3D printing,as a versatile additive manufacturing technique,offers high design flexibility,rapid prototyping,minimal material waste,and the capability to fabricate complex,customized geometries.These attributes make i...3D printing,as a versatile additive manufacturing technique,offers high design flexibility,rapid prototyping,minimal material waste,and the capability to fabricate complex,customized geometries.These attributes make it particularly well-suited for low-temperature hydrogen electrochemical conversion devices—specifically,proton exchange membrane fuel cells,proton exchange membrane electrolyzer cells,anion exchange membrane electrolyzer cells,and alkaline electrolyzers—which demand finely structured components such as catalyst layers,gas diffusion layers,electrodes,porous transport layers,and bipolar plates.This review provides a focused and critical summary of the current progress in applying 3D printing technologies to these key components.It begins with a concise introduction to the principles and classifications of mainstream 3D printing methods relevant to the hydrogen energy sector and proceeds to analyze their specific applications and performance impacts across different device architectures.Finally,the review identifies existing technical challenges and outlines future research directions to accelerate the integration of 3D printing in nextgeneration low-temperature hydrogen energy systems.展开更多
In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved cerami...In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved ceramic substrate,and laser sintering and microdroplet spraying processes are used to add the conductive metal on the curved substrate.The problems of gain loss,bandwidth reduction,and frequency shift caused by high temperatures are addressed by using a proper antenna design,with parasitic patches,slots,and metal resonant cavities.The antenna prototype is characterized by the curved substrates and the conductive metals for the power dividers,the patch,and the ground plane;its performance is examined up to a temperature of 600℃in a muffle furnace and compared with the results from the numerical analysis.The results show that the antenna can effectively function at 600℃and even higher temperatures.展开更多
As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands...As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ regeneration.Curated by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable organs.We further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control measures.Finally,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.展开更多
Ceramic matrix composites(CMCs)structural components encounter the dual challenges of severe mechanical conditions and complex electromagnetic environments due to the increasing demand for stealth technology in aerosp...Ceramic matrix composites(CMCs)structural components encounter the dual challenges of severe mechanical conditions and complex electromagnetic environments due to the increasing demand for stealth technology in aerospace field.To address various functional requirements,this study integrates a biomimetic strategy inspired by gradient bamboo vascular bundles with a novel dual-material 3D printing approach.Three distinct bamboo-inspired structural configurations Cf/SiC composites are designed and manufactured,and the effects of these different structural configurations on the CVI process are analyzed.Nanoindentation method is utilized to characterize the relationship between interface bonding strength and mechanical properties.The results reveal that the maximum flexural strength and fracture toughness reach 108.6±5.2 MPa and 16.45±1.52 MPa m1/2,respectively,attributed to the enhanced crack propagation resistance and path caused by the weak fiber-matrix interface.Furthermore,the bio-inspired configuration enhances the dielectric loss and conductivity loss,exhibiting a minimum reflection loss of−24.3 dB with the effective absorption band of 3.89 GHz.This work introduces an innovative biomimetic strategy and 3D printing method for continuous fiber-reinforced ceramic composites,expanding the application of 3D printing technology in the field of CMCs.展开更多
Electromagnetic devices have been widely used in the fields of information communication,medical treatment,electrical engineering,and national defense,and their properties are strongly dependent on the constituent ele...Electromagnetic devices have been widely used in the fields of information communication,medical treatment,electrical engineering,and national defense,and their properties are strongly dependent on the constituent electromagnetic materials.Conversely,electromagnetic metamaterials(EMMs),which are artificially engineered with distinctive electromagnetic properties,can overcome the limitations of natural materials owing to their structural advantages.Three-dimensional(3D)printing is the most effec-tive technique for fabricating EMM devices with different geometric parameters and associated proper-ties.However,conventional 3D-printed EMM devices may lack manufacturing flexibility and environmental adaptability to different physical stimuli,such as electric and magnetic fields.Four-dimensional(4D)printing is an ideal technique for schemes to integrate structural design with intelligent materials environmentally adaptive to external fields,for example,the printed components can change shape under electric stimulation.Given the rapid advancements in the EMM field,this paper first reviews typical EMM devices,their design theories,and underlying principles.Subsequently,it presents various EMM structural topologies and manufacturing technologies,emphasizing the feasibility of combining 3D and 4D printing.In addition,we highlight the important applications of EMMs and their future trends and the challenges associated with functional EMMs and additive manufacturing.展开更多
Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on...Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on traditional thermal processing or direct ink writing three-dimensional(3D)printing.These methods are not conducive to manufacturing complex structures and present challenges such as time inefficiency,poor accuracy,and the necessity of multiple steps,significantly limiting SR applications.In this study,we developed an SR-based ink suitable for vat photopolymerization 3D printing using a multi-thiol monomer.This ink enables the one-step fabrication of complex architectures with high printing resolution at the micrometer scale,providing excellent mechanical strength and superior chemical stability.Specifically,the optimized 3D printing SR-20 exhibits a tensile stress of 1.96 MPa,an elongation at break of 487.9%,and an elastic modulus of 225.4 kPa.Additionally,the 3D-printed SR samples can withstand various solvents(acetone,toluene,and tetrahydrofuran)and endure temperatures ranging from-50℃ to 180℃,demonstrating superior stability.As a emonstration of the application,we successfully fabricated a series of SR-based soft pneumatic actuators and grippers in a single step with this technology,allowing for free assembly for the first time.This ultraviolet-curable SR,with high printing resolution and exceptional stability performance,has significant potential to enhance the capabilities of 3D printing for applications in soft actuators,robotics,flexible electronics,and medical devices.展开更多
Dermal substitutes have provided a template for the regeneration and reconstruction of the dermis.However,the healed skin tissue often exhibits abnormal morphology and functionality,including scarring and inflammation...Dermal substitutes have provided a template for the regeneration and reconstruction of the dermis.However,the healed skin tissue often exhibits abnormal morphology and functionality,including scarring and inflammation.In this study,a composite bioink composed of methacrylated gelatin(GelMA)and chitosan oligosaccharide(COS)was proposed for printing a dermal scaffold using digital light processing(DLP)technology.The GelMA/COS bioink exhibited suitable porosity,swelling,degradation rate,and mechanical properties.The inclusion of COS demonstrated antibacterial effects against both Gram positive and Gram-negative bacteria,while simultaneously fostering the proliferation of human dermal fibroblasts(HDFs).Additionally,the application of COS could effectively reduce the expression levels of fibrosis-related genes,such as collagen I,collagen III,and fibronectin I.The three-dimensionally printed cell-laden dermal scaffold exhibited excellent shape fidelity and high cellular viability,facilitating the extension of HDFs along the scaffold and the simultaneous secretion of extracellular matrix proteins.Furthermore,the HDF-laden dermal scaffold transplanted into full-thickness skin defect sites in nude mice was shown to accelerate wound closure,reduce inflammation,and improve wound healing.Overall,the DLP-printed dermal scaffold provides an appealing approach for effectively treating full-thickness skin defects in clinical settings.展开更多
Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exa...Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exacerbates this challenge by rendering the process vulnerable to environmental changes and unexpected factors,resulting in defects and inconsistent product quality,particularly in unmanned long-term operations or printing in extreme environments.To address these issues,we developed a process monitoring and closed-loop feedback control strategy for the 3D printing process.Real-time printing image data were captured and analyzed using a well-trained neural network model,and a real-time control module-enabled closed-loop feedback control of the flow rate was developed.The neural network model,which was based on image processing and artificial intelligence,enabled the recognition of flow rate values with an accuracy of 94.70%.The experimental results showed significant improvements in both the surface performance and mechanical properties of printed composites,with three to six times improvement in tensile strength and elastic modulus,demonstrating the effectiveness of the strategy.This study provides a generalized process monitoring and feedback control method for the 3D printing of continuous fiber-reinforced composites,and offers a potential solution for remote online monitoring and closed-loop adjustment in unmanned or extreme space environments.展开更多
Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and hi...Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.展开更多
As a novel 2D material,Ti_(3)C_(2)T_(x)-MXene has become a major area of interest in the field of microwave absorption(MA).However,the MA effect of common Ti_(3)C_(2)T_(x)-MXene is not prominent and often requires com...As a novel 2D material,Ti_(3)C_(2)T_(x)-MXene has become a major area of interest in the field of microwave absorption(MA).However,the MA effect of common Ti_(3)C_(2)T_(x)-MXene is not prominent and often requires complex processes or combinations of other ma-terials to achieve enhanced performance.In this context,a kind of gradient woodpile structure using common Ti_(3)C_(2)T_(x)-MXene as MA ma-terial was designed and manufactured through direct ink writing(DIW)3D printing.The minimum reflection loss(RL_(min))of the Ti_(3)C_(2)T_(x)-MXene-based gradient woodpile structures with a thickness of less than 3 mm can reach-70 dB,showing considerable improve-ment compared with that of a completely filled structure.In addition,the effective absorption bandwidth(EAB)reaches 7.73 GHz.This study demonstrates that a Ti_(3)C_(2)T_(x)-MXene material with excellent MA performance and tunable frequency band can be successfully fab-ricated with a macroscopic structural design and through DIW 3D printing without complex material hybridization and modification,of-fering broad application prospects by reducing electromagnetic wave radiation and interference.展开更多
Vat photopolymerization 3D printing creates structures by projecting patterns onto a photosensitive resin within a vat.However,the presence of resin vats limits the printing of multiscale multimaterial structures.In t...Vat photopolymerization 3D printing creates structures by projecting patterns onto a photosensitive resin within a vat.However,the presence of resin vats limits the printing of multiscale multimaterial structures.In this context,a novel 3D printing process is presented in which a cured structure is produced from acoustically levitated droplets without a physical vat.This enables the printing process to achieve high flexibility in the printing orientation and material supply.In pursuit of the envisioned 3D acoustic levitation printing strategy,acoustic levitation technology was utilized to suspend a photosensitive resin.Objects with small features were successfully produced by projecting patterns onto levitated resin droplets.Transforming printing orientations allows the fabrication of multiscale structures.Levitating resin droplets on-demand enables the rapid replacement of materials,thereby realizing effortless multimaterial 3D printing.By exploiting the flexibility of printing on levitation resin droplets,the capability of 3D printing on existing objects was established.Finally,an interesting example was illustrated,in which an object integrating liquid,gas,and solid materials was fabricated using the proposed 3D printing strategy.The results show that 3D printing on levitated droplets is feasible for fabricating multiscale and multimaterial objects,which contributes to the development of new 3D printing methods and potential applications.展开更多
The aim of this study is to develop magnetopolymer composites suitable for fabricating soft magnetoactive robots via extrusion-based3D printing.Polysiloxane copolymers with urea fragments were synthesized and characte...The aim of this study is to develop magnetopolymer composites suitable for fabricating soft magnetoactive robots via extrusion-based3D printing.Polysiloxane copolymers with urea fragments were synthesized and characterized,and their thermophysical and rheological properties were investigated.This study provides an assessment of the potential for their further use in additive manufacturing.The obtained materials were utilized as matrices for creating magnetically active polymer composites by incorporating microparticles of carbonyl iron.Samples of complex geometries were printed using both neat and filled filaments,demonstrating the feasibility of employing these materials in extrusion-based 3D printing.展开更多
Hydrocolloids are widely used in meat products and pureed foods as they offer thickening and viscosityenhancing effects that facilitate shaping and improve stability.In this study,the static shear rheological and dyna...Hydrocolloids are widely used in meat products and pureed foods as they offer thickening and viscosityenhancing effects that facilitate shaping and improve stability.In this study,the static shear rheological and dynamic viscoelastic properties of pumpkin puree(S)and pork mince(P)with the addition of various hydrocolloids were considered.Dedicated material printing experiments were conducted by means of a three-dimensional printing platform by using a coaxial dual-nozzle for sandwich composite printing of four different materials.In particular,the impact of different process parameters(printing speed 10~30 mm/s,filling density 10%~50%)was assessed in terms of 3D printing adaptability and final shape of the pumpkin puree-pork mince products.The results have indicated that the addition of hydrocolloids significantly improves the rheological properties of these materials,enhancing their stability in the 3D printing process.Experiments have revealed that with an increase in the xanthan gum conte nt,the viscosity of pumpkin puree decreases.The relationship between the elastic modulus and viscous modulus for the minced pork follows the inequality P4<P3<P2<P1(1.17%,1.75%,2.13%,and 2.88%xanthan gum content,respectively).A“material formula”(detailed composition of the material)suitable for 3D food printing has been derived accordingly.展开更多
The combination of silicon carbide(SiC)ceramics and stereolithography technology shows promise for manufacturing complex-shaped SiC components,expanding application possibilities.However,high sintering temperature and...The combination of silicon carbide(SiC)ceramics and stereolithography technology shows promise for manufacturing complex-shaped SiC components,expanding application possibilities.However,high sintering temperature and structural-performance anisotropy limit the practical use of 3D-printed SiC components.Herein,a novel method is introduced to produce high-specific-strength SiC-based ceramics at a relatively low temperature of 1100℃.A mixed SiC/SiO_(2) slurry(30%SiO_(2) and 70%SiC by volume)with a solid loading of up to 40%was prepared to improve UV light penetration and printability.Additionally,incorporating a high content of methyl-phenyl-polysiloxane(PSO)solution(75%by weight)enabled low-temperature pyrolysis of SiC/SiO_(2)/PSO ceramics.The SiC/SiO_(2)/PSO ceramic lattices after pyrolysis achieved a specific strength as high as(1.03×10^(5))N·m·kg^(-1) and a density of 1.75 g·cm^(-3),outperforming similar SiC-based lattices structures of similar porosities.The bending strength of(95.49±8.79)MPa was comparable to that of ceramics sintered at 1400℃ or higher.Notably,the addition of the silicon carbide oxide(SiOC)phase reduced anisotropy,lowering the transverse and longitudinal compression strength ratios from 1.87 to 1.08,and improving mechanical properties by 79%.This improvement is attributed to SiOC shrinkage,promoting a uniform distribution of sintered components,resulting in a more robust and balanced material structure.This method offers valuable insight into the additive manufacturing(AM)of SiC-based ceramics at lower temperatures and provides new guidance for controlling anisotropy in 3D-printed ceramic parts.展开更多
Two-and three-component deep eutectic solvents(DES)based on acrylic acid(AA),acrylamide(AAm),and choline chloride(ChCl)were used to disintegrate bacterial cellulose into cellulose nanofibers(CNF).As a result,polymeriz...Two-and three-component deep eutectic solvents(DES)based on acrylic acid(AA),acrylamide(AAm),and choline chloride(ChCl)were used to disintegrate bacterial cellulose into cellulose nanofibers(CNF).As a result,polymerizable precursors suitable for 3D printing with CNF as a rheology modifier and reinforcer with formation of interpenetrating double polymer network were obtained after UV curing.Composite hydrogels were formed by replacing ChCl with water.It was found that the introduction of amide groups into the acrylate polymer matrix resulted in an increase in compressive strength.The layered architecture of the 3D printed products provides greater mechanical strength compared to molded products.The structure of the composites was investigated using wide-angle X-ray scattering(WAXS),small-angle X-ray scattering(SAXS),atomic force microscopy(AFM)and polarized light microscopy.These studies suggest that the enhanced mechanical properties of the 3D printed hydrogels are associated with swelling and branching of CNF in the DES,as well as alignment of the filler during extrusion.For comparative analysis,composite hydrogels were also prepared using aqueous solutions of AA and AA/AAm with dispersed CNF.However,the 3D printing process was hampered in this case due to cellulose agglomeration.Mechanical testing revealed the formation of premature microcracks in these samples,which were not observed in composites produced using DES.Cytotoxicity of the composite hydrogels was also tested.The results provide valuable insights into the production of strong(up to 3.4 MPa)homogeneous composite hydrogels using 3D printing with nanocellulose filler.展开更多
Ceramic cores are important in the fabrication of superalloy hollow blades,which are increasingly characterized by intricate internal cavity channels.This complexity poses significant challenges to traditional manufac...Ceramic cores are important in the fabrication of superalloy hollow blades,which are increasingly characterized by intricate internal cavity channels.This complexity poses significant challenges to traditional manufacturing processes.The vat photopolymerization 3D printing technology provides a new choice for ceramic cores with complex structures.However,the lamellar structure of the vat photopolymerization 3D printed ceramic cores leads to the anisotropy.Meanwhile,the low strength and high shrinkage of ceramic cores restrict their industrial application.In this study,using Al_(2)O_(3)powder as the main material,the effects of zircon content on the sintering shrinkage,open porosity,fiexural strength,and other properties of Al_(2)O_(3)-based ceramic cores were studied to address the aforementioned issues.The influencing mechanism of zircon distribution on sintering shrinkage was analyzed,and the strengthening mechanism of mullite on ceramic cores was discussed from both thermodynamics and dynamics aspects.Through the comprehensive evaluation of ceramic core properties,the Al_(2)O_(3)-based ceramic core with 15vol.%zircon exhibites the optimal performance.Compared with the core samples without zirconium addition,the fiexural strength of the Al_(2)O_(3)-based ceramic core with 15vol.%zircon increases from 14.80 MPa to 61.54 MPa at 25°C,an increase of 315.8%;and from 4.91 MPa to 11.59 MPa at 1,500°C,an increase of 136.0%.The shrinkage in the Z-axis is reduced by 21%,which better weakens the anisotropy of the shrinkage of 3D printed Al_(2)O_(3)-based ceramic cores.ZrO_(2)phase and mullite phase are formed by zircon,which improve the comprehensive properties of Al_(2)O_(3)-based ceramic cores.The successful 3D printing of high-performance Al_(2)O_(3)-based ceramic cores via vat photopolymerization has promoted its industrial application for fabricating ceramic cores with complex structures.展开更多
This research investigates the behavior of sandwich glued laminated bamboo(Glubam)structures with a core formed by biodegradable plastic fibers,specifically polylactic acid(PLA),fabricated using 3D printing technology...This research investigates the behavior of sandwich glued laminated bamboo(Glubam)structures with a core formed by biodegradable plastic fibers,specifically polylactic acid(PLA),fabricated using 3D printing technology.The influence of various fiber printing orientations(0°and 45/135°)on tensile and compressive properties was investigated.The experimental results indicated that polylactic acid with calcium carbonate(PLA+)printed unidirectionally and aligned with the loading direction(0°)exhibits superior tensile and compressive strengths compared to specimens printed bidirectionally at 45/135°.Furthermore,the effect of additives on bioplastics of carbon fiber(PLA-CF)and glass fiber(PLA-GF)additives in PLA-based composites was evaluated in comparison with PLA+specimens.The finding indicated that PLA+has a higher strength-to-cost ratio compared to PLA-CF and PLA-GF.Therefore,unidirectionally printed PLA+was selected as the core material in two geometries:honeycomb and honeycomb lattice.These cores were sandwiched between Glubam panels on the top and bottom surfaces of the structures.Flexural performance was evaluated through four-point bending tests,which revealed that sandwich structures with a honeycomb core achieved a flexural strength-to-weight ratio 56.51%higher than those with a honeycomb lattice core.A parametric study using the finite element model was conducted to evaluate the effect of core scale,cross-sectional depth,Glubamthickness,core depth,and the number of honeycomb elements.The results showed that reducing the Glubam thickness while increasing the 3D-printed core depth significantly improved the flexural performance of honeycomb sandwich structures.Notably,reduced Glubam panel thickness coupled with increased core depth enhanced their flexural performance.展开更多
With organ transplantation facing many dilemmas,tissue and organ regeneration as an alternative has bright prospects.In regenerative medicine,Three-dimensional(3D)printing technology and stem cells has been widely app...With organ transplantation facing many dilemmas,tissue and organ regeneration as an alternative has bright prospects.In regenerative medicine,Three-dimensional(3D)printing technology and stem cells has been widely applied to the treatment of diseases related to tissue or organ replacement in dentistry,respectively.However,there are very few studies on the combination of the two,and even fewer clinical studies have been reported in dentistry.In this review,the current oral tissue engineering in vivo and in vitro based on 3D printing and stem cell technology will be summarized,and the discussion on the development prospects of this research direction will be given.Besides,the working principles and advantages&disadvantages of several types of 3D printers,as well as the mechanism of stem cells in tissue engineering will be elucidated.This review provides clinicians and researchers with the current state of research and trends in the combination of stem cells and 3D printing technology to treat oral-related diseases.In the future,3D bioprinters are poised for ongoing innovation with the advancement of relevant technologies,catalyzing an increase in clinical studies focused on treating oral diseases using stem cells and 3D scaffolds.Consequently,these developments will further advance the field of oral tissue engineering.展开更多
The performance of an aero-engine is closely related to the cooling ability of the hollow turbine blades.Ceramic core is an important component in the production of hollow turbine blades with a complex structure.As th...The performance of an aero-engine is closely related to the cooling ability of the hollow turbine blades.Ceramic core is an important component in the production of hollow turbine blades with a complex structure.As the pace of updating and iteration in turbine blade design continues to accelerate,the internal cavity structures of turbine blades have become increasingly complex.Traditional hot injection process is difficult to meet the production requirements of ceramic cores with complex structures.3D printing technology can manufacture ceramic cores without the need for moulds,significantly shortening the production cycle and providing a new technology for the production of ceramic cores with complex structures.To meet the technical requirements of the investment casting process,ceramic cores must possess adequate mechanical strength and appropriate porosity.In this work,the ceramic slurry with polysilazane(PSZ)precursor was successfully prepared,and the Al_(2)O_(3)-based ceramic cores with high performance were fabricated using 3D printing technology.The regulation mechanism of polysilazane on the performance of ceramic cores was investigated.The results show that with the increase of PSZ content,the fiexural strength of ceramic cores firstly increases and then decreases.When the content of PSZ is 5%,the fiexural strength at 25℃and 1,500℃are 31.5 MPa and 13.1 MPa,respectively,and the porosity is 36.7%.This work is expected to advance the research and practical application of high-performance ceramic cores fabricated via 3D printing.展开更多
As a biomass material with biodegradability and biocompatibility, sodium alginate (SA) is a good candidate for constructing hydrogels for tissue-mimicking and biomedical scaffold fabricating through extrusion-based 3D...As a biomass material with biodegradability and biocompatibility, sodium alginate (SA) is a good candidate for constructing hydrogels for tissue-mimicking and biomedical scaffold fabricating through extrusion-based 3D printing technology. However, the mechanical strength and stiffness of alginate hydrogels are still not comparable with biological tissues such as tendons and the printability of SA solutions is often poor. Here, a novel strategy for 3D printing of alginate hydrogels with high mechanical performance is developed by using glycerol as a co-solvent for SA solutions. The addition of glycerol (GL) enables the formation of a homogenous SA/GL solution with a high solid content of 12–20 wt.% and endows crosslinked SA hydrogels with high stretchability. By applying uniaxial stretches, hydrogel filaments prepared with concentrated SA/GL solutions reveal a high tensile strength of 36.6–161.3 MPa, Young's modulus of 59.2–1964.2 MPa, and elongation at break of 8.5 %–106.2 % due to the high orientated and closely packed SA chains. SA/GL solutions become more solid-like with increasing SA concentration, and the solution with a solid content of 16 wt.% exhibits optimal 3D printability because of the appropriate rheological properties and thixotropic behavior. By designing the deforming-and-fixing process, 3D printed high-strength alginate hydrogels with complex structures are prepared, broadening the application of alginate hydrogels in load-bearing and biomedical fields.展开更多
基金the support from the National Natural Science Foundation of China(Nos.22208376,UA22A20429)the Qingdao New Energy Shandong Laboratory Open Project(QNESL OP 202303)+3 种基金Shandong Provincial Natural Science Foundation(Nos.ZR2024QB175,ZR2023LFG005)Fundamental Research Funds for the Central Universities(No.25CX07002A)National Natural Science Foundation of China(Z202401390008)The Hunan Provincial Natural Science Foundation(2025JJ60301)。
文摘3D printing,as a versatile additive manufacturing technique,offers high design flexibility,rapid prototyping,minimal material waste,and the capability to fabricate complex,customized geometries.These attributes make it particularly well-suited for low-temperature hydrogen electrochemical conversion devices—specifically,proton exchange membrane fuel cells,proton exchange membrane electrolyzer cells,anion exchange membrane electrolyzer cells,and alkaline electrolyzers—which demand finely structured components such as catalyst layers,gas diffusion layers,electrodes,porous transport layers,and bipolar plates.This review provides a focused and critical summary of the current progress in applying 3D printing technologies to these key components.It begins with a concise introduction to the principles and classifications of mainstream 3D printing methods relevant to the hydrogen energy sector and proceeds to analyze their specific applications and performance impacts across different device architectures.Finally,the review identifies existing technical challenges and outlines future research directions to accelerate the integration of 3D printing in nextgeneration low-temperature hydrogen energy systems.
基金National Natural Science Foundation of China(No.U2241205)the Natural Science Basic Research Program of Shaanxi(Nos.2022JC-33,2023-GHZD-35,and 2024JC-ZDXM-25)+1 种基金the Fundamental Research Funds for the Central Universitiesthe National 111 Project to provide fund for conducting experiments。
文摘In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved ceramic substrate,and laser sintering and microdroplet spraying processes are used to add the conductive metal on the curved substrate.The problems of gain loss,bandwidth reduction,and frequency shift caused by high temperatures are addressed by using a proper antenna design,with parasitic patches,slots,and metal resonant cavities.The antenna prototype is characterized by the curved substrates and the conductive metals for the power dividers,the patch,and the ground plane;its performance is examined up to a temperature of 600℃in a muffle furnace and compared with the results from the numerical analysis.The results show that the antenna can effectively function at 600℃and even higher temperatures.
基金supported by the National Natural Science Foundation of China(Nos.52325504,52235007,and T2121004).
文摘As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ regeneration.Curated by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable organs.We further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control measures.Finally,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.
基金supported by The National Key Research and Development Program of China(No.2019YFB1901001).
文摘Ceramic matrix composites(CMCs)structural components encounter the dual challenges of severe mechanical conditions and complex electromagnetic environments due to the increasing demand for stealth technology in aerospace field.To address various functional requirements,this study integrates a biomimetic strategy inspired by gradient bamboo vascular bundles with a novel dual-material 3D printing approach.Three distinct bamboo-inspired structural configurations Cf/SiC composites are designed and manufactured,and the effects of these different structural configurations on the CVI process are analyzed.Nanoindentation method is utilized to characterize the relationship between interface bonding strength and mechanical properties.The results reveal that the maximum flexural strength and fracture toughness reach 108.6±5.2 MPa and 16.45±1.52 MPa m1/2,respectively,attributed to the enhanced crack propagation resistance and path caused by the weak fiber-matrix interface.Furthermore,the bio-inspired configuration enhances the dielectric loss and conductivity loss,exhibiting a minimum reflection loss of−24.3 dB with the effective absorption band of 3.89 GHz.This work introduces an innovative biomimetic strategy and 3D printing method for continuous fiber-reinforced ceramic composites,expanding the application of 3D printing technology in the field of CMCs.
基金sponsored by the National Natural Science Foundation of China(52275331 and 52205358)the National Key Research and Development Program of China(2023YFB4604800)+1 种基金the Key Research and Development Program of Hubei Province(2022BAA011)the Hong Kong Scholars Program(XJ2022014).
文摘Electromagnetic devices have been widely used in the fields of information communication,medical treatment,electrical engineering,and national defense,and their properties are strongly dependent on the constituent electromagnetic materials.Conversely,electromagnetic metamaterials(EMMs),which are artificially engineered with distinctive electromagnetic properties,can overcome the limitations of natural materials owing to their structural advantages.Three-dimensional(3D)printing is the most effec-tive technique for fabricating EMM devices with different geometric parameters and associated proper-ties.However,conventional 3D-printed EMM devices may lack manufacturing flexibility and environmental adaptability to different physical stimuli,such as electric and magnetic fields.Four-dimensional(4D)printing is an ideal technique for schemes to integrate structural design with intelligent materials environmentally adaptive to external fields,for example,the printed components can change shape under electric stimulation.Given the rapid advancements in the EMM field,this paper first reviews typical EMM devices,their design theories,and underlying principles.Subsequently,it presents various EMM structural topologies and manufacturing technologies,emphasizing the feasibility of combining 3D and 4D printing.In addition,we highlight the important applications of EMMs and their future trends and the challenges associated with functional EMMs and additive manufacturing.
基金supported by the Strategic Priority Program of the Chinese Academy of Sciences(XDB0470303)the National Key R&D Program of China(2022YFB4600102and 2023YFE0209900)+4 种基金the National Natural Science Foundation of China(52175201 and 51935012)the science and technology projects of Gansu province(22JR5RA093,24JRRA044,24YFFA014 and 24ZDGA014)the Innovation and Entrepreneurship Team Project of YEDA(2021TD007)the special supporting project for provincial leading talents of Yantaithe Taishan Scholars Program。
文摘Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on traditional thermal processing or direct ink writing three-dimensional(3D)printing.These methods are not conducive to manufacturing complex structures and present challenges such as time inefficiency,poor accuracy,and the necessity of multiple steps,significantly limiting SR applications.In this study,we developed an SR-based ink suitable for vat photopolymerization 3D printing using a multi-thiol monomer.This ink enables the one-step fabrication of complex architectures with high printing resolution at the micrometer scale,providing excellent mechanical strength and superior chemical stability.Specifically,the optimized 3D printing SR-20 exhibits a tensile stress of 1.96 MPa,an elongation at break of 487.9%,and an elastic modulus of 225.4 kPa.Additionally,the 3D-printed SR samples can withstand various solvents(acetone,toluene,and tetrahydrofuran)and endure temperatures ranging from-50℃ to 180℃,demonstrating superior stability.As a emonstration of the application,we successfully fabricated a series of SR-based soft pneumatic actuators and grippers in a single step with this technology,allowing for free assembly for the first time.This ultraviolet-curable SR,with high printing resolution and exceptional stability performance,has significant potential to enhance the capabilities of 3D printing for applications in soft actuators,robotics,flexible electronics,and medical devices.
基金supported by the National Natural Science Foundation of China(Nos.51975400 and 62031022)the Shanxi Provincial Key Medical Scientific Research Project(No.2020XM06)+2 种基金the Shanxi Provincial Basic Research Project(Nos.202103021221006,20210302123040,and 202103021223069)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2021L044)the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SX-TD026).
文摘Dermal substitutes have provided a template for the regeneration and reconstruction of the dermis.However,the healed skin tissue often exhibits abnormal morphology and functionality,including scarring and inflammation.In this study,a composite bioink composed of methacrylated gelatin(GelMA)and chitosan oligosaccharide(COS)was proposed for printing a dermal scaffold using digital light processing(DLP)technology.The GelMA/COS bioink exhibited suitable porosity,swelling,degradation rate,and mechanical properties.The inclusion of COS demonstrated antibacterial effects against both Gram positive and Gram-negative bacteria,while simultaneously fostering the proliferation of human dermal fibroblasts(HDFs).Additionally,the application of COS could effectively reduce the expression levels of fibrosis-related genes,such as collagen I,collagen III,and fibronectin I.The three-dimensionally printed cell-laden dermal scaffold exhibited excellent shape fidelity and high cellular viability,facilitating the extension of HDFs along the scaffold and the simultaneous secretion of extracellular matrix proteins.Furthermore,the HDF-laden dermal scaffold transplanted into full-thickness skin defect sites in nude mice was shown to accelerate wound closure,reduce inflammation,and improve wound healing.Overall,the DLP-printed dermal scaffold provides an appealing approach for effectively treating full-thickness skin defects in clinical settings.
基金supported by National Key Research and Development Program of China(Grant No.2023YFB4604100)National Key Research and Development Program of China(Grant No.2022YFB3806104)+4 种基金Key Research and Development Program in Shaanxi Province(Grant No.2021LLRH-08-17)Young Elite Scientists Sponsorship Program by CAST(No.2023QNRC001)K C Wong Education Foundation of ChinaYouth Innovation Team of Shaanxi Universities of ChinaKey Research and Development Program of Shaanxi Province(Grant 2021LLRH-08-3.1).
文摘Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exacerbates this challenge by rendering the process vulnerable to environmental changes and unexpected factors,resulting in defects and inconsistent product quality,particularly in unmanned long-term operations or printing in extreme environments.To address these issues,we developed a process monitoring and closed-loop feedback control strategy for the 3D printing process.Real-time printing image data were captured and analyzed using a well-trained neural network model,and a real-time control module-enabled closed-loop feedback control of the flow rate was developed.The neural network model,which was based on image processing and artificial intelligence,enabled the recognition of flow rate values with an accuracy of 94.70%.The experimental results showed significant improvements in both the surface performance and mechanical properties of printed composites,with three to six times improvement in tensile strength and elastic modulus,demonstrating the effectiveness of the strategy.This study provides a generalized process monitoring and feedback control method for the 3D printing of continuous fiber-reinforced composites,and offers a potential solution for remote online monitoring and closed-loop adjustment in unmanned or extreme space environments.
基金supported by the Innovative Research Group Project of the National Natural Science Foundation of China(T2121004)Key Programme(52235007)National Outstanding Youth Foundation of China(52325504).
文摘Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.
基金support from the National Key Research and Development Program of China(No.2021YFB3701503)the Key Research and Development Program of Ningbo,China(No.2023Z107).
文摘As a novel 2D material,Ti_(3)C_(2)T_(x)-MXene has become a major area of interest in the field of microwave absorption(MA).However,the MA effect of common Ti_(3)C_(2)T_(x)-MXene is not prominent and often requires complex processes or combinations of other ma-terials to achieve enhanced performance.In this context,a kind of gradient woodpile structure using common Ti_(3)C_(2)T_(x)-MXene as MA ma-terial was designed and manufactured through direct ink writing(DIW)3D printing.The minimum reflection loss(RL_(min))of the Ti_(3)C_(2)T_(x)-MXene-based gradient woodpile structures with a thickness of less than 3 mm can reach-70 dB,showing considerable improve-ment compared with that of a completely filled structure.In addition,the effective absorption bandwidth(EAB)reaches 7.73 GHz.This study demonstrates that a Ti_(3)C_(2)T_(x)-MXene material with excellent MA performance and tunable frequency band can be successfully fab-ricated with a macroscopic structural design and through DIW 3D printing without complex material hybridization and modification,of-fering broad application prospects by reducing electromagnetic wave radiation and interference.
基金supported by National Natural Science Foundation of China(Grant No.52305398)Chengdu University of Information Technology Project(Grant No.KYTZ202145).
文摘Vat photopolymerization 3D printing creates structures by projecting patterns onto a photosensitive resin within a vat.However,the presence of resin vats limits the printing of multiscale multimaterial structures.In this context,a novel 3D printing process is presented in which a cured structure is produced from acoustically levitated droplets without a physical vat.This enables the printing process to achieve high flexibility in the printing orientation and material supply.In pursuit of the envisioned 3D acoustic levitation printing strategy,acoustic levitation technology was utilized to suspend a photosensitive resin.Objects with small features were successfully produced by projecting patterns onto levitated resin droplets.Transforming printing orientations allows the fabrication of multiscale structures.Levitating resin droplets on-demand enables the rapid replacement of materials,thereby realizing effortless multimaterial 3D printing.By exploiting the flexibility of printing on levitation resin droplets,the capability of 3D printing on existing objects was established.Finally,an interesting example was illustrated,in which an object integrating liquid,gas,and solid materials was fabricated using the proposed 3D printing strategy.The results show that 3D printing on levitated droplets is feasible for fabricating multiscale and multimaterial objects,which contributes to the development of new 3D printing methods and potential applications.
基金financially supported by the Russian Science Foundation(No.23-43-00057)the International Cooperation Program of the Natural Science Foundation of China(No.52261135542)。
文摘The aim of this study is to develop magnetopolymer composites suitable for fabricating soft magnetoactive robots via extrusion-based3D printing.Polysiloxane copolymers with urea fragments were synthesized and characterized,and their thermophysical and rheological properties were investigated.This study provides an assessment of the potential for their further use in additive manufacturing.The obtained materials were utilized as matrices for creating magnetically active polymer composites by incorporating microparticles of carbonyl iron.Samples of complex geometries were printed using both neat and filled filaments,demonstrating the feasibility of employing these materials in extrusion-based 3D printing.
基金supported by National Science Fund for Distinguished Young Scholars of China(Grant No.62203198)Key R&D project of Shandong Province,China(Grant No.2022XGC010701).
文摘Hydrocolloids are widely used in meat products and pureed foods as they offer thickening and viscosityenhancing effects that facilitate shaping and improve stability.In this study,the static shear rheological and dynamic viscoelastic properties of pumpkin puree(S)and pork mince(P)with the addition of various hydrocolloids were considered.Dedicated material printing experiments were conducted by means of a three-dimensional printing platform by using a coaxial dual-nozzle for sandwich composite printing of four different materials.In particular,the impact of different process parameters(printing speed 10~30 mm/s,filling density 10%~50%)was assessed in terms of 3D printing adaptability and final shape of the pumpkin puree-pork mince products.The results have indicated that the addition of hydrocolloids significantly improves the rheological properties of these materials,enhancing their stability in the 3D printing process.Experiments have revealed that with an increase in the xanthan gum conte nt,the viscosity of pumpkin puree decreases.The relationship between the elastic modulus and viscous modulus for the minced pork follows the inequality P4<P3<P2<P1(1.17%,1.75%,2.13%,and 2.88%xanthan gum content,respectively).A“material formula”(detailed composition of the material)suitable for 3D food printing has been derived accordingly.
基金financially supported by the Key Project of Department of Education of Guangdong Province(Grant No.2022ZDZX3017)Special Support Plan of Guangdong Province(Grant No.2021TQ05Z151)+2 种基金Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515010049)SZU Research Fund(Grant No.GFPY-YB-2024-03)Shenzhen Science and Technology Programs(Grant Nos.GJHZ20210705141803011 and 20200731211324001).
文摘The combination of silicon carbide(SiC)ceramics and stereolithography technology shows promise for manufacturing complex-shaped SiC components,expanding application possibilities.However,high sintering temperature and structural-performance anisotropy limit the practical use of 3D-printed SiC components.Herein,a novel method is introduced to produce high-specific-strength SiC-based ceramics at a relatively low temperature of 1100℃.A mixed SiC/SiO_(2) slurry(30%SiO_(2) and 70%SiC by volume)with a solid loading of up to 40%was prepared to improve UV light penetration and printability.Additionally,incorporating a high content of methyl-phenyl-polysiloxane(PSO)solution(75%by weight)enabled low-temperature pyrolysis of SiC/SiO_(2)/PSO ceramics.The SiC/SiO_(2)/PSO ceramic lattices after pyrolysis achieved a specific strength as high as(1.03×10^(5))N·m·kg^(-1) and a density of 1.75 g·cm^(-3),outperforming similar SiC-based lattices structures of similar porosities.The bending strength of(95.49±8.79)MPa was comparable to that of ceramics sintered at 1400℃ or higher.Notably,the addition of the silicon carbide oxide(SiOC)phase reduced anisotropy,lowering the transverse and longitudinal compression strength ratios from 1.87 to 1.08,and improving mechanical properties by 79%.This improvement is attributed to SiOC shrinkage,promoting a uniform distribution of sintered components,resulting in a more robust and balanced material structure.This method offers valuable insight into the additive manufacturing(AM)of SiC-based ceramics at lower temperatures and provides new guidance for controlling anisotropy in 3D-printed ceramic parts.
基金financially supported by part of the state assignment(No.1023031700043-2-1.4.4)。
文摘Two-and three-component deep eutectic solvents(DES)based on acrylic acid(AA),acrylamide(AAm),and choline chloride(ChCl)were used to disintegrate bacterial cellulose into cellulose nanofibers(CNF).As a result,polymerizable precursors suitable for 3D printing with CNF as a rheology modifier and reinforcer with formation of interpenetrating double polymer network were obtained after UV curing.Composite hydrogels were formed by replacing ChCl with water.It was found that the introduction of amide groups into the acrylate polymer matrix resulted in an increase in compressive strength.The layered architecture of the 3D printed products provides greater mechanical strength compared to molded products.The structure of the composites was investigated using wide-angle X-ray scattering(WAXS),small-angle X-ray scattering(SAXS),atomic force microscopy(AFM)and polarized light microscopy.These studies suggest that the enhanced mechanical properties of the 3D printed hydrogels are associated with swelling and branching of CNF in the DES,as well as alignment of the filler during extrusion.For comparative analysis,composite hydrogels were also prepared using aqueous solutions of AA and AA/AAm with dispersed CNF.However,the 3D printing process was hampered in this case due to cellulose agglomeration.Mechanical testing revealed the formation of premature microcracks in these samples,which were not observed in composites produced using DES.Cytotoxicity of the composite hydrogels was also tested.The results provide valuable insights into the production of strong(up to 3.4 MPa)homogeneous composite hydrogels using 3D printing with nanocellulose filler.
基金financially supported by the National Natural Science Foundation of China(Nos.52402094,U234120139,and U22A20129)the National Defense Basic Scientific Research Program of China(No.JCKY2022130C005)+8 种基金the China Postdoctoral Science Foundation(No.2023M743571)the Postdoctoral Fellowship Program of CPSF(N o.GZC20232743)the Innovation Project of IMR(2024-PY11)the Open Research Fund of National Key Laboratory of Advanced Casting Technologies(No.CAT2023-006)the Graduate Education Quality Engineering Project of Anhui Province(No.2023cxcysj015)the Science and Technology Plan Project of Liaoning Province(No.2024JH2/101900011)the Nationa Key Research and Development Program of China(Nos2024YFB3714500 and 2018YFB1106600)the China United Gas Turbine Technology Co.Ltd.under the project of J790。
文摘Ceramic cores are important in the fabrication of superalloy hollow blades,which are increasingly characterized by intricate internal cavity channels.This complexity poses significant challenges to traditional manufacturing processes.The vat photopolymerization 3D printing technology provides a new choice for ceramic cores with complex structures.However,the lamellar structure of the vat photopolymerization 3D printed ceramic cores leads to the anisotropy.Meanwhile,the low strength and high shrinkage of ceramic cores restrict their industrial application.In this study,using Al_(2)O_(3)powder as the main material,the effects of zircon content on the sintering shrinkage,open porosity,fiexural strength,and other properties of Al_(2)O_(3)-based ceramic cores were studied to address the aforementioned issues.The influencing mechanism of zircon distribution on sintering shrinkage was analyzed,and the strengthening mechanism of mullite on ceramic cores was discussed from both thermodynamics and dynamics aspects.Through the comprehensive evaluation of ceramic core properties,the Al_(2)O_(3)-based ceramic core with 15vol.%zircon exhibites the optimal performance.Compared with the core samples without zirconium addition,the fiexural strength of the Al_(2)O_(3)-based ceramic core with 15vol.%zircon increases from 14.80 MPa to 61.54 MPa at 25°C,an increase of 315.8%;and from 4.91 MPa to 11.59 MPa at 1,500°C,an increase of 136.0%.The shrinkage in the Z-axis is reduced by 21%,which better weakens the anisotropy of the shrinkage of 3D printed Al_(2)O_(3)-based ceramic cores.ZrO_(2)phase and mullite phase are formed by zircon,which improve the comprehensive properties of Al_(2)O_(3)-based ceramic cores.The successful 3D printing of high-performance Al_(2)O_(3)-based ceramic cores via vat photopolymerization has promoted its industrial application for fabricating ceramic cores with complex structures.
基金provided by the Thailand Science Research and Innovation(TSRI)through the Basic Research Fund,Fiscal Year 2026,for the project“Numerical Modeling and Structural Analysis of Composite Sections Built-up from Local Timber inThailand”.
文摘This research investigates the behavior of sandwich glued laminated bamboo(Glubam)structures with a core formed by biodegradable plastic fibers,specifically polylactic acid(PLA),fabricated using 3D printing technology.The influence of various fiber printing orientations(0°and 45/135°)on tensile and compressive properties was investigated.The experimental results indicated that polylactic acid with calcium carbonate(PLA+)printed unidirectionally and aligned with the loading direction(0°)exhibits superior tensile and compressive strengths compared to specimens printed bidirectionally at 45/135°.Furthermore,the effect of additives on bioplastics of carbon fiber(PLA-CF)and glass fiber(PLA-GF)additives in PLA-based composites was evaluated in comparison with PLA+specimens.The finding indicated that PLA+has a higher strength-to-cost ratio compared to PLA-CF and PLA-GF.Therefore,unidirectionally printed PLA+was selected as the core material in two geometries:honeycomb and honeycomb lattice.These cores were sandwiched between Glubam panels on the top and bottom surfaces of the structures.Flexural performance was evaluated through four-point bending tests,which revealed that sandwich structures with a honeycomb core achieved a flexural strength-to-weight ratio 56.51%higher than those with a honeycomb lattice core.A parametric study using the finite element model was conducted to evaluate the effect of core scale,cross-sectional depth,Glubamthickness,core depth,and the number of honeycomb elements.The results showed that reducing the Glubam thickness while increasing the 3D-printed core depth significantly improved the flexural performance of honeycomb sandwich structures.Notably,reduced Glubam panel thickness coupled with increased core depth enhanced their flexural performance.
基金supported by 1.3.5 project for disciplines of excellence,West China Hospital,Sichuan University(No.ZYGD23030)National Natural Science Foundation of China(No.82172254)Science and Technological Supports Project of Sichuan Province,China(No.2024YFFK0214).
文摘With organ transplantation facing many dilemmas,tissue and organ regeneration as an alternative has bright prospects.In regenerative medicine,Three-dimensional(3D)printing technology and stem cells has been widely applied to the treatment of diseases related to tissue or organ replacement in dentistry,respectively.However,there are very few studies on the combination of the two,and even fewer clinical studies have been reported in dentistry.In this review,the current oral tissue engineering in vivo and in vitro based on 3D printing and stem cell technology will be summarized,and the discussion on the development prospects of this research direction will be given.Besides,the working principles and advantages&disadvantages of several types of 3D printers,as well as the mechanism of stem cells in tissue engineering will be elucidated.This review provides clinicians and researchers with the current state of research and trends in the combination of stem cells and 3D printing technology to treat oral-related diseases.In the future,3D bioprinters are poised for ongoing innovation with the advancement of relevant technologies,catalyzing an increase in clinical studies focused on treating oral diseases using stem cells and 3D scaffolds.Consequently,these developments will further advance the field of oral tissue engineering.
基金supported by the National Natural Science Foundation of China(Nos.52402094,U234120139,and U22A20129)National Defense Basic Scientific Research Program of China(No.JCKY2022130C005)+7 种基金China Postdoctoral Science Foundation(No.2023M743571)Postdoctoral Fellowship Program of CPSF(No.GZC20232743)Innovation Project of IMR(No.2024-PY11)Open Research Fund of National Key Laboratory of Advanced Casting Technologies(No.CAT2023-006)Graduate Education Quality Engineering Project of Anhui Province(No.2023cxcysj015)Science and Technology Plan Project of Liaoning Province(No.2024JH2/101900011)National Key Research and Development Program of China(Nos.2024YFB3714500 and 2018YFB1106600)the China United Gas Turbine Technology Co.,Ltd.(No.J790)。
文摘The performance of an aero-engine is closely related to the cooling ability of the hollow turbine blades.Ceramic core is an important component in the production of hollow turbine blades with a complex structure.As the pace of updating and iteration in turbine blade design continues to accelerate,the internal cavity structures of turbine blades have become increasingly complex.Traditional hot injection process is difficult to meet the production requirements of ceramic cores with complex structures.3D printing technology can manufacture ceramic cores without the need for moulds,significantly shortening the production cycle and providing a new technology for the production of ceramic cores with complex structures.To meet the technical requirements of the investment casting process,ceramic cores must possess adequate mechanical strength and appropriate porosity.In this work,the ceramic slurry with polysilazane(PSZ)precursor was successfully prepared,and the Al_(2)O_(3)-based ceramic cores with high performance were fabricated using 3D printing technology.The regulation mechanism of polysilazane on the performance of ceramic cores was investigated.The results show that with the increase of PSZ content,the fiexural strength of ceramic cores firstly increases and then decreases.When the content of PSZ is 5%,the fiexural strength at 25℃and 1,500℃are 31.5 MPa and 13.1 MPa,respectively,and the porosity is 36.7%.This work is expected to advance the research and practical application of high-performance ceramic cores fabricated via 3D printing.
基金supported by the National Natural Science Foundation of China(Nos.52203025,52072193,52361165657,and U22A20131)the Shandong Provincial Natural Science Foundation(Nos.ZR2021JQ16,ZR2023YQ040,and ZR2022QE266)the Shandong Provincial College Students'Innovation and Entrepreneurship Training Program(No.S202311065122)。
文摘As a biomass material with biodegradability and biocompatibility, sodium alginate (SA) is a good candidate for constructing hydrogels for tissue-mimicking and biomedical scaffold fabricating through extrusion-based 3D printing technology. However, the mechanical strength and stiffness of alginate hydrogels are still not comparable with biological tissues such as tendons and the printability of SA solutions is often poor. Here, a novel strategy for 3D printing of alginate hydrogels with high mechanical performance is developed by using glycerol as a co-solvent for SA solutions. The addition of glycerol (GL) enables the formation of a homogenous SA/GL solution with a high solid content of 12–20 wt.% and endows crosslinked SA hydrogels with high stretchability. By applying uniaxial stretches, hydrogel filaments prepared with concentrated SA/GL solutions reveal a high tensile strength of 36.6–161.3 MPa, Young's modulus of 59.2–1964.2 MPa, and elongation at break of 8.5 %–106.2 % due to the high orientated and closely packed SA chains. SA/GL solutions become more solid-like with increasing SA concentration, and the solution with a solid content of 16 wt.% exhibits optimal 3D printability because of the appropriate rheological properties and thixotropic behavior. By designing the deforming-and-fixing process, 3D printed high-strength alginate hydrogels with complex structures are prepared, broadening the application of alginate hydrogels in load-bearing and biomedical fields.
