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Adopting additive manufacturing in investment casting, known as rapid investment casting, can significantly reduce lead time and cost. Despite many publications on these technologies, no quantitative techno-economic analyses refer to rapid investment casting. The paper provides helpful insights and a decision-making approach for replacing conventional production technologies (i.e. wax injection) with additive manufacturing technologies. The study is based on a techno-economic analysis framework. It allows assessing key performance indicators (e.g. crossover points and payback periods) for stakeholders to decide the suitable VAT photopolymerisation processes (i.e. stereolithography, digital light processing, and material jetting) according to specific production scenarios (i.e. load factors). Analytical cost models were developed in the frame of this work to assess the time and cost of the overall manufacturing process of the resin model for investment casting, considering the post-processing stages for each of the technologies investigated. The cost models were used to assess the benefits introduced by additive manufacturing in rapid investment casting. A sensitivity analysis evaluated the impact of energy, material, and labour costs for both key performance indicators (crossover points and payback periods). The techno-economic analysis yielded the following results: (i) crossover points in terms of production costs vary, ranging from thousands of units for small components in the jewellery or fashion industries to a few dozen units for larger parts in the mechanical industry, and (ii) crossover points in terms of time are lower than those related to cost. Additionally, digital light processing is regarded as the most promising technology, offering the best crossover points and payback periods across various scenarios, mainly when 3D printers are used at a low utilisation rate. [ABSTRACT FROM AUTHOR]

AbstractMosquitoes, as major vectors of dangerous diseases, demand effective control measures for public health. Larvicides, while offering a potential solution, can exhibit varying effects on different mosquito species and developmental stages during efficacy studies. Standardizing mosquito developmental stages and ensuring optimal, synchronized development rates of various larval stages are crucial for larvicidal experiments and maximizing pupal production. Manual separation of different stages of larvae is labor intensive, time consuming and error prone. Therefore, this study aimed to investigate the use of a stereolithography 3D-printed device for the separation of mosquito larvae. This device is designed to have three modules to collect different larval stages based on their radial size differences. Each module of the device was equipped with small vibration motors to enable vibration-assisted filtration to prevent clogging. The accuracy of the larvae separation device was studied by repeated experiments and collected samples were analyzed under an optical microscope. The 3D-printed device was demonstrated to be orders of magnitude faster and more accurate compared to manual separation process. A larvicidal bioassay was also designed to investigate larvicidal assay impact on the survival of collected L3 and L4 specimens. Overall, it was shown that the presented device carries an important potential for rapid and accurate separation of different size larvae for larvicidal studies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Due to the small number of autologous bone sources and the risk of immune rejection and disease spread caused by the use of allogeneic bone, artificial bone materials have played an irreplaceable role in bone transplantation today. Along with functional customization, biocompatibility requirements, and the emergence of biodegradable materials, a variety of biomaterials and a variety of preparation methods have emerged. OBJECTIVE: To summarize the preparation methods of scaffolds used in bone tissue engineering, and the advantages and disadvantages, research status and progress of various preparation methods. METHODS: A computer search was conducted on CNKI, WanFang Data, PubMed, and ScienceDirect databases for literature related to bone tissue engineering scaffold from January 2008 to August 2023. Chinese and English search terms were “tissue engineering, bone scaffold, gas foaming, cryotropic gelation, additive manufacturing”. After excluding irrelevant and repetitive studies, a total of 80 articles were retained for summary. RESULTS AND CONCLUSION: (1) Compared with the traditional preparation process of scaffolds, the emerging additive manufacturing and electrospinning technologies have shown great potential in the production of complex structures such as bone and cartilage for tissue engineering in recent years, demonstrating enormous potential. (2) In addition to the advantages of speed, precision and the range of materials used, additive manufacturing methods also provide the feasibility of manufacturing highly complex geometry and topologically optimized structures, achieving precise adjustment and high repeatability of the structure. (3) Electrospinning is one of the most adaptable and promising technologies for the production of a series of fiber mats. The nanofiber scaffolds produced by electrospinning are biomaterials with surprisingly similar microstructures to the cytoplasmic matrix. (4) At present, hydroxyapatite and tricalcium phosphate are the best in ceramic materials, and there are a variety of materials in polymer materials, with excellent biocompatibility. (5) Therefore, the selection of materials should be based on a better understanding of their properties, avoiding complexity, and producing more enhanced scaffolds. However, most of the literature reports so far are exploratory in terms of clinical applicability, and the specific diseases for which they are suitable for treatment remain to be tested. The future development of bone scaffolds is reflected in the following aspects: mechanical properties matching the missing bone, controllable degradation rate, strong ability to promote bone regeneration, and specific functions. [ABSTRACT FROM AUTHOR]

The constant improvement of stereolithography (SL) in terms of achievable resolution and printing time has sparked high expectations that SL will enable the rapid prototyping of truly microfluidic chips with features below 100 µm. However, most commercial high‐resolution stereolithography devices are based on Digital Light Processing (DLP) and thus sacrifice lateral printing size for resolution. Consequently, even 10 years after the advent of microstereolithography there is no commercialized 3D printing system that can effectively fulfill all the demands to replace soft lithography for microfluidic prototyping. In this work, for the first time, This study demonstrates that a commercial laser‐based stereolithography device is capable of manufacturing microfluidic chips with embedded channels smaller than 100 µm with a footprint of 7.24 × 0.3 cm2. A chip fabricated in poly(ethylene glycol) diacrylate (PEGDA) that can readily be used for fluid mixing, is presented in this study. This research shows that the accessibility of high‐resolution chips with footprints of several cm2, using laser‐based stereolithography, enables the manufacturing of truly microfluidic systems with high impact on prototyping and manufacturing. [ABSTRACT FROM AUTHOR]

The exothermic nature of acrylate photopolymerizations enables room temperature 3D printing of a quaternary formulation that incorporates an acrylate monomer, and an epoxy/thiol‐ene system (ETES). The latter comprises an epoxy monomer, a multifunctional thiol and a tetraallyl functionalized ditertiary amine curing agent. Pristine ETES necessitates temperatures of 85–95 °C for curing. Several mechanisms operate simultaneously during this process: homopolymerization of acrylates, thiol‐acrylate photopolymerization, thiol‐ene photopolymerization between the double bonds of curing agent and the multifunctional thiol, the Michael addition between thiolates derived from ETES and the double bonds of acrylates, and the anionic polymerization of the epoxy resin via the tertiary amine groups. To optimize the quaternary formulations for printing, parameters, such as reactivity, exothermicity, and viscosity, was explored. Subsequently, the thermal and viscoelastic properties of the printed cross‐linked polymers derived from these formulations were analyzed using Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA). The polymers derived from quaternary formulations exhibited lower crosslinked density compared to those obtained from the pristine acrylates. This reduction in crosslink density contributes to the improved toughness of the hybrid polymers. [ABSTRACT FROM AUTHOR]

Stereolithography (SLA) and other photopolymerization-based additive manufacturing approaches are becoming popular for the fabrication of microfluidic devices and cell-infused platforms, but many of the resins employed in these techniques are cytotoxic to cells or do not have the appropriate mechanical properties for microfluidic components. Here, using a commercially available resin, we demonstrate that biocompatibility and a range of mechanical properties can be achieved through post-print optimization involving baking, soaking, network swelling, and UV exposure. We show that UV-vis spectrophotometry can be used to detect methacrylate monomer/oligomer, and utilizing this method, we found that baking at 120 °C for 24 hours was the optimal method for removing cytotoxic chemical species and creating nontoxic cell culture platforms, though UV exposure and soaking in 100% ethanol also can substantially reduce cytotoxicity. Furthermore, we show that the mechanical properties can be modified, including up to 50% for the Young's modulus and an order of magnitude for the flexural modulus, through the post-processing approach employed. Based on the study results, users can choose post-processing approaches to achieve needed cytotoxicity and mechanical profiles, simultaneously. [ABSTRACT FROM AUTHOR]

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]

Background: With the rise of new 3D printers, assessing accuracy is crucial for obtaining the best results in patient care. Previous studies have shown that the highest accuracy is achieved with SLS printing technology; however, SLA printing technology has made significant improvements in recent years. Methods: In this study, a realistic anatomical model of a mandible and skull, a cutting guide for mandibular osteotomy, and a splint for orthognathic surgery were replicated five times each using two different 3D printing technologies: SLA and SLS. Results: The SLA group had a median trueness RMS value of 0.148 mm and a precision RMS value of 0.117 mm. The SLS group had a median trueness RMS value of 0.144 mm and a precision RMS value of 0.096 mm. There was no statistically significant difference in RMS values between SLS and SLA technologies regarding trueness. Regarding precision, however, the RMS values for SLS technology were significantly lower in the splint and cutting guide applications than those printed with SLA technology. Conclusions: Both 3D printing technologies produce modern models and applications with equally high dimensional accuracy. Considering current cost pressures experienced by hospitals, the lower-cost SLA 3D printer is a reliable choice for point-of-care 3D printing. [ABSTRACT FROM AUTHOR]

This study presents an innovative approach to improving the mechanical and viscoelastic properties of 3D-printed stereolithography (SLA) nanocomposites by incorporating graphene nanoplatelets (xGNP) into photopolymer matrices. Utilizing an SLA 3D printer, photopolymer formulations with xGNP concentrations of up to 0.25 wt% were successfully produced. Post-print curing was carried out using two different methods: ultraviolet (UV) curing and high-temperature curing at 160 °C. Mechanical characterization using nanoindentation showed a significant increase in elastic modulus by 104% and an increase in hardness by 85% for nanocomposites containing 0.25 wt% xGNP. Furthermore, dynamic mechanical analysis (DMA) revealed a 39% improvement in storage modulus for samples without post-curing and an improvement of approximately 30% for samples subjected to high-temperature curing. These significant improvements highlight xGNP's potential to not only increase the performance of SLA 3D-printed components but also streamline the manufacturing process by reducing or eliminating energy-intensive post-curing steps. This innovative integration of graphene nanoplatelets paves the way for the production of high-performance, functional 3D-printed products and offers significant advances for various industries with a high impact. The results highlight the transformative role of nanomaterials in additive manufacturing and position this work at the forefront of materials science and 3D printing technology. [ABSTRACT FROM AUTHOR]

In comparison to monolithic materials, cellular solids have superior energy absorption capabilities. Of particular interest within this category are the periodic lattice materials, which offer repeatable and highly customizable behavior, particularly in combination with advances in additive manufacturing technologies. In this paper, the crashworthiness of engineering multi-layer, multi-topology (MLMT) resin lattices is experimentally examined. First, the response of a single- and three-layer single topology cubic and octet lattices, at a relative density of 30%, is investigated. Then, the response of MLMT lattices is characterized and compared to those single-topology lattices. Crashworthiness data were collected for all topology arrangements, finding that while the three-layer cubic and octet lattices were capable of absorbing 9.8 J and 7.8 J, respectively, up to their respective densification points, the unique MLMT lattices were capable of absorbing more: 19.0 J (octet-cube-octet) and 22.4 J (cube-octet-cube). These values are between 94% and 187% greater than the single-topology clusters of the same mass. [ABSTRACT FROM AUTHOR]

Solvent‐free photopolymerization of vinyl monomers to produce high modulus materials with applications in 3D printing and photoswitchable materials is demonstrated. Polymerizable eutectic (PE) mixtures are prepared by simply heating and stirring various molar ratios of N‐isopropylacrylamide (NIPAM), acrylamide (AAm) and 2‐hydroxyethyl methacrylate (HEMA). The structural and thermal properties of the resulting mixtures are evaluated by 1D and 2D NMR spectroscopy as well as differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). UV photocuring kinetics of the PE mixtures is evaluated via in situ photo‐DSC and photorheology measurements. The PE mixtures cure rapidly and display storage moduli that are orders of magnitude greater than equivalent copolymers cured in an aqueous medium. The versatility of these PE systems is demonstrated through the addition of a photoswitchable spiropyran acrylate monomer, as well as applying the PE formulation as a stereolithography (SLA)‐based 3D printing resin. Due to the hydrogen‐bonding network in PE systems, 3D printing of the eutectic resin is possible in the absence of crosslinkers. The addition of a RAFT agent to reduce average polymer chain length enables 3D printing of materials which retain their shape and can be dissolved on demand in appropriate solvents. [ABSTRACT FROM AUTHOR]

To formulate an experimental methacrylate-based photo-polymerizable resin for 3D printing with ytterbium trifluoride as filler and to evaluate the mechanical, physicochemical, and biological properties. Resin matrix was formulated with 60 wt% UDMA, 40 wt% TEGDMA, 1 wt% TPO, and 0.01 wt% BHT. Ytterbium Trifluoride was added in concentrations of 1 (G 1 %), 2 (G 2 %), 3 (G 3 %), 4 (G 4 %), and 5 (G 5 %) wt%. One group remained without filler addition as control (G C). The samples were designed in 3D builder software and printed using a UV-DLP 3D printer. The samples were ultrasonicated with isopropanol and UV cured for 60 min. The resins were tested for degree of conversion (DC), flexural strength, Knoop microhardness, softening in solvent, radiopacity, colorimetric analysis, and cytotoxicity (MTT and SRB). Post-polymerization increased the degree of conversion of all groups (p < 0.05). G 2 % showed the highest DC after post-polymerization. G 2 % showed no differences in flexural strength from the G 1 % and G C (p > 0.05). All groups showed a hardness reduction after solvent immersion. No statistical difference was found in radiopacity, softening in solvent (ΔKHN%), colorimetric spectrophotometry, and cytotoxicity (MTT) (p > 0.05). G 1 % showed reduced cell viability for SRB assay (p < 0.05). It was possible to produce an experimental photo-polymerizable 3D printable resin with the addition of 2 % ytterbium trifluoride as filler without compromising the mechanical, physicochemical, and biological properties, comparable to the current provisional materials. • Ytterbium trifluoride was inserted up to 5 wt% to a 3D printing resin. • Inorganic fillers could be used as reinforcements 3D printing resin. • Ytterbium trifluoride as filler did not affect the properties of the experimental resin. [ABSTRACT FROM AUTHOR]

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 paper reports the successful preparation of high-strength 3D-printed alumina ceramic cores using stereolithography (SLA) and vacuum sol impregnation. Zirconia, alumina, and silica sols (ZS, AS and SS) were chosen as impregnating agents for alumina ceramics. The effects of different types of sols, various ratios of alumina sol to silica sol, and different pH values of sols on the mechanical properties of the ceramics were investigated. The flexural strength of the samples increased significantly after silica sol impregnation, reaching a maximum of 63.51 ± 3.67 MPa, which is 2.06 times higher than that of the unimpregnated samples (UN). Silica particles fill the original pores of the ceramics, and after high-temperature sintering, mullite is formed to increase the density and strength of the ceramics. The flexural strength of alumina ceramics decreases and then increases as the percentage of silica sol in the alumina-silica mixed sol increases. The optimal impregnation ratio for the mixed sols was found to be 1:4, which led to a flexural strength of 62.2 ± 2.09 MPa for the alumina ceramics. In addition, the pH of the sol plays a crucial role in maintaining stable sols. The silica sol is more susceptible to gelation as the pH of the sol increases within the range of 3.5–5.5, which can have a negative impact on its impregnation effectiveness. At a pH of 6.5 in the silica sol, the alumina ceramics exhibited the highest flexural strength of 92.57 ± 2.43 MPa, which is 3.01 times higher than the flexural strength of the unimpregnated samples. The research of impregnation process parameters suitable for 3D printing of alumina ceramics aim to enhance the material's strength, offering a novel solution for applications as high-performance components in the energy sector. [ABSTRACT FROM AUTHOR]

Recent innovations in Drug-Eluting Stents (DES) technology have led to the development of new stents with further reduction in strut width, the ultrathin DES, with struts thinner than 70 µm. Ultrathin DES may further improve the efficacy and safety profile of Percutaneous Coronary Intervention (PCI) by reducing the risk of target-lesion and target-vessel failures compared to the current-generation DES. However, the ultrathin DES metallic platform still presents some associated problems, such as biofilm formation, infection, and migration, all related to the cellular response. The present work aims to produce an ultrathin permanent polymeric platform for a new generation of polymeric drug-eluting stents (PDES). In this work, the cellular response was compared with the traditional stainless steel (SS316L) and polycaprolactone (PCL) to determine whether these polymers could address this challenge. An innovative method of tubular 3D micro stereolithography tubular (ST3DT) was used. Different PDES platforms were fabricated with different polymeric materials (based on polyurethane and urethane dimethacrylate). Subsequently, HFL1 fibroblasts were seeded on the PDES, PCL and SS316L for 3 days. The findings from the assays of cell biocompatibility and proliferation (75%PCL), coupled with the successful fabrication of stent struts below 70 µm using the Surgical Guide resin and the ST3DT method, suggest that resin is a promising candidate for a PDES. [ABSTRACT FROM AUTHOR]

A 3D‐printed array of hollow microneedles (HMNs) is designed and fabricated using a high‐resolution stereolithography 3D printer and assembled with a 3D‐printed reservoir that incorporates a Luer lock mechanism, ensuring standard and secure connection to syringes. The proof‐of‐concept needle designs consist of half‐eccentric and concentric conical tip shapes, each arrayed with two different interspacing values. After the geometrical features of the devices are characterized, the devices are tested ex vivo in porcine skin to evaluate the impact of tip shape and interspacing on the depth of penetration and the efficacy of the devices in delivering fluids (such as tattoo ink) into the dermis. Overall, the 3D‐printed HMNs can deliver fluids into the target layer of skin. Refinement of the design is ongoing with the ultimate aim to provide alternatives for intradermal drug delivery and diagnostic imaging, such as superficial lymphography. [ABSTRACT FROM AUTHOR]

The printing accuracy in ceramic stereolithography is deteriorated by shrinkage due to photopolymerization of monomers and broadening owing to scattering of light. To improve the accuracy of printed alumina parts, a series of experiments involving the reduce of shrinkage and broadening were conducted. Firstly, the dependence of conversion of monomers, shrinkage of suspensions and warpage of parts on energy doses was quantitively investigated and correlated, with which the shrinkage was well controlled through optimization. Besides, the warpage problem was effectively resolved when adding 30 wt% PEG-200 in the suspensions to release the accumulated internal stress. Next, the broadening under different energy doses was observed and reduced by addition of absorbers, after which a self-defined parameter C d / W e was applied to suggest strategies in the selection of appropriate processing parameters and absorber content. On this basis, the holes with a diameter ranging from 50–200 μm were successfully printed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the effect of the printing method on the mechanical characteristics and printing time of test specimens created by masked stereolithography (MSLA) using a commercially available gray resin. In addition, the research intended to optimize the printing procedure to maximize ultimate tensile strength (UTS) while minimizing printing time. A MSLA printer was used to manufacture standard gray resin specimens, which were then tested according to ASTM standards. Response surface methodology (RSM) is then used to investigate several process variables, and optimization techniques are used to identify their ideal printing procedure. The p-values for the layer thickness, exposure time, and build orientation linear coefficients for UTS are less than 0.05. Layer thickness is the most influential factor influencing UTS and printing time response when f and p values are considered together. Corresponding to the results taken from the optimization, best operating parameters of the MSLA printing were found to be 0.01 mm layer thickness, a normal exposure time of 5 seconds, and a build orientation of 0°. The optimal output parameters were finally found to be 151.9574 minutes for printing time and 64.7344 MPa for UTS, respectively. The novelty of this study comes in the optimization of the MSLA printer's printing process using RSM. There has also been no investigation to analyze the printing time in conjunction with the mechanical qualities of the MSLA produced part. [ABSTRACT FROM AUTHOR]

Stereolithography enables the fabrication of three-dimensional (3D) freeform structures via light-induced polymerization. However, the accumulation of ultraviolet dose within resin trapped in negative spaces, such as microfluidic channels or voids, can result in the unintended closing, referred to as overcuring, of these negative spaces. We report the use of injection continuous liquid interface production to continuously displace resin at risk of overcuring in negative spaces created in previous layers with fresh resin to mitigate the loss of Z-axis resolution. We demonstrate the ability to resolve 50-µm microchannels, breaking the historical relationship between resin properties and negative space resolution. With this approach, we fabricated proof-of-concept 3D free-form microfluidic devices with improved design freedom over device material selection and resulting properties. [ABSTRACT FROM AUTHOR]

Recently, advancements in fabrication technology have brought a new aspect to the field of tissue engineering. By utilizing advanced techniques in 3D manufacturing and biomaterials, scientists have successfully created tissue engineering scaffolds with complex three-dimensional structures and customized chemical compositions that closely mimic the natural environment of living tissues. These methodologies show potential not only for developing therapies that restore lost tissue function but also for creating in vitro models that replicate living tissue. The current investigation involved the synthesis of methacrylated polycaprolactone (PCLMA) by incorporating methacryloyl chloride (Meth-Cl) into polycaprolactone (PCL) with a molecular weight of 80,000 Da. Afterwards, PCLMA was subjected to crosslinking with glycerol acrylate (GA) and, by utilizing Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator, achieved the three-dimensional (3D) printing of tissue materials using Stereolithography (SLA). Analytical techniques included nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Cell viability was investigated using Human Osteoblast (HOB) cells. The biocompatibility of glycerol acrylate (GA) crosslinked polymethacrylated polycaprolactone (PCLMA) was confirmed using cell viability experiments. Overall, the GA-crosslinked PCLMA bioresin, particularly PCLMA-8, shows promise for further use in tissue engineering applications. [ABSTRACT FROM AUTHOR]

Accurate prediction of renal mass subtypes, along with the WHO/ISUP grade and pathological T (pT) stage of clear cell renal cell carcinoma (ccRCC), is crucial for optimal decision making. Our study aimed to investigate the feasibility and reproducibility of motion-robust radial T2 mapping in differentiating lipid-poor angiomyolipoma (MFAML) from RCC and characterizing the WHO/ISUP grade and pT stage of ccRCC. Finally, 92 patients undergoing renal radial T2 mapping and ZOOMit DWI were recruited. The T2 values and apparent diffusion coefficient (ADC) were analyzed. Correlation coefficients were calculated between ADC and T2 values. Notably, ccRCC exhibited higher T2 and ADC values than MFAML (p < 0.05). T2 values were lower in the higher WHO/ISUP grade and pT stage of ccRCC (all p < 0.05). ADC showed no significant difference for pT stage (p = 0.056). T2 values revealed a higher area under the curve (AUC) in evaluating the WHO/ISUP grade compared to ADC (0.936 vs. 0.817, p = 0.027). T2 values moderately positively correlated with ADC (r = 0.675, p < 0.001). In conclusion, quantitative motion-robust radial T2 mapping is feasible for characterizing solid renal masses and could provide additional value for multiparametric imaging in predicting WHO/ISUP grade and pT stage of ccRCC. [ABSTRACT FROM AUTHOR]

The laying process is crucial in using stereolithography (SL) for molding Al2O3 parts. However, most studies focus on the laying process of macroscopic slurry; there needs to be more focus on microscopic exploration. Studying from a microscopic perspective can help us understand the influence of its parameters on droplet spreading and infer the macroscopic changes of the slurry based on the changes in droplet spreading to understand why parameters cause macroscopic changes in the slurry. A pseudopotential model based on Sisko's non-Newtonian behavior in lattice Boltzmann method is proposed to study the spreading process of droplets and validated using wetting characteristics. The previous layers of the platform and the printed solid are investigated to understand the effect of laying velocity on the spreading diameter, the thickness, and the both-sided contact angles. The results indicate that a higher laying velocity leads to a larger spreading diameter, a smaller spreading thickness, and a smaller left contact angle. However, it also increases the contact angle difference between the two sides, leading to uneven slurry. The droplet spreads more unevenly when the previous laying surface is the printed solid. At the same velocity, the droplet spreads with a smaller diameter, thicker thickness, and larger contact angle on the printed solid surface. Therefore, a higher laying velocity in the SL laying process is not recommended, especially when the front layer is a printed solid. Although a higher laying velocity will increase the laying area and reduce laying time, it will cause protrusions at the front edge, and inconsistent laying thickness of the same layer will affect the following photosensitive curing process. The Harris Hawks optimization-generalized regression neural network algorithm is proposed and compared with other common artificial intelligence algorithms to predict the spreading parameters. The comparison shows that the proposed algorithm provides a more stable and accurate prediction of spreading parameters. [ABSTRACT FROM AUTHOR]

Ceramic slurry is the raw material used in stereolithography, and its performance determines the printing quality. Rheological behavior, one of the most important physical factors in stereolithography, is critical in ceramic printing, significantly affecting the flow, spreading, and printing processes. The rheological behavior of SiO2 slurry used in stereolithography technology is investigated in the current research using different powder diameters and temperatures. The results present the apparent non-Newtonian behavior. The yielding characteristics occur in all cases. For single-powder cases, the viscosity decreases when the powder diameter is increased. When the nano-sized and micro-sized powders are mixed in different proportions, a more significant proportion of micron-sized powders will decrease the viscosity. With an increase in the nano-sized powders, the slurry exhibits the shear thinning behavior; otherwise, the shear thickening behavior is observed. Thus, the prediction model is built based on the use of the pelican optimization algorithm-deep extreme learning machine (POA-DELM), and the model in then compared with the fitted and traditional models to validate the effectiveness of the method. A more accurate viscosity prediction model will contribute to better fluid dynamic simulation in future work. [ABSTRACT FROM AUTHOR]

The modern additive manufacturing process enables the fabrication of innovative structural designs of lattice structures with enhanced mechanical properties. Characterizing the designability of lattice geometries and the corresponding mechanical performance, particularly the compressive strength is vital to commercializing lattice structures for lightweight components. In this paper, a Novel hybrid type of lattice structure was developed inspired by the overlapping pattern of scales on dermal layers of the species like fish and circular patterns observed from the bamboo tree structure. This research designed the lattice cell with 20%,30%,40%, and 50% overlapping areas based on the proposed circular area. The unit cell wall thickness varies between 0.4 mm and 0.6 mm. The designed structures with a constant volume of 40x40x40 mm, varied circular diameters, overlapping areas, and unit wall thickness are modeled in Fusion 360 software. 3D-printed lattice structures were fabricated using the vat polymerization type three-dimensional printing machine using the principle of stereolithography (SLA) technique. Then, the 3D-printed specimens are tested for quasi-static compressive response in a universal testing machine (UTM) by following ASTM standards. The test results are evaluated and compared with the simulation results. Finally, the best lattice structure is selected for energy absorption application in the aerospace and defense sectors. [ABSTRACT FROM AUTHOR]

Reconstruction in cases of osteoporosis or accidents often requires the use of synthetic bones or scaffolds, with hydroxyapatite standing out as a preferred material due to its biocompatibility. This study focuses on the production and characterization of hydroxyapatite-coated 3D-printed bone scaffolds. The 3D-printed structures were fabricated by blending hydroxyapatite powder, synthesized through the solution combustion technique, with a liquid photopolymer, followed by exposure to UV irradiation. The resulting hydroxyapatite/photopolymer scaffolds were characterized by a uniform distribution of fine hydroxyapatite powder on the surface. Subsequently, these scaffolds underwent coating with a hydroxyapatite slurry, experimenting with various coating and sintering conditions. Despite the decomposition of the photopolymer during the sintering process, the coated scaffold displayed an increased thickness of the infill line within the pattern, resulting in reduced void size and enhanced compressive strength. Weibull analysis of the compressive strength indicated a high likelihood of survival at 4 MPa, falling within the acceptable range for cancellous bone strength. This comprehensive study showcased the potential of hydroxyapatite-coated 3D-printed bone scaffolds with a favorable microstructure and mechanical strength, making them promising for applications in bone reconstruction. [ABSTRACT FROM AUTHOR]

This study investigates the influence of microstructure patterns on the hydrophobic properties of surfaces of 3D-printed objects generated using photopolymer resin. Various arrangements and designs of microstructures on the surface of 3D-printed objects were examined. Leveraging the superior resolution of stereolithography printers (SLA) over fused deposition modeling, intricate microfeature designs were well-implemented. The experiments involved a range of structures on the surface of the 3D-printed objects, including precisely defined arrays of microcylinders, microchannels, and other complex designs generated by parametric equations. The hydrophobicity of the 3D-printed objects was assessed through the water droplet test, revealing a spectrum of results ranging from hydrophobic to weakly hydrophobic, and to hydrophilic surfaces. Light microscopy was employed to characterize the surface morphological properties of the 3D-printed objects, which were then correlated with the measured contact angles. It was discovered that the 3D-printed objects with microstructures formed using parametric functions exhibited patterns with irregularities and fluctuations along all directions or axes, resulting in a higher degree of hydrophobicity compared to structured matrices with pillared arrays. However, some surfaces created with parametric functions resulted in an anisotropic system where the material properties varied along one direction, while the other direction exhibited a flat, planar surface. These anisotropic systems were found to be less hydrophobic according to the water droplet test. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) have significantly advanced portable electronics, yet their reliance on flammable organic solvents and lithium dendrite formation pose safety risks. Solid-state batteries (SSBs), utilizing solid electrolytes, offer a safer alternative with higher energy and power densities. This study explores the fabrication of solid electrolytes using ceramic stereolithography, focusing on lithium lanthanum zirconate (LLZ) due to its high ionic conductivity and chemical stability. A photosensitive paste containing 40–43 vol% LLZ was suitable for processing by stereolithography, and optimized processing parameters of 100 mW laser power and 1000 mm/s laser scanning speed with a 50 μm laser spot size were identified for sufficient material curing and interlayer lamination of LLZ. Thin embossed sheets were designed to enhance ion exchange and reduce internal resistance and were fabricated by the ceramic stereolithography method. The effect of cold isostatic pressing (CIP) on the sintered microstructure was investigated, and the potential for CIP to promote solid-phase diffusion during sintering was demonstrated, particularly at 67 MPa. The resulting LLZ-embossed sheets exhibited dense ceramic microstructures. These findings support the potential application of ceramic stereolithography for fabricating efficient solid electrolytes for next-generation telecommunications and mobile devices. [ABSTRACT FROM AUTHOR]

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This study investigates the fabrication of 3D-printed microfluidic devices for solid/liquid separation, focusing on additive manufacturing technologies. Stereolithography (SLA) and fused filament fabrication (FFF) were used to create microseparators with intricate designs optimized for separation efficiency. Model suspensions containing quartz sand, nano-calcium carbonate, and talc-based baby powder in water were prepared using an electric magnetic stirrer and conveyed into the microseparator via a peristaltic pump. Different flow rates were tested to evaluate their influence on the separation efficiency. The highest separation efficiency for the model systems was observed at a flow rate of 200 mL min−1. This was due to the increased turbulence at higher flow rates, which hindered the secondary flow perpendicular to the primary flow direction. The particle size distribution before and after separation was analyzed using sieve and laser diffraction, and particle morphology was inspected by scanning electron microscopy. The laser diffraction analysis revealed post-separation particle size distributions, indicating that Outlet 1 (external stream) consistently captured larger particles more effectively than Outlet 2 (internal stream). This work highlights the potential of additive manufacturing to produce customized microfluidic devices, enabling rapid prototyping and fine-tuning of complex geometries, thus enhancing separation efficiency across various industrial applications. [ABSTRACT FROM AUTHOR]

Additive Manufacturing (AM) is advancing technologically towards the production of components for high-demand mechanical applications with stringent dimensional accuracy, leveraging metallic and ceramic raw materials. The AM process for ceramic components, known as Ultraviolet Laser Stereolithography (SLA), enables the fabrication of unique parts or small batches without substantial investments in molds and dies, and avoids the problems associated with traditional manufacturing, which involves multiple stages and final machining for precision. This study addresses the need to produce reference elements or targets for metrological applications, including verification, adjustment, or calibration of 3D scanners and mid- to high-range optical sensors. Precision spheres are a primary geometry in this context due to their straightforward mathematical definition, facilitating rapid and accurate error detection in equipment. Our objective is to exploit this novel SLA process along with the advantageous optical properties of technical ceramics (such as being white, matte, lightweight, and corrosion-resistant) to materialize these reference objects. Specifically, this work involves the fabrication of alumina hemispheres using SLA. The manufacturing process incorporates four design variables (wall thickness, support shape, fill type, and orientation) and one manufacturing variable (the arrangement of spheres on the printing tray). To evaluate the impact of the design variables, dimensional and geometric parameters (GD&T), including diameters, form errors, and their distribution on the surface of the sphere, have been characterized. These measurements are conducted with high accuracy using a Coordinate Measuring Machine (CMM). The study also examines the influence of these variables in the dimensional and geometric accuracy of the spheres. Correlations between various parameters were identified, specifically highlighting critical factors affecting process precision, such as the position of the piece on the print tray and the wall thickness value. The smallest diameter errors were recorded at the outermost positions of the tray (rear and front), while the smallest shape errors were found at the central position, in both cases with errors in the range of tens of micrometers. In any case, the smallest deformations were observed with the highest wall thickness (2 mm). [ABSTRACT FROM AUTHOR]

Sarcomas are malignant tumors from mesenchymal tissue and are characterized by their complexity and diversity. The high recurrence rate making it important to understand the mechanisms behind their recurrence and to develop personalized treatments and drugs. However, previous studies on the association patterns of multi-modal data on sarcoma recurrence have overlooked the fact that genes do not act independently, but rather function within signaling pathways. Therefore, this study collected 290 whole solid images, 869 gene and 1387 pathway data of over 260 sarcoma samples from UCSC and TCGA to identify the association patterns of gene–pathway–cell related to sarcoma recurrences. Meanwhile, considering that most multi-modal data fusion methods based on the joint non-negative matrix factorization (NMF) model led to poor experimental repeatability due to random initialization of factorization parameters, the study proposed the singular value decomposition (SVD)-driven joint NMF model by applying the SVD method to calculate initialized weight and coefficient matrices to achieve the reproducibility of the results. The results of the experimental comparison indicated that the SVD algorithm enhances the performance of the joint NMF algorithm. Furthermore, the representative module indicated a significant relationship between genes in pathways and image features. Multi-level analysis provided valuable insights into the connections between biological processes, cellular features, and sarcoma recurrence. In addition, potential biomarkers were uncovered, while various mechanisms of sarcoma recurrence were identified from an imaging genetic perspective. Overall, the SVD–NMF model affords a novel perspective on combining multi-omics data to explore the association related to sarcoma recurrence. [ABSTRACT FROM AUTHOR]

Rapid prototyping has produced accessible manufacturing methods that offer faster and more cost-effective ways to develop microscale systems for cellular testing. Commercial 3D printers are now increasingly adapted for soft lithography, where elastomers are used in tandem with 3D-printed substrates to produce in vitro cell assays. Newfound abilities to prototype cellular systems have begun to expand fundamental bioengineering research in the visual system to complement tissue engineering studies reliant upon complex microtechnology. This project used 3D printing to develop elastomeric devices that examined the responses of retinal cells to flow. Our experiments fabricated molds for elastomers using metal milling, resin stereolithography, and fused deposition modeling via plastic 3D printing. The systems were connected to flow pumps to simulate different flow conditions and examined phenotypic responses of endothelial and neural cells significant to neurovascular barriers of the retina. The results indicated that microdevices produced using 3D-printed methods demonstrated differences in cell survival and morphology in response to external flow that are significant to barrier tissue function. Modern 3D printing technology shows great potential for the rapid production and testing of retinal cell responses that will contribute to both our understanding of fundamental cell response and the development of new therapies. Future studies will incorporate varied flow stimuli as well as different extracellular matrices and expanded subsets of retinal cells. [ABSTRACT FROM AUTHOR]

Recent progress in additive manufacturing has enabled the application of stereolithography (SLA) in bioprinting to produce 3D biomimetic structures. Bioinks for SLA often require synthetic polymers as supplements to ensure the structural integrity of the printed cell‐laden constructs. High molecular weight (MW) poly(ethylene‐glycol)‐diacrylate (PEGDA) (MW ≥ 3400 Da) is commonly used to enhance the mechanical property of crosslinked hydrogels. However, the production of bioink with high MW PEGDA requires in‐house polymer synthesis or the acquisition of costly reagents, which may not be readily available in all laboratory settings. As an alternative to high MW PEGDA, this research investigated the use of poly(ethylene‐glycol)‐dimethacrylate (PEGDMA) (MW = 1000 Da) as a supplement of a bioink to enhance the mechanical properties of the SLA‐printed constructs. The successful demonstration showcases 1) the fabrication of 3D constructs with overhang and complex architecture, and 2) the cytocompatibility, with high cell viability of 71–87% over 6 days of culture, of the GelMA‐PEGDMA bioink to enable cell‐laden bioprinting. This study suggests PEGDMA as a viable supplement in the formulation of SLA bioink. The accessibility to PEGDMA will facilitate the advance in 3D bioprinting to fabricate complex bioinspired structures and tissue surrogates for biomedical applications. [ABSTRACT FROM AUTHOR]

The remediation of polluted water is a major concern for public health and the environment. Catalytic removal of model organic and inorganic pollutants in water using carbon catalysts has shown promising results. In the present work, stereolithographically 3D‐printed bio‐based carbon monoliths with different textural and surface chemistry properties were used as catalysts for oxalic acid oxidation and catalyst supports for bromate reduction in continuous systems. A significant synergistic effect between ozone or dihydrogen and carbon catalyst was evidenced by mineralization of 14–25 % of oxalic acid or reduction of 15–45 % of bromates in the steady state, respectively. The best results were achieved with samples with the highest mesoporous surface area or, in the case of lower surface area, with samples having the strongest basic character. As materials with great potential, optimizing the textural properties of architected carbon monoliths will enable them to compete with other macro‐structured carbon catalysts. [ABSTRACT FROM AUTHOR]

This study proposes porous block structures as a viable alternative to conventional pebble bed structures, aiming to overcome the structural drawbacks including low packing fractions, extensive stress concentrations, and low thermal conductivity. To validate the feasibility of the porous block structures, Gyroid Li 2 TiO 3 block breeders were prepared by the hybrid process of stereolithography and gelcasting. The resulting Gyroid Li 2 TiO 3 block breeders, measuring ∼18.8 × 18.8 × 18.8 mm3, achieved a high packing fraction of ∼78.8% through optimized slurry and sintering at 1100 °C for 3 h. These Gyroid Li 2 TiO 3 block breeders exhibited clear contours, integrated channels, a compressive strength of 8.78 MPa, and a low isotropic sintering shrinkage of ∼6%. The hybrid process demonstrated enormous advantages over the reported 3D printing for the preparation of porous block breeders with low shrinkage and large-sized dimensions. This study offers an effective avenue for the manufacture of porous block breeders with tunable tritium-releasing channels and large-sized configurations. [ABSTRACT FROM AUTHOR]

Microneedles offer a promising avenue for painless drug delivery through micro‐perforation, and additive manufacturing, particularly stereolithography, has proven effective for their fabrication. This study focuses on developing a novel biocompatible resin for 3D printing microneedles. Spectroscopic methods are employed to confirm the structures of all intended resin monomers, with a specific analysis of the crystallographic structure of cyclohexanedimethanol methacrylate (CDMM) using x‐ray diffraction. The results indicate that CDMM crystallizes in the monoclinic system, aligning with the P21/c space group. The fabricated conical microneedles, standing at approximately 655 μm in height, underwent thorough mechanical and thermal characterization. Depth analyses of micro‐perforations in Parafilm M and pig skin were performed using optical coherence tomography and histological sections, demonstrating successful penetration through the stratum corneum and epidermal layers into the superficial dermal layer (1.5–4 mm thickness) without affecting nerve endings. Cytocompatibility tests affirm the biocompatibility of the microneedles. This work highlights the potential of the newly developed biocompatible material for printable drug delivery systems, emphasizing microneedles and other implant forms. [ABSTRACT FROM AUTHOR]

Modern polymer‐based technical components not only have to fulfill demanding mechanical‐structural properties but need to integrate different functions to yield hybrid systems for complex operations. Typically, neither materials nor processing technologies are fully compatible with each other. The aim of the work is to combine the advantages of seemingly incompatible manufacturing processes such as high‐volume injection molding (IM) and precision additive manufacturing to produce functional and customized hybrid materials. IM is widely used for polymer processing but stands against high investment costs for tailor‐made molds with high‐resolution features. They focus on overprinting of injection‐molded parts made of thermoplastic polyurethane (TPU) with microstructures via projection‐microstereolithography (PµSL) to generate hybrid polymer materials with spatially tailored stiffness, enabling selective reinforcement, resulting in an E modulus increase of 195% compared to mere IM‐processed TPU. With that, the hybridization of processing methods is showcased to extend the product properties of polymer materials obtained via either IM or PµSL printing that have, prospectively, a maximum degree of individualization as well as a multitude of structural and functional features at the same time. To achieve optimum interfacial adhesion, the influence of surface roughness is studied, and reinforcement effects of different overprinted microstructure types are evaluated. [ABSTRACT FROM AUTHOR]

Highlights This review paper delves into the manufacturing methods, material properties, and applications of polymer‐based composites in the field of advanced manufacturing, offering a detailed explanation of their production through various additive manufacturing (AM) techniques and their diverse applications across multiple industries. Polymer‐based composite materials have emerged as crucial elements in AM due to their enhanced properties and design versatility, enabling the creation of components with unprecedented performance characteristics. The paper comprehensively covers the major AM methods employed for composite materials, including fused filament fabrication, Digital Light Processing/Stereolithography, Direct Ink Writing, and Selective Laser Sintering. Each of these methods is explored in terms of its mechanism, suitability for different composite materials, and the resulting material properties. The review also provides an insightful analysis of how these AM techniques are revolutionizing industries such as soft robotics, mechanical, electrical, and biomedical fields. The paper concludes by discussing the current challenges in this domain and projecting future trends in the development and application of composite materials in advanced manufacturing. This review aims to offer a comprehensive resource for researchers and practitioners in the field, highlighting the transformative impact of polymer‐based composites in AM and their growing significance across various sectors. Comprehensive review and classification of novelties in printing method for polymer based composite material manufacturing. Introduces innovative techniques to create and enhance material properties of composites. Explores interdisciplinary applications in biomedical, electronics, and sensors, demonstrating material versatility. Provides a systematic correlation between manufacturing method, material properties, and applications of novel polymer‐based composites. [ABSTRACT FROM AUTHOR]

Buccal cavernous hemangiomas are uncommon vascular lesions, particularly in adult patients. We present a case of a 23-year-old male with a progressive left cheek swelling over three years. Clinical examination and radiographic imaging revealed a solid, multilobulated mass in the left buccal and masticator spaces. Surgical excision was performed, and histopathological analysis confirmed the diagnosis of a cavernous hemangioma. This case underscores the importance of recognizing and appropriately managing rare vascular lesions in adult patients. [ABSTRACT FROM AUTHOR]

We used stereolithography to print polymer nanocomposite samples of stimuli-responsive spin crossover materials in the commercial photo-curable printing resins DS3000 and PEGDA-250. The thermomechanical analysis of the SLA-printed objects revealed not only the expected reinforcement of the polymer resins by the introduction of the stiffer SCO particles, but also a significant mechanical damping, as well as a sizeable linear strain around the spin transition temperatures. For the highest accessible loads (ca. 13–15 vol.%) we measured transformation strains in the range of 1.2–1.5%, giving rise to peaks in the coefficient of thermal expansion as high as 10−3 °C−1, which was exploited in 3D printed bilayer actuators to produce bending movement. The results pave the way for integrating these advanced stimuli-responsive composites into mechanical actuators and 4D printing applications. [ABSTRACT FROM AUTHOR]

This study presents a short overview of the main 3D polymer composite items that are fabricated by extrusion and stereolithography printing. By coupling polymers traditionally used in additive manufacturing, such as PEGDA, and polymers of biomedical interest, such as PVA, with carbon nanostructures, such as nanodiamond and graphene nanoplates, and conductive polymers, such as PEDOT and PANI, it has been possible to produce objects with specific functional properties exploited for fabricating scaffolds for cell growth and proliferation as well as soft electrodes for developing organic compounds sensing devices and electrocardiogram monitoring systems under real‐time conditions. [ABSTRACT FROM AUTHOR]

The present study is dedicated to the manufacturing of highly porous triply periodic minimal surface (TPMS) constructs, fabricated from recycled end of life borosilicate pharmaceutical glass employing masked stereolithography. The structures were prepared from a simple blend of photocurable resin with glass powder (<38 µm). The gyroid model was selected with the porosity varying from 75 to 90%. Hot stage microscopy was applied to examine the glass sintering behaviour to improve the translucency of the 3D scaffolds. The obtained 3D scaffolds were dip-coated with TiO 2 and further utilized for the photocatalytic degradation of dyes. The photocatalytic efficiency of the 3D scaffolds was evaluated by the degradation of methylene blue in water. It was found that 3D scaffolds coated with TiO 2 showed a 40% higher degradation rate in comparison to bare 3D scaffolds under UV irradiation, which determines the significant role of TiO 2 in the organic dye degradation. The better efficiency of 3D scaffolds coated with TiO 2 , compared with uncoated BSG 3D scaffolds is attributed to a better recombination rate, and the migration of electrons to the surface of the scaffold, where the charges participate in the photodecomposition of MB dye. The efficiency of the scaffolds was assessed for five consecutive cycles. The degradation efficiency after the fifth cycle was 75%, confirming the stability of the system. [ABSTRACT FROM AUTHOR]

The pyramid lattice sandwich structure, characterized by high load‐bearing capacity, lightweight nature, and fully open internal space, is considered an extremely promising super‐strong structure. Stereolithography technology was utilized to achieve the monolithic formation of single‐layer multi‐cell pyramidal lattice sandwich structures. Quasi‐static compression tests and finite element simulations were conducted to characterize the compressive properties and failure modes. Results indicate that the compressive strength, compressive modulus, specific strength, and specific stiffness of the single‐layer multi‐cell pyramidal lattice sandwich structure increase as the relative density increases. Moreover, fracture failure was observed in the structures with various relative densities. Additionally, the compressive failure of multi‐layer density gradient pyramidal lattice sandwich structures was investigated. Experimental and numerical findings indicate that the optimal density gradient scheme for the ZCMLG structure is I‐III‐II, resulting in a peak compression force that is 342.14% and 288.55% higher than that of the ZAMLG and ZBMLG structures, respectively. Highlights: The mechanical properties and failure modes of the lattice structure are investigated.The effect of density gradients on lattice structure failure modes is investigated.The failure mode of the lattice structure is verified by finite element simulation. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive analysis of the utilization of 3D printing technology for the fabrication of ceramic shells in the context of investment casting. This study encompasses an exploration of various 3D printing techniques such as binder jetting technology and lithography-based ceramic manufacturing applied to ceramic materials tailored for investment casting applications for different materials. Comparative analyses between conventionally manufactured shells and those produced through 3D printing techniques are presented, shedding light on the potential advantages and challenges associated with the adoption of additive manufacturing in investment casting processes. The findings of this study reveal that both methods offer viable solutions for creating ceramic materials suitable as shells for investment casting. Both lithography-based ceramic manufacturing and binder jetting technology exhibit unique advantages and challenges. Lithography-based ceramic manufacturing demonstrates a superior surface finish and resolution, making it particularly suitable for intricate designs and fine details. On the other hand, binder jetting technology presents advantages in terms of speed and scalability, allowing for the rapid production of larger components. [ABSTRACT FROM AUTHOR]

Purpose: This in vitro study aimed to create a graded structured dental crown using 3D printing technology and investigate the fracture resistance and the adaptation of this new design. Materials and Methods: A dental crown with a uniform thickness of 1.5 mm was designed, and the exported stereolithography file (STL) was used to manufacture 30 crowns in three groups (n = 10), solid (SC), bilayer (BL), and multilayer (ML) crowns using 3D jet printing technology. Marginal and internal gaps were measured using the silicone replica technique. Crowns were then luted to a resin die using a temporary luting agent and the fracture resistance was measured using a universal testing machine. One‐way ANOVA and Tukey post hoc tests were used to compare the fracture resistance and the adaptation of crowns at a significance level of 0.05. Results: Mean marginal and internal gap of the ML group were 80 and 82 mm, respectively; which were significantly (p < 0.05) smaller than BL (203 and 183 mm) and SC (318 and 221 mm) groups. The SC group showed the highest mean load at fracture (2330 N) which was significantly (p < 0.05) higher than the BL (1716 N) and ML (1516 N) groups. Conclusion: 3D jet printing technology provides an opportunity to manufacture crowns in a graded structure with various mechanical properties. This study provided an example of graded structured crowns and presented their fracture resistance. SC group had the highest fracture resistance; however, ML had the best marginal and internal adaptation. [ABSTRACT FROM AUTHOR]

3D printing (3DP) is increasingly utilized to achieve quick turnaround on various geometric designs and prototypes, being the growing part of additive manufacturing technology (AMT). The 3DP technique effectively improves the production of complex models in terms of low-cost, time-consuming production, and with less material volume. The key to results optimisation with 3DP is the preparation of the geometry. The following techniques can effectively reduce the required time of the 3D printing process for complex and non-linear CAD files. The fused deposition modelling/fabrication (FDM/FFF) techniques become the first choice in many applications, including biomedical ones. Still, some obstacles exist in the geometry roughness and quality zones. This paper proposes an optimisation method for 3D printed shapes used in biomedical devices and instrumentation by minimising the support structure attached to the model using the FDM technique. In this research, we proposed a method for dynamic compensation against gravity-affected parts extended from the main object's geometry using a forward planar learning (FPL) algorithm to minimise cusp height in 3D printed objects. After the slicing stage, the outcomes proved to be of good quality, optimised the object's surfaces, and minimised the printing time by 32%-38%. The proposed method is promising in defining a better setting for slicing and toolpath for FDM 3D printing. However, this method was not tested on other 3DP methods (Stereolithography (SLA), Selective laser sintering (SLS), and Digital Light Processing (DLP)), as more verification efforts need to be done on these 3D printing processes. [ABSTRACT FROM AUTHOR]

Additive manufacturing is the state‐of‐the‐art method for producing complex ceramic parts. For cellular materials, the freedom of design is particularly advantageous, as pore networks and shapes can be tailored. Herein, the direct printing of complex parts with high porosity using the cost‐effective manufacturing method of Liquid Crystal Display‐based stereolithography on low‐cost printers is determined. It is investigated how the architecture of the alumina Kelvin cells topology, their fabrication process, the printing parameters, and the microstructure affect the accuracy and mechanical properties of the printed samples. A notable reduction to a strut thickness of Kelvin cells down to 0.20 mm is achieved corresponding to a reduction of 1.5 compared with the state‐of‐the‐art literature (min. 0.35 mm). Ultrahigh porosities between 89.5% and 97.2% and a maximum compressive strength of 1.84 ± 0.17 MPa are reached due to the dense struts of the structure. Low‐cost and simple vat ceramic photopolymerization with high accuracy printing proves to be a promising candidate for the rapid and cost‐effective fabrication of highly porous and complex ceramic structures. [ABSTRACT FROM AUTHOR]

Two‐photon lithography is considered a promising technology because it can achieve high resolution up to scale of 100 nm among additional processing technologies; further, it can be used to fabricate nano‐/microstructures. However, it requires an unrealistic long time to obtain a practical model that is close to the human organ diameter in the order of millimeters. In this study, an in‐process‐resolution‐tunable (iPRT) stereolithography system is reported, that realizes an optimal laser processing pathway using a new algorithm that automatically generates the processing pathway obtained by dividing the fabrication area by the effect of microstructure disappearance during the surface offset. It is demonstrated that the aforementioned algorithm can produce structures up to 50 times faster than the conventional methods and can be applied to cell culture scaffold for regenerative medicine. [ABSTRACT FROM AUTHOR]