Fabrication Method Research Articles

Integration of acoustic micromixing with cyclic olefin copolymer microfluidics for enhanced lab-on-a-chip applications in nanoscale liposome synthesis

The integration of acoustic wave micromixing with microfluidic systems holds great potential for applications in biomedicine and lab-on-a-chip technologies. Polymers such as cyclic olefin copolymer (COC) are increasingly utilized in microfluidic applications due to its unique properties, low cost, and versatile fabrication methods, and incorporating them into acoustofluidics significantly expands their potential applications. In this work, for the first time, we demonstrated the integration of polymer microfluidics with acoustic micromixing utilizing oscillating sharp edge structures to homogenize flowing fluids. The sharp edge mixing platform was entirely composed of COC fabricated in a COC-hydrocarbon solvent swelling based microfabrication process. As an electrical signal is applied to a piezoelectric transducer bonded to the micromixer, the sharp edges start to oscillate generating vortices at its tip, mixing the fluids. A 2D numerical model was implemented to determine the optimum microchannel dimensions for experimental mixing assessment. The system was shown to successfully mix fluids at flow rates up to 150 µl h−1 and has a modest effect even at the highest tested flow rate of 600 µl h−1. The utility of the fabricated sharp edge micromixer was demonstrated by the synthesis of nanoscale liposomes.

Laser Additive Manufacturing of Three-Dimensional Ti/TiN Nanotube Arrays with Hierarchical Pore Structures and Promoted Supercapacitor Performances.

Titanium-based composites hold great promise in versatile functional application fields, including supercapacitors. However, conventional subtractive methods for preparing complex-shaped titanium-based composites generally suffer from several significant shortcomings, including low efficiency, strictly simple geometry, low specific surface area, and poor electrochemical performance of the products. Herein, three-dimensional composites of Ti/TiN nanotube arrays with hierarchically porous structures were prepared using the additive manufacturing method of selective laser melting combined with anodic oxidation and nitridation. The resultant Ti/TiN nanotube array composites exhibit good electrical conductivity, ultrahigh specific surface areas, and outstanding supercapacitor performances featuring the unique combination of a large specific capacitance of 134.4 mF/cm2 and a high power density of 4.1 mW/cm2, which was remarkably superior to that of their counterparts. This work is anticipated to provide new insights into the facile and efficient preparation of high-performance structural and functional devices with arbitrarily complex geometries and good overall performances.

Fabrication method may enable epitaxial graphene for electronics

Fabrication method may enable epitaxial graphene for electronics

Design and Analysis of Various Formwork Systems

Concrete is a fundamental material in the construction industry, with formwork playing a crucial role in shaping and strengthening concrete elements. It also represents a significant cost in building projects. The history of formwork is extensive, and diverse systems have been employed across various projects. When selecting a formwork system, considerations such as safety, cost, structural requirements, construction duration, and environmental impact must be carefully weighed. This project provides a comprehensive review of different formwork systems used in concrete construction, encompassing their materials, flexibility, fabrication methods, application in structures, and environmental implications. The advantages and limitations of these systems are analysed and compared, culminating in practical recommendations. Formwork systems are pivotal in determining the success of construction projects in terms of efficiency, quality, cost-effectiveness, and safety. Recent innovations, particularly modular formwork systems, have revolutionized the construction industry in countries like Japan, Singapore, Malaysia, and the Middle East. These systems have proven to be cost- effective, enhance construction quality, and accelerate project timelines. Their adaptability makes them particularly suitable for mass construction projects in India, where achieving high-quality, rapid construction is crucial. By leveraging modern formwork technologies, construction practices can achieve safer, faster, and more sustainable outcomes, aligning with advancements

Highly Stretchable Thermoelectric Fiber with Embedded Copper(I) Iodide Nanoparticles for a Multimodal Temperature, Strain, and Pressure Sensor in Wearable Electronics

AbstractThermoelectric (TE) fibers have excellent potential for multimodal sensor, which can detect mechanical and thermal stimuli, used in advanced wearable electronics for personalized healthcare system. However, previously reported TE fibers have limitations for use in wearable multimodal sensors due to the following reasons: 1) TE fibers composed of carbon or organic materials have low TE performance to detect thermal variations effectively; 2) TE fibers composed of rigid inorganic materials are not stretchable, limiting their ability to detect mechanical deformation. Herein, the first stretchable TE fiber‐based multimodal sensor is developed using copper(I) iodide (CuI), an inorganic TE material, through a novel fabrication method. The dense CuI nanoparticle networks embedded in the fiber allow the sensor to achieve excellent stretchability (maximum tensile strain of ≈835%) and superior TE performance (Seebeck coefficient of ≈203.6 µV K−1) simultaneously. The sensor exhibits remarkable performances in strain sensing (gauge factor of ≈3.89 with tensile strain range of ≈200%) and pressure sensing (pressure resolution of ≈250 Pa with pressure range of ≈84 kPa). Additionally, the sensor enables independent and simultaneous temperature change, tensile strain, and pressure sensing by measuring distinct parameters. It is seamlessly integrated into a smart glove, demonstrating its practical application in wearable technology.

Manufacturing fused silica hemispherical resonators using polymer glass suspension and replication molding

This work introduces a new method for manufacturing fused silica (FS)-based hemispherical resonators (HSRs) using a printable polymer glass mixture and replication molding. This process involves 3D printing to create the mold, followed by the casting of a photo-reactive pre-polymer glass mixture. This technique allows us to produce complex 3D geometries and offers faster production of resonators compared to other traditional methods. In this study, we manufactured three devices and successfully identified resonance modes with two (N = 2), three (N = 3) and four (N = 4) nodes/antinodes in all three HSRs, demonstrating the repeatability of our new manufacturing method. The highest quality factor of 482 k was achieved for the N = 3 resonance mode using the ring-down method. Some of the key advantages of our method include producing multiple devices efficiently with relatively good surface quality, making it a viable option for producing high-precision devices in the future. Our new fabrication technique results in a device surface roughness of ∼100 nm (measured over an area of 250 μm × 250 μm) and manufacturing yield of over 90%. Moreover, all the steps involved in this method can be completed outside of a specialized cleanroom environment.

Controlled Crystal Growth of All-Inorganic CsPbI2Br via Sequential Vacuum Deposition for Efficient Perovskite Solar Cells.

Vacuum deposition of perovskites is a promising method for scale-up fabrication and uniform film growth. However, improvements in the photovoltaic performance of perovskites are limited by the fabrication of perovskite films, which are not optimized for high device efficiency in the vacuum evaporation process. Herein, we fabricate CsPbI2Br perovskite with high crystallinity and larger grain size by controlling the deposition sequence between PbI2 and CsBr. The nucleation barrier for perovskite formation is significantly lowered by first evaporating CsBr and then PbI2 (CsBr-PbI2), followed by the sequential evaporation of multiple layers. The results show that the reduced Gibbs free energy of CsBr-PbI2, compared with that of PbI2-CsBr, accelerates perovskite formation, resulting in larger grain size and reduced defect density. Furthermore, surface-modified homojunction perovskites are fabricated to efficiently extract charge carriers and enhance the efficiency of perovskite solar cells (PeSCs) by modulating the final PbI2 thickness before thermal annealing. Using these strategies, the best PeSC exhibits a power conversion efficiency of 13.41% for a small area (0.135 cm2), the highest value among sequential thermal deposition inorganic PeSCs, and 11.10% for a large area PeSC (1 cm2). This study presents an effective way to understand the crystal growth of thermally deposited perovskites and improve their performance in optoelectronic devices.

Fabric defect detection based on feature enhancement and complementary neighboring information

Abstract Fabric defect detection is a crucial aspect of quality control in the textile industry. Given the complexities of fabric backgrounds, the high similarity between patterned backgrounds and defects, and the variety of defect scales, we propose a fabric defect detection method based on feature enhancement and complementary neighboring information . The core of this method lies in two main components: the feature enhancement module and the neighboring information complementation strategy. The feature enhancement module includes two sub-modules: similarity feature enhancement(SFE) and edge detail feature enhancement(EDFE). The SFE aims to capture the similarities between features to strengthen the distinction between defects and complex backgrounds, thereby highlighting the correlations among defects and the differences between defects and the background. The EDFE focuses on improving the network's ability to capture the edge details of fabrics, preventing edge information from becoming blurred or lost due to deeper network layers. The neighboring information complementation strategy consists of shallow-level information complementation(SLIC) and top-down information fusion complementation(TDIFC). The SLIC integrates newly introduced shallow features with neighboring features that have a smaller semantic gap, injecting richer detail information into the network. The TDIFC adaptively guides the interaction of information between adjacent feature maps, effectively aggregating multi-scale features to ensure information complementarity between features of different scales. Additionally, to further optimize model performance, we introduced partial convolution(PConv) in the backbone of the feature extraction network. PConv reduces redundant computations and decreases the model's parameter count. Experimental results show that our proposed method achieved an mAP@50 of 82.4%, which is a 6.6% improvement over the baseline model YOLOv8s. The average inference frame rate reached 61.8 FPS, meeting the real-time detection requirements for fabric defects. Moreover, the model demonstrated good generalization capabilities, effectively adapting to detecting defects in different types and colors of fabrics.

Fabrication of Highly Efficient ZIF-8@PEI Monoliths for CO2 Capture Using Phosphorylated Cellulose Nanofiber as a Binder.

This study involves the synthesis and comparison of zeolitic imidazolate frameworks (ZIFs), specifically ZIF-8 and ZIF-67 pristine with a commercial zeolite, emphasizing their CO2 affinity and sorption capability. To overcome challenges persisting in the handling and integration of these materials into industrial adsorption processes, particularly when limited to microcrystalline fine powders, we present herein an innovative manufacturing method to produce standalone monolithic supports. This process involves pseudoplastic paste formulations utilizing polyethylenimine (PEI) as a coagulant and locally fabricated phosphorylated cellulose nanofiber (PCNF) as a binding agent. Rheological investigation was conducted to anticipate the required shaping and design by means of paste flowability, consistency, and stiffness. XRD and FTIR results confirm the preservation of crystalline structure and the occurrence of amine functionalization associated with the presence of PEI, respectively. The proposed method significantly enhances the CO2 adsorption performance of the produced ZIF-8 monolith in comparison with that reached when using the pristine material, achieving a capacity of 1.25-2 mmol·g-1 at 30 °C under dry conditions in a pressure range of 1-13 bar, respectively. In other words, this work clearly highlights an effective applicability of the ZIF-8 monolith as an innovative sorbent for further designing CO2 capture industrial setups.

Determining the Size of Representative Volume Elements for a Two-Dimensional Random Aggregate Numerical Model of Asphalt Mortar without Damage

The size of the representative volume element (RVE) for the two-dimensional (2D) random aggregate numerical model of asphalt mortar in a non-destructive state, which directly affects the time required to simulate the linear viscoelastic behavior from asphalt mastic to asphalt mortar. However, in the existing literature, limited research has been conducted on the size determination of the numerical model RVE for asphalt mortar. To provide a recommended size for the typical 2D random aggregate numerical model RVE of asphalt mortar in a nondestructive state, this paper first applies the virtual specimen manufacturing method of asphalt concrete 2D random aggregate to asphalt mortar. Then, it generates numerical model RVEs of asphalt mortar with different maximum particle sizes, after which geometric and numerical analyses are conducted on these models. Finally, based on the geometric and numerical analysis results, the recommended minimum sizes of RVE for the 2D asphalt mortar numerical model are provided.

Experimental study on manufacturing of vacuum-brazed grinding tools with diamond grains

AbstractThis work provides an experimental study on manufacturing methods for vacuum-brazed diamond grinding for edge machining of carbon fiber-reinforced polymers (CFRP). Therefore, various methods for applying active brazing alloys and diamond grains were investigated. The application methods were evaluated regarding practicability and the possibility of automation. Additionally, the samples were examined after vacuum brazing and brazing results were compared concerning method, amount and type of brazing alloy, diamond grains and binding agent. It was found that the best results could be achieved by using fluidized bed coating for diamond application and a brazing alloy containing a 15% binding agent. The method and brazing alloy were then used to produce cylindrical mounted points for grinding tests. It was possible to show that vacuum-brazed tools performed as good as commercially available electroplated tools.

Building in vitro models for mechanistic understanding of liver regeneration in chronic liver diseases.

The liver has excellent regeneration potential and attains complete functional recovery from partial hepatectomy. The regenerative mechanisms malfunction in chronic liver diseases (CLDs), which fuels disease progression. CLDs account for 2 million deaths per year worldwide. Pathophysiological studies with clinical correlation have shown evidence of deviation of normal regenerative mechanisms and its contribution to fueling fibrosis and disease progression. However, we lack realistic in vitro models that can allow experimental manipulation for mechanistic understanding of liver regeneration in CLDs and testing of candidate drugs. In this review, we aim to provide the framework for building appropriate organotypic models for dissecting regenerative responses in CLDs, with the focus on non-alcoholic steatohepatitis (NASH). By drawing parallels with development and hepatectomy, we explain the selection of critical components such as cells, signaling, and, substrate-driven biophysical cues to build an appropriate CLD model. We highlight the organoid-based organotypic models available for NASH disease modeling, including organ-on-a-chip and 3D bioprinted models. With the focus on bioprinting as a fabrication method, we prescribe building in vitro CLD models and testing schemes for exploring the regenerative responses in the bioprinted model.

Investigation of Electrical and Dielectrically Properties of a Novel Structure of PANI-PPy--GO-MWCNTs Composite/MnO2/Fe3O4/n-Si Structure

Abstract We investigated here the electrical properties of the novel structure of PANI-PPy-GO-MWCNTs composite/MnO2/Fe3O4/n-Si. This structure has not been addressed in literature before, the manufacture of this novel structure is carried out using a simple technique. So, we introduce here a novel structure with a simple method of manufacture. The imaginary part of modulus M՝՝ has two behaviors, the first behavior at high and low frequency and the second behavior at mid frequency, so the M՝՝ gives two contrarian behaviors, The M՝՝ is a strong function of frequency and we can change the behavior of M՝՝ by change of frequencies. The Col – Col diagram of modulus has ideal figures at some voltages including two semicircles of grains and grain boundaries. The imaginary part of impedance Z՝՝ versus frequency creates peaks, the peaks shift toward the low frequencies. The novel here the Z՝՝ has positive and negative values, despite the Z՝՝ should have negative values only. The real part of impedance Z՝ keeps on without change at high frequencies and splits for all temperatures at low and mid frequencies. Some electrical properties such as barrier height ɸb,Wd the width of the depletion layer, Nss the density of states,

Residual deformation analysis of laser powder bed fusion-fabricated lattice structures

ABSTRACT Lattice structures are crucial for weight reduction, and laser powder bed fusion (LPBF) is an efficient fabrication method. However, there's a notable research gap in understanding the residual deformation of LPBF-fabricated lattice structures. This study investigates the residual deformation of three basic lattice structures, body centre cell (BCC), face centre cell (FCC), and diamond cell (DC), fabricated via LPBF to reveal their deformation mechanisms. Analysis covers horizontal direction, building direction, and total deformations, unveiling complex structural responses. Lower relative densities exhibit a prevalent structural deformation mode (SDM) causing significant deformations, while higher densities shift to an intrinsic deformation mode (IDM) dominated by contraction during fabrication. The FCC structure shows optimal stability with minimal residual deformation across most densities. This study offers insightful findings and a detailed mechanistic analysis of residual deformation in LPBF-fabricated lattice structures, applicable across various configurations, ensuring design process uniformity and reliability.

An economical self-coalescing microfluidic device with an easily observable readout

Introduction: Self-coalescing microfluidic devices represent an exciting opportunity for leveraging viscous dominated flow phenomena to reconstitute a series of reagents with a single sample infusion. In a self-coalescing microfluidic device, spatially separated dried reagents are reconstituted using a single infusion. Due to the unique device geometry, the reagents remain spatially separated after infusion. As such, self-coalescing microfluidic devices have the potential to simplify point-of-care testing by simultaneously performing multiple colorimetric tests in one device. The current versions of these devices use standard, more costly microfabrication processes and are too small to be easily read by eye.Methods: Here, we created a low cost and scaled up version of a self-coalescing microfluidic device by using laser-cut-roll-based silicone tape. In addition to eliminating the need for cleanrooms, our approach simplifies the integration of assay reagents since they can be spotted onto a coverslip and covered with the tape microfluidic device. We empirically optimized our device, finding that flow rate significantly influenced the formation of self-coalescence as well as proper reagent reconstitution.Results and Discussion: When flow rates were too slow or fast, reagents would streak, leading to inadvertent mixing between different spatial locations. Our studies further revealed that geometry had a stronger influence on device operation in low-flow conditions. Our final optimized device exhibited a 100% success rate, demonstrated through self-coalescence with no reagent streaking at 100 μL/min, which enabled the isotropic diffusion of reagents. Furthermore, the spots are spatially separated and large enough to be visualized by the naked eye and captured by a smartphone camera for downstream analysis. Taken together, our innovative device leverages the advantages of sticker microfluidics and low-cost manufacturing methods to offer standalone functionality. This approach has the potential to significantly impact point-of-care diagnostics, particularly in resource-limited regions. By enabling multiplexed diagnostic assays through our novel technology, we aim to provide accessible and affordable healthcare solutions.

The Production and Materials of Mouthguards: Conventional vs Additive Manufacturing - A Systematic Review

This investigation presents a critical analysis of mouthguard production, focusing on the evaluation of conventional vs additive manufacturing methods, the materials involved, and aspects such as their failure and prevention. It also summarizes the current trends, perspectives, and the main limitations. It is shown that some of the shortcomings can be solved by implementing additive manufacturing technologies, which are systematically reviewed in this research. Due to the specific materials used to produce mouthguards, there are certain additive manufacturing technologies that dominate and a wide variety of raw materials. The costs vary depending on the technology.

A Comprehensive Review on Effects of Material Composition, Mix Design, and Mixing Regimes on Rheology of 3D-Printed Geopolymer Concrete

Recent years have witnessed a significant growth in the research and development of additive manufacturing methods involving concrete and cementitious materials, with technologies like three-dimensional (3D) printing becoming more widely used in the construction industry. Construction has the possibility to be revolutionized, not only in the context of cost savings but also in the context of increased sustainability and functionality. 3D printing of concrete is a cutting-edge technology that has the potential to speed up construction, reduce labor costs, give architects more creative freedom, improve precision, obviate requirements for formwork, and result in less construction wastes. In addition, 3D printing can be a long-term solution for both economy and environment. Even though 3D printing in concrete has made tremendous strides recently, developing an effective 3D-printable material that decreases material usage and enhances performance is critical for carbon dioxide reduction. Robust geopolymer formulations for 3D printing concrete technology in current construction applications have emerged as the subject of much research among scientists to find novel ways to circumvent this constraint. This study intends to highlight the current state of the art in developing 3D-Printed Geopolymer Concrete (3DPGC) with a comprehensive review related to the material composition, mix design, and mixing regimes on rheology of 3DPGC. The rheology of 3DPGC in terms of printability and buildability is discussed. The mixing regimes employed for the preparation of one-part and two-part 3DPGC are tabulated and commented on. Lastly, the research gaps are identified and summarized, and several research directions are also provided for future investigations to expedite the ubiquitous use of 3DPGC in versatile construction applications.

Mimicking nature to develop halide perovskite semiconductors from proteins and metal carbonates

Halide perovskite (HPs) nanostructures have recently gained extensive worldwide attentions because of their remarkable optoelectronic properties and fast developments. However, intrinsic instability against environmental factors—i.e., temperature, humidity, illumination, and oxygen—restricted their real-life applications. HPs are typically synthesized as colloids by employing organic solvents and ligands. Consequently, the precise control and tuning of complex 3D perovskite morphologies are challenging and have hardly been achieved by conventional fabrication methods. Here, we combine the benefits of self-assembly of biomolecules and an ion exchange reaction (IER) approach to customize HPs spatial shapes and composition. Initially, we apply a biomineralization approach, using biological templates (such as biopolymers, proteins, or protein assemblies), modulating the morphology of MCO3 (M = Ca2+, Ba2+) nano/microstructures. We then show that the morphology of the materials can be maintained throughout an IER process to form surface HPs with a wide variety of morphologies. The fabricated core–shell structures of metal carbonates and HPs introduce nano/microcomposites that can be sculpted into a wide diversity of 3D architectures suitable for various potential applications such as sensors, detectors, catalysis, etc. As a prototype, we fabricate disposable humidity sensors with an 11–95% detection range by casting the formed bio-templated nano/micro-composites on paper substrate.

Polymer composites with advanced pigments: enhancing properties and applications

Purpose This study aims to explore the synthesis, characteristics and utilization of polymer composites integrated with cutting-edge pigments. Design/methodology/approach The incorporation of advanced pigments introduces functionalities such as enhanced mechanical strength, thermal stability, ultraviolet resistance and color stability, thus extending the range of applications in diverse fields including automotive, aerospace, electronics and construction. Findings This review discusses the mechanisms underlying the property enhancements achieved through the incorporation of advanced pigments and highlights recent developments in the field. Originality/value Polymer composites incorporating advanced pigments have garnered significant attention in recent years because of their potential to enhance various material properties and broaden their applications. This paper explores the fabrication methods of polymer composites reinforced with organic/inorganic advanced pigments in brief along with their characteristics and applications.

Maximizing the mRNA productivity for in vitro transcription by optimization of fed-batch strategy

In vitro transcription (IVT) is the main manufacturing method to produce mRNA vaccines. In this study, a fed-batch strategy was systematically optimized for IVT process with dual goals of achieving a high reaction rate and maximizing the final mRNA yield simultaneously. Initially various experimental conditions were investigated including Mg2+, nucleotide triphosphates (NTP), dithiothreitol (DTT), spermidine, as well as the temperature and ionic strength. It was found that the concentrations of Mg2+ and NTP had a significant impact on IVT process. Subsequently, under the optimized conditions, dividing the IVT reaction into three distinct phases was proposed to enable more efficient transcription. By optimizing the concentrations of Mg2+ and NTP in two replenishment processes, our fed-batch strategy resulted in the production of 367.8 μg of mRNA with reduced dsRNA byproducts within 180 min. This was achieved under conditions of a final volume of 30 μL, 250 U T7 RNA polymerase (RNAP), and 2 μg DNA template. In conclusion, the IVT process using a fed-batch approach, rather than an excessive one-time NTP input, is an efficient method to improve productivity given a fixed amount of T7 RNAP and DNA template.