Strategy For Fabrication Research Articles

Conductive Hydrogel Materials for Flexible Supercapacitor Electrodes

Flexible supercapacitors (SCs), as promising energy storage devices, have shown great potential for both next-generation wearable electronics and addressing the global energy crisis. Conductive hydrogels (CHs) are suitable electrode materials for flexible SCs on account of their intrinsic characteristics and functional advantages, such as a unique 3D porous structure, remarkable conductivity, tunable chemical and physical properties, and outstanding mechanical properties. Herein, an overview of the fabrication strategies for CHs as electrode materials in flexible SCs, as well as their advantages and disadvantages, and perspectives on CH-based SCs is provided. First, the fabrication strategies for CHs are systematically introduced. Second, various multifunctional CH-based SCs are presented and discussed. Finally, this review concludes with insights into the challenges and opportunities related to CHs or CH-based SCs, indicating future research prospects and application orientations in this field.

Liquid-Phase Fabrication of Janus 2D Materials: Defect-Rich MoS2 Ultrathin Layers Asymmetrically Decorated with Au Nanoparticles.

Asymmetrically decorated nanoparticles (NPs), also known as "Janus nanoparticles", possess at least two differently functionalized surfaces. This coexistence results in novel features that surpass the inherited benefits of the initial counterparts. Despite significant advances in spherical morphologies, research on Janus two-dimensional (2D) materials is limited, as fabrication strategies primarily focus on dry deposition techniques. To produce Janus 2D materials in large quantities, solution-based techniques are proposed. However, this approach remains largely unexplored for 2D materials other than graphene and its derivatives, and it yields Janus 2D materials in very low amounts. This study develops a liquid-phase fabrication strategy for the asymmetric decoration of MoS2 ultrathin layers with gold nanoparticles. This approach builds on previous advances in the asymmetric functionalization of spherical nanoparticles, using SiO2 microbeads as a masking template. Interestingly, the photoluminescence (PL) spectrum of the processed material is unusually dominated by the B exciton emission. The reported versatile method has proven to be scalable, enabling the production of 2D Janus flakes in appreciable quantities, whether as 1T or 2H-polytypes. Overall, the novel synthetic strategy is highly adaptable and can be extended to a variety of other 2D materials and functionalizing agents.

Making aerogel films like playing LEGO: A universal fabrication strategy for Kevlar based aerogel films with arbitrarily designed functions

Highly flexible, ultrathin and mechanically robust aerogel films activated by functional nanofillers exhibit tremendous potentials for wide applications. However, it is difficult to design different functionalities in a single aerogel film, as different nanofillers often possess opposing properties. Herein, a LEGO®-inspired fabrication strategy to construct Kevlar-based aerogel film with arbitrarily designed functions is introduced by stacking functionalized aerogel film units as stacking LEGO® bricks. The aerogel film units are reliably connected by precursor dispersion-derived LEGO® embossed nodes, leading to superior mechanical strength. Moreover, owing to the flexibility of the LEGO®-inspired assembly method, targeted functions of the aerogel films can be achieved by designing and purposefully combining various stacks. As demonstrations, optimized joule heating, greatly enhanced electromagnetic wave shielding and excellent flame-retardant properties are realized with stacking of different aerogel film units. The unique fabrication strategy opens up opportunities for the design and fabrication of aerogel film with tunable and tailored properties for wide applications.

Ultrathin surface-amination-modified membrane with ion-charge shielding effect for ultraselective nanofiltration

While membrane-based separation represents the preeminent technology for addressing the global challenge of water scarcity through desalination and potable wastewater reuse, existing nanofiltration membranes with monocharged surface properties remain deficient at achieving high-precision selectivity for harmful constituents with varying chargeability. In response to these issues, a membrane fabrication strategy was devised in this study to achieve ultraselective separation; essentially, a neutral-charged polyamide-based membrane was prepared by grafting of polyallylamine (PAA) onto the terminus of carboxylic nanochannels. The PAA monomers, which had controllable amine sites, were aligned at the membrane interface to neutralize the surface charge and minimize the pore size. The newly developed ultrathin (~23-nm thickness) surface-aminated membrane, with intensified ion-charge shielding and promoted size-exclusion effects, achieved remarkably precise separation property for a wide range of solutes, including near-perfect rejection of mixed-charge multivalent ions, near-complete removal of various trace emerging contaminants (ECs), and high boron retention (>74.7 %). The PAA-modified membrane demonstrated an exceptionally comprehensive desalination performance that exceeded the existing upper bound of ion permselectivity versus water permeability (14.2 L·m−2·h−1·bar−1), thereby surpassing state-of-the-art nanofiltration membranes.

Comparison of ultrasound and high-pressure homogenization emulsification: A promising fabrication strategy for total nutritional double emulsion-based product enriched with low-molecular-weight oyster peptides

Comparison of ultrasound and high-pressure homogenization emulsification: A promising fabrication strategy for total nutritional double emulsion-based product enriched with low-molecular-weight oyster peptides

Recent Advances in Biomaterial‐Based Scaffolds for Guided Bone Tissue Engineering: Challenges and Future Directions

ABSTRACTBone tissue engineering (BTE) has emerged as a promising approach for the regeneration and repair of bone defects caused by trauma, disease, or aging. This review provides an overview of recent advancements in BTE, with a focus on the development and application of biomaterial‐based scaffolds, including natural (e.g., collagen, chitosan), synthetic (e.g., polylactic acid [PLA], polycaprolactone [PCL]), and composite materials (e.g., hydroxyapatite‐based composites). It discusses their properties, benefits, and limitations. Additionally, this review examines innovative fabrication strategies such as 3D printing, electrospinning, and freeze‐drying, which enhance scaffold customization and performance. This review aims to provide insights into future directions of BTE research and its potential applications in regenerative medicine. Functionalization strategies, including surface modifications, coating, and the incorporation of growth factors and cells, are reviewed for their roles in improving scaffold bioactivity. In vivo and in vitro research have demonstrated the therapeutic promise of these scaffolds, while current clinical trials offer insights into their translational use. Challenges facing the translation of these technologies into clinical practice are also highlighted.

Enhancing strength and ductility synergy through heterogeneous laminated structure design in high-entropy alloys

Heterogeneous laminated structure (HLS) design offers new opportunities to enhance the mechanical performance of high-entropy alloys (HEAs) through synergistic effects from heterogeneity. However, it remains challenging to introduce the HLS into HEAs via severe plastic deformation due to their strong work-hardening capacity. In this study, a specially designed multi-level HLS, characterized by alternatively stacked micro-grained soft CoCrFeNi layers and nanostructured ultra-hard Al0.3CoCrFeNi layers containing a three-phase microstructure (composed of nanograined face-centered cubic matrix, (Al, Ni)-rich B2 precipitates, and Cr-rich σ precipitates), is controllably introduced into FCC HEAs via a conventional thermo–mechanical processing involving hot-pressing, cold-rolling, and annealing. Meanwhile, thermo–mechanical processing induces Al element diffusion across the layer interface, resulting in the formation of an interfacial transition layer and the establishment of a strong interface bonding between the neighboring CoCrFeNi and Al0.3CoCrFeNi layers. As a result, the multi-level HLSed CoCrFeNi/Al0.3CoCrFeNi composite exhibits a yield strength as high as 1127±25.4 MPa while maintaining a large fracture elongation (up to (26.3±2.4)%). Such an excellent strength–ductility synergy surpasses that of most previously reported high-performance monolithic bulk CoCrFeNi and Al0.3CoCrFeNi HEAs prepared through careful chemical composition optimization and/or thermo–mechanical processing. Strong hetero-deformation induced strengthening benefited from the apparent microstructural/microhardness difference and the strong interface bonding between the neighbouring CoCrFeNi and Al0.3CoCrFeNi layers, together with simultaneous activation of multiple strain hardening mechanisms containing mechanical twinning, stacking faults and precipitation strengthening, is responsible for the excellent strength–ductility combination. This multi-level HLS and its fabrication strategy provide an enlightening way to develop strong and ductile HEAs and can also be applied to high-performance designs of other metallic materials.

Cellulose acetate-decorated and siloxane-modified hydrophobic melamine foam with excellent selectivity and durability for efficient oil/water separation

The construction of hydrophobic porous adsorption materials, which are cost-effective, green, stable, and efficient, are urgently demanded for the large-scale and effective oily wastewater treatment. Herein, a facile and low-cost two-step fabrication strategy of hydrophobic melamine foam (MF) was demonstrated, including cellulose acetate (CA) decoration and siloxane modification. Cellulose acetate initially assembled on the skeleton of MF with the aid of hydrogen bond formation between the hydroxyl groups of CA and imimo groups of MF. At an optimal concentration of CA, the as-prepared composite foam (CA/MF) exhibited good hydrophobicity. To further improve the oil/water selectivity, the above foam was enhanced by chemical vapor deposition (CVD) of methyltrimethoxysilane (MTMS). The successful silicification reaction between CA/MF and MTMS decreased the surface energy and improved the surface topological structure, leading to excellent hydrophobicity (water contact angle of 147.4°) and superoliophilicty. Such hydrophobized cellulose acetate/melamine foam (H-CA/MF) presented low density, favorable porosity (97.78%), and distinguished pore volume (88.66 mL/g), leading to a high oil adsorption capacity of up to 56.6 g/g. Due to the excellent mechanical elasticity of H-CA/MF, the oil absorption and recovery can be achieved easily by a simple manual adsorption-squeezing method and lab-made pump-assisted separation device with satisfactory recyclability. Moreover, H-CA/MF displayed marvelous stability and environmental adaptability in different harsh environment, further enlarging its practical application scenarios. Along with the green and cost-effective preparation process, the present study provides a facile strategy to fabricate hydrophobized melamine-based foam, which is of great significance for scalable and efficient oil/water separation.

Advanced functional polymer materials for biomedical applications

AbstractPolymer structures are essential in biomedical applications due to their biocompatibility, biodegradability, and ability to form intricate structures on micro‐ to nanometer scales. This review, emphasizing electrospinning and phase inversion techniques, examines the fabrication strategies and chemical design of polymer structures for biomedical use. Electrospinning, particularly needleless electrospinning, produces nanofibres with high porosity and flexibility and is widely applied in tissue engineering and drug delivery. Phase inversion, including thermal, nonsolvent‐, vapor‐ and evaporation‐induced phase separation, allows precise control over polymer properties but faces challenges in terms of cooling rates and solvent characteristics. Chemical design through doping, functionalization, cross‐linking and copolymerization enhances the biocompatibility, biodegradability and mechanical properties of polymers, facilitating advanced applications in drug delivery, tissue scaffolding and biosensors. Advanced functional polymers are revolutionizing biomedical fields, offering innovative solutions for therapeutic medicine delivery, disease detection, diagnostics, and regenerative medicine. Despite remarkable progress, challenges, such as scalability, cost‐effectiveness, and environmental impact, persist. This review underscores the transformative potential of advanced polymer materials in medical treatments and advocates for continuous research and interdisciplinary collaboration to overcome existing challenges and fully exploit the capabilities of these materials in improving patient care and medical outcomes. Future perspectives highlight enhancing precision control mechanisms, integrating phase inversion with other techniques and developing large‐scale production methods to advance the field further.

A Global Snapshot of 3D-Printed Buildings: Uncovering Robotic-Oriented Fabrication Strategies

This paper aims to provide a global snapshot of concrete 3D-printed buildings and to uncover robotic-oriented large-scale fabrication strategies. Therefore, an extensive internet search and literature review was carried out to investigate 3D-printed buildings. In this study, 154 construction projects with 204 buildings were systematically recorded and evaluated from 2013 up to 2023. Using an exploratory mixed-methods approach and a comparative case study analysis, a total of 88 3D-printed buildings were first evaluated descriptively. Thereafter, different existing printing strategies for in situ, on-site, and off-site production were identified, using an iterative approach. In addition to the geographical distribution, the descriptive evaluation also showed the key players as drivers for the spread of the 3D-printing technology and the correlations between printer type, fabrication strategy, and the building size. With regard to the printing strategy, three different approaches for in situ and off-site fabrication can be defined, depending on the printer types and their characteristics (work size and mobility): print-in-one-go, horizontal or vertical segmentation, and the multi-element vs. full-scaled wall strategy. However, the study showed that the data quality was sometimes difficult due to a lack of information and essential details of the printing process and segmentation.

Bioinspired Hydro- and Hydrothermally Responsive Tubular Soft Actuators.

Soft actuators made of thermoresponsive polymers have great potential for intelligent robotics and biomedical devices due to their reversible deformation capability in response to temperature fluctuations. However, they are constrained by a predefined phase transition temperature, limited directional deformation, and nonbiocompatible formulations, thereby restricting their practical utility. Herein a new biomimicry approach is presented to overcome these limitations by developing hydro- and hydrothermally responsive soft actuators made of biocompatible and pliable materials i.e. cotton yarn and polyurethane. We mimic the tubular shape of elephant trunks with their unique muscle orientation by embedding a helical cotton yarn within a hydrophilic polyurethane tube, followed by targeted surface patterning. Unlike the narrow-range shape morphing across the phase transition temperature boundary of typical thermoresponsive hydrogel actuators, we harness hydrothermal stiffness variations in polyurethane to obtain consistent morphing capabilities over a much wider temperature range. The developed actuators can perform versatile activities such as linear, bending, curvilinear, and rotating movements, overcoming the unidirectional motion limitations of conventional soft actuators. The cell viability assay on the building block materials also confirms the high biocompatibility of the actuators. The reported facile fabrication strategy provides new insights for designing complex yet free-standing soft actuators from readily available supple materials.

High-performance cobalt-embedded SiC nanofiber fabric for microwave dissipation

The incorporation of magnetic ingredients is critical for ceramic-based microwave absorbers with high efficiency. However, this task is becoming challenging due to the dispersion and oxidation issues. In this study, metal-organic framework (MOF) ZIF-67 was employed as the precursor of magnetic compounds and combined with a polymer solution to fabricate SiC textiles using the electrospinning technique. The microstructure analysis confirmed the successful introduction of MOF particles within the SiC nanofibers. Further examination of chemical compositions and magnetic properties revealed the encapsulation of magnetic compounds in hybrid SiC textiles. Since the applied fabrication approach ensures a superior dispersion and protection of metal compounds in a ceramic matrix, the microwave absorption of SiC fabric with both dielectric loss and magnetic loss exhibits a high reflection loss of −59.4 dB and a wide effective absorption band of 5.70 GHz. The current fabrication strategy for fabricating microwave absorbers with dual loss mechanisms advances the development of ceramic-based microwave absorption materials.

An effective strategy for the continuous fabrication of melt‐spun sea‐island bicomponent fibers with structural regulation via stretching

AbstractControlling viscosity in bicomponent melt spinning is crucial for ensuring spinnability and interfacial stability. However, the significant difference in viscosity between PPS and CoPET poses a challenge to establishing the CoPET‐PPS sea‐island melt spinning system. Herein, the viscosity of PPS is regulated by blending high melt index PPS with spinning grade PPS, resulting in a viscosity ratio of CoPET to PPS over 0.5, thereby demonstrating the good spinnability of the CoPET‐PPS spinning system. The mathematical models for velocity, shear rate, and pressure distribution of CoPET‐PPS melts within the sea‐island spinning assembly are developed using Polyflow software, providing theoretical analysis for sea‐island melt spinning. CoPET‐PPS sea‐island bicomponent fibers are successfully fabricated via the facile bicomponent melt spinning technique, guided by the results of capillary rheology and simulation analysis. In addition, the condensed state structure and mechanical properties of CoPET‐PPS sea‐island fibers are significantly enhanced with increasing draw ratios. This straightforward strategy, combined with experimental and numerical simulations, is anticipated to effectively improve the spinnability of multicomponent melt spinning, especially in cases of significant viscosity differences between polymers.Highlights The CoPET‐PPS spinning system was constructed by regulating PPS viscosity. The distribution of the CoPET‐PPS melt in the spinneret holes was simulated. CoPET‐PPS fibers were fabricated based on rheology and simulation results. The mechanical properties of CoPET‐PPS fibers improve with higher draw ratios.

Tight focusing of fractional-order topological charge vector beams by cascading metamaterials and metalens

Vector beams have attracted widespread attention because of their unique optical properties; in particular, their combination with tight focusing can produce many interesting phenomena. The rise of 3D printing technology provides more possibilities for exploration. In this work, a cascading method involving a metamaterial and a metalens is used to generate a tightly focused field of vector beams in the terahertz band, which is prepared via 3D printing. As a proof-of-concept demonstration, a series of metamaterial modules capable of generating states of different orbital angular momentum are proposed by cascading with a metalens. The experimental results are in good agreement with the simulation results, fully verifying the feasibility of the scheme. The proposed design and fabrication strategy provides a new idea for the tight focusing of terahertz vector beams.

Electrospun fine-diameter polyimide nanofiber membranes via metal wire-based needle-free technique for high-efficiency PM0.3 filtration at high-temperature

Polyimide (PI) nanofiber materials have garnered attention in the field of high-temperature filtration due to their exceptional thermal stability. Enhancing their filtration efficiency for fine particulate matter (PM2.5–0.3) and exploring their performance limits under high-temperature conditions are crucial for high-temperature filtration applications. In this study, a metal wire-based needle-free electrospinning technique was employed to electrospin polyimide (PI) material, successfully fabricating nanofiber membranes with an average fiber diameter of 122 nm within just 10 min at an elevated electrospinning voltage of 80 kV (electric field:333.33 kV/m). The Fine-diameter PI nanofiber membrane achieved a filtration efficiency of 99.99 % for PM0.3 and operated at a low resistance of 189.18 Pa. After continuous treatment at a high temperature of 390 °C for one hour, the Fine-diameter PI nanofiber membrane still maintained a filtration efficiency of 99.96 % for PM0.3 and was capable of completely filtering PM2.5. This demonstrates the excellent stability and reliability of the Fine-diameter PI nanofiber membrane under extreme temperature conditions. Additionally, the membrane exhibited outstanding hydrophobic properties, with a static contact angle of 130 ± 3°, aiding in maintaining its filtration performance in humid environments. The Fine-diameter PI nanofiber membrane developed in this study offers a novel fabrication strategy for PM filtration in high-temperature environments and provides new insights into its limit performance.

One-pot fabrication of bio-inspired shape-morphing bilayer structures

Soft bilayer structures capable of shape morphing in response to external stimuli have been commonly adopted in the design of soft robots, flexible electronics and many other smart systems. However, existing methods to fabricate such structures generally require multiple steps and may end up a weak interface between the two layers. Here, we report a one-pot fabrication strategy to generate elastomer-based shape-morphing bilayer structures with a seamless interface. Our strategy leverages on a recently developed bioinspired polymer-NaCl particle composite system which can undergo significant osmotic swelling in water. Bilayer structures are readily formed after the precipitation of NaCl particles in liquid polymers under gravity and the crosslinking of the polymers. The shape-morphing behavior of the fabricated bilayer structures can be well controlled by tuning the particle precipitation kinetics, NaCl content, and crosslinking level of the polymer matrix. More importantly, the bilayer structures fabricated using this strategy exhibit more complex shape-morphing responses than typical bilayer structures. Considering the wide applicability of NaCl particle-induced osmotic swelling of polymer composites, our one-pot bilayer formation strategy will greatly benefit many shape-morphing applications with a simplified fabrication workflow and enhanced configurational versatility.

One-pot microfluidic fabrication of micro ceramic particles

In the quest for miniaturization across technical disciplines, microscale ceramic blocks emerge as pivotal components, with performance critically dependent on precise scales and intricate shapes. Sharp-edged ceramic microparticles, applied from micromachining to microelectronics, require innovative fabrication techniques for high-throughput production while maintaining structural complexity and mechanical integrity. This study introduces a “one-pot microfluidic fabrication” system incorporating two device fabrication strategies, “groove & tongue” and sliding assembling, achieving an unprecedented array of microparticles with diverse, complex shapes and refined precision, outperforming traditional methods in production rate and quality. Optimally designed sintering profiles based on derivative thermogravimetry enhance microparticles’ shape retention and structural strength. Compression and scratch tests validate the superiority of microparticles, suggesting their practicability for diverse applications, such as precise micromachining, sophisticated microrobotics and delicate microsurgical tools. This advancement marks a shift in microscale manufacturing, offering a scalable solution to meet the demanding specifications of miniaturized technology components.

Electrospun Smart Hybrid Nanofibers for Multifaceted Applications.

Smart electrospun hybrid nanofibers represent a cutting-edge class of functional nanostructured materials with unique collective properties. This review aims to provide a comprehensive overview of the applications of smart electrospun hybrid nanofibers in the fields of energy, catalysis, and biomedicine. Electrospinning is a powerful tool to fabricate different types of nanofibers' morphologies with precise control over structure and compositions. Through the incorporation of various functional components, such as nanoparticles, nanomoieties, and biomolecules, into the (co)polymer matrix, nanofibers can be tailored into smart hybrid materials exhibiting responsiveness to external stimuli such as temperature, pH, or light among others. Herein recent advancements in fabrication strategies for electrospun smart hybrid nanofibers are discussed, focusing on different electrospinning tools aimed at tailoring and developing smart hybrid nanofibers. These strategies include surface functionalization, doping, and templating, which enable fine-tuning of mechanical strength, conductivity, and biocompatibility. The review explores the challenges and recent progress in the development of smart hybrid nanofibers. Issues such as scalability, reproducibility, biocompatibility, and environmental sustainability are identified as key for improvement. Furthermore, the applications of smart nanofibers in biomedicine, environment, energy storage, and smart textiles underscore their potential to address the challenges in development of nanostructured materials for emerging technologies.

Flexible yet Durable Microneedle Electrodes Based on Nanowire-Embedded Polyimide for Precise Wearable Electrophysiological Monitoring.

A precise recording of electrophysiological signals requires high-performance flexible bioelectrodes to build a robust skin interface. The past decade has witnessed encouraging progress in the development of elastomeric electrodes for wearable electrophysiological monitoring; however, it remains challenging to achieve excellent flexibility, conformal contact, and high durability simultaneously. Herein, we report on an effective method to fabricate flexible yet durable microneedle electrodes (MEs) based on vertically aligned gold nanowires (Au NWs) embedded polyimide (PI), which meet the above three design requirements. The Au NWs embedded PI MEs could build conformal contact with human skin and maintain electrical stability with minimal contact impedance by effectively penetrating the stratum corneum of the skin. In comparison studies, we found our MEs outperformed conventional gel or elastomeric soft electrodes. We further integrated the vertical Au-NW MEs into a wearable healthcare system and achieved wireless real-time recordings of electromyography (EMG) and electrocardiography (ECG) with high signal-to-noise ratios (SNRs) and low motion artifacts. Our fabrication strategy opens a new route to improve the durability and reliability of emerging nanomaterial-based soft bioelectrodes for long-term wearable healthcare applications.

Growing polyion complex micelles: kinetics and mechanism of electrostatic template polymerization and assembly

HypothesisElectrostatic-templated polymerization (ETP) is a recently developed strategy for robust fabrication of stable polyion complex (PIC) micelles with regulated size and morphology, yet the kinetics and mechanism about this one pot process remain elusive. ExperimentsIn ETP method, ionic monomers are polymerized in the presence of an oppositely charged ionic-neutral diblock copolymer as template. We investigate the monomer conversion and electrostatic assembly as a function of time, under different polymerization conditions of ionic strength, pH, template/monomer molar ratio and the presence of a cross-linker. FindingsThe template copolymer accelerates the monomer conversion and formation of PIC micelles dependent on ionic strength and pH. The process follows the “Pick-up” mechanism, where monomers first convert into oligomers which complex with template to induce further chain growth and electrostatic assembly. Introducing cross-linker hardly impacts the reaction kinetics and “Pick-up” route, while it creates PIC micelles containing cross-linked ionic network assembly with the template. Further removing the template by concentrated salt provides purified ionic nanogels. The disclosed findings not only provide a better understanding of the polymerization-assembly process, but also optimize the controls of electrostatic-templated polymerization for the rational design and fabrication of diverse PIC micelles and polyelectrolyte particles.