Digital Light Processing (DLP) is a powerful technique for the preparation of ceramic parts with high resolution and complex shapes. In the last years, the development of photosensitive slurries for ...the production of ceramics with good mechanical properties has received much attention. In this work, ZrO2 UV-curable slurries were prepared in two steps for their application in DLP. Firstly, the surface modification of the ZrO2 particles was carried out using a dispersing agent and secondly, the modified powder was dispersed in an acrylate based mixture. Parts with different geometries were printed and a resolution experiment was also carried out in order to determine the limitations of the slurry. Finally, 30 bars were produced to study the mechanical properties of the sintered parts (ρ = 6.00 ± 0.01 g/mL) by 4-point bending tests and Weibull analysis, obtaining a flexural strength σ0 = 741 (718–765) MPa with a Weibull coefficient of 11.4.
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•Lignin-derivable photo-curable resins for digital light processing were developed.•The resins were based on methacrylated vanillin or vanillyl alcohol and eugenol.•Lignin ...nanoparticles served as UV absorbers that enhanced printing resolution.•Modulation of crosslinking degree enabled the tuning of mechanical properties.•A multi-model material featuring both soft and rigid domains was 3D printed.
The more widespread applicability of photopolymerization-based three-dimensional (3D) printing is limited by the availability of light-curable resins, most of which are based on fossil-derived compounds. We developed a biobased lignin-derivable resin by utilizing methacrylated derivatives of vanillin, vanillyl alcohol, and eugenol as aromatic monomers. Lignin nanoparticles (LNPs) were incorporated as functional fillers that enhance print resolution and material properties. The crosslinking degree, and thereby the tensile properties, was modulated through the use of mono- or dimethacrylated vanillin derivatives in the resin formulation. The LNPs acted as UV absorbers, conferring better control of the photopolymerization process by preventing light penetration across unintended layers, leading to enhanced print resolution. The LNPs showed excellent dispersion stability due to their size and morphology. The inclusion of up to 2 wt% of LNPs improved the ductility of the 3D printed nanocomposites through toughening mechanisms enabled by the rigid nanoparticles. Finally, exploiting the differences in crosslinking degree of the resin formulations, a multi-material model featuring both soft and rigid domains was fabricated. This study demonstrates a simple but effective strategy for the design of biobased photocurable resins with tailorable mechanical properties that are suitable for high-resolution and multi-material 3D printing.
This manuscript proposed a new approach to manufacture SiBOC ceramic samples with complex structures via DLP 3D printing technique from ceramic precursors. High ceramic yield photosensitive SiBOC ...resin for 3D printing was synthesized based on the condensation reaction of boric acid and siloxanes. The stability of printed block samples significantly improved by increasing the content of diethoxydimethyl silane. And this strategy was applicable to most systems of UV cured ceramic precursors. The DLP-printed SiBOC ceramics maintained high ceramic yield (>76 %) and exhibited perfect 25 % isotropic shrinkage after pyrolysis at 1000 ℃. They experienced only a 0.5 % weight loss in an argon environment at 1450 ℃, and exhibited better mechanical properties at 1000 ℃ compared to room temperature. The results indicated that the DLP-printed SiBOC ceramics had excellent thermal stability and mechanical properties, which could significantly expand the application range of SiBOC ceramics.
Personalized zirconium dioxide (ZrO2) all-ceramic teeth are expected to be widely used in the field of oral restoration. Here, ZrO2 all-ceramic teeth were fabricated for biological engineering by ...photosensitive resin based digital light processing (DLP) technology. When sintered at 1500 °C for 3 h, dense ZrO2 ceramics were obtained with relative density of 98.02 ± 0.32%, Vickers hardness of 12.62 ± 0.15 GPa and fracture toughness of 6.11 ± 0.36 MPa∙m1/2, which were close to those of the ZrO2 ceramics prepared by dry pressing. To confirm whether the prepared ZrO2 ceramics possessed good biosafety, in vitro biological experiments were further performed with rat bone marrow mesenchymal stem cells (rBMSCs) and preferable cell attachment was observed at the initial stages. Results illustrated that the compositions with cytotoxicity in green samples were completely decomposed after debinding and sintering process, and the ZrO2 ceramics could provide an ideal biocompatible environment for mesenchymal stem cells. This study shows that ZrO2 all-ceramic teeth with personalized structure prepared by DLP technology have good mechanical properties and biocompatibility, exhibiting strong potential in the field of oral restoration.
In this study, four types of triply periodic minimal surface (TPMS) were implemented to create cellular ceramics via digital light processing (DLP) technology, namely p-cell, gyroid, IWP and s14. The ...mechanical properties of these TPMS structures were investigated experimentally. Results showed that compressive strength of TPMS structures increases with relative density. IWP and s14 structures exhibit similar mechanical response under stress. In general, all TPMS structures can sustain >2% strain without failure and the compressive strength followed the order of s14 > IWP > gyroid > p-cell. The s14 structure can reach a high compressive strength of 105 MPa at a structural density of 30.5 % while gyroid structure can provide a compressive strength of 5.6 MPa at a very low structural density of 6.7 %. The porosity dependence of Young’s modulus of sintered zirconia TPMS demonstrated that the Pabst-Gregorova exponential relation can provide a better prediction than the classical Gibson-Ashby model.
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•The design method based on Voronoi was proposed to mimic the characteristics of cancellous bone in human body.•Ceramic Digital light processing (DLP) method was adopted to satisfy ...the forming requirements of irregular scaffolds.•The compressive strength of scaffolds can be increased by 30% through the regulation of irregularity.•Cell experiments confirmed that structural changes also had influence on the biocompatibility of scaffolds.
Ideal bone scaffolds require good biocompatibility and moderate mechanical properties, so as to promote the proliferation and differentiation of osteoblast cells, and achieve the good bone repair. Inspired by the porous structure of cancellous bone, 15 groups of bone scaffolds with variable irregularity (Ir1-5) and porosity (35.53–61.75%) were designed and fabricated by ceramic digital light processing (DLP) using 20 wt% hydroxyapatite doped zirconia as the matrix material. The effects of structural parameters and material on mechanical properties and biocompatibility were studied. The shrinkage test results showed that the density of scaffolds was mainly affected by the porosity. The mechanical test results showed that Ir2 and Ir3 scaffolds had better compressive behaviors, and the compressive strength could be increased by 30% by regulating the irregularity. All scaffolds showed comparable mechanical properties to that of cancellous bone. Cell experiments showed that the effect of structure on cell proliferation, differentiation, and mineralization was most evident at the early stage of implantation. Meanwhile, the biocompatibility variation with the irregularity was consistent with mechanical properties. This study proved that a bio-inspired bone scaffold with excellent comprehensive properties could be obtained through reasonable design.
•DLP technology was used to manufacture lattices with CAD designed struts of 200–500 μm.•The slurry prepared with the pre-treated powder showed appropriate properties for successful processing on the ...Admaflex 130.•The cure depth necessary for successful manufacturing was found to be inversely proportional to the exposed area.•DOE showed the most significant parameters that influence the dimensional accuracy were the exposure time, the exposure power and their interaction.•The broadening parameters were found to be dependent on the layer thickness as well as the energy dose and the feature size.
Digital Light Processing (DLP) technology demonstrates the potential for manufacturing parts with complex structures for various engineering applications. The purpose of this study is to evaluate Al2O3 ceramic slurry preparation techniques, establish optimal processing window and assess the manufacturability and dimensional accuracy of lattice structures with CAD strut diameters of up to 500 μm. Two preparation techniques of the ceramic slurry were investigated. The slurry with the pre-treated powder showed appropriate rheological and photopolymerization behaviour. Full factorial Design of Experiments (DOE) was conducted to generate an experimental plan and assess the influence of the printing parameters on the dimensional accuracy. Analysis of Variance (ANOVA) revealed the exposure time, the exposure power, and the interaction effect of both had a significant influence on the dimensional accuracy of lattice strut diameters. The excess cure width was found to be dependent on the feature size, the energy dose and the layer thickness.
Three-dimensional printing with Digital Lighting Processing (DLP) printer has come into the new wave in the tissue engineering for regenerative medicine. Especially for the clinical application, it ...needs to develop of bio-ink with biocompatibility, biodegradability and printability. Therefore, we demonstrated that Silk fibroin as a natural polymer fabricated with glycidyl-methacrylate (Silk-GMA) for DLP 3D printing. The ability of chondrogenesis with chondrocyte-laden Silk-GMA evaluated in vitro culture system and applied in vivo. DLP 3D printing system provided 3D product with even cell distribution due to rapid printing speed and photopolymerization of DLP 3D printer. Up to 4 weeks in vitro cultivation of Silk-GMA hydrogel allows to ensure of viability, proliferation and differentiation to chondrogenesis of encapsulated cells. Moreover, in vivo experiments against partially defected trachea rabbit model demonstrated that new cartilage like tissue and epithelium found surrounding transplanted Silk-GMA hydrogel. This study promises the fabricated Silk GMA hydrogel using DLP 3D printer could be applied to the fields of tissue engineering needing mechanical properties like cartilage regeneration.
