high stress levels. The microstructural analysis showed that the addition of glass fiber improves adhesion and prevents microcracking while acting as a stress transfer bridge, enhancing the behavior of the specimen under cyclic loading. Based on the experimental results and cost, 1.5% glass fiber is the optimal concentration. The research results provide new ideas for the application of glass fiber in defective and brittle materials and contribute toward the sustainable development of the construction industry. [ABSTRACT FROM AUTHOR]

Biodegradable metals have gained attention in the field of bone repair, to be used as temporary bone implants. Among those metals, iron shows good biocompatibility properties, but has high stiffness when compared to bone and exhibits a low degradation rate. There are several approaches that may be applied to overcome those disadvantages. Porous materials have become important in the design of bone substitutes, since the porosity allows for a decrease in strength and for an increase in the degradation rate, due to their high surface areas. The aim of this work is to develop iron porous structures that lead to a mechanical and corrosion performance adequate for temporary implants. Three types of structures, with different relative densities and geometries, were studied: porous graded, cellular graded truss-lattices and a sort of random distribution of pores. The mechanical properties were evaluated through a finite-element analysis using the software NX Nastran. The degradation behaviour of the iron porous samples in a simulated body fluid environment was simulated using the software COMSOL. Results show that both mechanical and corrosion properties depend on the relative density and on the arrangement of pores. Moreover, structures with low relative density exhibit compressive strength values similar to the ones of human trabecular bone, showing degradation rates in the range established for ideal bone substitutes. This means that it is possible to match the iron properties to the ones required for biodegradable devices, by choosing adequate porous arrangements that tailor the mechanical and the corrosion behaviour. [ABSTRACT FROM AUTHOR]

This paper aims to propose a topology optimization method on generating porous structures comprising multiple materials. The mathematical optimization formulation is established under the constraints of individual volume fraction of constituent phase or total mass, as well as the local volume fraction of all phases. The original optimization problem with numerous constraints is converted into a box-constrained optimization problem by incorporating all constraints to the augmented Lagrangian function, avoiding the parameter dependence in the conventional aggregation process. Furthermore, the local volume percentage can be precisely satisfied. The effects including the global mass bound, the influence radius and local volume percentage on final designs are exploited through numerical examples. The numerical results also reveal that porous structures keep a balance between the bulk design and periodic design in terms of the resulting compliance. All results, including those for irregular structures and multiple volume fraction constraints, demonstrate that the proposed method can provide an efficient solution for multiple material infill structures. [ABSTRACT FROM AUTHOR]

Fiber solar cells can be woven into textiles to effectively supply electricity for wearables and have attracted increasing interests in the past decade. However, achieving high power conversion efficiencies in real‐world applications remains a significant challenge for power supply textiles. Here a unique hybrid counter electrode made from metal current collector fiber with high electrical conductivity, aligned carbon nanotube sheet with high electrocatalytic property, and porous titanium dioxide/poly(vinylidene fluoride‐co‐hexafluoropropylene) film with high light reflectance is designed. For the resulting fiber dye‐sensitized solar cell, a rapid charge collection and transport are achieved, and the unique advantage of absorbing light from all directions is effectively realized, producing a record power conversion efficiency of 12.52%. The power conversion efficiency varies below 10% after bending, twisting, or pressing for 1000 cycles. These fiber dye‐sensitized solar cells are further integrated with fiber batteries as power systems for a smart bracelet, demonstrating the effective power solution for wearables. [ABSTRACT FROM AUTHOR]

With an increasing interest in fabricating complex structures in architectural design, the concept of porosity has become a vital topic, opening up new avenues for tectonic thinking and functional demands in architecture. Porous structures typically consist of minute interstices or modular structural grids that allow fluids to pass through and are typically present on a micro scale. By adopting a biomimetic approach, which moves from the micro to the macro scale, the application of digital tools has enabled the design of functional building elements. For example, the 30 St Mary Axe tower by Foster and Partners imitates the shape and porosity of a Venus Flower Basket Sponge, resulting in enhanced endurance capabilities. Furthermore, porous structures can improve the building's thermal, light, and air circulation conditions. However, porous structures have a highly complex topology that poses a challenge for the fabrication process, and is primarily limited to 3D printing and CNC milling manufacturing approaches, with the addition of casting and chemical processes depending on the material. In this research, we propose a novel design and manufacturing approach for porous structure fabrication that uses a hot knife tool with an industrial robot to cut expanded polystyrene materials. This approach offers a faster and more efficient way to fabricate porous structures than additive or milling techniques, with an integrated design approach that enables a range of design scenarios to be explored. Additionally, our method provides hands-on experience and practical testing of a large-scale prototype. [ABSTRACT FROM AUTHOR]

The design of biomimetic porous scaffolds has been gaining attention in the biomedical sector lately. Shells, marine sponges, shark teeth, cancellous bone, sea urchin spine, and the armadillo armor structure are examples of biological systems that have already been studied to drive the design of innovative, porous, and multifunctional structures. Among these, triply periodic minimal surfaces (TPMSs) have attracted the attention of scientists for the fabrication of biomimetic porous scaffolds. The interest stems from their outstanding properties, which include mathematical controllable geometry features, highly interconnected porous architectures, high surface area to volume ratio, less stress concentration, tunable mechanical properties, and increased permeability. All these distinguishing features enable better cell adhesion, optimal integration to the surrounding tissue avoiding stress shieldings, a good permeability of fluid media and oxygen, and the possibility of vascularization. However, the sophisticated geometry of these TPMS-based structures has proven challenging to fabricate by conventional methods. The emergence of additive manufacturing (AM) and the enhanced manufacturing freedoms and flexibility it guarantees could solve some of the bottlenecks, thus leading to a surge of interest in designing and fabricating such structures in this field. Also, the feasibility of using AM technologies allows for obtaining size programmable TPMS printable in various materials, from polymers to metal alloys. Here, a comprehensive overview of 3D-printed TPMS porous structures is provided from a design for additive manufacturing (DfAM) and application perspective. First, design strategies, geometry design algorithms, and related topological optimization are introduced according to diverse requirements. Based on that, the performance control of TPMS and the pros and cons of the different AM processes for fabricating TPMS scaffolds are summarized. Lastly, practical applications of 3D-printed biomimetic TPMS porous structures for the biomedical field are presented to clarify the advantages and potential of such structures.

Additive manufacturing (AM) can be used to fabricate heat pipes and two-phase heat sinks which have integrated wicking structures. These devices can be customized and have superior performance when compared with devices with conventionally fabricated wicks. The current work investigates the impact of build rate on the capillary performance of AM wicks fabricated by laser powder bed fusion (LPBF). The build rate was examined by varying the layer thickness from 30 µm to 80 µm for four different strut-based wick geometries: (i) body-centered cubic (BCC), (ii) face-centered cubic (FCC), (iii) simple cubic (SC), and (iv) fluorite. The mass rate-of-rise method was used to quantify the wick hydraulic parameters (namely wick permeability, K, and effective pore radius, reff). Layer thickness has a significant influence on wick permeability; layer thickness of 40 µm result in the highest value for all configurations but have a small effect on the effective pore radius. Layer thickness of 40 µm and 60 µm reached the highest K/reff ratio, primarily because of the permeability increase. We attribute this to poor build quality such as missing struts and less defined edges which facilitate low resistance to fluid flow. The SC 60 and BCC 40 configurations achieved the maximum capillary performance with K/reff of 1.34 µm and 1.42 µm, respectively. Overall, it was found that while increasing the build rate by varying layer thickness may affect the part build quality, it promotes hydraulic performance for some configurations by creating random rough surface morphologies and arteries, which help increase permeability.

Recently, bioabsorbable vascular stents (BVSs) are actively studied owing to their ability to dissolve within the human body. However, despite their advantages, BVSs often dislodge from the expandable balloon‐based delivery system when transported to the lesion site. In this study, a novel methodology aiming at increasing the retention force between the stent and the delivery system is presented. The breath‐figure method is adopted to form a porous structure and enhance adhesion. Additionally, numerical and experimental methods are used to evaluate the effect of surface tension between two immiscible fluids (polymeric solutions and droplets). To control the interfacial tension between the solution and droplets, an amphiphilic polymer and NaCl‐added vapor are used. By selecting the appropriate parameters, a sponge‐like structure is prepared on the stent delivery system. To verify its applicability, the two types of structures presented in this study are experimentally compared. These findings provide valuable guidelines for understanding the mechanism of breath‐figure patterns. Thus, the innovative methodology developed in this study demonstrates simplicity and scalability for large‐area production, making it potentially applicable to industrial technologies and offering new insights into biomedical engineering. [ABSTRACT FROM AUTHOR]

Low-temperature post oxidation annealing of 4H-SiC at 900 °C for 90 min after photoelectric chemical (PEC) etching in alkaline solution can eliminate the porous structures that form during the etching process, reduce the porosity, and optimize the surface morphology, which has minimal effect on unetched surfaces, allowing for selective treatment between etched and unetched surfaces. Additionally, it can improve the etching depth and enable effective repetition of the etching process. These benefits make PEC etching a valuable technique for microstructure fabrication and surface treatment. [ABSTRACT FROM AUTHOR]

Metallic sulfide anodes show great promise for sodium‐ion batteries due to their high theoretic capacities. However, their practical application is greatly hampered by poor electrochemical performance because of the large volume expansion of the sulfides and the sluggish kinetics of the Na+ ions. Herein, a porous bimetallic sulfide of the SnS/Sb2S3 heterostructure is constructed that is encapsulated in the sulfur and nitrogen codoped carbon matrix (SnS/Sb2S3@SNC) by a facile and scalable method. The porous structure can provide void space to alleviate the volume expansion upon cycling, guaranteeing excellent structural stability. The unique heterostructure and the S, N codoped carbon matrix together facilitate fast‐charge transport to improve reaction kinetics. Benefitting from these merits, the SnS/Sb2S3@SNC electrode exhibits high capacities of 425 mA h g−1 at 200 mA g−1 after 100 cycles, and 302 mA h g−1 at 500 mA g−1 after 400 cycles. Moreover, the SnS/Sb2S3@SNC anode shows an outstanding rate performance with a capacity of over 200 mA h g−1 at a high current density of 5000 mA g−1. This study provides a new strategy and insight into the design of electrode materials with the potential for the practical realization and applications of next‐generation batteries. [ABSTRACT FROM AUTHOR]

In this study, glucan 1,4‐α‐maltotriohydrolase (AMTS) is used to modify corn starch granules to elucidate the structural and physical property changes following AMTS modification. The degree of hydrolysis (DH) of granular corn starch is modulated by adding various amounts of AMTS. Pore structures with more pores, deep channels, and cavities in starch granules with extended hydrolysis are observed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The short‐range ordered structure, lamellar structure, and crystalline structure are significantly enhanced under moderate AMTS modification, and then slightly decreased with further modification. These structural changes significantly improve oil and water absorption capacities, decrease solubility and swelling power, diminish pasting properties, and lower the digestibility of granular corn starch. When AMTS interferes with the starch system, the specific surface area of granular starch gradually increases with extended hydrolysis, with the maximum being almost 4.6‐fold that of native starch. All these results suggest AMTS hydrolysises of corn starch granules through an "inside‐out" pattern, preferential hydrolysis of the amorphous region, and subsequent alternate hydrolysis of the amorphous and crystalline regions. Overall, AMTS is a potential granular starch hydrolase for producing porous starch used as the carrier material in a variety of food applications. [ABSTRACT FROM AUTHOR]

Cobalt‐based compounds have been extensively studied due to their relatively high theoretical capacity as anode materials for sodium‐ion batteries (SIBs). However, the requirement for strong conductivity and excellent cycling stability is still an urgent challenge for the energy‐storage system. To address these problems, metal–organic‐framework‐74‐derived porous rod‐shaped nanostructure Co/C materials are designed as advanced anode materials for SIBs, which is beneficial for the reaction kinetics of SIBs. Moreover, the efficient synergistic utility of the nanostructure and the rich mesopores of Co/C materials provides the ion‐diffusion paths and active sites for the transfer and storage of Na+, which contributes to the energy‐storage ability. The indurative structure of the carbonization electrode material can alleviate the influence of volume change due to Na+ insertion/extraction. Therefore, the Co/C anode exhibits a high Coulombic efficiency of 94.3% at 0.1 A g−1. After 300 cycles, the Na+‐storage capacity is 200.4 mAh g−1, and the Coulombic efficiency is 99.0%, where the capacity retention rate is up to 88.2%. Herein, insight is provided into the role of porous Co/C material in improving the kinetics of Na+ reaction, supplying an effective strategy for the rational design of key materials for high‐performance rechargeable batteries. [ABSTRACT FROM AUTHOR]

The porous structure design of implants can not only obtain a more lightweight implant but also provide more space for its cell growth. The technology development of additive manufacturing (AM) offers an effective way for customized porous implants. To explore the suitable porous titanium bone implants made by AM, this paper reviews the research progress in the designing and manufacturing performance of porous titanium alloy implants, which are manufactured by AM. The design parameters that affect the bone ingrowth performance are analyzed, including the porosity, shape, and aperture of the pore. Based on the current technology trend, the future development of bone implants in advanced multi-materials, design methods, and post-treatment methods is prospected.

Metallic sulfide anodes show great promise for sodium‐ion batteries due to their high theoretic capacities. However, their practical application is greatly hampered by poor electrochemical performance because of the large volume expansion of the sulfides and the sluggish kinetics of the Na+ ions. Herein, a porous bimetallic sulfide of the SnS/Sb2S3 heterostructure is constructed that is encapsulated in the sulfur and nitrogen codoped carbon matrix (SnS/Sb2S3@SNC) by a facile and scalable method. The porous structure can provide void space to alleviate the volume expansion upon cycling, guaranteeing excellent structural stability. The unique heterostructure and the S, N codoped carbon matrix together facilitate fast‐charge transport to improve reaction kinetics. Benefitting from these merits, the SnS/Sb2S3@SNC electrode exhibits high capacities of 425 mA h g−1 at 200 mA g−1 after 100 cycles, and 302 mA h g−1 at 500 mA g−1 after 400 cycles. Moreover, the SnS/Sb2S3@SNC anode shows an outstanding rate performance with a capacity of over 200 mA h g−1 at a high current density of 5000 mA g−1. This study provides a new strategy and insight into the design of electrode materials with the potential for the practical realization and applications of next‐generation batteries.

Spreading the formic acid (HCOOH) fuel cells demands a better anode electrocatalyst for the oxidation of formic acid. The catalytic efficiency of platinum (Pt)– the only choice of practicability, is mainly limited by its intrinsic affinity to CO, thus desiring a proper release. Herein, theoretical calculations are first leveraged to find that the introduction of iridium (Ir) can facilitate HCOOH oxidation with robust CO tolerance through a dehydrogenation pathway. Then, this strategy experimentally by designing a new trimetallic catalyst of 2D porous PtIrBi nanoplates (p‐PtIrBi NPs) is implemented. The optimized p‐PtIrBi NPs/C exhibits a very high mass activity of 8.2 A mg−1pt and a high retention rate of 55.9% after the durability test, which is among the best formic acid oxidation catalysts reported to date, much higher than those of PtIrBi NPs/C, PtBi NPs/C, and Pt/C. The CO‐stripping and in situ Fourier transform infrared (FTIR) experiments collectively evidence that two types of due site, i.e., "Pt‐Bi" and "Ir‐Bi", endow the catalyst with suppressed CO‐poisoning property to achieve super‐high activity and stability for formic acid oxidation reaction. [ABSTRACT FROM AUTHOR]

Compliant pressure sensors are a key technology for wearable electronics and haptic interfaces. Making transistors pressure‐sensitive provides an opportunity to combine sensing and matrix readout characteristics. However, there is typically a trade‐off in pressure sensitivity, complexity of fabrication, and mechanical resilience. To overcome these challenges, an all solution‐processed kirigami‐inspired stretchable organic thin film transistor (OTFT) based pressure sensor array is introduced. The OTFTs integrate several novel processing and design strategies that include electrohydrodynamic (EHD) jet‐printed Ag nanowire (NW) electrodes that are partially embedded in a polyimide (PI) matrix. The EHD printing provides fine pattern control and the NW/PI composite improves mechanical stability. The OTFTs are made pressure sensitive by employing a porous styrene‐ethylene‐butylene‐styrene gate dielectric achieved using a breath figure method. The pore density can be controlled to achieve tunable pressure sensitivity. The OTFTs are shown to maintain performance under a small bending radius (1 mm) and can sense applied pressure from 0.75 to 25 kPa. Finally, a cut pattern is introduced into the substrate that imparts stretchability while maintaining pressure sensor functionality. The integration of the design features and processing methods introduced in this work enables mechanically resilient stretchable pressure sensors. [ABSTRACT FROM AUTHOR]

A new phenomenological model for lattice structures that exhibit crushing‐like failure mechanisms is presented. The model estimates the compressive stress–strain curves of such lattices based on their relative density. The model is derived from the underdamped oscillator's general equation and the rheological model's properties. The model applicability is tested on five circular cell lattice structures having various relative densities, as well as a body‐centered‐cubic and a square cell lattice, for further validation. The model accurately captures the curves' profile qualitatively and quantitatively compared with the experimental data. A relationship between each parameter and the relative density is established to extend the model's functionality as fourth‐order polynomial equations. Additionally, the energy absorption values between the measured data and the model up to the crushing of the first layer are in relatively good agreement ranging between 2.68% and 25.3%, proving the model's effectiveness. Overall, the new phenomenological model can estimate essential features of the lattice structures based solely on the relative density while reducing the time and the cost needed during the design phase. [ABSTRACT FROM AUTHOR]

As a means of harvesting solar energy for water treatment, solar-driven vapor generation is becoming more appealing. Due to their entangled fibrous networks and high surface area, fibers can be used as building blocks to generate water vapor. In this paper, using a two-dimensional fiber bundle model, we studied the generation of solar vapor based on the fiber height, distance between fibers, and input sun radiation. The performance of solar absorption system was also evaluated by evaluating thermal and water management. Results showed a constant increase in solar vapor generation with an increasing fiber height and decreasing inter-fiber distance. However, the gain rate of using taller and more densely packed fiber bundles dwindled quickly. On the other hand, a shorter fiber hadahigher evaporation rate per fiber height. The distance betweenfibershadanonlinear effectonthe fiberbundle evaporation rate. A new fiber bundle design was recommended with a fiber height of 15-20 mm and an inter-fiber distance of 1.5 mm. The results of this study can provide guidelines for future fiber bundle designs with increased efficiency, reduced cost, and versatile applications (i.e., desalination, water purification, and power generation). [ABSTRACT FROM AUTHOR]

Emulsion-based systems that combine natural polymers with vegetable oils have been identified as a promising research avenue for developing structures with potential for biomedical applications. Herein, chitosan (CHT), a natural polymer, and virgin coconut oil (VCO), a resource obtained from coconut kernels, were combined to create an emulsion system. Phytantriol-based cubosomes encapsulating sodium diclofenac, an anti-inflammatory drug, were further dispersed into CHT/VCO- based emulsion. Then, the emulsions were frozen and freeze-dried to produce scaffolds. The scaffolds had a porous structure ranging from 20.4 to 73.4 µm, a high swelling ability (up to 900%) in PBS, and adequate stiffness, notably in the presence of cubosomes. Moreover, a well-sustained release of the entrapped diclofenac in the cubosomes into the CHT/VCO-based system, with an accumulated release of 45 ± 2%, was confirmed in PBS, compared to free diclofenac dispersed (80 ± 4%) into CHT/VCO-based structures. Overall, the present approach opens up new avenues for designing porous biomaterials for drug delivery through a sustainable pathway. [ABSTRACT FROM AUTHOR]

As one of the most electrochemical energy storage devices, lithium‐ion batteries (LIBs) remain the workhorse of the energy market due to their unparalleled advantages. Remarkably, Si‐based materials play a pivotal role in LIBs anodes owing to ultrahigh theoretical capacity of Si and rich natural resources. However, bulk silicon materials are difficult to meet the current commercial demand because of their low conductivity, sluggish reaction kinetics, and huge volume expansion. The construction of porous structures has been acknowledged as an effective way to solve the above issues. Herein, the delicate design of porous Si‐based anode materials including synthetic strategies, the engineering of surface morphology and micro/nano‐structure, and the regulation of different compositions, as well as their applications in LIBs is systematically summarized. Particularly, the fine engineering of different pore parameters for Si‐based materials is on focus. Importantly, the relationship between thick electrodes and tortuosity/porosity, and the structural effect between pores and battery performance are also discussed in depth. Finally, the applications of porous Si‐based anodes in full‐cells and their commercial achievements are briefly described. This review is expected to provide a basic understanding and deep insight into developing porous Si‐based anodes for high‐energy lithium storage. [ABSTRACT FROM AUTHOR]