Search Results (15,735)

This study presents a systematic evaluation of 2-layer conductive Jacquard knitted fabrics with a birdseye backing designed for wearable electronic applications. Three sets of samples with 9 different proportions of conductive yarn (27 samples) are designed on a computerized flat-knitting machine, and three indicators (conductive yarn usage ratio, resistance change ratio after washing, and temperature variation) are examined. The 2-layer Jacquard structure enables conductive yarns to form loops on both the technical face and back, thus producing continuous and interlocked conductive pathways. The experimental results show that the proportions of pattern dots for the conductive yarns determine the amount of conductive yarn used in a 2-layer Jacquard structure with the same technical parameters. For the samples with 10–90% pattern dots, the conductive yarn consumption ratio ranges from 34.80% to 65.18%. After 10 washes, resistance change ratio ranges from 27.66~55.54%, which show a moderate electrical stability. After 10 washes, the heating temperature increases by 15.6 to 19.67 °C, which show good thermal properties. Finally, a fuzzy logic evaluation is conducted with objective indicator weights. The findings provide quantitative evidence for the material–structure integration of conductive knitted textiles and support their potential for applications in next-to-skin smart garments. Full article

This study investigates the fabrication of microcapsules using Nigella sativa (N.S.) oil as the core and alginate as the shell material. The N.S. oil microcapsules were prepared using the sol–gel method with different oil concentrations. The microcapsules were applied to the cotton fabric by the pad–dry–cure method, and their attachment was evidenced by scanning electron microscopy (SEM). Air permeability measurements were conducted for all developed samples, revealing that the sample with 8 g loading of N.S. oil and 4.5 g alginate exhibited a 43% reduction compared to the pristine sample. To further investigate the comfort characteristics of the samples, the functionalized cotton samples were subjected to the water vapor permeability index test. The results yielded an index value of 90, indicating that the encapsulation process preserved the comfort characteristics of the samples. Among the samples, the specimen with an oil concentration of 8 mL displayed the maximum antibacterial performance, achieving a 90% reduction in colony-forming units (CFUs) following quantitative testing protocol. However, the qualitative antibacterial assessment indicates no clear zone of inhibition, but no bacterial growth was observed on the samples. Furthermore, the fabric incorporating the maximum loadings of N.S. oil and alginate capsules exhibited the maximum antioxidant activity of 86.5%. These results underscore the critical role of N.S. oil microcapsules in enhancing the antibacterial and antioxidant properties of cotton fabric, while also revealing a harmony between functional performance and comfort characteristics. Full article

Due to the ultra-trace concentrations of perfluoroalkyl compounds (PFCs) existing in environmental aqueous matrices, it is imperative to develop sensitive and high-enrichment-efficiency approaches for the determination of these emerging pollutants. In this study, a nitrogen-doped carbon dot-functionalized hollow fiber membrane (NCDs@HFM) was fabricated and employed in solid-phase microextraction (SPME) mode for the simultaneous identification of eight perfluoroalkyl carboxylates (PFCAs). The NCDs@HFM offers several advantages, including multiple active binding sites, chemical durability, a large specific surface area and environmental compatibility. Owing to these properties, the NCDs@HFM-based SPME demonstrated high extraction efficiency for PFCAs, where enrichment factors for target molecules could reach 35–61 fold under the optimum conditions. This established method was then integrated with liquid chromatography–tandem mass spectrometry (LC-MS/MS) for the qualitative and quantitative analysis of eight representative PFCAs in drinking and environmental water samples. The limits of detection (LODs, S/N = 3) and quantitation (LOQs, S/N = 10) of the method were at the scale of 0.0018–0.015 μg/L and 0.006–0.050 μg/L, respectively. This proposed method exhibited good precision, with RSDs below 13.2% and satisfactory accuracy, with recoveries ranging from 70.6% to 122.5%. The developed method was successfully applied in the identification of eight typical PFCAs in drinking and environmental water samples. This method exhibits several merits, including low cost, high sensitivity, good reliability and reusability, representing a promising alternative for measuring trace levels of PFCAs in aqueous matrices. Full article

Background: Osteosarcoma (OS) is an aggressive bone tumor. The lack of physiologically relevant three-dimensional models that recapitulate the native tumor microenvironment hampers drug development and mechanistic studies. The study aimed to develop bone-mimetic microspheres for the construction of an OS model. Materials and Methods: We employed droplet microfluidics to fabricate bone-mimetic microspheres (named MSHA) from a composite of gelatin methacryloyl, polyethylene glycol diacrylate, and nano-hydroxyapatite (nHA). MNNG/HOS cells were cultured on MSHA microspheres and subsequently evaluated for their bioactivity and capabilities of stemness, migration, and invasion. Results: The microfluidic platform enabled efficient and scalable production of highly uniform MSHA microspheres with controlled sizes. MNNG/HOS cells cultured on MSHA maintained high viability and spontaneously formed compact tumor spheroids after 7 days. Compared with two-dimensional cultures, cells cultured on these microsphere-based platforms exhibited enhanced migration and invasion capacities, along with increased expression of relevant biomarkers. RNA sequencing further revealed the activation of cancer-related pathways. Notably, the incorporation of nHA into microspheres amplified these malignant phenotypes, potentially through the activation of ECM–receptor interaction and calcium signaling pathways. Conclusions: The microfluidics-fabricated MSHA microspheres, as biomimetic three-dimensional culture scaffolds, offer a promising platform for applications in mechanistic studies of osteosarcoma progression and drug screening. Full article

The translaminar fracture toughness of pultruded Glass Fiber Reinforced Polymers (GFRP) is influenced by several factors, including the type of matrix, fiber, the fiber volume ratio, the proportion of plies at each angle and the size of the test specimens. Conventional test approaches tend to overestimate the fracture toughness of GFRP composites due to imperfect specimen fabrication. This paper introduces an anisotropic two-dimensional adaptation of phase field theory to evaluate the translaminar fracture toughness of pultruded GFRP in conjunction with the size effect. It is found that the fracture toughness is linearly correlated with the fiber volume ratio when the proportion of 0° plies ranges from 30% to 60%. Additionally, it was found that at the same fiber volume ratio, the fracture toughness increases with the increase of 0° plies by 5%. Five machine learning algorithms, i.e., BP, RF, SVR, GA-BP, and PSO-BP, are employed to predict the fracture toughness of pultruded GFRP laminates. It has been found that the PSO-BP algorithm is robust in predicting the fracture toughness of pultruded GFRP laminates, with the correlation coefficient R² being 0.987 and 0.994 in the test and training set, respectively and the prediction error in fracture toughness being less than 4 kJ/m². The trained machine learning method can accurately predict GFRP fracture toughness. When the proportion of 0° plies is larger than 50%, the increase in the fracture toughness is approximately twice that of those taking up a proportion of 30–50%. Fracture toughness predictions are provided using the developed machine learning model for pultruded GFRP profiles, which are commonly used in infrastructure construction with fiber volume ratios range of 60–70% and 0° layup percentages of 60–75%. Full article

The puncture force during sewing is a critical factor affecting sewing quality. In this study, the puncture process is divided into five stages, a mechanical model of the puncture process is established, and a quantitative expression is achieved. Using the ANSYS Explicit Dynamics method, a finite element analysis model of the penetration process was developed to investigate the influence of fabric structure (thickness and warp and weft density) and needle geometric parameters (point height, taper angle, and shank diameter) on penetration force. The results indicate the following: Two distinct force peaks occur during needle penetration—one at the instant of fabric piercing and another when the needle shaft enters the fabric. Increasing fabric thickness causes the former peak to rise significantly, while the latter peak increases more gradually. Puncture force decreases significantly with reduced warp and weft density. When density decreased from 85 × 85 TPI to 80 × 80 TPI, the first peak decreased by 18.5% and the second peak by 67.4%. A further decrease in warp and weft density to 75 × 75 TPI resulted in peak reductions of 58.48% and 20.64%, respectively. Additionally, the needle tip cone angle and tip height are critical parameters affecting the peak penetration force. The comparative analysis of improved standard needle tip cone angles and tip heights demonstrates that the modified machine needles exhibit lower peak penetration forces, confirming the effectiveness of the needle improvement methods proposed in this study. The research methodology and results presented herein provide an effective numerical simulation-based approach for needle selection and penetration force evaluation in fabric piercing and sewing. Full article

Objective: This study investigates the influence of selecting three thermoplastics as raw materials (PLA, PETG, and ABS) on dimensional accuracy, defect formation, and slicer-based mass prediction reliability in FFF 3D-printed UAV micro-frames. Methods: A factorial experimental design combining three materials, two micro-frame geometries, and two infill levels was implemented. Print quality was assessed through structured visual inspection of common FFF defects, while manufacturing reliability was evaluated by comparing slicer-predicted and experimentally measured mass. Dimensional fidelity was quantified at critical motor mount features using repeated micrometric measurements and dedicated accuracy and uniformity indices. Results: The results reveal strong material-dependent behaviour. PLA exhibited the highest dimensional consistency and near-zero mean mass prediction error, PETG showed intermediate performance, and ABS presented significant warping, together with a pronounced positive mass prediction bias. These findings indicate systematic discrepancies between predicted and measured mass values and highlight the need for material-dependent calibration of slicing software. Conclusions: Material selection and process calibration strongly affect dimensional fidelity and manufacturing reliability in FFF-printed UAV micro-frames. The findings provide practical guidance for material choice and slicing parameter adjustment in UAV fabrication and similar small-scale FFF applications. Full article

Background/Objectives: The objective assessment of natural tooth mobility remains challenging in clinical practice. This pilot study aimed to investigate the feasibility, repeatability, and agreement of a modified implant stability measurement system adapted for natural teeth using a custom-fabricated titanium bracket and a modified SmartPeg. Methods: Sixteen systemically healthy patients (10 males, six females) and 94 single-rooted permanent teeth with varying mobility grades were included. The tooth mobility was assessed using the Miller Mobility Index, Periotest M, and resonance frequency analysis (RFA) with the Osstell Beacon device. For the Osstell measurements, a custom titanium bracket bonded to the buccal tooth surface allowed for the placement of a modified SmartPeg. Each tooth was measured twice under standardized conditions, and mean values were recorded. The statistical analyses included Spearman correlation analysis, Cohen’s kappa for agreement with Miller categories, and intraclass correlation coefficients (ICCs) to assess the measurement repeatability. Results: The mean Periotest value was 12.70 ± 13.69, and the mean ISQ (implant stability quotient) value was 69.45 ± 19.37. The repeated measurements demonstrated excellent intra-examiner repeatability for both devices (ICC > 0.95). The Periotest values showed substantial agreement with the Miller mobility grades (κ = 0.763; p < 0.001), whereas the Osstell values demonstrated weak agreement with these ordinal categories (κ = 0.094; p = 0.048). A strong negative correlation was observed between the Periotest and Osstell measurements irrespective of the scales (r = −0.865; p < 0.001). Conclusions: In natural dentition, the resonance frequency analysis demonstrated reproducible measurements under controlled experimental conditions and showed measurable associations with conventional mobility assessments. However, the method remains investigational. The findings do not establish clinical validity for the routine assessment of natural tooth mobility. Further studies with larger sample sizes and statistical models accounting for patient-level clustering are required before clinical implementation can be considered. This study is registered at ClinicalTrials.gov (NCT07188168). Full article

Background/Objectives: Although digital workflows for complete denture fabrication are increasingly implemented in clinical practice, randomized controlled pilot trials directly comparing their clinical performance and patient satisfaction with conventional complete dentures (CCDs) remain scarce. This study aimed to compare patient satisfaction and clinical effectiveness between conventionally and digitally fabricated complete dentures (DCDs). Methods: In the present exploratory randomized controlled clinical pilot study using a cross-over design, 15 edentulous patients received both a conventionally fabricated and a digitally fabricated complete denture in randomized order. Each denture was worn for a three-month adaptation period. Patients were blinded to the fabrication method. Oral health-related quality of life was assessed using the OHIP-G49 questionnaire, and clinical performance was evaluated using standardized criteria at baseline, after three months with the first denture, and after three months with the second denture. Results: Both fabrication methods yielded satisfactory clinical outcomes in all patients. All 15 patients rated the DCDs as highly satisfactory, while 14 patients rated the CCDs equally favorably; one patient was unable to tolerate the conventional denture. DCDs demonstrated a slight but consistent advantage in oral health-related quality of life (OHRQoL) scores. Conclusions: Both conventional and digital complete dentures are clinically effective and well accepted by edentulous patients. However, DCDs offer a modest improvement in patient satisfaction and OHRQoL. Digitally fabricated complete dentures provide comparable clinical results to conventional methods while offering potential advantages in patient comfort and perceived quality of life. Given the exploratory nature of the study and the limited sample size, the results should be interpreted with caution and primarily serve to inform future, adequately powered randomized clinical trials. Full article

Background/Objectives: Resin 3D printing is widely used to fabricate orthodontic diagnostic models, but the practical performance of commercial desktop workflows compared to dental-certified workflows is still debated. This study compared the dimensional accuracy and 7-day stability of maxillary orthodontic models printed from the same master STL file using a dental-certified workflow versus two commercial desktop workflows. Methods: An ISO 20896-1:2019-based reference cast with four 6 mm calibration spheres was used to generate a master STL file. Fifteen models were printed (n = 5 per workflow) using Primeprint™ (dental-certified workflow) and two commercial desktop printers (Anycubic Photon Mono M5s; Phrozen Sonic Mighty 14K REVO). The models were digitized at baseline (T0, ≤48 h) and after 7 days (T7) using a laboratory scanner. Surface superimposition in CloudCompare^® calculated the RMS (root mean square) surface deviation and mean signed deviation, and two calibrated operators performed independent extractions. Results: The mean RMS deviations were <0.10 mm for all workflows at both time points. No between-workflow differences were detected at T0 (H = 2.000; p = 0.368) or T7 (H = 1.520; p = 0.468), no within-workflow T0–T7 changes were significant (all p > 0.05), and the inter-operator agreement was excellent (ICC 0.991–0.999). Conclusions: Under the tested workflows, dental-certified and commercial desktop resin printing produced orthodontic models with a comparable global surface accuracy and short-term dimensional stability. Full article

Silver films are key building blocks for plasmonic and nanophotonic devices, whose optical performance and device reliability are highly sensitive to particulate contamination introduced during fabrication and operation. Herein, a non-destructive surface cleaning strategy specifically applicable to silver film systems is proposed, based on the synergistic regulation of the mechanical properties of a polymer layer and its interfacial adhesion to the silver film. Such regulation is achieved by tuning hydrogen-bond-mediated interactions within a modified poly(vinyl alcohol) (PVA) layer, enabling effective control over the locus of fracture during peeling, such that fracture preferentially occurs at the polymer/silver interface. Unlike conventional polymer-assisted cleaning methods that suffer from an inherent trade-off between bulk cohesion and interfacial adhesion, this approach decouples the two properties through molecular-level hydrogen-bond redistribution. As a result, particulate contaminants can be efficiently removed from the silver surface while preserving the structural integrity of the silver film. The proposed method achieves a particle removal efficiency of up to 98% for contaminants larger than 30 nm and can be stably applied to silver films with lateral dimensions ranging from 1 inch to 12 inches, demonstrating excellent scalability. By further adjusting the processing parameters and compositional ratios of the polymer layer, this strategy is expected to be adaptable to silver films with different thicknesses and structural configurations, providing a reliable surface cleaning solution for improving the performance and reliability of plasmonic and optoelectronic thin-film devices. Full article

The Fused Deposition Modeling (FDM) process often produces parts with high surface roughness, limiting their end-use applications, especially in the biomedical field. This paper presents an experimental study on improving the surface finish of 3D-printed polycaprolactone (PCL) samples using a robotic burnishing process. A key innovation is the development of a low-cost sensorless setup using a 5-DOF manipulator, which controls the applied force by correlating a precise robotic displacement with the known stiffness of springs via Hooke’s law. Ten PCL samples were tested using two burnishing directions: 90° (perpendicular) and 0° (parallel) relative to the printing orientation. The as-printed samples showed a highly anisotropic surface. The 90° trajectory (group 1) proved to be more effective in reducing primary roughness ($R_{a_{\perp }}$), lowering the mean $R_a$ from $2.11\mathsf{\mu }\mathrm{m}$ to $1.44\mathsf{\mu }\mathrm{m}$ (a mean reduction of 29.9%). In contrast, the 0° trajectory (group 2) was more effective in reducing roughness $R_{a_{\Vert }}$, lowering its mean $R_a$ from $0.225\mathsf{\mu }\mathrm{m}$ to $0.144\mathsf{\mu }\mathrm{m}$ (a mean reduction of 34.0%). The results demonstrate that the proposed sensorless system is a valid method for surface post-processing of FDM parts when the required forces fall below a specific threshold, ensuring a significant reduction in roughness without damaging the samples. The lower surface roughness obtained with the proposed post-processing strategy may represent a promising approach for improving the surface characteristics of FDM-fabricated polymer scaffolds intended for biomedical applications. Full article

Photolithography is the mainstream technology used in micro/nanofabrication. While projection photolithography is widely used in production, with a resolution close to the wavelength of the light source, its processes are complicated and expensive. Moreover, in projection photolithography, scanning and splicing are required to achieve large-area exposure at the wafer level, which reduces throughput in production. Contact photolithography offers a cost-effective and parallel exposure solution, but achieving uniform resolution over large areas with micrometer or sub-micrometer resolution remains a challenge. In this study, we propose a conformal contact photolithography strategy based on a wafer-scale embedded elastomeric mask. By optimizing metal patterning and embedding transfer processes, we significantly improve the area (wafer-scale) and efficiency (lift-off and metal transfer process within seconds) of metal-embedded elastomeric mask fabrication. This method enables the rapid and cost-effective fabrication of large-area sub-micrometer-resolution structures, with broad applications in the production of sub-micrometer devices and academic research. Full article

Biopolymer-based packaging films possess outstanding performances and are being developed as the alternatives to traditional petroleum-based plastic packaging films with many non-ignorable shortcomings. In this study, chitosan, succinylated pullulan (SP), and berberine (BBR) were combined to fabricate novel biopolymer-based composite films (CSSPB) via the layer-by-layer assembly method. The effects of the incorporation of BBR on the physicochemical properties of the film were investigated. It was found that after BBR was added, the tensile strength (TS), elongation at break (EAB), hydrophobicity, and antioxidant capacities of the film were enhanced. The chemical bonding, crystalline properties, elemental composition, and thermal stability of the films were also characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA), respectively. The in vitro antifungal tests revealed the antifungal activities of the films with a relatively high BBR content against Colletotrichum gloeosporioides (CG). In the preservation experiments, the CSSPB films exhibited preservation effects on fresh-cut apples, which manifested as delaying browning, weight loss, an increase in the soluble solids content, and a decrease in hardness. The new CSSPB composite films were opined to hold application potential in the field of food packaging. Full article

Objectives: This study aimed to compare the retention and fit precision of removable partial denture circumferential clasps fabricated from cast cobalt–chromium, 3D-printed cobalt–chromium, and polyether ether ketone. Methods: A maxillary right first premolar abutment was prepared. Eighty circumferential clasps were allocated into three material groups: cast Co–Cr (n = 20), 3D-printed Co–Cr (n = 20), and PEEK (n = 40). The terminal third of metal retentive clasps was designed to engage 0.25 mm and 0.50 mm undercuts. PEEK clasps were fabricated with two designs: partial (two-thirds) and full-arm undercut engagement. Each group was examined for retentive forces after 1440 cycles (simulating 1 year). Initial and final retentive forces were recorded. Clasp deformation was assessed by measuring inter-arm distance before and after cycling using digital photography and ImageJ software. Results: All clasp groups demonstrated a statistically significant reduction in retention after 1440 cycles (p < 0.05). At both undercut depths, cast and 3D-printed Co–Cr clasps exhibited significantly higher retentive forces than PEEK (p < 0.001). Within the PEEK group, full-arm engagement showed significantly higher retention than partial engagement at the 0.25 mm undercut (p < 0.001), whereas no significant difference was observed between designs at the 0.50 mm undercut (p = 0.406). Fit precision revealed a significant increase in inter-arm distance after cycling (p < 0.05). PEEK clasps exhibited significantly smaller dimensional changes than Co–Cr clasps (p < 0.02). Conclusions: Clasp material, undercut depth, and design significantly influenced retention and fit precision. Co–Cr clasps maintained higher retentive forces, whereas PEEK clasps demonstrated reduced deformation after cycling. Full article