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Ceramic cores are the key components of precision casting hollow turbine blades, and 3D‐printed silica‐based ceramic cores are crucial to the development of the aerospace industry. However, silica‐based ceramic cores have problems in terms of mechanical properties and friction properties. In this paper, silica ceramics were prepared by stereolithography‐based 3D printing technology and processed at different sintering temperatures. The effect of sintering temperature on the microstructure, physical–mechanical properties, and friction and wear properties of the silica ceramics was investigated. The results show that, with the increase of sintering temperature, the average particle size and bulk density of the samples increased, while the open porosity and layer thickness decreased. The surface of ceramics became more and more flat with the increase in temperature. The flexural strength first increased with increasing temperature, and then suddenly decreased at 1350°C. The average surface roughness decreased with increasing temperature. The wear of the material decreased with increasing sintering temperature and increased at 1350°C. The optimum sintering temperatures were 1250°C and 1300°C, giving a flexural strength of 23.18 and 23.25 MPa, bulk density of 1.72 and 1.78 g/cm3, and open porosity of 24.49% and 23.66%, respectively. [ABSTRACT FROM AUTHOR]

High-quality transparent yttria (Y 2 O 3) is produced using various shaping techniques; however, the geometric control limits of shaping processes hinder its utilization and application. Thus, this study proposed digital light processing (DLP)-based additive manufacturing (AM). Although popular, transparent ceramic AM faces issues owing to limited transparency and simple shapes. This study fabricated a three-dimensional-structured transparent Y 2 O 3 ceramic using DLP-based AM assisted by vacuum sintering and revealed the critical factors governing its transparency. Zirconia and lanthana were utilized as sintering additives to regulate grain growth. Slurry conditions (dispersant concentration and solid loading) were optimized to control the homogeneity and density of the green body. After pre-sintering and vacuum sintering, the transparent Y 2 O 3 ceramics exhibited a transmittance of 94.86 % of the theoretical limit and a relative density of 99.89 % owing to a fine-grained dense microstructure. The fabricated lens array structures of Y 2 O 3 demonstrated a notable level of transparency and satisfactory optical imaging capabilities. [ABSTRACT FROM AUTHOR]

Photopolymerization‐based ceramic 3D printing, known as digital light processing (DLP), offers a valuable platform for rapidly prototyping previously unattainable intricate architectures without the need for additional molds. However, the presence of ceramic particles in photocurable suspensions introduces challenges, including elevated viscosity and diminished curing depth due to light‐ceramic particle interactions. This ultimately compromises the efficacy of the photocuring process, resulting in undesirable geometric inaccuracies. In this study, meticulously engineered lead‐free ferroelectric barium titanate (BaTiO3, BTO) ceramic granules, produced through a spray‐drying process, optimize ceramic suspension formulation. This approach enhances ceramic flowability and involves the judicious addition of a binder, yielding a uniform redispersion of ceramic particles within the matrix, while maintaining a bimodal particle size distribution with reduced diameters. Supported by both experimental and numerical simulations, this improves the rheological and curing properties, enabling the successful fabrication of highly dense, complex 3D‐printed BTO structures with excellent shape fidelity. Moreover, by carefully designing the thermal profiles, DLP 3D‐printed BTO ceramics exhibit impressive shape retention after debinding and sintering while demonstrating ferroelectric and dielectric performances comparable to their non‐3D‐printed counterparts. This study presents a transformative approach that unlocks the full potential of ceramic 3D DLP printing. [ABSTRACT FROM AUTHOR]

Ionic conductive hydrogels are widely used in many applications such as electrochemical energy storage, flexible electronic devices, and catalyst transistors due to their excellent ionic conductivity as well as chemical stability. However, the fragile mechanical properties and the lack of shaping methods severely limit their further applications. Herein, an ionic conductive composite hydrogel with reinforced mechanical properties is demonstrated that can be rapidly 3D printed using digital light processing technology. By using both γ‐methacryloxypropyltrimethoxysilane moderately modified attapulgite rigid particle and polyvinyl alcohol (PVA) semicrystal dual‐network reinforcement, the mechanically robust and highly conductive N,N,N‐trimethylethanaminium‐chloride‐based hydrogels are obtained, demonstrating a 5 times higher tensile strength than the initial one due to the turning and orienting of the attapulgite as well as the robust PVA secondary network. Furthermore, encapsulation strategy is used to avoid the dehydration of hydrogel, and strain sensors that exceed the strain limit of the hydrogel are fabricated through structural design. This work provides a reference for attapulgite‐reinforced hydrogel in biosensing. [ABSTRACT FROM AUTHOR]

Additive manufacturing has emerged as a promising technique in energy device research, owing to its ability to fabricate programmable geometries. Nevertheless, it remains a significant challenge to prepare three-dimensional electrode structures with finely resolved features. Herein, we propose a vat photopolymerization (VP) 3D printing process for Nickel Oxide-Yttria Stabilized Zirconia (NiO-YSZ) anode structure of solid oxide fuel cell (SOFC). A photosensitive NiO-YSZ slurry was prepared with appropriate curing properties, low viscosity, and stability. Optimal debinding processes, determined through thermo-gravimetric analysis, were employed to prevent green part cracking and deformation. Microstructural analysis demonstrated a uniform and finely distributed pore structure in the anode. Remarkably, cells featuring the VP-printed NiO-YSZ anode demonstrated notable performance with peak power densities of 239 mW·cm−2, 364 mW·cm−2, and 536 mW·cm−2 at 750 °C, 800 °C, and 850 °C, respectively. This novel method opens avenues for enhancing the performance of SOFCs through the optimization of anode structure. [ABSTRACT FROM AUTHOR]

3D printing provides the potential to enhance mechanical properties by fabricating complex structures with diverse materials; however, most high‐resolution 3D printing techniques require custom printers to incorporate multiple materials and/or result in poor material interfacial bonding. Here, energy absorption properties are enhanced with 3D lattice structures fabricated via vat photopolymerization comprising multiple materials forming a gradient‐interpenetrating polymer network (gradient‐IPN). The gradient‐IPN is incorporated by swelling the 3D printed elastomeric lattice in a photoresin that yields a stiff shell‐soft core structure. This straightforward post‐3D printing technique delivers an unprecedented degree of structural property customization through polymer gradients in lattice struts with shells of tunable stiffness and flexible elastomeric cores to achieve a broad continuum spectrum of mechanical properties within one simple system. The gradient aids in the distribution of stress and limits fracture between materials typically observed in multimaterial lattices. The gradient‐IPN lattices are fully recoverable and exhibit over 4 to 33 times higher toughness after compression, compared to copolymer (same composition as the gradient‐IPN) or purely elastomeric lattices, respectively. This highly versatile approach to modifying 3D printed lattices yields the unique combination of load bearing capabilities with viscoelasticity desirable for high performance materials in impact protection. [ABSTRACT FROM AUTHOR]

Photo‐triggered shape morphing structures can be found in myriads of areas. Utilizing light as a switch can effectively control and regulate the precise deformation of structures. However, the integration of photo‐switching functions in shape‐morphing structures with complex geometries remains a challenge. Here, photoswitchable digital light processing based 4D printing high‐resolution and highly complex geometries, based on UV curable WO2.9 nanoparticle doped shape memory polymer nanocomposites is reported, which are highly deformable (stretchability up to ≈1000% at rubbery state) and fatigue resistant (repeatedly loaded >1200 times at ambient temperature). The presence of just trace WO2.9 nanoparticles (<0.20 wt.‰) contributes to the controlled photothermal property of nanocomposite via selective absorption of light, which enables reversibly photoswitchable (>50 times), spatial and remote control of 4D printing shape morphing structures. These findings offer a promising approach to expanding the applications of photo‐triggered shape‐morphing structures. [ABSTRACT FROM AUTHOR]

3D‐printed cell‐laden hydrogels as tissue constructs show great promise in generating living tissues for medicine. Currently, the maturation of 3D‐printed constructs into living tissues remains challenge, since commonly used hydrogels struggle to provide an ideal microenvironment for the seeded cells. In this study, a cell‐adaptable nanocolloidal hydrogel is created for 3D printing of maturable tissue constructs. The nanocolloidal hydrogel is composed of interconnected nanoparticles, which is prepared by the self‐assembly and subsequent photocrosslinking of the gelatin methacryloyl solutions. Cells can get enough space to grow and migrate within the hydrogel through squeezing the flexible nanocolloidal networks. Meanwhile, the nanostructure can promote the seeded cells to proliferate and produce matrix proteins through mechanotransduction. Using digital light process‐based 3D printing technology, it can rapidly customize cartilage tissue constructs. After implantation, these tissue constructs efficiently matured into cartilage tissues for the articular cartilage defect repair and ear cartilage reconstruction in vivo. The 3D printing of maturable tissue constructs using the nanocolloidal hydrogel shows potential for future clinical applications. [ABSTRACT FROM AUTHOR]

Hydrogels are extensively explored as biomaterials for tissue scaffolds, and their controlled fabrication has been the subject of wide investigation. However, the tedious mechanical property adjusting process through formula control hindered their application for diverse tissue scaffolds. To overcome this limitation, we proposed a two-step process to realize simple adjustment of mechanical modulus over a broad range, by combining digital light processing (DLP) and post-processing steps. UV-curable hydrogels (polyacrylamide-alginate) are 3D printed via DLP, with the ability to create complex 3D patterns. Subsequent post-processing with Fe3+ ions bath induces secondary crosslinking of hydrogel scaffolds, tuning the modulus as required through soaking in solutions with different Fe3+ concentrations. This innovative two-step process offers high-precision (10 μm) and broad modulus adjusting capability (15.8–345 kPa), covering a broad range of tissues in the human body. As a practical demonstration, hydrogel scaffolds with tissue-mimicking patterns were printed for cultivating cardiac tissue and vascular scaffolds, which can effectively support tissue growth and induce tissue morphologies. [ABSTRACT FROM AUTHOR]

New gelatin methacryloyl (GelMA)—strontium-doped nanosize hydroxyapatite (SrHA) composite hydrogel scaffolds were developed using UV photo-crosslinking and 3D printing for bone tissue regeneration, with the controlled delivery capacity of strontium (Sr). While Sr is an effective anti-osteoporotic agent with both anti-resorptive and anabolic properties, it has several important side effects when systemic administration is applied. Multi-layer composite scaffolds for bone tissue regeneration were developed based on the digital light processing (DLP) 3D printing technique through the photopolymerization of GelMA. The chemical, morphological, and biocompatibility properties of these scaffolds were investigated. The composite gels were shown to be suitable for 3D printing. In vitro cell culture showed that osteoblasts can adhere and proliferate on the surface of the hydrogel, indicating that the GelMA-SrHA hydrogel has good cell viability and biocompatibility. The GelMA-SrHA composites are promising 3D-printed scaffolds for bone repair. [ABSTRACT FROM AUTHOR]

Shape memory polymers (SMPs) are smart materials that enable to transform back to their original shape from the deformed state when subjected to external stimuli. They have shown great potential used as sensors and actuators in diverse applications. However, current research on SMPs primarily focuses on the utilization of a single source of stimuli (e.g., electricity, magnetism, light, etc.), which heavily restricts their potential in complex circumstances. In this study, a novel approach is developed to fabricate multi‐layer electrically/magnetically dual‐driven shape memory composites (ML‐EMSMCs) based on a magnetic field‐assisted digital light processing (MF‐DLP) 4D printing technique. The fabricated ML‐EMSMCs contain alternating high electric conductive layers (up to 5.37 × 10−3 S cm−1) and magnetic responsive layers (10.7 emu g−1), enabling Joule heat‐based and high‐frequency magnetic field induction‐based stimuli. Furthermore, the ML‐EMSMCs exhibited excellent shape memory behavior, good formability, and magnetic properties. The developed 4D printing techniques allows for the alignment of magnetic particles with a unidirectional magnetic field, significantly improving their shape recovery speed. The developed electrically/magnetically dual‐driven and photocurable SMP composites shed light on the development of actuators and sensors with multiple functionalities. [ABSTRACT FROM AUTHOR]

The amalgamation of digital light processing (DLP) technology and pressureless sintering has emerged as a promising method for producing delicate, complex, and custom-made yttria-stabilized zirconia (YSZ) components. The procedure consists of fabrication of green part using DLP, debinding to remove the binders and sintering to densify the parts. Explorations in the parameter selection in each step are still far from maturity for producing defect-free densified parts. This study addresses the effect of DLP print parameters on the density of green parts and surface irregularities. DLP printing parameters, such as layer thickness, orientation, and light intensity, were selected, and a central composite design methodology was adopted for the design of experiments to investigate the impact of individual parameter as well as their interactions. The density of the green part decreased with an increase in layer thickness from 10 μm to 70 μm, whereas an increase in density was observed when the part orientation changed from 0 ° to 90°, and the intensity changed from 10 to 50 mW/cm2. The variations in layer thickness and part orientation substantially impact the surface roughness, but variations in intensity have comparatively less influence on the surface roughness. The in-layer and inter-layer voids of the samples fabricated with varying parameters were analyzed using scanning electron microscopy. The minimum surface roughness and maximum green part density responses were obtained using regression equations and a multi-objective optimization strategy. Subsequently, the samples were debinded and sintered to produce high-density zirconia components. To establish the importance of parameter optimization, a comparison of the specimen density and surface irregularity in the green and sintered states was performed for specimens fabricated with optimized parameters and a randomly chosen set of parameters. The novel study provides the parametric relation to fabricate as desired green and sintered density parts along with tuned surface roughness. [ABSTRACT FROM AUTHOR]

The complex structure of Ti/HA (HA: hydroxyapatite) implants prepared by additive manufacturing technology plays an essential role in its application in bone repair. Digital light processing (DLP) is widely used to prepare bioceramics with complex structures. However, it is a challenge to prepare Ti/HA biomaterials by DLP due to the high ultraviolet (UV) absorption of Ti powder. In the present work, TiH2 powder coated with a TiO2 layer is selected to reduce the UV absorption and improve the curing depth for DLP printed green bodies of TiO2@TiH2/HA, because the TiO2@TiH2 powder can be reduced by 12.7% compared to the TiH2 powder without any oxidation. Then, the shell layer of TiO2 undergoes dehydrogenation and reduction reaction with the core phase of TiH2 during the sintering process to transfer TiO2@TiH2/HA into TixOy@Ti/HA. In addition, the effects of HA content on compressive strength and biocompatibility are investigated in the TixOy@Ti/HA biomaterials. The results show that when adding 60 vol%HA, the maximum monolayer curing depth of the slurry reaches 90.1 ± 3.5 µm. 40%TixOy@Ti/60%HA shows the maximum effect in promoting the pre‐osteoblast differentiation and a relatively high compressive strength of 48.7 ± 3.5 MPa. This work provides an experimental basis for the preparation of ceramic–metal composites with high UV absorptivity using DLP. [ABSTRACT FROM AUTHOR]

The study investigates the fabrication and analysis of nickel microparticle-reinforced composites fabricated using the digital light processing (DLP) technique. A slurry is prepared by incorporating Ni-micro particles into a resin vat; it is thoroughly mixed to achieve homogeneity. Turbidity fluctuations are observed, initially peaking at 50% within the first two minutes of mixing and then stabilizing at 30% after 15–60 min. FTIR spectroscopy with varying Ni wt.% is performed to study the alterations in the composite material's molecular structure and bonding environment. Spectrophotometric analysis revealed distinctive transmittance signatures at specific wavelengths, particularly within the visible light spectrum, with a notable peak at 532 nm. The effects of printing orientation in the X, Y, and Z axes were also studied. Mechanical properties were computed using tensile strength, surface roughness, and hardness. The results indicate substantial enhancements in the tensile properties, with notable increases of 75.5% in the ultimate tensile strength and 160% in the maximum strain. Minimal alterations in surface roughness and hardness suggest favorable printability. Microscopic examination revealed characteristic fracture patterns in the particulate composite at different values for the wt.% of nickel. The findings demonstrate the potential of DLP-fabricated Ni-reinforced composites for applications demanding enhanced mechanical performance while maintaining favorable printability, paving the way for further exploration in this domain. [ABSTRACT FROM AUTHOR]

Gelatin-based photo-crosslinkable hydrogels are promising scaffold materials to serve regenerative medicine. They are widely applicable in additive manufacturing, which allows for the production of various scaffold microarchitectures in line with the anatomical requirements of the organ to be replaced or tissue defect to be treated. Upon their in vivo utilization, the main bottleneck is to monitor cell colonization along with their degradation (rate). In order to enable non-invasive visualization, labeling with MRI-active components like N-(2,2-difluoroethyl)acrylamide (DFEA) provides a promising approach. Herein, we report on the development of a gelatin-methacryloyl-aminoethyl-methacrylate-based biomaterial ink in combination with DFEA, applicable in digital light processing-based additive manufacturing towards bone tissue regeneration. The fabricated hydrogel constructs show excellent shape fidelity in line with the printing resolution, as DFEA acts as a small molecular crosslinker in the system. The constructs exhibit high stiffness (E = 36.9 ± 4.1 kPa, evaluated via oscillatory rheology), suitable to serve bone regeneration and excellent MRI visualization capacity. Moreover, in combination with adipose tissue-derived stem cells (ASCs), the 3D-printed constructs show biocompatibility, and upon 4 weeks of culture, the ASCs express the osteogenic differentiation marker Ca2+. [ABSTRACT FROM AUTHOR]

Inspired by nature's flexible and adaptable organisms, soft robotics are motorless robots made from highly compliant materials to work in confined environments and manipulate delicate objects. However, soft robots often suffer from early failure because of unexpected damage. At the same time, it is challenging to manufacture the geometrically complex structures of soft robots. This study introduces resins based on deep eutectic solvents (DES) to fabricate a pneumatically driven soft gripper using digital light processing (DLP). The resins consist of choline chloride (ChCl) as a hydrogen bond acceptor, glycerol (Gly), and acrylamide (AAm) as hydrogen bond donors. By utilizing the intense hydrogen bonding within DES, the resin can be rapidly cured by photopolymerization to form tough ionogels without chemical crosslinkers. The DES ionogels exhibit remarkable toughness and self‐healing performance compared to common hydrogels. Furthermore, the ionogels show not only efficient energy‐dissipating behavior but also achieve rapid self‐recovery. Finally, the DLP‐printed soft gripper from the DES‐based resin performs successful actuation and healing of macroscopic damages. This work presents a simple strategy to 3D print a soft robotic gripper with high toughness and self‐healing capability. [ABSTRACT FROM AUTHOR]

4D printing has emerged as a powerful strategy capable of revolutionizing additive manufacturing by enabling objects to dynamically transform overtime on demand. Despite significant progress, the full potential remains unrealized, particularly in the utilization of dynamic covalent chemistry. This study introduces a new approach using a multifunctional cross‐linker with alkoxyamine functionalities for 4D printing. Digital light processing (DLP) is employed for high‐resolution printing of complex objects. Leveraging alkoxyamine bonds' dynamic and living characteristics, the printed structures can be further modified through nitroxide‐mediated polymerization (NMP) using styrene and nitroxide exchange reactions (NER). The resulting "living" printed structures exhibit the unique ability to undergo both "growth" and "degrowth", dynamically adapting their size as well as the reduced Young's Modulus across a wide range (770 kPa–1.2 GPa). The chain extension by NMP and softening by NER are carefully characterized by IR and EPR spectroscopy. The presented approach opens avenues for the development of 4D printed structures with complex adaptive systems, showcasing enormous potential in a wide range of fields. [ABSTRACT FROM AUTHOR]

Tape casting is currently the mainstream method for preparing multilayer ceramic capacitor (MLCC). However, digital light processing (DLP) shows great promise for MLCC preparation due to its planar exposure and layer-by-layer printing characteristics. In this study, La x Ba (1-x) (Zr 0 · 1 Ti 0.9)O 3 (LBZT) ceramics were fabricated using DLP molding. The effects of La content change on the phase composition, microstructure, and properties of the materials were investigated. A stable ceramic slurry was formulated, and its rheological behaviors and cure properties were studied. TG-DTG was used to develop a two-step debinding process, and its debinding mechanism was analyzd. Finally, the samples were sintered by holding at 1300 °C for 4 h. The results showed that with the increase in La content, the phase composition gradually transformed from the rhombohedral to the tetragonal phase. The microstructure was initially gradually dense, and then the pores increased rapidly, resulting in a quick decrease in relative density. LBZT ceramics exhibited the densest structure at x = 0.006: ρ = 5.79 g/cm3 with a relative density of 95.74%, and have the most excellent dielectric properties (25 °C, 1 kHz): ε r = 7068, tanδ = 0.232. [ABSTRACT FROM AUTHOR]

To prepare bio-scaffolds with multi-stage pores, excellent mechanical and biological properties to meet the requirements of personalized bone repair, digital light processing using Pickering emulsion as paste has been proposed here firstly for porous hydroxyapatite scaffolds with complex shape and fine microstructure. It is found that dispersant content, solid loading and oil to water ratio of Pickering emulsions play vital roles on the controlling of pore morphology and pore size distribution of final hydroxyapatite ceramic foams. The multi-stage pores consist of millimeter-scale pores designed by 3D models and micro-pores below 10 µm derived from emulsion droplets. Due to the integration of hierarchical pores at different scale levels and micropores, hydroxyapatite ceramic foams possess outstanding compressive strength of 4.46–8.03 MPa at porosity of 76.59-72.96%. In vitro cell experiments illustrate that rat bone mesenchymal stem cells can spread and adhere to bio-scaffolds, promoting cell proliferation effectively and further verifying their good biocompatibility. [ABSTRACT FROM AUTHOR]

The digital light processing (DLP) printer has proven to be effective in biomedical and pharmaceutical applications, as its printing method does not induce shear and a strong temperature on the resin. In addition, the DLP printer has good resolution and print quality, which makes it possible to print complex structures with a customized shape, being used for various purposes ranging from jewelry application to biomedical and pharmaceutical areas. The big disadvantage of DLP is the lack of a biocompatible and non-toxic resin on the market. To overcome this limitation, an ideal resin for biomedical and pharmaceutical use is needed. The resin must have appropriate properties, so that the desired format is printed when with a determined wavelength is applied. Thus, the aim of this work is to bring the basic characteristics of the resins used by this printing method and the minimum requirements to start printing by DLP for pharmaceutical and biomedical applications. The DLP method has proven to be effective in obtaining pharmaceutical devices such as drug delivery systems. Furthermore, this technology allows the printing of devices of ideal size, shape and dosage, providing the patient with personalized treatment. [ABSTRACT FROM AUTHOR]

The leading cause of death worldwide and a significant factor in decreased quality of life are the cardiovascular diseases. Endovascular operations like angioplasty, stent placement, or atherectomy are often used in vascular surgery to either dilate a narrowed blood artery or remove a blockage. As an alternative, a vascular transplant may be utilised to replace or bypass a dysfunctional or blocked blood vessel. Despite the advancements in endovascular surgery and its popularisation over the past few decades, vascular bypass grafting remains prevalent and is considered the best option for patients in need of long-term revascularisation treatments. Consequently, the demand for synthetic vascular grafts composed of biocompatible materials persists. To address this need, biodegradable clopidogrel (CLOP)-loaded vascular grafts have been fabricated using the digital light processing (DLP) 3D printing technique. A mixture of polylactic acid-polyurethane acrylate (PLA-PUA), low molecular weight polycaprolactone (L-PCL), and CLOP was used to achieve the required mechanical and biological properties for vascular grafts. The 3D printing technology provides precise detail in terms of shape and size, which lead to the fabrication of customised vascular grafts. The fabricated vascular grafts were fully characterised using different techniques, and finally, the drug release was evaluated. Results suggested that the performed 3D-printed small-diameter vascular grafts containing the highest CLOP cargo (20% w/w) were able to provide a sustained drug release for up to 27 days. Furthermore, all the CLOP-loaded 3D-printed materials resulted in a substantial reduction of the platelet deposition across their surface compared to the blank materials containing no drug. Haemolysis percentage for all the 3D-printed samples was lower than 5%. Moreover, 3D-printed materials were able to provide a supportive environment for cellular attachment, viability, and growth. A substantial increase in cell growth was detected between the blank and drug-loaded grafts. [ABSTRACT FROM AUTHOR]

Abstract Hydrogels are extensively explored as biomaterials for tissue scaffolds, and their controlled fabrication has been the subject of wide investigation. However, the tedious mechanical property adjusting process through formula control hindered their application for diverse tissue scaffolds. To overcome this limitation, we proposed a two-step process to realize simple adjustment of mechanical modulus over a broad range, by combining digital light processing (DLP) and post-processing steps. UV-curable hydrogels (polyacrylamide-alginate) are 3D printed via DLP, with the ability to create complex 3D patterns. Subsequent post-processing with Fe3+ ions bath induces secondary crosslinking of hydrogel scaffolds, tuning the modulus as required through soaking in solutions with different Fe3+ concentrations. This innovative two-step process offers high-precision (10 μm) and broad modulus adjusting capability (15.8–345 kPa), covering a broad range of tissues in the human body. As a practical demonstration, hydrogel scaffolds with tissue-mimicking patterns were printed for cultivating cardiac tissue and vascular scaffolds, which can effectively support tissue growth and induce tissue morphologies.

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]

Vat photopolymerization (VPP) in ceramic additive manufacturing (CAM) faces challenges due to high viscosity from ceramic powder loading, necessitating interruptive recoating steps. Ceramic particles also attenuate and divert irradiated light, causing reduced cure depth and over-curing, leading to slow print, weak interlay adhesion, and dimensional errors. This study introduces photo inhibition-aided CAM (PinCAM) using dual-wavelength digital light processing to mitigate these issues. PinCAM employs two optical masks for initiation and inhibition at different wavelengths. While previous research focused on polymers, this work evaluates inhibition's effects in suspension-based VPP-CAM. Modeling and experiments examine inhibition and curing characteristics, print speed, dimensional accuracy, surface roughness, and microstructure. Preliminary results suggest that photoinhibition has the potential to enhance geometrical and surface properties as well as particle distribution homogeneity of green ceramic components without significantly compromising print speed. Understanding inhibition's impact will aid further research in PinCAM optimization for rapid and precise ceramic manufacturing. • First systematic study on two-wavelength Photoinhibition aided Ceramic AM (PinCAM). • Modeling and characterization of inhibition and curing characteristics in PinCAM. • Pilot study on curing light and inhibition ratio effects in PinCAM speed & product. • Optimal inhibition enhances geometry, surface, density, & homogeneity of green part. • Theoretical basis & methods to establish PinCAM for advanced ceramic manufacturing. [ABSTRACT FROM AUTHOR]

Bioactive ceramic bone scaffolds are limited by their brittleness. To address this limitation, we developed a new method for preparing β-tricalcium phosphate (β-TCP)/polycaprolactone (PCL) porous composite scaffolds with a gradient structure using digital light processing technology and an impregnation process. The composite scaffolds exhibited compressive strength comparable to that of pure β-TCP scaffolds but with substantially higher toughness and reliability, especially during in vitro degradation. Owing to the gradient structure, the composite scaffolds could gradually shift from high strength and stiffness to moderate strength and low stiffness, which is beneficial for bone healing and remodeling. In femoral condyle defects without mechanical stimulation, the β-TCP/PCL composite scaffolds exhibited slightly lower cellular compatibility and osteoinductive ability than those of the pure β-TCP scaffolds. However, in radial defects, composite scaffolds demonstrated a better mechanical response and bone growth capacity. The composite scaffolds maintained their structural integrity after 2–4 months, whereas the β-TCP scaffolds fractured within 2 months. This study provides a novel methodology for the development of effective scaffold fabrication strategies for load-bearing or large segmental defects with complex stress applications for use in bone healing and remodeling. [ABSTRACT FROM AUTHOR]

The digital light processing (DLP) for the preparation of alumina ceramics (Al2O3) is characterized by high molding accuracy and fast rates, making it show great promise for applications in high-end ceramic manufacturing. However, its forming process is greatly influenced by the photosensitive slurry. Although a large number of studies have been conducted to investigate the influence of different variables of the slurry on photo curing, the mechanism of the influence of the powder morphology of the Al2O3 raw material is still unclear. In this study, two kinds of slurry were prepared from spherical and laminated Al2O3 powders and DLP was carried out. The results showed that some of the spherical Al2O3 powder would break down after ball milling, resulting in a reduced flow-ability of the slurry. The relative density of the ceramic was 91.1 % and strength was 92.1 MPa. In contrast, the laminated Al2O3 could be oriented in the flow direction during flow, showing a lower viscosity. At the same time, the orientation allowed the lamellar powder to build up more tightly. The relative density of the ceramic was 93.2 % and strength was 165.5 MPa.

Mechanically strong magnesium-doped Ca-silicate bioceramic scaffolds have many advantages in repairing large segmental bone defects. Herein we combine β-TCP with 6 mol% magnesium-doped calcium silicate (Mg6) at three different ratios (TCP, TCP+15 %Mg6, TCP+85 %Mg6) to find an appropriate ratio which can exert considerable influence on bone regeneration. In this study, the bioceramic scaffolds were assessed for mechanical strength, bioactive ion release, biocompatibility, and osteogenic capacity through in vitro testing. Additionally, the potential for promoting bone regeneration was investigated through in vivo implantation of porous tube-like scaffolds. The results showed that the compressive strength increased with the augmentation of Mg6 component. Especially the compressive strength of the TCP+85 %Mg6 group reached 38.1 ± 3.8 MPa, three times that of the other two groups. Furthermore, extensive in vivo investigations revealed that the TCP+85 %Mg6 bioceramic scaffolds were particularly beneficial for the osteogenic capacity of critical-sized femoral defects (20 mm in length). Altogether, magnesium doping in bioceramic implants is a promising strategy to provide stronger mechanical support and enhance osteogenesis to accelerate the repair of large defects.

In this study, digital light processing (DLP) was utilized to generate 3D-printed blends composed of photosensitive acrylate-modified polylactic acid (PLA) resin mixed with varying weight ratios of lignin extracted from softwood, typically ranging from 5 wt% to 30 wt%. The microstructure of these 3D-printed blends was examined through X-ray microtomography. Additionally, the tensile mechanical properties of all blends were assessed in relation to the weight ratio and post-curing treatment. The results suggest that post-curing significantly influences the tensile properties of the 3D-printed composites, especially in modulating the brittleness of the prints. Furthermore, an optimal weight ratio was identified to be around 5 wt%, beyond which UV light photopolymerization experiences compromises. These findings regarding acrylate-modified PLA/lignin blends offer a cost-effective alternative for producing 3D-printed bio-sourced components, maintaining technical performance in reasonable-cost, low-temperature 3D printing, and with a low environmental footprint. [ABSTRACT FROM AUTHOR]

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Digital light processing (DLP) techniques are widely employed in various engineering and design fields, particularly additive manufacturing. Acrylate resins utilized in DLP processes are well known for their versatility, which enables the production of defect-free 3D-printed products with excellent mechanical properties. This study aims to improve the mechanical and thermal properties of 3D-printed samples by incorporating mica as an inorganic filler at different concentrations (5%, 10%, and 15%) and optimizing the dispersion by adding a KH570 silane coupling agent. In this study, mica was introduced as a filler and combined with epoxy acrylate resin to fabricate a 3D-printed sample. Varying concentrations of mica (5%, 10%, and 15% w/w) were mixed with the epoxy acrylate resin at a concentration of 10%, demonstrating a tensile strength increase of 85% and a flexural strength increase of 132%. Additionally, thermal characteristics were analyzed using thermogravimetric analysis (TGA), and successful morphological investigations were conducted using scanning electron microscopy (SEM). Digital light-processing technology was selected for its printing accuracy and cost-effectiveness. The results encompass comprehensive studies of the mechanical, thermal, and morphological aspects that contribute to the advancement of additive manufacturing technology. [ABSTRACT FROM AUTHOR]

Digital Light Processing is combined with two-step sintering to obtain bioactive scaffolds with improved strength and mechanical isotropy. Highly loaded photosensitive suspensions were prepared from β-TCP powder to create scaffolds consisting of interpenetrating struts with two different designs. Two sintering methods were used: conventional sintering (CS) and two-step sintering (2SS). The latter resulted in a microstructure with uniformly shaped grains and reduced porosity. Their compressive strength was determined by uniaxial testing under two different load configurations, with the force applied parallel or perpendicular to the building plane of the scaffolds. Design optimisation and fine-tuning of the sintering process helped in reducing the presence of interlayer defects and minimise the shear-dominated fractures. Isotropic fracture behaviour was achieved, with similar central values of the Weibull distribution (49 ± 1 MPa vs. 51 ± 1 MPa) along both testing directions, showing a great potential for their use in load-bearing bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

Digital light processing (DLP), derived from stereolithography (SL), is a lithography-based additive manufacturing (AM) process that offers the ability to tailor scaffold shape, size, material, and biometrics of fabricated scaffolds to patient requirements. The additive manufacturing of tricalcium phosphate (TCP) bioceramic scaffolds via DLP is explored in the proceeding research paper. Particularly, the role of exposure intensity and exposure time on resultant scaffold quality and mechanical properties is studied. Increased exposure intensity results in an increased deviation from the designed lattice structure and thus an increase in compressive strength. Scaffolds produced with the highest exposure intensity, resulted in a 27.6 % error increase in mean beam diameter, resulting from an increased scattering effect, penetration depth, and over-curing of peripheral slurry. TCP scaffolds with an exposure time of 3.5 s and exposure intensity of 40 mW/cm2 possessed the highest print accuracy, resulting in the lowest average compressive strength – 82 MPa for the scaffolds of cube structure and 48 MPa for the ones of I-WP structure. Digital light processing (DLP) is an effective additive manufacturing (AM) method applicable for bioceramics. This study focuses on the influence of light exposure intensity on scaffold quality and compressive strength. The increase of exposure intensity can improve the compressive strength with the sacrifice of structure accuracy. The conclusions of this study can provide insights into the relationship of DLP printing parameters and scaffolds quality. [Display omitted] [ABSTRACT FROM AUTHOR]

This study evaluated the biocompatibility and accuracy of 3D-printed β-tricalcium phosphate (β-TCP) pure ceramic scaffolds. A specific shaping process associating a digital light processing (DLP) 3D printer and a heat treatment was developed to produce pure β-TCP scaffolds leaving no polymer binder residue. The β-TCP was characterised using X-ray diffraction, infrared spectroscopy and the detection of pollutants. The open porosity of produced matrices and their resorption were studied by hydrostatic weighing and calcium release measures. The biocompatibility of the printed matrices was evaluated by mean of osteoblast cultures. Finally, macroporous cubic matrices were produced. They were scanned using a micro-Computed Tomography scanner (micro-CT scan) and compared to their numeric models. The results demonstrated that DLP 3D printing with heat treatment produces pure β-TCP matrices with enhanced biocompatibility. They also demonstrated the printing accuracy of our technique, associating top-down DLP with the sintering of green parts. Thus, this production process is promising and will enable us to explore complex phosphocalcic matrices with a special focus on the development of a functional vascular network. [ABSTRACT FROM AUTHOR]

Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular trend. Among various manufacturing technologies, magnetic-assisted digital light processing (DLP) stands out because it enables precise manufacturing of macro-scale structures and micro-scale distributions with the assistance of an external magnetic field. Current research on manufacturing magnetic flexible actuators mostly employs single materials, which limits the magnetic driving performance to some extent. Based on these characterizations, we propose a multi-material magnetic field-assisted DLP technology to produce flexible actuators with an accuracy of 200 µm. The flexible actuators are printed using two materials with different mechanical and magnetic properties. Considering the interface connectivity of multi-material printing, the effect of interfaces on mechanical properties is also explored. Experimental results indicate good chemical affinity between the two materials we selected. The overlap or connection length of the interface moderately improves the tensile strength of multi-material structures. In addition, we investigate the influence of the volume fraction of the magnetic part on deformation. Simulation and experimental results indicate that increasing the volume ratio (20% to 50%) of the magnetic structure can enhance the responsiveness of the actuator (more than 50%). Finally, we successfully manufacture two multi-material flexible actuators with specific magnetic arrangements: a multi-legged crawling robot and a flexible gripper capable of crawling and grasping actions. These results confirm that this method will pave the way for further research on the precise fabrication of magnetic flexible actuators with diverse functionalities. [ABSTRACT FROM AUTHOR]

Digital light processing (DLP) has emerged as a highly promising 3D printing technology, which is due to its ability to fabricate components and structures with low cost and high precision. The DLP is, therefore, applicable in a wide range of fields. The phenomenon of light-scattering plays a dominant role in the DLP manufacturing process, but the specific impact of ceramic particles on the distribution of incident light remains unclear. The present study has, therefore, focused on studying the effect of ceramic particles on light-scattering by performing extensive theoretical finite element simulations. The aim was then to improve the curing quality of the DLP 3D printing process. More specifically, spherically shaped particles with a uniform distribution, lower duty ratios, or materials with lower refractive indices were necessary conditions for enhancing the printing precision due to the mitigated lateral light scattering effects. The overall results of this study have provided valuable guidance for the control of the light-induced curing in the 3D printing process of ceramics, thereby facilitating advancements in ceramic-based fabrication techniques. [ABSTRACT FROM AUTHOR]

Four-dimensional (4D) printing unlocks new potentials for personalized biomedical implantation, but still with hurdles of lacking suitable materials. Herein, we demonstrate a bioresorbable shape memory elastomer (SME) with high elasticity at both below and above its phase transition temperature (T trans). This SME can be digital light 3D printed by co-polymerizing glycerol dodecanoate acrylate prepolymer (pre-PGDA) with acrylic acid monomer to form crosslinked Poly(glycerol dodecanoate acrylate) (PGDA)-Polyacrylic acid (PAA), or PGDA-PAA network. The printed complex, free-standing 3D structures with high-resolution features exhibit shape programming properties at a physiological temperature. By tuning the pre-PGDA weight ratios between 55 wt% and 70 wt%, T trans varies between 39.2 and 47.2 ℃ while Young's moduli (E) range 40–170 MPa below T trans with fractural strain (ε f) of 170 %-200 %. Above T trans , E drops to 1–1.82 MPa which is close to those of soft tissue. Strikingly, ε f of 130–180 % is still maintained. In vitro biocompatibility test on the material shows > 90 % cell proliferation and great cell attachment. In vivo vascular grafting trials underline the geometrical and mechanical adaptability of these 4D printed constructs in regenerating the aorta tissue. Biodegradation of the implants shows the possibility of their full replacement by natural tissue over time. To highlight its potential for personalized medicine, a patient-specific left atrial appendage (LAA) occluder was printed and implanted endovascularly into an in vitro heart model. 4D printed shape-memory elastomer (SME) implants particularly designed and manufactured for a patient are greatly sought-after in minimally invasive surgery (MIS). Traditional shape-memory polymers used in these implants often suffer from issues like unsuitable transition temperatures, poor biocompatibility, limited 3D design complexity, and low toughness, making them unsuitable for MIS. Our new SME, with an adjustable transition temperature and enhanced toughness, is both biocompatible and naturally degradable, particularly in cardiovascular contexts. This allows implants, like biomedical scaffolds, to be programmed at room temperature and then adapt to the body's physiological conditions post-implantation. Our studies, including in vivo vascular grafts and in vitro device implantation, highlight the SME's effectiveness in aortic tissue regeneration and its promising applications in MIS. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper proposes an experimental investigation of a commercial photopolymer resin followed by material modelling and manufacturing system characterization. We focus on the effect of the degree of cure and temperature on the material properties of the photopolymer materials. UV curing properties of the liquid resin are assessed with the thickness measurement by optical tomography. Besides, the specific heat capacity is determined for the almost completely cured and uncured samples with DSC measurements. Photo-DSC experiments are performed to investigate the curing reaction and modelling of the evolution of the degree of cure depending on the light intensity and temperature. In addition, chemical shrinkage behaviour is captured as function of the degree of cure by the high-precision balance set-up. As a result of our experimental studies, model equations are proposed to describe the material behaviour. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to study the design and characterization of a 3D printed tetrakaidecahedron cell-based acoustic metamaterial. At present, the mitigation of low-frequency noise involves the utilization of spatially demanding materials for the absorption of sound. These materials lack the ability for targeted frequency control adjustments. Hence, there is a requirement for an approach that can effectively manage low-frequency noise using lightweight and durable materials. Design/methodology/approach: The CAD model was created in SolidWorks and was manufactured using the Digital Light Processing (DLP) 3D printing technique. Experimental study and numerical simulations examined the metamaterial's acoustic absorption. An impedance tube with two microphones was used to determine the absorption coefficient of the metamaterial. The simulations were run in a thermoviscous module. Findings: The testing of acoustic samples highlighted the effects of geometric parameters on acoustic performance. Increment of the strut length by 0.4 mm led to a shift in response to a lower frequency by 500 Hz. Peak absorption rose from 0.461 to 0.690 as the strut diameter was increased from 0.6 to 1.0 mm. Increasing the number of cells from 8 to 20 increased the absorption coefficient and lowered the response frequency. Originality/value: DLP 3D printing technique was used to successfully manufacture tetrakaidecahedron-based acoustic metamaterial samples. A novel study on the effects of geometric parameters of tetrakaidecahedron cell-based acoustic metamaterial on the acoustic absorption coefficient was conducted, which seemed to be missing in the literature. [ABSTRACT FROM AUTHOR]

This study aims to investigate the influence of post-polymerization (post-curing) conditions on surface characteristics, flexural properties, water sorption and solubility, and cytotoxicity of additively manufactured denture base materials. The tested specimens were additively manufactured using digital light processing and classified into different post-curing condition groups: submerged in water (WAT), submerged in glycerin (GLY), and air exposure (AIR). An uncured specimen (UNC) was used as a control. The surface topography and roughness were observed. The flexural strength and modulus were determined via a three-point bending test. The water sorption and solubility were subsequently tested. Finally, an extract test was performed to assess cytotoxicity. Different post-curing conditions had no significant effects on the surface topography and roughness (Sa value). Various post-curing conditions also had no significant effects on the flexural strength. Notably, the flexural modulus of the WAT group (2671.80 ± 139.42 MPa) was significantly higher than the AIR group (2197.47 ± 197.93 MPa, p = 0.0103). After different post-curing conditions, the water sorption and solubility of the specimens met the ISO standards. Finally, all post-curing conditions effectively reduced cytotoxic effects. Post-curing with different oxygen levels improved flexural properties, and flexural modulus significantly increased after the specimens were submerged in water. In addition, water sorption and solubility, and cytocompatibility were optimized by post-curing, irrespective of the post-curing conditions. Therefore, the water-submerged conditions optimized the flexural modulus of the 3D-printed denture base materials. • The underwater method of post-curing resulted in the highest flexural modulus. • Flexural strength was not significantly affected by different oxygen content. • Different post-curing conditions did not induce cytotoxicity. • The underwater method is a promising post-processing procedure. [ABSTRACT FROM AUTHOR]

Pallets are a tertiary form of packaging used for stacking, storing, protecting, or transporting goods in supply chains. They are utilized as a base for the unitization of goods for logistics and warehousing. Moreover, pallets can be manufactured using wood, plastic, metal, and corrugated paper, which can be used as material-handling equipment. With several products being transported worldwide and with year-on-year growth, it would be beneficial to make lightweight pallets. Such pallets are recyclable, easy to clean, cheap, and durable to maintain and store. Though most of the pallets are widely available for basic purposes, applications involving high-end bio-packings and transportation of special chemicals require specialized pallets to be manufactured like polymers to ensure a negligible chemical reaction, light in weight, and attenuation in freight capacity, thereby widespread reduction in wastage. With advancements, job to job and immediate requirements, additive manufacturing has the potential to close the gap for jobs with short lead times. If the design process of new pallets has limits the creation of specific codes, the transitions will be smoother in rapid prototyping. This work describes the development of polymer pallets by taking advantage of stereolithography (SLA) and digital light processing (DLP) technology for 3D printing pallets in correlation to injection moulding. After the pallets are designed and manufactured, AM technologies can be applied to specified standards, and the pallets then undergo tensile strength, elongation, and hardness tests. The analysis was carried out for configurable geometries adapting to fork lifting, conveyor, racking, and stacking conditions. Analytical and numerical solutions were carried out to understand the stress and deflections for each geometry and its wide range of applications for pallets. [ABSTRACT FROM AUTHOR]

With the development of Internet of Things technology and the popularity of wearable devices, the need for remote monitoring of sports activities is also increasing. In this study, an efficient sports remote monitoring system is designed by using digital light processing technology and wearable equipment. The system collects and transmits motion data and video streams in real time by integrating sensors into an athlete's wearable device. After the processing of digital light processing technology, image and video data are optimized and compressed for transmission to remote servers over wireless networks. A series of experiments were carried out to verify the effectiveness and performance of the designed system in terms of optics. The experimental results show that the system optimizes the transmission bandwidth effectively and can realize high-quality remote monitoring. The experimental results show that the system can meet the needs of practical applications, and has good practicability and scalability. Through the application of optical technology and the integration of wearable devices, the system realizes efficient remote monitoring and can meet the needs of practical applications. [ABSTRACT FROM AUTHOR]

Digital Light Processing (DLP) enables intricate ceramic part production from photosensitive ceramic slurry. While ZrO2 and Al2O3 are commonly studied, their composites are underexplored despite diverse applications. This study investigates fabricating high-strength, fully dense alumina-toughened zirconia (ATZ) parts using a low-cost desktop DLP printer designed for polymer printing. Various ATZ-based ceramic slurries (30, 35, 42.5 vol%) with different binders and dispersants were prepared and evaluated for curing and rheological properties. Promising formulations underwent debinding and sintering, resulting in homogenous microstructures with a well-distributed blend of the two phases. For the doped samples, SEM analysis revealed a good distribution of dopants and elongated dopant grains infused at higher temperatures. The 35 vol% ATZ exhibited exceptional average flexural strength of 1321 MPa, surpassing previous DLP-fabricated composites. This suggests no need for increased solid loading content. The findings demonstrate the potential of DLP in producing high-performance ceramic parts with tailored properties.

Owing to their great potential to enhance the structural, mechanical, and electrical properties of materials, numerous researchers have dedicated their efforts to manufacturing multi-walled carbon nanotubes (MWCNTs)-reinforced composites via additive manufacturing (AM) to leverage AM's ability to fabricate intricate structural components. However, there is currently limited research on MWCNTs in photosensitive resin (PR) systems processed via a type of vat photopolymerization AM technique - digital light processing (DLP). Additionally, the distribution pattern of MWCNTs in PR systems is still unknown. To address these research gaps, this investigation focuses on fabricating MWCNTs-reinforced PR (MWCNTs-PR) via DLP and studying the effects of MWCNTs content on microstructure characterizations and mechanical properties of MWCNTs-PR. These results show that PR with 0.05 wt% MWCNTs addition exhibits a 25 % increase in elastic modulus and a 2 % increase in bending strength compared to pure PR. To achieve a more uniform distribution of MWCNTs in the PR, a combination of an ultrasonic bath and mechanical stirring was adopted. To further investigate the mechanism behind MWCNTs-enhanced bending resistance, a multi-material layered 3D printing structure was developed. The experimental findings reveal that the 10001 structure yields the highest bending modulus, surpassing the control group by 14.9 %. To validate the bending resistance mechanism attributed to MWCNTs-PR, finite element analysis was conducted.

Li 4 SiO 4 ceramic pebble is deemed as the most attractive tritium breeder for fusion reactor blanket. In this work, we fabricated a novel Li 4 SiO 4 pebble with micrometer-scale pore structure by digital light processing to verify the feasibility of complex pore structure manufacturing for future breeders. The effects of processing parameters on printing accuracy, microstructure and mechanical properties of Li 4 SiO 4 pebbles were investigated. For synthesizing the pure Li 4 SiO 4 phase, the optimal stoichiometric ratio of Li 2 SiO 3 to Li 2 CO 3 was 1:1.09 in the premixed powder. The photosensitivity of dual-phase ceramic suspension was investigated according to an attenuation model, and the overgrowth was reduced to ∼50 μm by using the dimension formula. After optimizing the post-processing, the radial pore structure Li 4 SiO 4 pebbles with excellent crush load (50.3 N, standard deviation = 4.4 N) and suitable open porosity (18.3 %) can be yielded. This work provides a fresh solution to control the pore structure of tritium breeding pebbles in an unprecedented micrometer scale. [Display omitted] • Radial pore Li 4 SiO 4 pebble was designed, and fabricated by vat photopolymerization. • Dual-phase premixed powder (Li 2 CO 3 –Li 2 SiO 3) was used to yield high purity Li 4 SiO 4. • Dimension modal was built, and the overgrowth was effectively reduced to 54.1 μm. • Optimized post-process led to higher crush load (50.3 N) and proper microstructures. [ABSTRACT FROM AUTHOR]

The present study aims to compare provisional single crowns on anterior implants made using conventional PMMA and 3D-printed workflows. The study assessed the occurrence of failures, color variation, signs of early deterioration, operating time, and patients' satisfaction with the treatment through a randomized controlled trial. This study was conducted as a randomized controlled trial, following the SPIRIT and CONSORT guidelines. Patients were included in the study after meeting the eligibility criteria and were randomly assigned to one of two groups (conventional and 3D-printed). FDI criteria, visible plaque index (VPI), bleeding on probing (BOP), and color variation were considered as the primary outcomes. Operating time and patient satisfaction were also assessed as secondary outcomes. Fisher's exact test was performed to analyze the association between the primary and secondary outcomes and the study groups. Mann-Whitney test was used to compare the mean VAS satisfaction scores between the conventional PMMA and 3D-printed groups (STATA 14™, with an α = 0.05). A total of 42 provisional single crowns (n = 21) were made for 33 patients. Only the fracture parameter (FDI) showed a statistically significant difference, with 3D-printed provisionals exhibiting higher rates of catastrophic failures compared to conventional ones (p = 0.05). Although the operating time for the 3D-printed group was shorter (p < 0.001), no statistical difference observed in patients' satisfaction regarding esthetics, phonetics, chewing, or comfort. 3D-printed and conventional PMMA provisional single crowns showed comparable clinical performance, except for the observed fracture types. Although 3D-printed provisional restorations showed a shorter operating time, overall patients' satisfaction was not affected. • Operating time for the 3D printed group was shorter than the conventional group. • Patient perception on esthetics, phonetics, chewing, and comfort was not impacted by 3D printing or conventional methods. • 3D printed provisionals presented higher catastrophic failures than conventional ones. [ABSTRACT FROM AUTHOR]

Infection prevention and public health are a vital concern worldwide, especially during pandemics such as COVID-19 and seasonal influenza. Frequent manual disinfection and use of chemical spray coatings at public facilities are the typical measures taken to protect people from coronaviruses and other pathogens. However, limitations of human resources and coating durability, as well as the safety of disinfectants used are the major concerns in society during a pandemic. Non-leachable antimicrobial agent poly(hexamethylene biguanide) (PHMB) was mixed into photocurable liquid resins to produce novel and tailor-made covers for public facilities via digital light processing, which is a popular 3D printing technique for satisfactory printing resolution. Potent efficacies of the 3D-printed plastics were achieved in standard antibacterial assessments against S. aureus, E. coli and K. pneumoniae. A total of 99.9% of Human coronavirus 229E was killed after being in contact with the 3D-printed samples (containing the promising PHMB formulation) for two hours. In an eight-week field test in Hong Kong Wetland Park, antibacterial performances of the specially designed 3D-printed covers analysed by environmental swabbing were also found to be satisfactory. With these remarkable outcomes, antimicrobial products prepared by digital light processing 3D printing can be regarded as a reliable solution to long-term infection prevention and control. [ABSTRACT FROM AUTHOR]

Magnetically driven miniature soft robots exhibit fast and dexterous responses to an applied external magnetic field. With remote manipulation, controlled navigation of robots can be realized within hard‐to‐access spaces for potential use in the human body. Existing magnetic miniature soft robots using digital light processing are fabricated from planar sheets, and thus have limited shape transformations and locomotive behaviors. Herein, a multilayer 3D printing method is reported for patterning magnetic nanoparticles in ultraviolet (UV)‐curable polymer matrix. Various multilayer 3D structures within 10 mm in overall size are fabricated with controlled volumes at different parts, which outperform 2D folded shapes in terms of robustness and kinematic flexibility. By programming heterogeneous magnetization within discrete multilayer robot segments, magnetic torque‐induced shape changes including gripping, rolling, swimming, and walking are induced by a global actuation field. Stacked design features with minimum dimension of 200 μm and encoded magnetization with resolution of 350 μm can be realized in the printing process. Meanwhile, enhanced deformation flexibility and formation of orientation‐anchoring mechanisms are created by integrating multiple materials with distinct mechanical and magnetic properties, respectively, which enables the creation of versatile 3D multi‐material actuators. [ABSTRACT FROM AUTHOR]