Search

Transparent flexible display devices have attracted massive attention in recent years owing to their practical applications that can be compatibly adapted to human demand and technological development. Worldwide researchers have studied flexible transparent thin film transistors (TFTs) to qualify them for the backplane component of future transparent and flexible displays. Simplifying the fabrication process of a TFT can be considered a critical need for reducing consumed cost, time, toxic chemicals. In this study, sputtering was utilized as a major fabrication method for manufacturing a transparent oxide TFT device, which demonstrated good mechanical flexibility. A simple surface treatment process was applied to enhance the susceptibility of the sputtered Al 2 O 3 dielectric through multiple coatings of solution processed Al 2 O 3. It is noteworthy that the transparent oxide TFT device exhibits a high optical transparency of 81.12% and good electrical switchability at low operating voltage (3 V) with a decent mobility of 4.37 cm2 V−1 s−1 and proven mechanical durability. [ABSTRACT FROM AUTHOR]

The promising routes of metallic additive manufacturing favor the fabrication of refined functional components. Nonetheless, dealing with the Laser Powder Bed Fusion (L-PBF) parameters and costs for making the most of this technology is still an issue. The challenge gets bigger when considering less explored parameters, such as the process atmosphere and build location. So, this study aimed to address the main differences in microstructure, crystallography, mechanical properties, and surface finishing of maraging steel components manufactured under two different atmospheres (N2 and a mixture of 75%Ar-25%He atmospheres) and three build locations arranged along the gas flow direction. Based on experimental characterizations, the porosity fraction, microstructural constituents and metallurgical flaws, phase composition and martensite matrix crystallographic parameters, macrotexture, mechanical properties, roughness, and surface residual stress were investigated and compared for the different manufacturing conditions. The porosity fraction had the most expressive changes with the gas type and the build location, reaching a 53% overall reduction under N2 and a 112 to 302% rise for the front located sample compared to the others. The underlying mechanisms involved in the observed results, mainly related to process by-products behavior, were discussed. Broadly, the N2 atmosphere stands out over the analyzed properties. These findings underscore the role of atmospheric selection in the LPBF process, considering the overall quality and performance of the fabricated material and the possibility of cost reduction. [ABSTRACT FROM AUTHOR]

In this study, pure ZnO and Al-doped ZnO thin films at different concentrations were successfully grown on an ITO substrate using the SILAR method. The produced thin films were characterized by SEM/EDS, XRD, and UV-Vis spectroscopy. According to the XRD analysis results, it was observed that the produced thin films crystallized on a nanometer scale, and the crystallization quality varied depending on the concentration of Al doping. SEM/EDS analysis results indicated that Al-doped ZnO thin films affected the morphology, forming nano-root structures. UV-Vis analysis results showed that the band gap values of the thin films produced varied depending on the Al dopant, with decreased values, sharper absorption edges, and increased absorption intensities. [ABSTRACT FROM AUTHOR]

The presence of missing components in incomplete instances precludes a kernel-based model from incorporating partially observed components of incomplete instances and computing kernels, including Gaussian kernels that are extensively used in machine learning modeling and applications. Existing methods with Gaussian kernels to handle incomplete data, however, are based on independence among variables. In this study, we propose a new method, the expected Gaussian kernel with correlated variables, that estimates the Gaussian kernel with incomplete data, by considering the correlation among variables. In the proposed method, the squared distance between two instance vectors is modeled with the sum of the correlated squared unit-dimensional distances between the instances, and the Gaussian kernel with missing values is obtained by estimating the expected Gaussian kernel function under the probability distribution for the squared distance between the vectors. The proposed method is evaluated on synthetic data and real-life data from benchmarks and a case from a multi-pattern photolithographic process for wafer fabrication in semiconductor manufacturing. The experimental results show the improvement by the proposed method in the estimation of Gaussian kernels with incomplete data of correlated variables. [ABSTRACT FROM AUTHOR]

Injection moulding has been a pivotal technology in the mass production of polymer optics for many years. The surface quality of the moulding inserts exerts a significant influence on the quality of the optics produced. In the production of micro-structured polymer optics, such as Fresnel lenses, conventional isothermal injection moulding is unable to achieve the requisite surface accuracy. Variothermal injection moulding allows for improved surface accuracy and reduced residual stresses, but increases technical effort and cycle times. To reduce the cycle time and residual stresses of variothermal injection moulding, the potential of additive manufacturing of Al-40Si for the fabrication of moulding inserts is investigated. In order to achieve these objectives, the offered design freedom of additive manufacturing is investigated with a view to developing optimised conformal cooling channels. Numerical methods will be used for thermal and structural analyses. The performance of the newly developed moulding insert is evaluated experimentally by thermographic measurements and the measurement of stress birefringence on replicated PMMA samples. [ABSTRACT FROM AUTHOR]

Biosensors are a new type of sensor that utilize biologically sensitive materials and microbially active analytes to measure a variety of biological signals. The purpose of monitoring is achieved by combining these sensitive materials with analytes such as proteins, cells, viruses, and bacteria, inducing changes in their physical or chemical properties. The use of nanomaterials in fabricating surface acoustic wave (SAW) biosensors is particularly noteworthy for the label-free detection of organisms due to their compact size, portability, and high sensitivity. Recent advancements in the manufacturing techniques of SAW biosensors have significantly enhanced sensor performance and reliability. These techniques not only ensure precise control over sensor dimensions and material properties but also facilitate scalable and cost-effective production processes. As a result, SAW biosensors are poised to become powerful tools for various clinical and rapid detection applications. [ABSTRACT FROM AUTHOR]

We present a sensor array of microscale organic electrochemical transistors (OECTs) using poly (3,4−ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) as the channel material. The devices show high sensitivity and selectivity to detect dopamine (DA) with platinum (Pt) as a pseudo−reference gate electrode. First, we describe the wafer−scale fabrication process for manufacturing the PEDOT:PSS OECTs, and then we introduce a dilution method to adjust the thickness of the PEDOT:PSS film. Next, we investigate the effect of the film thickness on the sensitivity of DA detection. Reducing the film thickness enhances the sensitivity of DA detection within the concentration range of 1 μM to 100 μM. The OECTs show impressive sensitivitywith a limit of detection (LoD) as low as 1 nM and a high selectivity against uric acid (UA) and ascorbic acid (AA). Finally, we modify the surface of the Pt gate electrode with chitosan to improve the selectivity of OECTs at high concentrations of up to 100 µM to expand the detection range. [ABSTRACT FROM AUTHOR]

This paper presents a methodological approach to conducting a literature review on additive manufacturing (AM), which is a groundbreaking manufacturing technique that involves the successive layering of materials to create components. The use of AM not only reduces manufacturing waste but also saves time and simplifies assembly processes. The current research focused on exploring the advances of AM in fabricating self-lubricating components. By using specific keywords, relevant data sources were extracted from databases. The literature review highlights the extensive exploration of AM in tribological research, demonstrating its successful application in creating self-lubricating components that have yielded positive results. [ABSTRACT FROM AUTHOR]

We present the design of an on-chip integrated photon pair source based on Spontaneous Four Wave Mixing (SFWM), implemented on a ring resonator in the 4H Silicon Carbide On Insulator (4H-SiCOI) platform, compatible with a solid state quantum memory in the telecommunications band. Through careful engineering of the waveguide dispersion and micro-ring resonator dimensions, we found solutions where the signal photons are emitted at 1536.48 nm with a bandwidth of ∼ 150 MHz, enabling the interaction with the hyperfine structure of Er 3 + ions. Simultaneously, the idler photons are generated at 1563.86 nm, matching the central wavelength of a specific channel in a commercial dense wavelength division multiplexing system. The proposed device fulfill all the spectral requirements in a simple ring-bus coupled waveguide configuration with design parameters within the range of reported values for similar resonators, making feasible its manufacturing with current fabrication capabilities. [ABSTRACT FROM AUTHOR]

Industrial thin-film composite (TFC) membranes achieve superior gas separation properties from high-performance selective layer materials, while the success of membrane technology relies on high-performance gutter layers to achieve production scalability and low-cost manufacturing. However, the current literature predominantly focuses on the design of polymer architectures to obtain high permeability and selectivity, while the art of fabricating gutter layers is usually safeguarded by industrial manufacturers and appears lackluster to academic researchers. This is the first report aiming to provide a comprehensive and critical review of state-of-the-art gutter layer materials and their design and modification to enable TFC membranes with superior separation performance. We first elucidate the importance of the gutter layer on membrane performance through modeling and experimental results. Then various gutter layer materials used to obtain high-performance composite membranes are critically reviewed, and the strategies to improve their compatibility with the selective layer are highlighted, such as oxygen plasma treatment, polydopamine deposition, and surface grafting. Finally, we present the opportunities of the gutter layer design for practical applications. [ABSTRACT FROM AUTHOR]

Multiphase microfluidic has emerged as a powerful platform to produce novel materials with tailor-designed functionalities, as microfluidic fabrication provides precise controls over the size, component, and structure of resultant materials. Recently, functional materials with welldefined micro-/nanostructures fabricated by microfluidics find important applications as environmental and energy materials. This review first illustrated in detail how different structures or shapes of droplet and jet templates are formed by typical configurations of microfluidic channel networks and multiphase flow systems. Subsequently, recent progresses on several representative energy and environmental applications, such as water purification, water collecting and energy storage, were overviewed. Finally, it is envisioned that integrating microfluidics and other novel materials will play increasing important role in contributing environmental remediation and energy storage in near future. [ABSTRACT FROM AUTHOR]

In recent years, additive manufacturing (AM) has played a significant role in various fashion industries, especially the textile and jewelry manufacturing sectors. This review article delves deeply into the wide range of methods and materials used to make intricately designed jewelry fabrication using the additive manufacturing (AM) process. The Laser Powder Bed Fusion (L-PBF) process is examined for its suitability in achieving complex design and structural integrity in jewelry fabrication even with respect to powder metallurgy methods. Moreover, the review explores the use of precious materials, such as gold, silver, copper, platinum, and their alloys in additive manufacturing. Processing precious materials is challenging due to their high reflectivity and thermal conductivity, which results in poor densification and mechanical properties. To address this issue, the review article proposes three different strategies: (i) adding alloying elements, (ii) coating powder particles, and (iii) using low-wavelength lasers (green or blue). Finally, this review examines crucial post-processing techniques to improve surface quality, robustness, and attractiveness. To conclude, this review emphasizes the potential of combining additive manufacturing (AM) with traditional craftsmanship for creating jewelry, exploring the potential future directions and developments in the field of additive manufacturing (AM) for jewelry fabrication. [ABSTRACT FROM AUTHOR]

Vat photopolymerization (VP) additive manufacturing enables fabrication of complex 3D objects by using light to selectively cure a liquid resin. Developed in the 1980s, this technique initially had few practical applications due to limitations in print speed and final part material properties. In the four decades since the inception of VP, the field has matured substantially due to simultaneous advances in light delivery, interface design, and materials chemistry. Today, VP materials are used in a variety of practical applications and are produced at industrial scale. In this perspective, we trace the developments that enabled this printing revolution by focusing on the enabling themes of light, interfaces, and materials. We focus on these fundamentals as they relate to continuous liquid interface production (CLIP), but provide context for the broader VP field. We identify the fundamental physics of the printing process and the key breakthroughs that have enabled faster and higher-resolution printing, as well as production of better materials. We show examples of how in situ print process monitoring methods such as optical coherence tomography can drastically improve our understanding of the print process. Finally, we highlight areas of recent development such as multimaterial printing and inorganic material printing that represent the next frontiers in VP methods. [ABSTRACT FROM AUTHOR]

Concrete slurry waste (CSW) is an industrial by-product retrieved in large quantities from ready-mix concrete plants. The present work aims to study the feasibility of the incorporation of this residue in the production of concrete to reduce the dilemma of its disposal on huge amounts, decrease the quantities of natural materials used in concrete assembly and produce a lower carbon footprint concrete. Hence, the CSW were divided into three parts, the first part contains the fraction of fine particles (< 80 µm) (residue 1), the second part contains the entire CSW (residue 2) and the third part contains the rest of CSW after the elimination of residue 1 by sieving (residue 3). Then, the introduction of CSW into concrete was achieved, on one hand, by replacing 2, 4, 6, 8 and 10% of cement by residue 1 and, on the other hand, by substituting 5, 10, 15, 20 and 25% of river sand and crushed sand by residues 2 and 3, separately. In order to qualify and analyze the behavior of this residues in the company of other components of concrete, several chemical and physical characteristics of CSW were evaluated. In addition, CSW were characterized by x-ray fluorescence (XRF), x-ray diffraction (XRD), fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The various constituents used in the manufacturing of concrete were characterized physically including particle size distribution, fineness modulus, cleanliness of the sand, flattening coefficient, hardness, apparent density and actual density to conclude the formulation used for the development of the specimens. In addition, the properties of fresh and hardened concretes were also investigated, including Abrams cone subsidence, density and compressive strength. The outcome of this study concludes that modest amounts of CSW improve the physical properties of concretes and consequently their compressive strength, especially at 90 days, whatever the type of martial being substituted. Thus, the introduction of residue 1 into the cement must not exceed 2%, the replacement of residue 2 by river and crushed sands can be done at rates up to 5 and 10%, respectively, while the residue 3 can only substitute river sand at a rate up to 10%. [ABSTRACT FROM AUTHOR]

Microfluidic paper-based analytical devices (μPADs) and microfluidic thread-based analytical devices (μTADs) have recently been introduced as a new class of on-site monitoring devices. Creating hydrophilic channels with hydrophobic barriers on papers/threads produces μPADs/μTADs. Fabrication is a crucial step in creating durable μPADs/μTADs that can withstand various liquids and impact the device's performance. Fabrication materials with distinct physicochemical properties allow microfluidic systems with sophisticated functions to be customized for specific applications. We present flexible and low-cost fabrication methods for μPAD and μTAD platforms. Platform designs and fabrications were implemented using a trial-and-error method for various designs with varying parameters. All production methods presented in the method section were used in |PAD production. For comparison studies, only the dipping method was used in μTAD production due to its ease of application. In this study, we tried to reveal the strengths and weaknesses of the production techniques and the resulting microfluidic platforms. A leaching test was performed with water solutions containing red ink. The compatibility of the hydrophobic walls of the platforms was tested with several solvents (isopropanol, methanol, and acetone), deionized (DI) water, and phosphate buffer solution PBS and compared. Patterning paper with polydimethylsiloxane (PDMS), white glue, alkyl ketene dimer (AKD), beeswax, and paraffin are much more flexible and simpler than traditional photoresist-based fabrications. The advantages and disadvantages of fabrication techniques; solvent resistance and wicking behaviors of platforms were discussed in the last part. The fabricated microfluidic platforms can be functionalized and used in many areas where analytical tests are applied. Studies on diversifying channel geometries and increasing resolution need to be continued. It should be investigated which devices can be used to obtain qualitative and quantitative results. To make simple and cheap production techniques suitable for mass production, studies should be carried out from different branches. [ABSTRACT FROM AUTHOR]

A compact two-element Asscher-shaped wideband MIMO antenna system is proposed in this communication. The Asscher-shaped MIMO system consists of a partial ground plane, an Asscher-shaped patch loaded with CSRR. The bandwidth of the antenna is from 2.5 to 6.4 GHz with a notch at 5.7 GHz which covers WLAN (4,6.2 GHz), WiMAX (4, 5.5 GHz), GSMA (3.5 to 4.2 GHz) and Mid band 5G (3.5 to 4.2 GHz). A decoupling structure enhances the isolation between its elements. The fabricated antenna accommodates 35.2 x67.5 x1.6 mm³. The performance of Asscher shaped MIMO antenna is assessed using the S-parameters, radiation pattern, ECC, DG, TARC, MEG, and CCL. The results from simulation and measurement are validated and both accord well. The antenna design involves simple geometry with no intricate process in fabrication. [ABSTRACT FROM AUTHOR]

The healing of damaged skin is a complex and dynamic process, and the multifunctional hydrogel dressings could promote skin tissue healing. This study, therefore, explored the development of a composite multifunctional hydrogel (HDCP) by incorporating the dopamine modified hyaluronic acid (HA-DA) and phenylboronic acid modified chitosan (CS-PBA) crosslinked using boric acid ester bonds. The integration of HA-DA and CS-PBA could be confirmed using the Fourier transform infrared spectrometer and 1H nuclear magnetic resonance analyses. The fabricated HDCP hydrogels exhibited porous structure, elastic solid behavior, shear-thinning, and adhesion properties. Furthermore, the HDCP hydrogels exhibited antibacterial efficacy against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Subsequently, the cytocompatibility of the HDCP hydrogels was verified through CCK-8 assay and fluorescent image analysis following co-cultivation with NIH-3T3 cells. This research presents an innovative multifunctional hydrogel that holds promise as a wound dressing for various applications within the realm of wound healing. [ABSTRACT FROM AUTHOR]

LED devices are increasingly gaining importance in lithography approaches due to the fact that they can be used flexibly for mask-less patterning. In this study, we briefly report on developments in mask-free lithography approaches based on nano-LED devices and summarize our current achievements in the different building blocks needed for its application. Individually addressable nano-LED structures can form the basis for an unprecedented fast and flexible patterning, on demand, in photo-chemically sensitive films. We introduce a driving scheme for nano-LEDs in arrays serving for a singularly addressable approach. Furthermore, we discuss the challenges facing nano-LED fabrication and possibilities to improve their performance. Additionally, we introduce LED structures based on a hybrid nanocrystal/nano-LED approach. Lastly, we provide an outlook how this approach could further develop for next generation lithography systems. This technique has a huge potential to revolutionize the field and to contribute significantly to energy and resources saving device nanomanufacturing. [ABSTRACT FROM AUTHOR]

Aerogels have emerged as appealing materials for various applications due to their unique features, such as low density, high porosity, high surface area, and low thermal conductivity. Aiming to bring the advantages of these materials to the environmental field, this study focuses on synthesizing magnetic silica aerogel-based films suitable for water decontamination. In this respect, a novel microfluidic platform was created to obtain core-shell iron oxide nanoparticles that were further incorporated into gel-forming precursor solutions. Afterward, dip-coating deposition was utilized to create thin layers of silica-based gels, which were further processed by 15-hour gelation time, solvent transfer, and further CO2 desiccation. A series of physicochemical analyses (XRD, HR-MS FT-ICR, FT-IR, TEM, SEM, and EDS) were performed to characterize the final films and intermediate products. The proposed advanced imaging experimental model for film homogeneity and adsorption characteristics confirmed uniform aerogel film deposition, nanostructured surface, and ability to remove pesticides from contaminated water samples. Based on thorough investigations, it was concluded that the fabricated magnetic aerogel-based thin films are promising candidates for water decontamination and novel solid-phase extraction sample preparation. [ABSTRACT FROM AUTHOR]

Additive manufacturing has advantages over other traditional manufacturing technologies for the fabrication of complex thin-walled parts. Previous correlation path strategies, when applied to laser metal deposition processes, suffer from contour deposition transboundary and surface "scar" type overstacking. Therefore, this paper proposes a hybrid path generation method for the laser metal deposition process. First, the topological logic of the STL model of the part is restored to reduce redundant calculations at the stage of obtaining the layered contour. Then, the path points are planned on the basis of the offset contours in a helical upward trend to form a globally continuous composite path in space considering the melt channel width. Finally, vectors that adaptively fit to the model surface are generated for the path points as tool orientations and they are optimized by smoothing the rotation angles. The results of experiments conducted on a multi-axis machine equipped with a laser metal deposition module show that the path generated by the proposed method is not only capable of thin-walled structures with overhanging and curved surface features but also improves the surface imperfections of the part due to sudden changes in the angle of rotation while ensuring the boundary dimensions. [ABSTRACT FROM AUTHOR]

Recently, the challenges pertaining to the recycling of metal-based electrode materials and the resulting environmental pollution have impeded the advancement of battery technology. Consequently, biomass-derived carbon materials, distinguished by their eco-friendliness and consistent performance, stand as a pivotal solution to this predicament. Researchers have made significant strides in the integration of porous carbon materials derived from biomass into battery systems. Nevertheless, these materials face issues such as limited efficiency, modest yields, and a complex fabrication process. This paper endeavors to summarize the recent advancements in the utilization of biomass-derived carbon materials within the realm of batteries, offering a comprehensive examination of their battery performance from three distinct perspectives: synthesis, structure, and application. We posit that composite materials composed of biomass-derived carbon align with the trajectory of future development and present extensive potential for application. Ultimately, we will expound upon our profound outlook regarding the furtherance of biomass-derived carbon materials. [ABSTRACT FROM AUTHOR]

Additive manufacturing has emerged as a transformative methodology in numerous engineering domains, with the fabrication of antennas and electromagnetic devices being a promising application area. This study presents a comprehensive review of the application of these technologies for manufacturing electromagnetic devices, offering a categorized analysis based on different types of additive manufacturing techniques. Each category is examined, and its characteristics are briefly described, highlighting not only the most innovative and significant devices fabricated using specific technologies, but also identifying their limitations and strengths. Through a dual analysis, this paper provides a deep understanding of the potential of and challenges associated with using different additive manufacturing technologies in the design and crafting of electromagnetic components. Moreover, this review offers recommendations for future studies, suggesting how the unique features of this new manufacturing paradigm could be further leveraged for breakthroughs in the electromagnetic field. [ABSTRACT FROM AUTHOR]

Additive manufacturing technology has fostered its significant application in soft robotics fabrication due to the design freedom and ease of realizing complex geometries. The selection of an appropriate additive manufacturing process (out-of-material extrusion, vat photopolymerization, and powder bed fusion) is vital for the fabrication of soft robotics as the process greatly influences the quality of the part further affecting the functionality and service life. These pneumatically actuated robots in their service life are subjected to fatigue loading and handling of very delicate tasks; thus, the porosity (including pores characterization) and surface roughness are two critical quality parameters which should be considered while choosing the fabrication process. In this study, a three-way decision-making (a multi-criteria decision-making tool) approach is implemented for selecting an appropriate additive manufacturing process for the fabrication of high-quality parts for soft robotics applications. The results (ranking of AM processes) obtained using the proposed approach are compared with the conventional decision-making techniques, namely TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), MOORA (Multi-Objective Optimization by Ratio Analysis), and VIKOR (VIseKriterijumska Optimizacija). The sensitivity analysis carried out in this work also suggests that three-way decision-making is as effective as other MCDM tools and the vat photopolymerization process is the most suitable out of all for fabricating TPU actuators. [ABSTRACT FROM AUTHOR]

Coastal biogenic structures, formed by ecosystem engineering species, often feature rough surfaces characterized by intricate topographies and highly threedimensional reliefs. Their surfaces are shaped by waves and tidal currents and reciprocally influence the ambient hydrodynamics, reflecting an equilibrium. Despite their significance, the impact of these surfaces on the ambient hydrodynamics remains underexplored due to limited knowledge of accurately replicating their complex topographies in experimental setups. The recent advent of advanced digital manufacturing presents an efficient means to manufacture highly complex, three-dimensional surrogate models for experimental modeling. This work explores the accurate replication of rough coastal biogenic structures for experimental modeling on the examples of an oyster reef and a mussel bed, utilizing a flexible design methodology and, for the first time, particle bed 3D printing with Selective Cement Activation (SCA) as a fabrication and manufacturing method. A workflow is proposed, which includes an iterative surrogate model development based on in-situ topographical features, requirements of the experimental setup, and parameters of the particle bed 3D printer with SCA. The results demonstrate the effectiveness of the methodology in achieving highly accurate surrogate surfaces of complex coastal biogenic structures by validation against a set of topographical features relevant to hydraulic roughness. Particle bed 3D printing with SCA proved to be a suitable method to manufacture complex surrogate surfaces for experimental modeling, offering advantages such as independence of production time from surface complexity. However, challenges persist in achieving exact comparability between the manufactured surrogate surface and the real coastal biogenic structures, particularly for surfaces with very high complexity. Nonetheless, the manufactured generic surrogate surfaces enable detailed investigations into the influence of complex coastal biogenic structures on the ambient hydrodynamics, thereby enhancing the understanding of the processes governing wave energy dissipation attenuation, turbulence production, and vertical mixing - critical for efficient application as a nature-based solution on coastal protection or restoration efforts. [ABSTRACT FROM AUTHOR]

Powder bed fusion (PBF) is an attractive additive manufacturing option for fabrication of SiC object with complex geometries. However, the density and microstructure controls remain a challenge. This study is aimed at understanding laser–SiC interactions, with emphasis on microstructure‐processing relationships, to identify potential solutions for the process improvement. SiC tubes were fabricated by PBF of pure SiC powders without sintering additives. Comprehensive analysis by X‐ray diffraction, Raman spectroscopy, and electron microscopy indicated that binding of SiC particles was achieved by incongruent melting of SiC to a Si/C mixture containing SiC micro‐ and nanocrystallites. The phase evolution under laser irradiation of SiC was explained by phase diagrams. This study uncovered the PBF SiC microstructure at different length scales and the relationship between the microstructure and the processing parameters. [ABSTRACT FROM AUTHOR]

This study is a digital form-finding and manual fabrication experiment in woven architectural design, with one traditional weaving style, Kagome, used to scale the craft up into an architectural-scale bamboo woven artifact. Kagome is a trihexagonal pattern employed in traditional bamboo basketry as a triaxial weaving system, resulting in an object with a self-bracing capacity without the use of fasteners owing to its interlacing lattices. Although existing studies and tools have addressed triaxial weaving design and representation, the current consideration of the advantages of weaving with bamboo is insufficient. To address this research gap, this study develops a computational design method based on studies on bamboo basketry. This allows for the representation and exploration of design geometries using combinations of regular triangular meshes for the fabrication of Kagome woven bamboo artifacts. A full-scale mock-up was fabricated to evaluate the effectiveness of the method. The mock-up demonstrated the self-bracing properties of Kagome, but there were discrepancies between the mock-up and the design. Factors affecting bamboo weaving on an architectural scale have been identified within this study to inform future research on woven bamboo structures. [ABSTRACT FROM AUTHOR]

Membrane separation is an energy-efficient separation process. Two-dimensional (2D) materials have shown potential as a new generation of membrane materials due to their unique structures and physicochemical properties. The separation performance of 2D material membranes crucially depends on how 2D nanosheets are assembled in membranes, such as interlayer spacing between stacked nanosheets, chemical properties of nanosheet surfaces, alignment of nanosheets and thickness of membranes, which are closely related to their fabrication methods. This short review concisely overviews commonly used membrane fabrication methods for different types of 2D materials, including graphene-based materials, 2D covalent organic frameworks, 2D metal-organic frameworks, MXenes and other 2D materials. The representative 2D material membranes resulting from their essential fabrication methods are discussed. The advantages and shortcomings of different fabrication methods are compared. The critical challenges to realising large-scale production of 2D material membranes for practical applications are highlighted. [ABSTRACT FROM AUTHOR]

Controlled drug delivery is a key strategy aimed at reducing both the frequency of therapeutic dosages and potential systemic side effects, particularly in the case of high drug concentrations. The nanocomposite hydrogel systems presented in this study were synthesized by combining carboxymethyl cellulose, polyvinyl alcohol, and (3-aminopropyl)triethoxysilane-functionalized halloysite nanotubes (fHNTs). This hydrogel system is a potential candidate for the controlled release of cefadroxil monohydrate. These hydrogels are analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and rheological measurements. Additionally, swelling properties, porosity, hydrophilicity, drug release, and in vitro and in vivo analyses were also evaluated. The observed trends in swelling and drug release demonstrated that the outcomes are dependent on the presence of fHNTs in the hydrogel matrix. Notably, fHNTs-loaded hydrogels displayed sustained drug release patterns. This innovative approach eliminates the need for traditional encapsulation and presents promising and translatable strategies for achieving more effective drug release. [ABSTRACT FROM AUTHOR]

Developing gelled environmentally friendly dispersions in oil media is a hot topic for many applications. This study aimed to investigate the production of electrospun cellulose triacetate (CTA) nanofibers and to explore their potential application as a thickening agent for castor oil. The key factors in the electrospinning process, including the intrinsic properties of CTA solutions in methylene chloride (DCM)/ethanol (EtOH), such us the shear viscosity, surface tension, and electrical conductivity, were systematically studied. The impact of the CTA fiber concentration and the ratio of DCM/EtOH on the rheological properties of the gel-like dispersions in castor oil was then investigated. It was found that dispersions with a non-Newtonian response and above a critical concentration (5 wt.%), corresponding to approximately 2–2.5 times the entanglement concentration, are required to produce defect-free nanofibers. The average fiber diameter increased with CTA concentration. Further, the morphology and texture of the electrospun nanofibers are influenced by the ratio of solvents used. The rheological properties of dispersions are strongly influenced by the concentration and surface properties of nanofibers, such as their smooth or porous textures, which allow their modulation. Compared to other commonly used thickeners, such as synthetic polymers and metal soaps, CTA electrospun nanofibers have a much higher oil structuring capacity. This work illustrated the potential of using CTA nanofibers as the foundation for fabricating gel-like dispersions in oil media, and thus exerting hierarchical control of rheological properties through the use of a nanoscale fabrication technique. [ABSTRACT FROM AUTHOR]

Gelatin nanofibers are known as wound-healing biomaterials due to their high biocompatible, biodegradable, and non-antigenic properties compared to synthetic-polymer-fabricated nanofibers. The influence of gamma radiation doses on the structure of gelatin nanofiber dressings compared to gelatin of their origin is little known, although it is very important for the production of stable bioactive products. Different-origin gelatins were extracted from bovine and donkey hides, rabbit skins, and fish scales and used for fabrication of nanofibers through electrospinning of gelatin solutions in acetic acid. Nanofibers with sizes ranging from 73.50 nm to 230.46 nm were successfully prepared, thus showing the potential of different-origin gelatin by-products valorization as a lower-cost alternative to native collagen. The gelatin nanofibers together with their origin gelatins were treated with 10, 20, and 25 kGy gamma radiation doses and investigated for their structural stability through chemiluminescence and FTIR spectroscopy. Chemiluminescence analysis showed a stable behavior of gelatin nanofibers and gelatins up to 200 °C and increased chemiluminescent emission intensities for nanofibers treated with gamma radiation, at temperatures above 200 °C, compared to irradiated gelatins and non-irradiated nanofibers and gelatins. The electron paramagnetic (EPR) signals of DMPO adduct allowed for the identification of long-life HO● radicals only for bovine and donkey gelatin nanofibers treated with a 20 kGy gamma radiation dose. Microbial contamination with aerobic microorganisms, yeasts, filamentous fungi, Staphylococcus aureus, Escherichia coli, and Candida albicans of gelatin nanofibers treated with 10 kGy gamma radiation was under the limits required for pharmaceutical and topic formulations. Minor shifts of FTIR bands were observed at irradiation, indicating the preservation of secondary structure and stable properties of different-origin gelatin nanofibers. [ABSTRACT FROM AUTHOR]

Low-quality cotton fibers, often overlooked as low-value materials, constitute a marginalized waste stream in the cotton industry. This study endeavored to repurpose these fibers into mulch gel films, specifically exploring their efficacy in covering moisture-controlled soil beds. Through a meticulously designed series of processing methods, cellulose/glycerol film was successfully fabricated by regenerating cellulose hydrogels in N,N-dimethylacetamide/lithium chloride solutions, followed by plasticization in glycerol/water solutions and hot pressing. The film was then employed to cover soil beds for a duration of up to 252 days, followed by soil burial assessments. Despite expectations of degradation, the film maintained structural integrity throughout the soil covering period but underwent complete biodegradation after 80 days of soil burial, thereby completing a closed carbon cycle. Intriguingly, both tensile strength and modulus exhibited no diminishment but instead increased after soil covering, contrary to expectations given the usual role of degradation. Mechanistic insights revealed that the removal of glycerol contributed to the mechanical enhancement, while microbial activity predominately decomposed the amorphous regions in soil covering and targeted the crystalline portions in soil burial, elucidating the main biodegradation mechanisms. In summary, this study presents, for the first time, the potential of upcycling low-quality cotton fibers into high-value mulch gel films for agricultural practices within a closed carbon cycle. [ABSTRACT FROM AUTHOR]

Low carbon alcohol fuels electrolysis under ambient conditions is promising for green hydrogen generation instead of the traditional alcohol fuels steam reforming technique, and highly efficient bifunctional catalysts for membrane electrode fabrication are required to drive the electrolysis reactions. Herein, the efficient catalytic promotion effect of a novel catalyst promoter, CoTe, on Pt is demonstrated for low carbon alcohol fuels of methanol and ethanol electrolysis for hydrogen generation. Experimental and density functional theory calculation results indicate that the optimized electronic structure of Pt-CoTe/C resulting from the synergetic effect between Pt and CoTe further regulates the adsorption energies of CO and H* that enhances the catalytic ability for methanol and ethanol electrolysis. Moreover, the good water activation ability of CoTe and the strong electronic effect of Pt and CoTe increased the tolerance ability to the poisoning species as demonstrated by the CO-stripping technique. The high catalytic kinetics and stability, as well as the promotion effect, were also carefully discussed. Specifically, 71.9% and 75.5% of the initial peak current density was maintained after 1000 CV cycles in acid electrolyte for methanol and ethanol oxidation; and a low overpotential of 30 and 35 mV was required to drive the hydrogen evolution reaction in methanol and ethanol solution at the current density of 10 mA cm-2. In the two-electrode system for alcohol fuels electrolysis, using the optimal Pt-CoTe/C catalyst as bi-functional catalysts, the cell potential of 0.66 V (0.67 V) was required to achieve 10 mA cm-2 for methanol (ethanol) electrolysis, much smaller than that of water electrolysis (1.76 V). The current study offers a novel platform for hydrogen generation via low carbon alcohol fuel electrolysis, and the result is helpful to the catalysis mechanism understanding of Pt assisted by the novel promoter. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman spectroscopy (SERS) has been widely used in the analysis of analytes because of its unique fingerprint characteristics, high sensitivity, and fast detection response. MXene is widely used in SERS studies among the various substrates due to its ultra-high chemical stability, excellent conductivity, hydrophilicity, and low fabrication cost. This mini-review summarizes MXene's research in the SERS field from two aspects. We reviewed MXene materials used as SERS substrates alone and combined with noble metal particles primarily. Subsequently, we outlined representative applications of MXene-based SERS in biomedicine, food safety, and environmental monitoring. Moreover, we discussed the technical bottleneck and the prospect of future development in this field. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) technologies have transformed manufacturing, by providing greater control over material deposition and consumption. Thanks to greater customization and their high strength-to-mass ratio, the AM of composite materials has significantly grown over the past few years. The main focus in this research area is improving printing precision and higher production rates. However, there is a lack of thorough analysis on the energy consumption of fused filament fabrication (FFF) machines for composite manufacturing, especially when associated with mechanical and economic aspects. We designed an experimental method, based on flow analysis for measuring the impact of temperature parameters on total cost, energy consumption, and tensile resistance of composite parts made by FFF. The user should be able to improve FFF efficiency regarding economic, energy, and technical aspects and obtain recommendations for setting up and using the machine. This study confirms that combining traditional economic and technical indicators (total cost and tensile resistance) with emerging energy indicators (specific energy consumption) can be successfully applied to additive manufacturing to provide an overview of printing parameters impact. Results are yielding information to support optimization investigations depending on the need and goal. For example, two tested parameter combinations that offer similar tensile properties (4% reduction in tensile resistance compared to the best combination) show a 20% difference with lower energy consumption. [ABSTRACT FROM AUTHOR]

Multicomponent interpenetrating polymer network (mIPN) hydrogels are promising tissue-engineering scaffolds that could closely resemble key characteristics of native tissues. The mechanical and biochemical properties of mIPNs can be finely controlled to mimic key features of target cellular microenvironments, regulating cell-matrix interactions. In this work, we fabricated hydrogels made of collagen type I (Col I), fibrin, hyaluronic acid (HA), and poly (ethylene glycol) diacrylate (PEGDA) using a network-by-network fabrication approach. With these mIPNs, we aimed to develop a biomaterial platform that supports the in vitro culture of human astrocytes and potentially serves to assess the effects of the abnormal deposition of fibrin in cortex tissue and simulate key aspects in the progression of neuroinflammation typically found in human pathologies such as Alzheimer's disease (AD), Parkinson's disease (PD), and tissue trauma. Our resulting hydrogels closely resembled the complex modulus of AD human brain cortex tissue (~7.35 kPa), promoting cell spreading while allowing for the modulation of fibrin and hyaluronic acid levels. The individual networks and their microarchitecture were evaluated using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Human astrocytes were encapsulated in mIPNs, and negligible cytotoxicity was observed 24 h after the cell encapsulation. [ABSTRACT FROM AUTHOR]

Sepsis, a life-threatening condition resulting from a failing host response to infection, causes millions of deaths annually, necessitating rapid and simple prognostic assessments. A variety of genomic and proteomic biomarkers have been developed for sepsis. For example, it has been shown that the level of plasma cell-free DNA (cfDNA) and circulating histones increases considerably during sepsis, and they are linked with sepsis severity and mortality. Developing a diagnostic tool that is capable of assessing such diverse biomarkers is challenging as the detection methodology is quite different for each. Here, a fully integrated microfluidic device capable of detecting a genomic biomarker (cfDNA) and a proteomic biomarker (total circulating histones) using a common detection platform has been demonstrated. The microfluidic device utilizes dehydrated agarose gates loaded with pH-specific agarose to electrophoretically trap cfDNA and histones at their respective isoelectric points. It also incorporates fluorescent dyes within the device, eliminating the need for off-chip sample preparation and allowing the direct testing of plasma samples without the need for labeling DNA and histones with fluorescent dyes beforehand. Xurography, which is a low-cost and rapid method for fabrication of microfluidics, is used in all the fabrication steps. Experimental results demonstrate the effective accumulation and separation of cfDNA and histones in the agarose gates in a total processing time of 20 min, employing 10 and 30 Volts for cfDNA and histone accumulation and detection, respectively. The device can potentially be used to distinguish between the survivors and non-survivors of sepsis. The integration of the detection of both biomarkers into a single device and dye immobilization enhances its clinical utility for rapid point-of-care assessment of sepsis prognosis. [ABSTRACT FROM AUTHOR]

Thin metal layers such as silver (Ag) are being utilized for various optical and plasmonic applications as well as for electrical purposes, e.g., as transparent electrodes in display devices or solar cells. This paper focuses on optical MEMS applications such as the Fabry–Pérot interferometer (FPI). Within such filters, reflector materials such as distributed Bragg reflectors (DBRs) or subwavelength gratings (SWGs) have been widely used so far, whereas metallic thin films (MTFs) were limited in application due to their comparatively higher absorption. In this paper, thin sputtered Ag layers with thicknesses of 20, 40 and 60 nm on glass substrates have been investigated, and it is shown that the absorption is very low in the visible spectral range (VIS) and increases only in near-infrared (NIR) with increasing wavelength. Thus, we consider Ag-thin layers to be an interesting reflector material at least for the VIS range, which can be easily fabricated and integrated. However, Ag is not inert and stable when exposed to the atmosphere. Hence, it needs a passivation material. For this purpose, AlN has been chosen in this contribution, which can be deposited by sputtering as well. In this contribution, we have chosen thin AlN layers for this purpose, which can also be deposited by sputtering. Thus, various AlN/Ag/AlN-reflector stacks were created and patterned by lift-off technology preferably. The fabricated reflectors were characterized with respect to adhesion, stress, cohesion, homogeneity, and most importantly, their optical properties. It was found that the thickness of the AlN can be used to adjust the reflectance–transmittance ratio in the VIS range, and influences the adsorption in the NIR range as well. Based on the measured values of the reflectors with 40 nm Ag, an exemplary transmission filter characteristics has been predicted for a wavelength range from 400 to 800 nm. Both the maximum transmittance and the full width at half maximum (FWHM) can be tuned by variation of the AlN thickness from 20 to 60 nm. [ABSTRACT FROM AUTHOR]

A miniaturized electrochemical sensor was developed for the remote detection of chemical warfare agent (CWA) simulants. To facilitate drone-based remote sensing, this present study focuses on advancing the miniaturized and compact electrochemical sensor for monitoring two CWA simulants, diisopropyl fluorophosphate (DFP) and O,S-diethylmethylphosphonothioate (O,S-DEMPT). The differential pulse voltammetry (DPV) signal was processed, and the DPV signature features were extracted on the basis of the redox properties associated with the absence and the presence of DFP and O,S-DEMPT. Upon the addition of 0.10 equivalence of DFP or O,S-DEMPT, a shift in potential (E) of ~0.13 V was recorded. The limit of detection (LOD) was calculated to be 0.25 µM (0.046 ppm) and 0.10 µM (0.017 ppm) for DFP and O,S-DEMPT, respectively. These results were validated using a portable Palmsens Emstat HR potentiostat, which corroborated the results obtained using a lab benchtop potentiostat. Additionally, Boolean logic ("AND" operation) was implemented for future drone technology deployment. This advancement enables the fabrication of a networked device capable of autonomously executing tasks without constant oversight. [ABSTRACT FROM AUTHOR]

This article discusses the importance of shape and size-dependent nanostructures for environmental applications. It highlights the role of nanostructured materials in areas such as green energy, environmental monitoring, and pollution treatment. The article emphasizes the impact of morphology and dimension on the catalytic properties of nanostructures and explores the potential of anisotropic and dimensional factors in addressing environmental challenges. The authors also discuss the synthesis strategies and applications of nanostructured materials in catalysis and CO2 remediation. Overall, the article provides a comprehensive overview of the topic and offers insights for future research in this field. [Extracted from the article]

Polymer filaments represent the fundamental materials employed in fused filament fabrication additive manufacturing. This paper uses an innovative nondestructive evaluation technique for gauging the elastic properties of these polymer filaments. The method hinges on acoustic wave scattering theory, wherein a polymer filament is immersed in water and exposed to an incident acoustic wave. The waves scattered from the cylinder contain crucial information concerning the elastic properties of the filament. To extract these properties, an inverse method is applied which compares the resonance frequencies of the scattered signal with those anticipated based on a theoretical model. To improve the performance of this method in identifying the resonance frequencies, the derivative of the unwrapped phase within the backscattered pressure spectrum is analyzed. This is an advantageous approach as it can be equally applied to both experimental and theoretical pressure spectra, simplifying the task of identification of resonance frequencies considerably. The method's effectiveness is exemplified through its application to an aluminum rod followed by its application to two polymer filaments. Comparing the elastic constants of the polymer filaments determined through the proposed method with values reported in the literature underscores the method's capability to accurately measure the elastic constants of polymer filaments. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles (MNPs) in a suspension have been shown to change resistance by an order of magnitude based on an applied field. We have prepared the MNPs samples with matrices of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PDOT:PSS) or H2O, and Co MNPs and carried out the magnetoresistive measurements. A switch-based model is used to understand the mechanism for the change in resistance. We further propose devices for memory based on MNPs. Building blocks for these devices are then fabricated using additive manufacturing techniques and measurements of change in resistance under the influence of a magnetic field are conducted. Niche applications of additive manufacturing techniques to the fabrication of these devices are proposed. The device uses MNPs suspended in a soft matter matrix. The application of a magnetic field is used to move the MNPs to or away from electrical contacts. Depending on the change of position of the MNPs, a connection is either made or broken, which can act as a 1 or a 0. The measured change in resistance observed in such devices is more than an order of magnitude depending on the matrix solution. The proposed device and its manufacturing process could be feasible for magnetic memory and in-memory computing devices on any flexible substrates. [ABSTRACT FROM AUTHOR]

In semiconductor fabrication, the deposition process generates layers of materials to realize insulating and conducting functionality. The uniformity of the deposited thin film layers' thickness is crucial to create high-performance semiconductor devices. Tuning fabrication process parameters (e.g., for evenly distributed gas flow on the semiconductor wafer) is one of the dominant factors that affect film uniformity, as evidenced by both experimental and numerical studies. Conventional trial and error methods employed to change and test a range of fabrication conditions are time-consuming, and few studies have explored the effect of changing the geometry of hardware components, such as the showerhead. Here, we present a design optimization of the showerhead for flow uniformity based on numerical simulation data using machine learning surrogate models. Accurate machine learning models and optimization algorithms are developed and implemented to achieve 10% more flow uniformity compared to a benchmark traditional showerhead design. Moreover, the developed Bayesian optimization method saves 10-fold computational cost in reaching the optimal showerhead designs compared to conventional approaches. This machine learning enabled optimization platform shows promising results which could be implemented for other optimization problems in various manufacturing systems such as semiconductor fabrication and additive manufacturing. [ABSTRACT FROM AUTHOR]

Thermoelectric materials have advanced significantly in terms of machinery, manufacturing technique and technology over the last 10 years. However, conventional processing methods still necessitate a multitude of processing steps, thereby yielding material loss and imposing a substantial surge in manufacturing expenditures, which significantly obstructs the advancement of intricate and scalable thermoelectric devices. Additive manufacturing technology (AM) is an emerging and innovative technology offering rapid manufacturing cycles and efficient production of intricate geometries. While additive manufacturing has been utilized for fabricating thermoelectric materials, its application in the manufacturing of thermoelectric devices remains somewhat restricted. Although there have been some research reviews of AM thermoelectric materials in recent years, they are basically focused on the development and achievements of AM thermoelectric materials. This paper presents a comprehensive review of the research advancements of additive manufacturing technology in the fabrication of thermoelectric materials. It discusses the impacts of various processing parameters on the quality of the fabricated thermoelectric materials and their resulting thermoelectric properties. Simultaneously, each additive manufacturing technology for the fabrication of thermoelectric devices, as well as future research objectives and problems, is thoroughly examined. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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 last several decades, textile-reinforced composites have emerged as a unique class of materials offering intricate features, reduced fabrication costs, introduced multiaxial reinforcement, and enhanced damaged tolerance. Despite these benefits, textile-reinforced composites face challenges as predicting their performance often relies on heuristics and past experiences without gaining insights into the underlying structure of the textile material and its constituents. This tutorial-based mini-review aims to delve into the fundamentals of textile architecture in the context of textile-reinforced composites and provide an overview of their significant physical and structural features that influence the performance characteristics of textile-reinforced composites. [ABSTRACT FROM AUTHOR]

Turmeric extract (TE)-loaded oleogels (TE-OG) was fabricated by an emulsion template technique using xanthan gum (XG) and soy lecithin (SL) as oleogelators. The formulation for TE-OG was optimized using 0.32% XG, 1.2% SL, and 1.0% TE. The optimized TE-OG had a minimal particle size of 810.23 ± 10.68 nm as measured by the dynamic light scattering (DLS) method, and a high encapsulation efficiency (EE) of 96.62 ± 0.56%. Additionally, the optimized TE-OG exhibited a favorable zeta potential of -27.73 ± 0.44 mV, indicating the good stability of the TE-OG due to the electrostatic repulsion between particles. TE-OG formulated with 0.32% XG and 1.2% SL was subjected to frequency sweep testing to evaluate its solid-like rheological behavior. The oil-binding capacity (OBC) of TE-OG was consistently maintained above 99.99%. In vitro digestion of TE-OG demonstrated the potential of the emulsion template for controlled release, with less than 20% of the encapsulated curcumin being released in simulated gastric fluid (SGF), whereas nearly 70% was released in the simulated intestinal fluid (SIF). Moreover, TE-OG affected the rapid release of free fatty acids (FFAs), which have a positive effect on the digestion of triacylglycerols found in soybean oil (SO). TE-OG was further used as an alternative to commercial butter to produce pound cakes, and their rheological properties were compared to those of the pound cake prepared using commercial butter. The pound cake prepared using TE-OG showed a noticeable decrease in hardness from 10.08 ± 1.39 N to 7.88 ± 0.68 N and increased porosity, demonstrating the inherent capability of TE-OG to enhance the overall quality standards of bakery products. [ABSTRACT FROM AUTHOR]

Microneedles are of great interest in diverse fields, including cosmetics, drug delivery systems, chromatography, and biological sensing for disease diagnosis. Self-dissolving ultrafine microneedles of pure sodium hyaluronate hydrogels were fabricated using a UV-curing TiO2-SiO2 gas-permeable mold polymerized by sol-gel hydrolysis reactions in nanoimprint lithography processes under refrigeration at 5 °C, where thermal decomposition of microneedle components can be avoided. The moldability, strength, and dissolution behavior of sodium hyaluronate hydrogels with different molecular weights were compared to evaluate the suitability of ultrafine microneedles with a bottom diameter of 40 μm and a height of 80 μm. The appropriate molecular weight range and formulation of pure sodium hyaluronate hydrogels were found to control the dissolution behavior of self-dissolving ultrafine microneedles while maintaining the moldability and strength of the microneedles. This fabrication technology of ultrafine microneedles expands their possibilities as a next-generation technique for bioactive gels for controlling the blood levels of drugs and avoiding pain during administration. [ABSTRACT FROM AUTHOR]

Carbon nanotube–glue composite gel-based surface-type elastic sensors with a cylindrical shape deformable (flexible) metallic body were fabricated for tactile pressure and compressive displacement sensing. The fabrication of the sensors was performed using the rubbing-in technique. The effect of the pressure and the compressive displacement on the capacitance and the impedance of the sensors were investigated at various frequencies (in the range of 1 kHz to 200 kHz). It was found that under the effect of pressure from 0 to 9 g/cm2, the capacitance increased by 1.86 and 1.78 times, while the impedance decreased by 1.84 and 1.71 times at the frequencies of 1 kHz to 200 kHz, respectively. The effect of displacement on the impedance and the capacitance of the device was also investigated at various frequencies from 1 kHz to 200 kHz. The results showed that under the effect of compressive displacement up to 25 µm, the impedance of the sensors decreased on average by 1.19 times, while the capacitance increased by 1.09 times, accordingly. The frequency response of the displacement sensor showed that it matched with the low-pass filter. The obtained results are explained based on changes in the shape and geometrical parameters of the cylindrical-shaped conductive body. These results have also been explained on the basis of the distance between the conductive plates of the capacitive sensors during compression, which takes place under the effect of applied pressure or displacement. Moreover, the design of the sensors is simple and easy to fabricate, and their use is also earthy. The fabricated sensors have great potential for commercialization. [ABSTRACT FROM AUTHOR]

Natural polymers, such as alginate and chitosan, are widely exploited for drug delivery applications due to their biocompatibility, low toxicity, and sustainable sourcing. In this study, pH-responsive gel microspheres were fabricated from an alginate/Ozoile emulsion. Ozoile (Stable Ozonides) is a biological inducer, derived from olive oil, which stimulates the endogenous defense system by promoting the repair of tissue damage and restoration of proper physiology through the regulation of gene transcription. Here, the versatile and cost-effective electrospray technique without the use of organic solvents was used to fabricate alginate/Ozoile microspheres with high throughput. The process parameters (voltage, flow rate, and needle gauge) were optimized to obtain microspheres with good sphericity factor and tailored diameter (250–700 μm). The microspheres were additionally optimized through a chitosan coating to enhance their stability and regulate the gel matrix's degradation process. Morphological analysis, FTIR spectroscopy, and degradation tests confirmed the structural integrity and pH-responsive behavior of the gel microspheres. This research offers a promising route for targeted drug delivery systems, particularly in applications related to the modulation of oxidative stress and management of inflammation. [ABSTRACT FROM AUTHOR]

Multi-layered hydrogels consisting of bi- or tri-layers with different swelling ratios are designed to soft hydrogel actuators by self-folding. The successful use of multi-layered hydrogels in this application greatly relies on the precise design and fabrication of the curvature of self-folding. In general, however, the self-folding often results in an undesired mismatch with the expecting value. To address this issue, this study introduces an interfacial layer formed between each layered hydrogel, and this layer is evaluated to enhance the design and fabrication precision. By considering the interfacial layer, which forms through diffusion, as an additional layer in the multi-layered hydrogel, the degree of mismatch in the self-folding is significantly reduced. Experimental results show that as the thickness of the interfacial layer increases, the multi-layered hydrogel exhibits a 3.5-fold increase in its radius of curvature during the self-folding. In addition, the diffusion layer is crucial for creating robust systems by preventing the separation of layers in the muti-layered hydrogel during actuation, thereby ensuring the integrity of the system in operation. This new strategy for designing multi-layered hydrogels including an interfacial layer would greatly serve to fabricate precise and robust soft hydrogel actuators. [ABSTRACT FROM AUTHOR]