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The aim of this study is to determine experimentally the higher material parameter g$g$ of a metamaterial with a triangular substructure and to verify a higher‐gradient elasticity model for beams with internal substructures or microstructures. The investigations of the higher‐gradient elasticity models of Bernoulli‐Euler and Timoshenko beams with a periodic triangular substructure in Khakalo et al. show that the bending stiffness strongly depends on the geometrical parameters of the lattice structure. To achieve this goal, beams with triangular substructures were additively manufactured using fused deposition modeling and stereolithography. They were experimentally investigated in tensile and bending tests. Three different types of beams with triangular substructures were produced, consisting of one, two and four layers of triangular beams, using two different materials: Polylactide and epoxy resin. The higher material parameter g was quantitatively determined based on the experimental results using inverse analysis. The results are valid for these specific variations of the substructure and can adequately represent the elastic size effects. In addition, this study investigates the relationship between the bending stiffness and the geometric parameters of the lattice structure as well as the influence of the curing time on the elastic properties of epoxy resin. The experiments involved testing the triangular beams under tensile and bending loads. The numerical and experimental results were compared using digital image correlation. Based on the experimental data, a higher gradient material parameter representing the geometric structure of the lattice was determined. [ABSTRACT FROM AUTHOR]

In this study, the fatigue behavior of FDM‐3D printed polylactic acid (PLA) materials was investigated by rotary bending fatigue tests and finite element studies with varying printing speed and raster angle parameters. Fatigue test specimens were manufactured at five different raster angles (0°, 30°, 45°, 60°, and 90°) and two different printing speeds (20 and 80 mm/s). The effect of printing speed was evaluated at high print speed variation range (20 and 80 mm/s print speeds). It was noticed that the change in raster angle affects the fatigue life very significantly. The highest fatigue life was obtained at 30° raster angle, while the lowest fatigue life was found at 90° raster angle. Increasing the printing speed from 20 to 80 mm/s decreased the fatigue life of all specimens. The derived results from the finite element analyses were consistent with the experimental results. Highlights: The fatigue behavior of 3D printed polylactic acid (PLA) materials was examined by rotary bending fatigue tests and FEAs with different printing speed and raster angle parameters.Fatigue test specimens were manufactured at five different raster angles (0°, 30°, 45°, 60°, and 90°) and two different printing speeds (20 and 80 mm/s).The highest fatigue life was achieved at 30° raster angle, while the lowest fatigue life was found at 90° raster angle.Increasing the printing speed from 20 to 80 mm/s decreased the fatigue life of all specimens. [ABSTRACT FROM AUTHOR]

The objective of this research is to explore the scale effect on the mechanical properties of sheet‐based triply periodic minimal surface (TPMS) uniform lattice structures fabricated with PLA (polylactic acid) under quasi‐static loading conditions. The scale dependency was evaluated by two additional breakdown categories, namely, wall thickness effect and unit cell size effect. Deformation mechanisms and failure modes as well as mechanical properties including stiffness, yield strength, first peak stress, and energy absorption based on the categories of wall thickness, unit cell size, and scale were evaluated experimentally. The assessment of the scale effect involved considering the combined influence of wall thickness and unit cell size. In addition, numerical analysis was also performed to investigate the stress distributions and compare with the experimental results for certain geometries. Ultimately, the relation between the normalized mechanical properties and relative density is evaluated and categorized, which can be used as an indication for future design practices. Highlights: Scale, wall thickness, and unit cell size effect of lattice structures were studied.Relative density played a significant role in determining mechanical properties.Unit cell size to wall thickness ratio is critical for different failure mechanisms.Normalized mechanical properties were evaluated for the future design. [ABSTRACT FROM AUTHOR]

Architected metamaterials are known as materials with unique mechanical and topological behavior. This paper presents architected twist-compression metamaterials, which twist around their axis under compression, for energy absorption and effective mechanical properties. The proposed metastrcutures are designed through novel generative algorithms that enable the parametric design in which the geometrical parameters of the produced metastructures are tunable. Several experimental tests were carried out to determine accurate material properties for the finite element analysis and to evaluate the capability of the presented metastructures. Specimens printed from acrylonitrile butadiene styrene (ABS) using fused deposition modeling techniques (FDM). To evaluate the effect of geometrical parameters on the properties of the twist-compression metastructures a four-step parametric study was conducted by virtue of the verified finite element models. These finite element models contain damage criteria to model the failure behavior of the metastrucutures under quasi-static loading. The influencing geometrical parameters on the mechanical properties, as well as energy absorption capacity, have been considered via numerical and experimental analysis. Obtained results showed some unique features of these structures in elastic and plastic behaviors. [ABSTRACT FROM AUTHOR]

The use of biomodels in the laboratory for studying and training cervical laminoplasty has not yet been reported. We propose the use of a cervical spine biomodel for surgical laminoplasty training. This is an experimental study. Ten 3D identical cervical spine biomodels were printed based on computed tomography (CT) and magnetic resonance imaging scans of a patient diagnosed with spondylotic cervical myelopathy. The additive manufacturing method used fused deposition modeling and polylactic acid (PLA) was selected as the raw material. The sample was divided into 2 groups: control (n = 5; the biomodels were submitted to CT scanning) and open-door (n = 5; the biomodels were submitted to open-door laminoplasty and postoperative CT). The area and anteroposterior diameter of the vertebral canal were measured on CT scans. Printing each piece took 12 hours. During the surgical procedure, there was sufficient support from the biomodels to keep them immobilized. Using the drill was feasible; however continuous irrigation was mandatory to prevent plastic material overheating. The raw material made the biomodel CT study possible. The vertebral canal dimensions increased 24.80% (0.62 cm2) in area and 24.88% (3.12 mm) in anteroposterior diameter The cervical spine biomodels can be used for laminoplasty training, even by using thermosensitive material such as PLA. The use of continuous irrigation is essential while drilling. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate glycol (PETG) is a novel amorphous shape memory polymer with excellent printability for 4D printing. In this article, ethylene‐vinyl acetate (EVA) is used as a biocompatible and non‐toxic copolymer to improve plasticity and shape memory performance of PETG. PETG‐EVA blends are prepared and 3D printed using a melt mixing method and an upgraded fused deposition modeling (FDM) with a pneumatic feeding system. The results of the thermal analysis show that the blends exhibit two tan‐delta peaks, each related to their components, and morphology images confirm that they are biphasic and immiscible with good compatibility. The morphology of both EVA10 and EVA30 matrix droplets is observed, with the droplets being larger for EVA30. The use of a pneumatic feeding system, along with the ability to control the output melt flow, results in the best printing ability for EVA30, with minimal microholes between the grids and interlayer cracks. The tensile strength of PETG‐EVA blends ranged from 25.38 to 20.14 MPa, with the highest tensile strength achieved for EVA30. The shape memory performance of all three blends is similar; with shape recovery exceeding 90% in 20 s. Blends with higher EVA content exhibited faster shape recovery within the first 10 s. [ABSTRACT FROM AUTHOR]

This work aims to analyze the effects of the main process parameters of fused filament fabrication (FFF) on the mechanical properties and part weight of 3D-printed thermoplastic polyurethane (TPU). Raster angle (RA), infill percentage (IP), and extruder temperature (FFF) in the ranges of 0–90°, 15–55%, and 220–260 °C, respectively, were considered as the FFF input parameters, and output variables part weight (PW), elongation at break (E), maximum failure load (MFL), ratio of the maximum failure load to part weight (Ratio), and build time (BT) were considered as responses. The Response Surface Methodology (RSM) and Design of Experiments (DOE) were applied in the analysis. Subsequently, the RSM approach was performed through multi-response optimizations with the help of Design-Expert software. The experimental results indicated a higher maximum failure load is achieved with an increased raster angle and decreased extruder temperature. ANOVA results show that ET has the most significant effect on elongation at break, with elongation at break decreasing as ET increases. The raster angle does not significantly affect the part weight of the TPU samples. The ratio of the maximum failure load to part weight of samples decreases with an increase in IP and ET. The results also indicated that the part weight and build time of FFF-printed TPU samples increase with an increase in IP. An ET of 220 °C, RA of 0°, and IP of 15% are the optimal combination of input variables for achieving the minimal part weight; minimal build time; and maximum elongation at break, maximum failure load, and ratio of the maximum failure load to part weight. [ABSTRACT FROM AUTHOR]

Composite materials are used in many engineering applications and industrial fields due to their superior properties, such as high strength, lightweight, and stiffness. These outstanding properties have made these materials an alternative to metallic materials. The vital need for new lightweight and inexpensive materials with superior strength properties has led to research on "hybridisation". Hybrid composites with more than one type of polymer in the same structure are needed to achieve a better balance of properties and to combine many desired properties in a single material. Many researchers have studied the hybrid effect and contributed to the understanding and modelling of the subject. Studies to explain the primary mechanism of the hybrid effect are limited and insufficient to explain the complex interaction. In this study, a three-dimensional printer using fused deposition modelling technique was used to produce hybrid materials, and the influence of printing parameters on the mechanical, absorptive, and morphological properties of poly (lactic acid) (PLA), Tough PLA, and PLA/Tough PLA hybrid materials were investigated. The hybrid material form exhibited superior properties when selecting specific production parameters from individual raw elements. It can be said that the mechanical properties of the PLA/Tough PLA hybrid material increased with the increase in production temperature. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) 3D printing has the advantages of a simple molding principle, convenient operation, and low cost, making it suitable for the production and fabrication of complex structural parts. Moving forward to mass production using 3D printing, the major hurdle to overcome is the achievement of high dimensional stability and adequate mechanical properties. In particular, engineering plastics require precise dimensional accuracy. In this study, we overcame the issues of FDM 3D printing in terms of ternary material compounds for polyamides with gradient structures. Using multi-walled carbon nanotubes (MWCNTs) and boron nitride (BN) as fillers, polyamide 6 (PA6)-based 3D-printed parts with high dimensional stability were prepared using a single-nozzle, two-component composite fused deposition modeling (FDM) 3D printing technology to construct a gradient structure. The ternary composites were characterized via DSC and XRD to determine the optimal crystallinity. The warpage and shrinkage of the printed samples were measured to ensure the dimensional properties. The mechanical properties were analyzed to determine the influence of the gradient structures on the composites. The experimental results show that the warpage of pure polymer 3D-printed parts is as high as 72.64%, and the introduction of a gradient structure can reduce the warpage to 3.40% by offsetting the shrinkage internal stress between layers. In addition, the tensile strength of the gradient material reaches up to 42.91 MPa, and the increasing filler content improves the interlayer bonding of the composites, with the bending strength reaching up to 60.91 MPa and the interlayer shear strength reaching up to 10.23 MPa. Therefore, gradient structure design can be used to produce PA6 3D-printed composites with high dimensional stability without sacrificing the mechanical properties of PA6 composites. [ABSTRACT FROM AUTHOR]

This review focuses on advancements in polymer science as it relates to three-dimensional (3D) and four-dimensional (4D) printing technologies, with a specific emphasis on applications in the biomedical field. While acknowledging the breadth of 3D and 4D printing applications, this paper concentrates on the use of polymers in creating biomedical devices and the challenges associated with their implementation. It explores integrative modeling and experimental insights driving innovations in these fields, focusing on sustainable manufacturing with biodegradable polymers, a comparative analysis of 3D and 4D printing techniques, and applications in biomedical devices. Additionally, the review examines the materials used in both 3D and 4D printing, offering a detailed comparison of their properties and applications. By highlighting the transformative potential of these technologies in various industrial and medical applications, the paper underscores the importance of continued research and development. The scope of this review also includes an overview of future research directions to address current challenges, enhance material capabilities, and explore practical applications. [ABSTRACT FROM AUTHOR]

To explore the tailoring of hydrophobicity in 3D-printed polylactide (PLA) composites for advanced applications using additive manufacturing (AM), this study focuses on the use of Fused Deposition Modeling (FDM) 3D printing. PLA, a material derived from renewable sources, is favored for its eco-friendliness and user accessibility. Nonetheless, PLA's inherent hydrophilic properties result in moisture absorption, negatively affecting its performance. This research aims to modify PLA with organosilicon compounds to enhance its hydrophobic and anti-icing properties. Incorporating fluorinated siloxane derivatives led to significant increases in water contact angles by up to 39%, signifying successful hydrophobic modification. Mechanical testing demonstrated that the addition of organosilicon additives did not compromise the tensile strength of PLA and, in some instances, improved impact resistance, especially with the use of OSS-4OFP:2HEX:2TMOS, which resulted in an increase in the tensile strength value of 25% and increased impact strength by 20% compared to neat PLA. Differential scanning calorimetry (DSC) analysis indicated that the modified PLA exhibited reduced cold crystallization temperatures without altering the glass transition or melting temperatures. These results suggest that organosilicon-modified PLA has the potential to expand the material's application in producing moisture and ice-resistant 3D-printed prototypes for various industrial uses, thereby facilitating the creation of more durable and versatile 3D-printed components. [ABSTRACT FROM AUTHOR]

In this research work, a piezoelectric sensor and actuator model was designed. Carbon fibre-reinforced polylactic acid (CF/PLA) composites were fabricated using the fused deposition modelling (FDM) technique using many parameters to achieve this goal. For instance, the primary key parameters were 0.1 mm (layer height) and 25 mm/s (print head). Besides, the fabricated samples were subjected to a tensile study. Besides, MATLAB® Partial Differential Equation (PDE) tool was used to develop a finite element analysis (FEA) model for the piezoelectric actuator using the experimentally tested results. The MATLAB® was also used to examine the geometry and tip deflection. The experimental works were carried out to measure the sample's strain using piezoelectric sensors. This approach could be used to establish the accuracy of the model. The CF/PLA composites were fabricated using 20 wt.% of reinforcements. The experimental results and finite element simulation were good agreement on results. Results reported that the deflections of 6.5765 mm, 5.197 mm, and 7.6328 mm, respectively embedded with PZT 5J, PZT 5H, and PZT 5A. [ABSTRACT FROM AUTHOR]

The 3D printing (or additive manufacturing) of energetic materials (EMs) has gained attention due to its innovative manufacturing method and excellent performance of products. To explore the application of 3D printing technology in melt-cast explosives, a fused deposition modeling (FDM) 3D printer was developed to fabricate TNT/HMX-based explosive grains (φ20 mm×20 mm) that were composed of 60 wt.% TNT and 40 wt.% superfine HMX. The influences of printing speed, printing temperature, and layer thickness on the printed grains were investigated by factorial design experiments. According to the printing process, the formation mechanism of FDM 3D-printed TNT/HMX-based explosives was explored and proposed, which mainly included extruded, contacted, micro-fused and solidified, and bonded. Then, a series of characterization methods were used to investigate the morphology and structure of the printed grains. The tested results showed that the density of the printed grains reached 98.6% of the theoretical density, and the compressive strength and tensile strength of printed grains were 87.5% and 66.7% higher than the cast ones, respectively, which indicated the printed grains have higher density and mechanical performance. This work was expected to provide a valuable idea and basis for the 3D printed melt-cast explosives with complex structure and high performance. [ABSTRACT FROM AUTHOR]

This article discusses the mechanical evaluation of recycled PETG filament for 3D printing. The authors emphasize the importance of plastic recycling and the potential of 3D printing in manufacturing. They focus on PETG as a leading material for 3D printing and examine the feasibility of recycling PETG for additive manufacturing. The study demonstrates that PETG 3D printing waste can be effectively recycled into new filament with promising mechanical properties. The research aims to contribute to the understanding of sustainable usage of PETG in 3D printing and inform future efforts in optimizing recycling processes. Another document provides information on the mechanical properties and testing of a specific material used in 3D printing. The material is tested in two different forms, filament and pellets, to compare their characteristics. The testing includes tensile, compression, and impact tests, with results showing slight differences between the two forms of the material. The document also describes the equipment used for the testing process. Additionally, another document presents the results of a study on the behavior of PETG filament in 3D printing when comparing specimens printed from new material versus recycled material. The study conducted compression, tensile, and impact tests on the specimens. The findings indicate a marginal difference in stiffness, with recycled material exhibiting slightly higher stiffness and increased brittleness. However, caution is advised in drawing definitive conclusions based on this initial data, as the sample size was small and only one recycling cycle was examined. Further research is needed to understand the effects of recycling on material [Extracted from the article]

This review article provides a deep dive into the diverse landscape of Additive Manufacturing (AM) technologies and their significant impact on the automotive and aviation sectors. It starts by exploring various AM methodologies such as Fused Deposition Modeling (FDM), Stereolithography (SLA), Digital Light Processing (DLP), Selective Laser Sintering (SLS), Metal Jet Fusion (MJF), Binder Jetting (BJ), and Directed Energy Deposition (DED), with a specific focus on their applicability, strengths, and challenges within these industries. The article then delves into the practical applications of AM in rapid prototyping, functional part production, and component repair. The results highlight the versatility and precision of SLA and DLP, the strength and durability of SLS, and the potential of metal-based technologies like LPBF, SLM, EBM, and DMLS in manufacturing critical components. The integration of AM with automotive and aviation design underscores the transformative nature of these technologies, driving advancements in lightweight, intricate, and high-performance components. The review concludes by emphasising AM's significant opportunities and acknowledging the ongoing challenges in material properties, post-processing, and production scalability, thereby underscoring the necessity for future research and innovation in these sectors. [ABSTRACT FROM AUTHOR]

This study focuses on fabricating lattice structural Al 2 O 3 ceramics with lattice infill densities ranging from 25 % to 70 % using filament-based fused deposition modeling (FDM) technology. A specialized filament for FDM printing was developed, comprising 53 vol% Al 2 O 3 powder and ethylene vinyl acetate (EVA) as the primary binder component. The filament demonstrated excellent flexibility as assessed by a self-designed three-point bending test. The impact of lattice infill density and sintering temperature on dimensional changes, microstructure evolution, compressive strength, and strength-to-density ratio was explored. It was found that with increasing sintering temperature, the samples became more compact, resulting in higher levels of shrinkage, bulk density, and compressive strength. At a sintering temperature of 1600 °C, the sintered parts reached their maximum density through the solid-state sintering process. The sample sintered at 1600 °C with 70 % infill density exhibited the maximum compressive strength of 31.47 MPa, with a corresponding strength-to-density ratio of 20.84 MPa/g·cm−3. These findings highlight the successful fabrication of lattice structural Al 2 O 3 with low density and high compressive strength by FDM technology. • Lattice structural Al 2 O 3 ceramics were fabricated by FDM technique. • The filament for FDM with 53 vol% Al 2 O 3 was developed. • Filament demonstrated excellent flexibility. • Sintered lattice structural Al 2 O 3 ceramics at 1600 °C exhibited the maximum compressive strength of 31.47 MPa. [ABSTRACT FROM AUTHOR]

Smart hinges for self-deployable solar sails have been prototyped by using shape memory polymer composites (SMPCs). During hinge lamination, a shape memory (SM) epoxy resin is deposited between carbon fiber reinforced (CFR) plies, and consolidation is obtained by an out-of-autoclave (OOA) process. The smart hinges have been assembled with CFR booms to prototype a small self-deployable square sail. Polymeric supports, made by fused deposition modelling (FDM), have been added for correct assembly and to drive the recovery of the SMPC hinges. Flexible heaters have been used as heating elements for SMPC hinge activation. The sail consisted of a polyimide membrane which was connected with the composite booms by flexible joints. The solar sail prototype size has been limited to 260 × 260 mm2 for on-Earth testing, with 4 hinges at the middle length of the composite booms. Recovery tests have shown the ability of the smart hinges to overcome the sail weight and additional friction forces, and the small sail has been successfully deployed in laboratory. Full recovery has been achieved in less than 3 min under different configurations. [ABSTRACT FROM AUTHOR]

Carbon-fiber-reinforced polymer (CFRP) composites are widely used across industries due to their enhanced strength and stiffness properties. Fused deposition modeling (FDM) enables the cost-effective production of polymer samples, such as carbon-fiber-reinforced PLA (CFR-PLA). However, CFRP's hardness and anisotropic nature present significant challenges in conventional machining, including rapid tool wear and thermal sensitivity. Consequently, abrasive water jet machining (AWJM) has proven to be an effective alternative for machining CFRP materials, offering benefits such as reduced tool wear, minimized thermal damage, and improved cutting quality. This study focuses on a comparative analysis of the effects of AWJM parameters on PLA and CFR-PLA samples, specifically to evaluate the influence of carbon fiber reinforcement on machining performance. The findings highlight the critical role of reinforcements in machining behavior. The results suggest that optimizing cutting parameters significantly reduces taper formation and improves machining accuracy. In particular, adjustments to process parameters resulted in lower taper angles and reduced surface roughness in the cutting zones of the CFR-PLA samples. [ABSTRACT FROM AUTHOR]

This work describes, through experimental and numerical investigations, the mechanical behavior and energy absorption characteristics of 3D-printed sandwich panels with cellular cores subjected to low-velocity impact. Using fused deposition modeling techniques (FDM), three different sandwich panels, one with a regular hexagonal core and two with re-entrant cores at 0 and 90 degrees, were fabricated. The sandwich panels were subjected to low-velocity impact, at impact energies of 10 J and 15 J. A comprehensive investigation of the panels' behavior through experimental testing and numerical simulation was conducted. The results indicate that the sandwich panel with a 90 degrees re-entrant core is stiffer and absorbs the largest amount of impact energy but, at the same time, suffers significant damage to the upper facesheet. The 0 degrees re-entrant core is compliant and provides both impact resistance and good energy absorption characteristics. Such a sandwich panel finds its application in the construction of personal protective equipment, where the aim is to minimize the forces transmitted during low-velocity impacts and maximize the total absorbed energy. Re-entrant core sandwich panels prove to be very good candidates for replacing the honeycomb core sandwich, depending on the desired engineering application. [ABSTRACT FROM AUTHOR]

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With the rapid development of additive manufacturing (AM) technology, quality inspection has become one of the most crucial research topics in additive manufacturing. Although numerous image-based deep learning methods have been successfully developed to monitor and inspect AM product quality effectively, many require substantial labels in order to achieve satisfactory training, which is often impractical in real-life AM processes. In this article, a novel image feature-based self-supervised learning (IFSSL) model is proposed for effective quality inspection in AM. Through a feature-based image fusion approach based on defect-relevant feature extraction, the IFSSL model is able to guide machine vision to focus on highlighted defect-relevant regions in the AM product image. In addition, the defect-relevant features are used to generate pseudo-labels for self-supervised learning. With self-supervision, the IFSSL model leverages the advantages of supervised learning and unsupervised learning by requiring no sample label while retaining defect-relevant information. The effectiveness of the proposed IFSSL method is demonstrated through a real case study of fused deposition modeling product image dataset. Results show that the IFSSL model can guide machine vision to pay more attention to potential defective regions, enabling it to detect and locate faults effectively and automatically for machine vision guided quality inspection. [ABSTRACT FROM AUTHOR]

This article presents a study on influence of Copper Concentration Electrolyte (CCE) and voltage on deposition rate of electroformed Conductive Acrylonitrile Butadiene Styrene (CABS) produced through Fused Deposition Modeling. Additive manufacturing is widely recognized as a rapid production technology. In this research, copper electroforming was selected as subsequent treatment following additive manufacturing. The novelty lies in implementation of pre-treatment process involving electroforming. The pre-treatment process employs carbon conductive paint to render the ABS part conductive. The copper electroforming process involves the use of variable parameters such as electrolyte content of (100, 150, and 200 gram CuSO4 and 50 ml H2SO4) in 1 liter H2O, voltage (1, 2, and 3 Volts), and time (2, 4, 6 and 8 hours). The variables under observation include the copper deposition rate and the microstructure. The analysis of research based on Kruskal-Wallis test. The difference in electrolyte copper concentration and the coating time does not provide significant differences, while the duration of electroforming affects the thickness of the copper deposit. Furthermore, the concentration of copper electrolyte influences the solution's conductivity, at high concentrations leading to improve conductivity and consequently facilitating a fast deposition rate. The difference in voltage has a significant effect on the deposition rate and microstructure. [ABSTRACT FROM AUTHOR]

The advent of 3D printing has transformed manufacturing. However, extending the library of materials to improve 3D printing quality remains a challenge. Defects can occur when printing parameters like print speed and temperature are chosen incorrectly. These can cause structural or dimensional issues in the final product. This review investigates closed‐loop artificial intelligence‐augmented additive manufacturing (AI2AM) technology that integrates AI‐based monitoring, automation, and optimization of printing parameters and processes. AI2AM uses AI to improve defect detection and prevention, improving additive manufacturing quality and efficiency. This article explores generic 3D printing processes and issues using existing research and developments. Next, it focuses on fused deposition modeling (FDM) printers and reviews their parameters and issues. The current remedies developed for defect detection and monitoring in FDM 3D printers are presented. Then, the article investigates AI‐based 3D printing monitoring, closed‐loop feedback systems, and parameter optimization development. Finally, closed‐loop 3D printing challenges and future directions are discussed. AI‐based systems detect and correct 3D printing failures, enabling current printers to operate within optimal conditions and minimizing the risk of defects or failures, which in turn leads to more sustainable manufacturing with minimum waste and extending the library of materials. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) is a model of additive manufacturing (AM) which uses layer by layer-based methodology to fabricate a component. In the current digital manufacturing era, FDM process is widely used as it can construct intricate and complex part geometries in short time, its simplicity and economical behavior as compared to conventional manufacturing. Despite of such advantages, literature argued various machine learning approaches adopted to increase the performance of FDM addressing the issues of irregularities in part properties, accuracy, and reliability due to challenging task of best parametric selection. In this context, the present study proposed a deep neural network strategy to predict the best parametric combination with optimized mechanical properties (tensile and compressive strength) of printed parts. In the present research, the design variables as nozzle diameter, width of print line and layer thickness, print speed are considered as input parameters with their levels values that are trained to the proposed system. Adhering to ASTM standards with predefined dimensions total 256 experiments have been carried for each output, in which 204 result data used for training and 52 for testing the model using PYTHON programming language. Subsequently, the proposed model has gained the accuracy of 88.46% and root mean square value as 0.3396 is validated by relating the performance with existing models. Hence, the efficient outcomes of the developed model have been verified by gaining the best combination of process parameters and Taguchi analysis interpreted their influence on the tensile and compressive strength of FDM printed parts. [ABSTRACT FROM AUTHOR]

The increasing application of additively manufactured (AM) materials in engineering and biomedical fields highlights the necessity of understanding their mechanical behavior, particularly with complex lattice structures. Polylactic acid (PLA), a popular biopolymer in additive manufacturing, exhibits mechanical characteristics highly dependent on its structural design. This research investigates the quasi‐static puncture failure analysis and mechanical characteristics of additively manufactured (AM) polylactic acid (PLA) materials with various lattice structures. The mechanical behavior, including tensile strength, flexural properties, interlaminar shear strength (ILSS), Izod impact resistance, and quasi‐static punch shear strength (QS‐PSS), was investigated following the respective ASTM protocols. Results indicate a 6% increase in tensile strength, to ca. 28 MPa, for the triangular PLA lattice structure compared with plain lattice structures. In the flexural test, the hexagonal structure showed a 13% increase in bending strength, to ca. 45 MPa, compared with the plain structure. Additionally, the hexagonal PLA lattice structure exhibited a 24% increase in shear strength, to approximately 8 MPa, over the plain lattice structure in the interlaminar shear strength analysis. In the Izod impact analysis, the plain lattice structure demonstrated a 17% increase in impact strength, to ca. 278 J/m, compared with the circular structure. A stainless‐steel hemispherical indenter was employed to investigate the quasi‐static punch shear behavior (QS‐PSS) of different lattice structures. The triangular structure displayed increased total energy absorption capacity and specific energy absorption of ca. 19 J and 0.529 J/g, respectively, compared with other lattice structures. These results are important for the creation of additively manufactured PLA lattice structures, improving the puncture resistance of advanced composites. Highlights: Polylactic acid (PLA) lattice structures were fabricated.Plain, circular, triangular, and hexagonal lattice structures were investigated.Lattice structures were used as reinforcements.The triangular structure demonstrated improved strength.The triangular structure reduced crack formation and propagation. [ABSTRACT FROM AUTHOR]

Currently, standard quadruple therapy is the primary treatment for Helicobacter pylori infection; however, compliance is low due to its complicated dose regimen. 3D‐printed combination tablets offer a promising strategy to simplify dose regimens due to their flexible structure. However, it is difficult to print combination tablets with a single printing technique because of the different physicochemical properties of the drugs. In this study, a hybrid deposition modeling (HDM) 3D printer is developed for the first time, concentrating the advantages of fused deposition modeling technology and semi‐solid extrusion technology, to prepare “rocket‐separated” combination tablets containing four drugs with different release behaviors. In 0.1 m HCl medium (mimicking gastric environment), the interlayer of the tablet containing bismuth potassium citrate erodes within 5 min, then the top and bottom layers separate, with the top one floating up to the surface of the medium, starting to release metronidazole and doxycycline after 1.5 h, the omeprazole enteric bottom layer releases in PBS 6.8 medium (mimicking intestinal environment) within 2 h. Overall, this combination tablet is suitable for actual clinical needs and avoids the chance of missed or wrong dosing. Moreover, HDM technology opens the door for future integration of multiple technologies in 3D printing formulations. [ABSTRACT FROM AUTHOR]

Prototyping analytical devices with three-dimensional (3D) printing techniques is becoming common in research laboratories. The attractiveness is associated with printers' price reduction and the possibility of creating customized objects that could form complete analytical systems. Even though 3D printing enables the rapid fabrication of electrochemical sensors, its wider adoption by research laboratories is hindered by the lack of reference material and the high "entry barrier" to the field, manifested by the need to learn how to use 3D design software and operate the printers. This review article provides insights into fused deposition modeling 3D printing, discussing key challenges in producing electrochemical sensors using currently available extrusion tools, which include desktop 3D printers and 3D printing pens. Further, we discuss the electrode processing steps, including designing, printing conditions, and post-treatment steps. Finally, this work shed some light on the current applications of such electrochemical devices that can be a reference material for new research involving 3D printing. [ABSTRACT FROM AUTHOR]

Three‐dimensional Printing (3DP) and computer‐assisted design (CAD) are a boon for producing high‐quality analytical and electrochemical devices using low‐cost components. This review briefly explains various 3D printing techniques. The focus is on the fabrication of integrated miniature devices developed through the 3DP process, mainly by the Fused deposition modelling (FDM) technique. Examples of integrated electrochemical devices are presented to highlight the potential of 3DP. Special emphasis is given to surface activation of 3D printed electrodes to enhance their electrochemical activity and various activation methods. This paper discusses the opportunities and future applications in developing all‐in‐one miniature electrochemical devices that might lead to on‐site environmental measurements, point‐of‐care tests, and the development of portable instruments with reduced sample volume. [ABSTRACT FROM AUTHOR]

With the rapid development of the internet of things, the simple preparation of sensors has become a challenge. The present work presents the simple preparation of flexible sensors by using the fused deposition modeling (FDM) 3D printing combined with the microwave radiation‐assisted treatment of the thermoplastic polyurethane (TPU) with carbon nanotubes (CNTs) as conductive fillers to create the flexible sensors. The as‐prepared TPU/CNT composites exhibit the 7.27 MPa tensile strength and 401% elongation at break, similar to those of the pure TPU. After 200 tensile cycles, the TPU/CNT composites can still stably convert pressure into electrical signals, which can be used as flexible sensors with high sensitivity (0.879 kPa−1). In addition, shoe insoles and finger cover with sensing performance are fabricated through the FDM 3D printing technology, demonstrating the potential of the sensors to monitor human gait, finger straightening, and bending movements. The as‐proposed method involves the embedding CNTs as conductive fillers on the surface of TPU to form the TPU/CNT composite conductive layers on the surface of TPU, which is beneficial for maintaining the elasticity of the polymer matrix. The challenges in preparing stable, low‐cost, and scalable flexible sensors and highlights of the advantages of 3D printing technology in manufacturing flexible piezoresistive sensors are also deeply discussed. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA), a water-soluble polymer, can be used to produce smoother surfaces and better dimensional accuracy when used as dissolvable supports during the printing of functional polymers like polylactic acid (PLA). This study investigates the printability of neat PVA using a large-diameter nozzle screw extruder 3D printer and the effect of printing parameters on inter-track voids and surface uniformity. This addresses the limitations of the long print times of current polymer additive manufacturing processes using a large-scale fused granulate fabrication (FGF) process. Using rheology tests, the extrusion temperature was identified, and following an experimental design and regression analysis, the optimum process parameters, among which are motor speed, layer height, and overlap percentage, are determined which achieved minimized void fraction and increased surface uniformity. With optimized parameters, the void fraction was reduced to 1.18%, and the bead height difference reduced to 0.316 mm. The tensile tests showed that the 3D-printed PVA had comparable tensile strengths to those of the FDM-printed and injection-molded PLA and ABS. Through tensile testing, the UTS of PVA produced in this study is measured to be 67.99 MPA, with mean elongation of 15.91%. This study show that PVA can be used as support or binding in the 3D printing of complex composites, benefiting from the water solubility feature of PVA. [ABSTRACT FROM AUTHOR]

Fused filament fabrication, also known as fused deposition modeling and 3D printing, is the most common additive manufacturing technology due to its cost-effectiveness and customization flexibility compared to existing alternatives. It may revolutionize unmanned aerial vehicle (UAV) design and fabrication. Therefore, this study hypothesizes the 3D printing possibility of UAV using a simple desktop printer and polymeric material. The extensive literature analysis identified the acceptable prototyping object and polymeric material. Thus, the research focuses on applying polylactic acid (PLA) in manufacturing the flying wing-type UAV and develops a fabrication concept to replicate arial vehicles initially produced from a mixture of expanded polystyrene and polyethylene. The material choice stems from PLA's non-toxicity, ease of fabrication, and cost-effectiveness. Alongside ordinary PLA, this study includes lightweight PLA to investigate the mechanical performance of this advanced material, which changes its density depending on the printing temperature. This proof-of-concept study explores the mechanical properties of printed parts of the wing prototype. It also considers the possibility of fragmentation in fabricated objects because of the limitations of printing space. The simplified bending tests identified significant reserves in the mechanical performance regarding the theoretical resistance of the material in the wing prototype, which proves the raised hypothesis and delivers the object for further optimization. Focusing on the mechanical resistance, this study ignored rheology and durability issues, which require additional investigations. Fabricating the wing of the exact geometry reveals acceptable precision of the 3D printing processes but highlights the problematic technology issues requiring further resolution. [ABSTRACT FROM AUTHOR]

Tremendously negative effects have been generated in recent decades by the continuously increasing production of conventional plastics and the inadequate management of their waste products. This demands the production of materials within a circular economy, easy to recycle and to biodegrade, minimizing the environmental impact and increasing cost competitiveness. Bioplastics represent a sustainable alternative in this scenario. However, the replacement of plastics must be addressed considering several aspects along their lifecycle, from bioplastic processing to the final application of the product. In this review, the effects of using different additives, biomass sources, and processing techniques on the mechanical and thermal behavior, as well as on the biodegradability, of bioplastics is discussed. The importance of using bioplasticizers is highlighted, besides studying the role of surfactants, compatibilizers, cross-linkers, coupling agents, and chain extenders. Cellulose, lignin, starch, chitosan, and composites are analyzed as part of the non-synthetic bioplastics considered. Throughout the study, the emphasis is on the use of well-established manufacturing processes, such as extrusion, injection, compression, or blow molding, since these are the ones that satisfy the quality, productivity, and cost requirements for large-scale industrial production. Particular attention is also given to fused deposition modeling, since this additive manufacturing technique is nowadays not only used for making prototypes, but it is being integrated into the development of parts for a wide variety of biomedical and industrial applications. Finally, recyclability and the commercial requirements for bioplastics are discussed, and some future perspectives and challenges for the development of bio-based plastics are discussed, with the conclusion that technological innovations, economic incentives, and policy changes could be coupled with individually driven solutions to mitigate the negative environmental impacts associated with conventional plastics. [ABSTRACT FROM AUTHOR]

Orthoses are commonly used for treating injuries to improve the quality of life of patients, with customized orthoses offering significant benefits. Additive manufacturing, especially fused deposition modelling, enhances these benefits by providing faster, more precise, and more comfortable orthoses. The present study evaluates nine polymeric materials printed in horizontal and vertical directions by assessing their performance through compressive, flexural, and tensile tests. Among all materials, polycarbonate, polylactic acid, and ULTEMTM 1010 showed the most promising results, not only because they had the highest mechanical values, but also due to their minimal or no difference in performance between printing directions, making them advantageous in orthoses fabrication. Based on this, a finite element model of an ankle–foot orthosis was developed to simulate the deformation, strain, and stress fields under static conditions. The findings aim to optimize material selection for orthotic fabrication, where ULTEMTM 1010 is presented as the material with improved performance and durability. [ABSTRACT FROM AUTHOR]

This work aims at the determination of the coefficient of thermal expansion (CTE) of parts manufactured through the Fused Deposition Modeling process, employing fiber Bragg grating (FBG) sensors. Pure thermoplastic and composite specimens were built using different commercially available filament materials, including acrylonitrile butadiene styrene, polylactic acid, polyamide, polyether-block-amide (PEBA) and chopped carbon fiber-reinforced polyamide (CF-PA) composite. During the building process, the FBGs were embedded into the middle-plane of the test specimens, featuring 0° and 90° raster printing orientations. The samples were then subjected to thermal loading for measuring the thermally induced strains as a function of applied temperature and, consequently, the test samples' CTE and glass transition temperature (Tg) based on the recorded FBG wavelengths. Additionally, the integrated FBGs were used for the characterization of the residual strain magnitudes both at the end of the 3D printing process and at the end of each of the two consecutively applied thermal cycles. The results indicate that, among all tested materials, the CF-PA/0° specimens exhibited the lowest CTE value of 14 × 10−6/°C. The PEBA material was proven to have the most isotropic thermal response for both examined raster orientations, 0° and 90°, with CTE values of 117 × 10−6/°C and 108 × 10−6/°C, respectively, while similar residual strains were also calculated in both printing orientations. It is presented that the followed FBG-based methodology is proven to be an excellent alternative experimental technique for the CTE characterization of materials used in 3D printing. [ABSTRACT FROM AUTHOR]

Background: The intersubject variability which was related to the genetic makeup was the major cause of change in pharmacological and pharmacokinetic behavior of same dosage form in varied human being. 3D printing technology will help therapy evolve and eliminate the limitations of conventional technologies. Nebivolol's (NBL)-limited oral bioavailability is mainly due to its poor aqueous solubility. The research aims to combine advanced 3D printing technology and nanotechnology to design customized therapy and enhance the functionality of NBL using a statistical approach. Results and discussion: The results of the phase solubility indicated that NBL was a poorly aqueous soluble drug. Its solubility was increased by employing nanoparticle drug delivery, which is a promising solubility enhancement technique. The 32 full factorial design was employed to develop and optimize bionanoparticles (BNPs) by solvent evaporation technique using poly (lactic-co-glycolic acid 50:50) (PLGA 50:50) and poloxamer-407 as a surfactant. The BNPs were characterized by % encapsulation efficiency (% EE), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC), transmission electron microscope (TEM), zeta potential, polydispersity index (PDI), particle size, in vitro drug release, etc. The BNPs loaded of NBL were further incorporated into the multichannel 3D-controlled release tablets made by PVA filaments employing fused deposition modeling (FDM) technology optimized by central composite design (CCD). Multichannel 3D-printed bionanoparticles-loaded tablet (M3DPBT) was optimized using CCD. All designed M3DPBTs were evaluated for post-fabrication parameters. The optimized M3DPBT could release more than 85% NBL within 10 h. Conclusions: The newly fabricated M3DPBT was found stable. The amount of PLGA 50:50 and Polaxomer was significant for developing BNPs. % infill and layer height were observed as critical for the designing M3DPBT. The combined novel 3D printing and nanotechnology technology will open a new direction for patient compliance and better therapeutic effects. Designing and developing of M3DPBT is substantially improve the patient compliance and therapeutic effectiveness of Nebivolol. [ABSTRACT FROM AUTHOR]

Due to the increase in 3D printing popularity, optimizing the procedure has become an important aspect of fused deposition modeling (FDM) research. As such, a numerical framework that captures the effect of all parameters involved in the process can aid in manufacturing optimization by overcoming the cost and time limitations of experimental methods. In this work, a numerical physics-based model is created that takes as input process parameters, simulates the phenomenon, and identifies the temperature history and developed mechanical stresses during printing. Initially, this model is validated through images taken from an infrared camera. Then, a design of experiments (DOE) sequence that covers the range of each input variable is created and multiple designs are evaluated. Correlations are examined and factor analysis on each output is performed indicating that material and bed temperature are the most important parameters affecting mechanical stresses, while fan speed dominates cooling. The simulation data are fed into data-driven models to provide accurate estimations on cooling duration, plastic strain, and von Misses stress and in turn aid in optimal parameter selection. This work improves existing numerical approaches by incorporating multiple process parameters and aids in digital twinning of FDM. [ABSTRACT FROM AUTHOR]

Scaffolds for bone defect treatment should ideally support vascularization and promote bone formation, to facilitate the translation into biomedical device applications. This study presents a novel approach utilizing 3D-printed water-dissolvable polyvinyl alcohol (PVA) sacrificial molds to engineer polymerized High Internal Phase Emulsion (polyHIPE) scaffolds with microchannels and distinct multiscale porosity. Two sacrificial mold variants (250 µm and 500 µm) were generated using fused deposition modeling, filled with HIPE, and subsequently dissolved to create polyHIPE scaffolds containing microchannels. In vitro assessments demonstrated significant enhancement in cell infiltration, proliferation, and osteogenic differentiation, underscoring the favorable impact of microchannels on cell behavior. High loading efficiency and controlled release of the osteogenic factor BMP-2 were achieved, with microchannels facilitating release of the growth factor. Evaluation in a mouse critical-size calvarial defect model revealed enhanced vascularization and bone formation in microchanneled scaffolds containing BMP-2. This study not only introduces an accessible method for creating multiscale porosity in polyHIPE scaffolds but also emphasizes its capability to enhance cellular infiltration, controlled growth factor release, and in vivo performance. The findings suggest promising applications in bone tissue engineering and regenerative medicine, and are expected to facilitate the translation of this type of biomaterial scaffold. This study holds significance in the realm of biomaterial scaffold design for bone tissue engineering and regeneration. We demonstrate a novel method to introduce controlled multiscale porosity and microchannels into polyHIPE scaffolds, by utilizing 3D-printed water-dissolvable PVA molds. The strategy offers new possibilities for improving cellular infiltration, achieving controlled release of growth factors, and enhancing vascularization and bone formation outcomes. This microchannel approach not only marks a substantial stride in scaffold design but also demonstrates its tangible impact on enhancing osteogenic cell differentiation and fostering robust bone formation in vivo. The findings emphasize the potential of this methodology for bone regeneration applications, showcasing an interesting advancement in the quest for effective and innovative biomaterial scaffolds to regenerate bone defects. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights Printing polymers on metal surfaces using fused deposition modeling could enhance the versatility of hybrid structures. However, the differences between metals and plastics prevented the effective spreading of molten plastic on metal surfaces, challenging reliable plastic printing on metal substrates. This study employed a nanosecond laser to fabricate laser‐textured grids of varying widths (0.2–0.5 mm) on a 6061 aluminum alloy (6061Al) surface. Carbon fiber reinforced thermoplastic plastic (CFRTP) was printed on 6061Al surface in different printing directions (0°, 45°, and 90°). The influence of laser texturing and printing direction on joint performance was evaluated. The findings indicated the laser‐texturing increased 6061Al surface roughness, enhancing wettability of CFRTP on 6061Al surface. The 45° printing direction provided the best wetting, resulting in a tensile‐shear force of 1631.7 N, 218% higher than at 90°. Optimal performance was achieved with a 0.5‐mm texture width, increasing tensile‐shear force by 180% compared to 0.2 mm and 67% compared to 0.6 mm. Interfacial stress concentration decreased and then increased with the increase of laser‐textured width and the 45° printing direction provided the longest print path and best resin spreading. This research presented a novel approach to metal‐polymer joining, with significant implications for advanced lightweight hybrid structures. Printing carbon fiber reinforced thermoplastic plastic (CFRTP) on 6061 aluminum alloy (6061Al) surface was achieved by fused deposition modeling via laser texturing. The print direction affected the wetting and spreading space of the molten resin. Pinning effect of printed CFRTP/6061Al by laser texturing was studied. The spreading and wetting of resin determined the mechanical properties. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) represents a state‐of‐the‐art 3D printing technology that holds great promise in the field of electrochemistry as a fast, in‐house, and digital fabrication method of sustainable sensors. Despite the progress in FDM, existing practical 3D printed sensors still require post‐printing treatment to improve their operational features, either through (electro)chemical surface activation or surface modification with external functional materials. Herein, a novel lab‐made conductive biofilament with integrated two different types of metallic nanoparticles (NPs) for the 3D printing of ready‐to‐use and multiplexed electrochemical sensors is introduced. The filament is composed of biodegradable polylactic acid as a base, polyethylene glycol dimethyl ether as a plasticizer, carbon black as a conductive filler, and nanopowder oxides of bismuth and copper as integrated functional precursor materials. The as‐printed sensors serve as multifunctional transducers for the direct and sensitive determinations of several analytes, by exploiting the different properties of the two co‐existing NPs. Particularly, heavy metals (such as lead, and cadmium) are voltammetrically quantified by amalgamation with BiNPs electrogenerated from Bi2O3, while biomarkers (such as glucose, and uric acid) are determined in enzymatic‐free modes. Determination of glucose takes advantage of the electrocatalytic properties of CuO, while uric acid is directly oxidized at the sensor. [ABSTRACT FROM AUTHOR]

Highlights The utilization of continuous fiber‐reinforced thermoplastic composites (CFRTP) in additive manufacturing technology (AM) is envisioned to enable the production of high‐performance parts with enhanced mechanical properties. In the production of CFRTP filaments, ensuring proper impregnation plays a crucial role in improving the characteristics of the produced filament. Carbon fiber (CF) reinforced polyphenylene sulfide (PPS) composites find applications in secondary aerospace parts, automotive structural parts, and chemical process applications. Continuous CF‐reinforced PPS filaments enable the production of lightweight, high‐performance parts with mechanical strength, heat, and chemical resistance in AM. In the present study, continuous CF‐reinforced PPS filaments were produced using the melt impregnation method for use in fused deposition modeling technology. Filament diameter, geometrical evenness, and effective fiber impregnation are important criteria in filament production. An impregnation mold was designed and manufactured to provide impregnation. The influence of three different pin angles (56°, 70°, and 82°) on impregnation and mechanical properties has been investigated by developing an impregnation die for CFRTP filament production. Tensile testing, fiber content analysis, optical microscopy, and scanning electron microscope analysis were performed on the produced filaments. Furthermore, increasing the pin angle leads to an increase in both the spreading and impregnation of fibers. Impregnation die for effective wetting of fibers with polymer. Significance of pin angle in fiber spreading and wetting with polymer. Application of test standards for fiber content. [ABSTRACT FROM AUTHOR]

Highlights Adhesively bonded joints play a vital role in improving the structural performance of 3D‐printed components. This research aims to examine the effect of graphene inclusion on the failure load and vibrational behavior of polylactic acid flat‐joggle‐flat (FJF) joints prepared using fused deposition modeling. The present research focused on the effect of print directions (0°, 45°, 90°) and the inclusion of graphene nanofiller (0.25, 0.50, 0.75, and 1.00 wt%) on the performance of FJF joints. The effect of raster direction on mechanical properties was examined by tensile testing of dog‐bone samples. Results showed that 0° print orientation had higher tensile strength compared to other printing directions. Shear testing of FJF joints indicated that the inclusion of graphene has enhanced the strength of 3D‐printed FJF joints by 61.18%. Fractography results showed that the formation of the shear band with the inclusion of 0.50 wt% graphene helps to distribute the stress more evenly and prevent catastrophic failure of the FJF joint. The free vibrational test revealed that the inclusion of 0.50 wt% graphene had improved the natural frequencies, as the presence of graphene‐enhanced the interfacial bonding between FJF adherend and adhesive. 0° print orientation had higher tensile strength than other printing directions. Inclusion of graphene‐enhanced the shear strength of flat‐joggle‐flat (FJF) joints by 61.18%. Shear band formation delayed the failure of graphene‐reinforced FJF joints. FJF reinforced with 0.50 wt% graphene had adherend failure. FJF joint added with 1.0 wt% graphene had lower natural frequencies. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) is one of the most used polymeric materials worldwide, either as a neat material or as a matrix for composite manufacture employing a molding process. Fused deposition modeling (FDM) 3D printing is an alternative process that offers the potential for manufacturing value‐added products from PP. However, using neat PP for FDM is challenging because 3D‐printed PP warps and shrinks when cooled, and the mechanical properties of PP are poor. PP‐based composites with different fillers (e.g., glass, carbon, and natural fibers) have shown improved properties using FDM processes. An alternative filler for 3D‐printed PP‐based composites is basalt fiber (BF). The objective of this work was to assess the potential and impacts of BF as a filler for BF‐PP composites using FDM processes. PP was compounded with 15, 25, 35, and 45 wt% BF to produce filaments for 3D printing without adding any compatibilizer. Results of rheology studies, morphology, and mechanical and thermal properties of the 3D printed specimens showed that BF positively impacts Young's modulus (E), thermal stability, and dimensional stability of the composite. All composites, when processed at high shear rates (i.e., above 100 1/s), show approximately similar rheological behavior. E is almost doubled in the composite with 25 wt% BF and increased fourfold in the composite with 35 and 45 wt% BF, compared to neat PP. The Izod impact resistance of the formulations containing 35 and 45 wt% BF is ~70% that of neat PP. BF process easily and adequately reinforces PP composites manufactured via FDM. Highlights: Neat PP's poor mechanical properties are improved by adding basalt fiber (BF).Up to 45 wt% BF was used to reinforce PP‐based composites.PP‐BF composites are easier to process via DFM compared to neat PP.BF improves PP‐based composite's thermal and dimensional stability. [ABSTRACT FROM AUTHOR]

Highlights A high filling load (62% weight) printable magnetic composite has been elaborated from the dispersion of magnetocaloric Ni45Mn36.7In13.3Co5 metamagnetic shape memory alloy microparticles into a PCL polymer matrix. The composite material has been prepared by solution method, resulting in a very homogeneous particles dispersion into the matrix. The structural transitions in the polymer are not affected by the addition of the metallic microparticles, which in turn results in a significant increase of the mechanical consistency. The good ductility of the elaborated composite allows its extrusion in flexible printable filaments, from which 3D pieces with complex geometries have been grown. The heat transfer of the composite material has been assessed from finite element simulation. In spite of the achievable magnetocaloric values are moderated with respect to the bulk, numerical simulations confirm that, in terms of heat transference, a PCL/Ni‐Mn‐In‐Co wire is more efficient than a bulk Ni‐Mn‐In‐Co cubic piece containing the same amount of magnetic active material. The quite good magnetocaloric response of the composite and the possibility to print high surface/volume ratio geometries make this material a promising candidate for the development of heat exchangers for clean and efficient magnetic refrigeration applications. 3D printable magnetic composites developed from dispersion of MSMA in PCL. High filling factor and uniform dispersion characterized by SEM. Inclusion of microparticles does not affect polymeric structural transitions. Metallic fillers improve DMA response of 3D printed pieces. FEM simulations endorse PCL/MSMA composites for magnetic refrigeration. [ABSTRACT FROM AUTHOR]

Highlights: The stable periodic porous shielding materials were prepared by combining the strategies of 3D printing and metamaterial design. The relationship between porous material structure and electromagnetic interference shielding efficiency (EMI SE) effectiveness was deeply explored, revealing the important structural parameters for realizing tunable EMI SE property. The optimized design of the periodic porous shielding box achieves effective EMI shielding in a wide wavelength range (over 2.4 GHz). The new-generation electronic components require a balance between electromagnetic interference shielding efficiency and open structure factors such as ventilation and heat dissipation. In addition, realizing the tunable shielding of porous shields over a wide range of wavelengths is even more challenging. In this study, the well-prepared thermoplastic polyurethane/carbon nanotubes composites were used to fabricate the novel periodic porous flexible metamaterials using fused deposition modeling 3D printing. Particularly, the investigation focuses on optimization of pore geometry, size, dislocation configuration and material thickness, thus establishing a clear correlation between structural parameters and shielding property. Both experimental and simulation results have validated the superior shielding performance of hexagon derived honeycomb structure over other designs, and proposed the failure shielding size (Df ≈λ/8 − λ/5) and critical inclined angle (θf ≈43° − 48°), which could be used as new benchmarks for tunable electromagnetic shielding. In addition, the proper regulation of the material thickness could remarkably enhance the maximum shielding capability (85 − 95 dB) and absorption coefficient A (over 0.83). The final innovative design of the porous shielding box also exhibits good shielding effectiveness across a broad frequency range (over 2.4 GHz), opening up novel pathways for individualized and diversified shielding solutions. [ABSTRACT FROM AUTHOR]

AbstractThis study investigates the integration of modal analysis and topology optimization in the design of a robotic arm to enhance both its reliability and efficiency. The primary objectives are to reduce the weight and minimize the vibration of the robotic arm. Initially, the kinematics and dynamics of the robotic arm were examined to identify the joint experiencing the highest torque. Finite element analyses (FEA) were then conducted on this critical joint to assess its vibration characteristics and redesign the joint for improved performance through topology optimization. Comparative analysis of the initial and optimized designs has highlighted significant improvements in weight reduction and vibration control. The selected robot arm component was manufactured using fused deposition modeling (FDM). Experimental modal analysis validated the theoretical predictions, demonstrating the effectiveness of the optimized design. The selected component of the robotic arm was redesigned using three different topology geometries and two different unit cell sizes for each, resulting in a maximum weight reduction of 29.37%. Stresses were reduced by 41% under critical operating conditions, which contributed significantly to the system’s reliability. The improvements in efficiency were measured through reductions in weight and vibration, demonstrating the enhanced dynamic performance of the robotic arm. The optimized design was validated through experimental modal analysis, confirming the effectiveness of the redesign. This study underscores the synergy of modal analysis and topology optimization in advancing robotic arm technology, providing a comprehensive approach to design optimization for enhanced reliability. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) and melt electrowriting (MEW) are techniques that use polymer fibers as building blocks for printing complex 3D structures, with fibers at the macroscopic and micrometer scale. Here, FDM and MEW are used to produce fibers of shape memory polymer at two different scales, and compare the performance of these fibers, in terms of shape fixity, shape recovery, and self‐healing properties. FDM and MEW are used for 4D printing of a shape memory polymer blend of thermoplastic poly(ε‐caprolactone) (30% by wt.) and a soft thermoplastic elastomer polyurethane (70% by wt.) at two different scales. The shape transformation from a programmed temporary state to the printed permanent shape in response to temperature as the stimuli imparts the 4D aspect to the printing. The mean fiber diameter of shape memory polymer produced by FDM and MEW is 340 and 40 µm, respectively. The manufactured fibers show an excellent shape fixity ratio (≈95%) and shape recovery properties (>84%). MEW fibers show a 1.5x faster recovery rate than FDM fibers due to the scaling effect. The excellent shape memory properties are complemented by self‐healing characteristics in the printed fibers. Additionally, MEW of a shape memory polymer is directly performed on a cylindrical collector to obtain tubular constructs which can potentially be used as stents for coronary or vascular applications. [ABSTRACT FROM AUTHOR]

Highlights Flax fiber has emerged as a promising, eco‐friendly alternative to traditional synthetic reinforcement in polymer composites. However, manufacturing biocomposites using three‐dimensional (3D) printing technology is typically accompanied by significant processing challenges and weak product performance under dynamic loading conditions. This study aims to unlock the potential of 3D‐printed polylactic acid (PLA) by incorporating chemically modified chopped flax fibers and thermoplastic polyurethane elastomer to improve impact strength and processability. To achieve this, we employed the fused deposition modeling (FDM) technique to prepare composite specimens for the study. The crystallization behavior, tensile and impact properties, as well as the fracture behavior of the composites were investigated. The findings suggest that our approach stands out because it not only facilitates the challenging task of 3D printing PLA with fiber additives of high weight fraction and high aspect ratio but also results in a remarkable 120% enhancement in impact strength and an around 31.2% increase in tensile elongation compared to neat PLA, without compromising the elastic modulus. Flax fibers were modified through alkalization and silanization. Alkalization significantly enhanced printing quality. Silanization reduced fiber attrition and doubled the fiber aspect ratio. TPU particles facilitated the 3D printing of biocomposites. For the first time, the hybrid strategy doubled the impact strength of PLA. [ABSTRACT FROM AUTHOR]

Fused Deposition Modeling (FDM) is an extrusion type additive manufacturing (AM) method in which a molten polymer is selectively extruded in layer-by-layer manner. Although there are several other AM techniques, FDM is a suitable method to produce fabric structures as it is capable of processing polymers and is widely used in various engineering applications. This article summarizes the current research works in characterization of FDM parts, advancements in materials used in FDM and latest works related to making fabric samples using FDM. The results show that the mechanical properties and surface quality are compromised in FDM parts. Strength and flexibility with better surface finishing are essential parameters in fabric structures. There are mainly two techniques that are explored by researchers to enhance the quality of the parts. The first is optimizing process parameters and the second is improving material quality. FDM process parameters like extrusion temperature, layer height, print speed and built orientation can significantly influence the quality of the parts. Optimizing these parameters can significantly enhance the strength of the fabric produced. Moreover, a great amount of impetus is given to improve material by reinforcing it and making polymer blends with specific qualities. There has been studies related to the development of fabric structures and deposition of polymers on fabrics with FDM. It is concluded that the major concern with such structures is strength and processability. To address these issues, optimizing process parameters and developing new filaments for exclusively making fabrics can be the future work in this area. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) fabricated components have gained significant attention and widespread adoption across modern industries due to their versatility, serving as both prototypes and final products. FDM offers rapid and cost-effective prototyping and production capabilities; however, utilizing directly manufactured FDM parts is not practical. Secondary operations like post-processing, testing, and validation are typically required to ensure that the fabricated parts meet the necessary standards for their intended applications. Desired repeatability, reproducibility, reliability, and preciseness should be the main prerequisites of the part fabricated. It is desirable that additive manufacturing (AM) products should be produced with advanced control processes which should possess acceptable quality characteristics. Ensuring the dimensional accuracy of FDM parts is very crucial, and hence it is important to emphasize the key factors that influence the dimensional precision during their fabrication. Sharing insights into these critical factors is essential to steer scholars, researchers, and the AM industry towards informed decisions and future advancements in AM. We aimed to outline the significant factors influencing the dimensional accuracy of the FDM part. These research papers are collected from Scopus and web of science data using "FDM" and "dimensional accuracy" as the keywords. We include the latest papers published especially during 2020 to 2024, which were lacking in earlier research. [ABSTRACT FROM AUTHOR]

Purpose: Additive manufacturing (AM) is a layer-by-layer technique that helps to create physical objects from a three-dimensional data set. Fused deposition modeling is a widely used material extrusion (MEX)-based AM technique that melts thermoplastic filaments and selectively deposits them over a build platform. Despite its simplicity and affordability, it suffers from various printing defects, with partial warping being a prevalent issue. Warpage is a physical deformation caused by thermal strain incompatibility that results in the bending of the printed part away from the build platform. This study aims to investigate the warpage characteristics of printed parts based on geometrical parameters and build orientations to reduce the warpage extent. Design/methodology/approach: Cuboidal samples of thermoplastic acrylonitrile butadiene styrene ranging from 5 to 80 mm were printed using a commercial MEX system. A Taguchi method-based design of experiment trial was performed to optimize the placement and orientation of the part for minimal warpage. Findings: It was found that a lower value of the "in-plane" aspect ratio and a more prominent part thickness are favorable for minimal warpage. The part should always be placed near the region with the highest temperature (least thermal gradient) to minimize the warpage. Originality/value: A novel dimensionless parameter (Y) is proposed that should be set to a minimum value to achieve minimal warpage. The results of this study can help improve the design and part placement for the MEX technique, thus elevating the print quality. [ABSTRACT FROM AUTHOR]