Search Results (174)

The dynamic spreading behavior of droplets impacting surfaces with different wettability is a critical hydrodynamic issue in industrial applications such as inkjet printing, spray cooling, and pesticide spraying. The maximum spreading diameter coefficient (${\beta }_{max}$) is the key parameter characterizing this process. Existing theoretical models often overlook the gravitational potential energy of droplets, resulting in significant discrepancies between the calculated viscous dissipation times and experimental results, which compromises the prediction accuracy. In this study, we incorporated gravitational potential energy into the energy balance system based on the principle of system energy conservation. We introduced the Bond number (Bo) to characterize the coupling effect of gravity and surface tension. By fitting experimental data, we corrected the viscous dissipation time, obtaining $t_c$ = 3.17$d_0/v_0$, which improves the reliability of dissipated energy calculation. Using Young’s equation and the Cassie model, we derived a fourth-order ${\beta }_{max}$ prediction model that includes the Weber number (We), Reynolds number (Re), contact angle (${\theta }_c$), and Bo number. The results show that regulating the impact height and droplet diameter will affect the trend of the maximum spreading coefficient model curve: the crossover Weber numbers are 41.519 and 41.530 for different liquid viscosities under the specific experimental and modeling conditions of this study. Below these thresholds, the maximum spreading diameter coefficients are more sensitive to impact height (inertial and kinetic-energy) than to droplet diameter (volume, mass, surface energy, gravitational potential energy, Bond number). Above the critical value, the influence of droplet diameter on the maximum spreading diameter coefficient becomes more pronounced. These intersections reflect the balance between size-dependent effects and impact-inertia-related effects under specific conditions, rather than universal physical thresholds. Compared with selected classical models, the proposed model shows better consistency with experimental data and provides improved prediction for the maximum spreading coefficient of water droplets on surfaces with different wettability. This study supplements the perspective of energy analysis for the modeling of droplet impact dynamics, and can provide a basis for the theoretical optimization of spray systems and interfacial fluid control. Full article

The integration of advanced additive manufacturing technologies, particularly 3D printing (3DP), also known as Additive Construction (AC), could influence a shift in the construction industry towards improved efficiency and automation. This research evaluated the effect on hardened properties of two different concrete mixes for use in 3DP based on the presence or absence of alkaline-resistant (AR) glass fibers. Furthermore, three different curing methods were evaluated: air-curing, plastic-covered curing, and spray-curing. Concrete beams were printed for flexural testing, and cores were taken from other depositions to evaluate compressive strength and split-tensile strength. An analysis of the size and location of cracks on the beams after curing was performed for the different mixes and curing methods. For beams without fibers, plastic-covered curing produced the highest flexural modulus values, and air-curing produced the lowest flexural modulus values. Plastic-cured beams with fibers had higher flexural modulus values than the air-cured beams with fibers. However, the spray-cured beams with fibers produced somewhat anomalous results, with one flexural modulus value being larger than those of the plastic-cured beams, and the other flexural modulus value being less than those of the air-cured beams. All 28-day compressive strengths and split-tensile strengths across mixes and curing conditions fell within a small band ranging between ~19.3–22.1 MPa and ~1.7–2.0 MPa (~2800–3200 psi, and 240–290 psi), respectively. There was a large amount of scatter in some of the tests. It appears that neither the presence of the AR-glass fibers, nor the type of curing had a large influence on compressive strength or split-tensile strength. Results showed that the addition of fibers and the use of the plastic during curing significantly reduced the occurrence, the width, and the depth of cracks as a result resulting from the curing process. Plastic-curing was the most effective curing method for minimizing the occurrence of cracks. Any cracks that formed during plastic-curing were extremely fine and had little or no effect on mechanical properties. Full article

Extrusion-based three-dimensional food printing requires inks that can be smoothly extruded while maintaining sufficient structural stability after deposition. In this study, gelatin and κ-carrageenan were first mixed and then subjected to post-mixing pH regulation before spray drying, producing composite powders with different structural states. These powders were incorporated into yellow peach pulp gels to prepare fruit-based printing inks, and their printing performance, extrusion behavior, mechanical properties, particle-size distribution, and microstructure were systematically evaluated. The results showed that the structural state formed during gelatin–κ-carrageenan powder preparation was closely associated with the extrusion stability and shape retention of the final inks. Among the tested formulations, the ink prepared with gelatin–κ-carrageenan powder pre-regulated to pH 4.0 exhibited the best overall printability. Although its pore-area fidelity was slightly lower than that of the sample pre-regulated to pH 3.5, it produced more stable multilayer cylinders and better-defined lattice structures. In addition, the pH 4.0 sample showed the lowest and most stable extrusion force and the highest Young’s modulus, indicating a favorable balance between extrusion flowability and post-deposition support. Microstructural observations and particle-size analysis suggested that pH regulation altered the aggregation state and local morphology of the gelatin–κ-carrageenan system. Samples prepared at higher pH values tended to form larger and less uniform aggregates, which was unfavorable for stable extrusion and shape retention. Overall, post-mixing pH regulation of gelatin–κ-carrageenan provides a practical strategy for improving the printing-related properties of fruit-based gel inks. Full article

Children are often underserved by adult-oriented oral medicines, leading to off-label use and dosage-form manipulation that may compromise dosing accuracy. This review summarises recent advances in paediatric orodispersible tablets (ODTs), focusing on manufacturing technologies, superdisintegrants, taste masking, and in vitro disintegration testing. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance and a protocol registered with the International Platform of Registered Systematic Review and Meta-analysis Protocols (registration number INPLASY2025110022), we searched PubMed, EMBASE, MEDLINE, Scopus, and Google Scholar for experimental studies on paediatric-relevant ODT formulation and evaluation. Two reviewers screened studies and extracted data on manufacturing methods, excipients, disintegration/dissolution testing, and key outcomes. Risk of bias was assessed using a six-domain framework. Overall, 65 studies met the inclusion criteria for this review. Direct compression was the dominant method, with freeze-drying, sublimation, spray-drying, nanoparticle-in-tablet systems, and semi-solid extrusion/3D printing also reported. Crospovidone, croscarmellose sodium, and sodium starch glycolate were the most common superdisintegrants, while natural and co-processed disintegrants showed promise as cost-effective alternatives. Disintegration was usually assessed using pharmacopoeial methods, with some modified set-ups to better simulate oral conditions. Paediatric ODT development is advancing rapidly. Broader translation requires harmonised disintegration testing, age-stratified acceptability reporting, and GMP-ready workflows, alongside benchmarking of superdisintegrants and attention to dose flexibility, packaging, and affordability. Full article

The ability to efficiently tailor the surface properties of layered transition metal dichalcogenide (LTMD) dispersions is critical for optimizing performance and enabling scalable manufacturing techniques, such as spray coating and inkjet printing, for optoelectronic, energy storage, and sensing applications. Group VI LTMDs, owing to their unique properties in the monolayer architecture, offer exceptional potential; however, the properties of exfoliated dispersions are strongly dependent on the specific solution-processing techniques employed. These techniques determine the choice of subsequent surface functionalization strategies and, consequently, the characteristics of the resulting functionalized hybrids. Furthermore, the inherent heterogeneity of solution-processed dispersions—manifested, among other factors, in broad distributions of flake thickness and lateral size—remains a significant challenge and strongly influences the behavior of hybridized materials. As a result, exfoliation-method-dependent properties and dispersion heterogeneity introduce substantial complexity in the selection of appropriate surface-tailoring strategies, characterization methodologies, and data interpretation. To address these challenges, we systematically classify exfoliated Group VI LTMD dispersions according to their exfoliation methods and highlight recent findings that challenge previously accepted assumptions in the field. Finally, we provide perspectives on surface functionalization approaches for Group VI LTMDs and discuss key limitations associated with the characterization of these newly hybridized materials. Full article

Background/Objectives: Among vat polymerization technologies, liquid-crystal display (LCD) 3D printing has gained popularity in dentistry because of its affordability and acceptable resolution. However, the factors influencing the dimensional accuracy of LCD-printed surgical splints, particularly build platform position, remain insufficiently investigated. This study aimed to evaluate the influence of build platform position on the trueness and precision of orthognathic surgical splints fabricated using LCD 3D printing technology. Methods: Thirty-six surgical splints were printed from a master digital file using an LCD 3D printer. All surgical splints were printed with a 90-degree layer orientation to the building platform. The layer thickness was set at 100 μm. The surgical splints were divided into three groups according to their printing position on the building platform: middle (M), left (Lt), and right (Rt). Each 3D-printed surgical splint was sprayed with an opaque scanning spray and then rescanned to create digital files for testing. A surface-based superimposition and deviation analysis was performed using specialized 3D software to evaluate accuracy of surgical splints. Root mean square error (RMSE) values were statistically analyzed. Results: There were no statistically significant differences in trueness among the middle, left, and right printing positions on the build platform (p > 0.05). In contrast, printing position significantly affected precision, with surgical splints printed at the center of the build platform demonstrating significantly lower RMSE values compared with those printed at the left and right positions (p < 0.001). In addition, no significant difference in precision was detected between the left and right positions. Conclusions: The printing position on the build platform significantly influences the precision of orthognathic surgical splints fabricated using LCD 3D printing technology. Splints printed at the central region of the build platform exhibited the highest precision, whereas trueness was not significantly affected by printing position. These findings suggest that preferential placement of surgical splints at the center of the build platform may improve fabrication consistency and predictability in digital orthognathic surgery workflows. Full article

Pulmonary drug delivery has emerged as a powerful strategy for the treatment of respiratory infectious diseases, including bacterial, fungal, and viral infections such as influenza and COVID-19, by enabling high local drug concentrations while minimizing systemic exposure. However, the clinical success of inhaled anti-infective therapies critically depends on the precise engineering of particle properties that govern lung deposition, cellular targeting, and therapeutic efficacy. In this review, we provide a comprehensive and technology-driven overview of cutting-edge formulation and manufacturing strategies for pulmonary drug delivery, with particular emphasis on the key process and formulation parameters required to generate effective inhalable systems for the treatment of infectious diseases. Advanced particle-engineering approaches, including spray drying, spray freeze drying, jet milling, and supercritical fluid technologies are discussed as enabling tools to tightly control aerodynamic particle size, morphology, and solid-state properties. In parallel, emerging platforms such as nanoparticle-based delivery systems are examined for their ability to target specific lung cell populations, including epithelial cells and alveolar macrophages, thereby enhancing antimicrobial efficacy. Finally, innovative manufacturing concepts such as microfluidics and three-dimensional (3D) printing are highlighted as promising strategies to improve particle size uniformity, reproducibility, and formulation customization. By integrating formulation science with advanced manufacturing technologies, this review identifies the critical design and processing parameters that underpin effective pulmonary delivery of anti-infective therapies and outlines future directions for the development of next-generation inhaled treatments. Full article

In vitro models of the human nasal cavity are crucial for understanding the deposition dynamics of nasally administered drugs. Three-dimensional (3D) printing offers a powerful method for creating patient-specific, anatomically precise models for such experimental purposes. Background/Objectives: This study details the complete workflow for the development, design, and fabrication of a sectioned nasal cavity model intended for droplet deposition analysis of nasal sprays. Methods: A digital nasal cavity model was derived from medical imaging data and optimized for computer-aided design (CAD) operations. It was segmented into five therapeutically relevant regions: nasal vestibule, olfactory area, middle and upper turbinates, lower turbinate, and nasopharynx. Sections were 3D-printed in polypropylene for chemical compatibility, and a carbon fiber-reinforced fixation frame ensured precise alignment and airtight assembly. Results: Functional validation confirmed the model’s functional relevance through comparative deposition studies using automated actuation and high-performance liquid chromatography (HPLC) based regional quantification. Two devices with distinct spray characteristics (characterized separately by laser diffraction, plume geometry, and spray pattern imaging) were tested under varied administration conditions. The study demonstrated the model’s ability to discriminate between products, establishing a solid foundation for future investigations incorporating additional variables. Conclusions: Overall, the developed methodology provides a cost-effective and replicable platform for producing anatomically accurate, sectioned nasal cavity models. The newly developed in vitro system is well suited for detailed, region-specific analysis of nasal spray deposition, offering a valuable tool for pharmaceutical research and development. Full article

Droplet impact on porous mesh surfaces is a common phenomenon in fields such as thermal management systems, biomedical manufacturing, and precision agriculture. As a substrate with microstructures, the mesh surface allows liquid penetration upon droplet impact. The resulting loss of liquid mass significantly alters the impact dynamics of the residual droplet on the surface. This study experimentally compares the behavior of water droplets impacting superhydrophobic mesh surfaces with different pore sizes against that on smooth surfaces. It focuses on analyzing how liquid penetration affects parameters such as spreading time ($t_s$), maximum spreading factor (${\beta }_{max}$), contact time ($t_c$), and droplet height ($h$). The results show that the substantial liquid loss induced by large-pore meshes directly leads to a marked decrease in spreading time and maximum spreading factor. Furthermore, the “pancake bouncing” phenomenon observed on the superhydrophobic mesh surfaces significantly shortens the contact time, providing a new perspective for minimizing the contact duration between droplets and solid surfaces. By establishing the correlation between pore size and droplet impact behavior, this study provides key structural design guidelines for applications such as advanced printing systems and efficient pesticide spraying, thereby achieving the goal of proactively regulating liquid dynamics through surface microstructure. Full article

ZnO thin-film ultraviolet photodetectors are widely used in the military, space, environmental protection, medicine, and other fields. Accurate printing of ZnO photoelectric-sensitive films plays a key role in the detection results. Therefore, obtaining printing technology with a simple process and high precision has become a challenge for ZnO photoelectrically sensitive films. By adjusting the distance between the nozzle and the collecting plate, the jet is atomized in a straight line and deposited directly on the collecting plate, which effectively improves the stability and controllability of the jet spraying and deposition processes. ZnO thin films with a uniform distribution of nanoparticles, significantly improved density, and controllable deposition area linewidth were successfully prepared. The effects of different ZnO film structures on the performance of ultraviolet photodetectors were tested. When the ultraviolet light intensity is 500, 1000, and 2500 mW/cm², the $I_{light}$ of the photodetector is 4.62, 9.38, 14.67 mA, The on/off ratio ($I_{light}$/$I_{dark}$) is 20.7, 42.1, 65.8, implying satisfactory photoelectric performance as well as high stability and repeatability, providing an effective technical means for the precise printing application of micro-nano functional devices. Full article

The miniaturisation of electronic devices has intensified the demand for compact, high-performance lithium-ion batteries. This review synthesises recent progress in microscale battery development, focusing on microfabrication techniques, nanostructured materials, porosity-engineered architectures, and strategies for reducing non-active components. It explores both top–down and bottom–up fabrication methods, the integration of nanomaterials, the role of gradient electrode architectures in enhancing ion transport and energy density, along with strategies to reduce non-active components, such as separators and current collectors, to maximise volumetric efficiency. Advances in top–down and bottom–up fabrication methods, including photolithography, laser structuring, screen printing, spray coating, mechanical structuring, and 3D printing, enable precise control over electrode geometry and enhance ion transport and material utilisation. Nanostructured anodes, cathodes, electrolytes, and separators further improve conductivity, mechanical stability, and cycling performance. Gradient porosity designs optimise ion distribution in thick electrodes, while innovations in ultra-thin separators and lightweight current collectors support higher energy density. Remaining challenges relate to scalability, mechanical robustness, and long-term stability, especially in fully integrated micro-battery architectures. Future development will rely on hybrid fabrication methods, advanced material compatibility, and data-driven optimisation to bridge laboratory innovations with practical applications. By integrating microfabrication and nanoscale engineering, next-generation LIBs can deliver high energy density and long operational lifetimes for miniaturised and flexible electronic systems. Full article

This work investigates the penetration behavior of SiC particles into Digital Light Processing (DLP)-printed thermoset substrates under low-pressure cold-spray conditions, aiming to enhance surface hardness and wear resistance. A coupled simulation framework was established in which particle acceleration was obtained from CFD using ANSYS Fluent, and high-speed impact and embedding were modeled through ANSYS Explicit Dynamics. Two particle diameters (25 μm and 60 μm) were examined across inlet pressures from 2 to 5 bar to evaluate both the continuous influence of pressure and the two-level effect of particle size. Mesh convergence was achieved at a resolution of d_p/20, ensuring numerical stability and computational efficiency. The results showed a strong dependence of penetration depth on pressure and particle size: for 25 μm particles, penetration increased from 0.76 d_p at 2 bar to 1.53 d_p at 5 bar, while 60 μm particles exhibited deeper absolute embedding due to their significantly higher kinetic energy. Response-surface analysis further revealed nonlinear pressure effects and a predominantly linear size-dependent shift. Experimental validation at 3 bar confirmed a penetration depth of approximately 1 d_p, demonstrating good agreement between simulation and physical observation. Overall, the validated workflow provides quantitative insight into particle–substrate interaction in thermoset polymers and offers a practical basis for controlled particle embedding as a surface-strengthening strategy in additive manufacturing. Full article

Continuous use of clear aligners modifies the oral environment and may favor bacterial colonization. Integration of topical fluoride-based agents could strengthen enamel and reduce biofilm formation. This study evaluated the effects of a galenic fluoride-mint spray (225–250 ppm fluoride and 1–2% peppermint essential oil) on salivary fluoride concentration and bacterial biofilm during orthodontic treatment. Ten patients using 3D-printed nighttime aligners were enrolled. Saliva samples were analyzed with an ion-selective electrode (ISE) at baseline, immediately after inserting the sprayed aligners and after 15, 30, 45 min post application. Biofilm morphology was qualitatively assessed by scanning electron microscope (SEM) in three aligners: unused, worn 14 nights without spray, worn 14 nights with spray. Salivary fluoride increased from 0.7–0.8 mg/L at baseline to 5.96 mg/L when the spray was applied on a new aligner and 8.42 mg/L on a used aligner, then progressively decreased, returning close to baseline at 45 min with the new aligner and remaining higher with the used aligner. SEM images showed mature and heterogeneous biofilm on used aligners without the spray, while aligners with nightly spray application exhibited qualitatively reduced and less organized surface deposits. The fluoride- and mint-based spray rapidly increases salivary fluoride and reduces biofilm formation on nighttime clear aligners, improving preventive oral health during orthodontic treatment. Full article

Chemical control of weeds with the herbicide glyphosate under vines in the vineyards is currently easy, effective, and cheap. There are currently no completely equivalent alternative herbicides or suitable mechanical control methods that have the same efficacy in suppressing weeds under vines in vineyards as glyphosate. Therefore, in this research, we tested two alternative technologies for controlling weeds under the vines as a counterweight to the predominant control approach with the herbicide glyphosate: (1) chemical control with pelargonic acid, acetic acid, and the plant extract-based fertilizer Stopeco^® with herbicidal action, and (2) mechanical control with a combined tool consisting of a rotary star tiller and finger weeder. A comparative analysis was conducted on time and fuel consumption, the extent of the carbon footprint, grape yield, and quality, which showed that the tested alternative methods of weed control were not comparable to the herbicide glyphosate in terms of effectiveness in weed suppression but were comparable at grape yield. In our trial, at the number of treatments we performed, differences in environmental footprint between different treatments were significant (glyphosate variant 10.55–11.21 gha anno⁻¹; other variants 7.48–8.08 gha anno⁻¹). Alternative mechanical and chemical methods need to be applied at least three to four times a year to achieve results comparable to those from two applications of glyphosate. For this reason, it is possible that, in the case of a slightly increased number of passes by mechanical tools or a slightly increased number of sprayings with alternative preparations to reach the efficacy level of glyphosate treatments, the foot print parameter, CO₂ emissions and global warming potential (GWP) parameter in alternative treatments would no longer be more favorable than when using the herbicide glyphosate twice a year. Full article

Despite the widespread use of surgical guides, there is no universal sterilization protocol. Surgical guides are often designed for single use, but can become contaminated, which increases the risks of infection and implant failure. This study evaluates the effects of alcohol immersion, alcohol spray, low temperature, and steam sterilization on the dimensional stability of surgical guides to ensure accurate implant placement and reduce failure. One standard dental model was scanned using a laboratory scanner. Ninety guides were printed and were then divided into six groups allocated as control, alcohol spray, alcohol immersion with ultrasonication, low-temperature dry sterilization, and two autoclave methods. Specimens were stored in dry–dark media and scanned at 0, 3, and 7 days, with dimensional changes assessed using CloudCompare. The Shapiro–Wilk, Levene’s, Repeated measures one-way ANOVA, and Tukey’s post hoc tests were used to determine statistical differences. Time significantly affects stability, with RMS values improving over time. Autoclave 121 °C and low-temperature 54 °C sterilization showed the lowest RMS values, indicating better stability. Within the limitations of the present study, the most effective approach for maintaining the dimensional stability of surgical guides was autoclaving at 121 °C, +1 bar for 20 min, and the second-best technique was low-temperature dry sterilization at 54 °C for 1 h. Full article