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
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
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
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
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
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
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
Specially shaped permanent magnet structures can satisfy the requirements of equipment with limited space or unique shapes.Thereby,these optimize the distribution of magnetic fields.However,traditional manufacturing m...Specially shaped permanent magnet structures can satisfy the requirements of equipment with limited space or unique shapes.Thereby,these optimize the distribution of magnetic fields.However,traditional manufacturing methods are limited by the mold design and insufficient material utilization.In this study,a polymer-based Nd_(2)Fe_(14)B(NdFeB)magnetic slurry was developed based on direct ink writing(DIW)3D printing technology.A rapidly volatilizable magnetic slurry was used to achieve 3D oriented controllable layering,thus realizing the direct molding fabrication of NdFeB permanent magnets with complex structures.By exploring and optimizing the 3D printing process parameters,specially shaped bonded NdFeB permanent magnet structures with high precision and shape fidelity were prepared.The test results indicated that the remnant magnetization of the printed magnets was proportional to the NdFeB content in the slurry,the coercivity closely matched that of the original powder,and the mechanical properties of the printed magnets were favorable.Building on this,a magnetically driven helical-structure robot was designed and printed to achieve stable motion in low-Reynolds-number fluids.This paper presents a new,low-cost solution for the room-temperature preparation of shape-bonded NdFeB permanent magnets.展开更多
In-space 3D printing is transforming the manufacturing paradigm of space structures from ground-based production to in-situ space manufacturing,effectively addressing the challenges of high costs,long response times,a...In-space 3D printing is transforming the manufacturing paradigm of space structures from ground-based production to in-situ space manufacturing,effectively addressing the challenges of high costs,long response times,and structural size limitations associated with traditional rocket launches.This technology enables rapid on-orbit emergency repairs and significantly expands the geometric dimensions of space structures.High-performance polymers and their composites are widely used in in-space 3D printing,yet their implementation faces complex challenges posed by extreme space environmental conditions and limited energy or resources.This paper reviews the state-of-the-art in 3D printing of polymer and composites for on-orbit structure manufacturing.Based on existing research activities,the review focuses on three key aspects including the impact of extreme space environments on forming process and performance,innovative design and manufacturing methods for space structures,and on-orbit recycling and remanufacturing of raw materials.Some experiments that have already been conducted on-orbit and simulated experiments completed on the ground are systematically analyzed to provide a more comprehensive understanding of the constraints and objectives for on-orbit structure manufacturing.Furthermore,several perspectives requiring further research in future are proposed to facilitate the development of new in-space 3D printing technologies and space structures,thereby supporting increasingly advanced space exploration activities.展开更多
The technology of three dimensional(3D) printing,also known as additive manufacturing,is a cuttingedge type of fabrication method that utilizes a computer-aided design platform and employs layer-bylayer stacking to co...The technology of three dimensional(3D) printing,also known as additive manufacturing,is a cuttingedge type of fabrication method that utilizes a computer-aided design platform and employs layer-bylayer stacking to construct objects with exceptional flexibility.Due to its capacity to produce a substantial quantity of products within a short period of time,3D printing has emerged as one of the most significant manufacturing technology.Over the past two decades,remarkable advancements have been made in the application of 3D printing technology in the realm of bone tissue engineering.This review presents an innovative and systematic discussion on the potential application of 3D printing technology in bone tissue engineering,particularly in the treatment of infected bone defects.It comprehensively evaluates the materials utilized in 3D printing,highlights the interplay between cells and bone regeneration,and addresses and resolves challenges associated with current 3D printing technology.These challenges include material selection,fabrication of intricate 3D structures,integration of different cell types,streamlining design processes and material selection procedures,enhancing the clinical translational potential of 3D printing technology,and ultimately exploring future applications of four dimensional(4D) printing technology.The 3D printing technology has demonstrated significant potential in the synthesis of bone substitutes,offering consistent mechanical properties and ease of use.It has found extensive applications in personalized implant customization,prosthetic limb manufacturing,surgical tool production,tissue engineering,biological modeling,and cell diagnostics.Simultaneously,3D bioprinting provides an effective solution to address the issue of organ donor shortage.However,challenges still exist in material selection,management of structural complexity,integration of different cell types,and construction of functionally mature tissues.With advancements in multi-material printing techniques as well as bioprinting and 4D printing technologies emerging on the horizon;3D printing holds immense prospects for revolutionizing the means by which infectious bone defects are repaired.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
The rapid advancement of energy storage technologies highlights the urgent need for innovative electrochemical energy storage(EES)systems featuring complex geometries.Three-dimensional(3D)printing has emerged as a gro...The rapid advancement of energy storage technologies highlights the urgent need for innovative electrochemical energy storage(EES)systems featuring complex geometries.Three-dimensional(3D)printing has emerged as a groundbreaking solution,enabling the fabrication of customized,high-performance electrodes with precise structural control.This approach enhances accuracy,convenience,and facilitates improved ion and electron transport.In this review,we systematically summarize recent advancements in leveraging 3D printing techniques for lithium-ion and sodium-ion batteries.We begin by comparing the unique capabilities of various 3D printing methods against traditional fabrication techniques for producing tailored electrodes.We then address critical challenges across different battery module architectures-cathodes,anodes,electrolytes,and integrated systems-highlighting breakthroughs in material selection,ink formulation,and post-processing.Finally,we explore the future potential of 3Dprinted batteries in next-generation EES devices,emphasizing their role in advancing customizable,high-efficiency solutions.The insights provided herein illuminate how 3D printing can significantly accelerate the development of advanced battery materials,fostering innovation in energy storage technology.展开更多
Fabricating damage tolerant porous ceramics with efficient energy absorption and impact-resistant capability has been a challenge because of the brittle nature of ceramic materials.In nature,mineralized tissues or org...Fabricating damage tolerant porous ceramics with efficient energy absorption and impact-resistant capability has been a challenge because of the brittle nature of ceramic materials.In nature,mineralized tissues or organisms such as cuttlebones and diatoms have evolved with hierarchical porous structures to overcome this difficulty.A bioinspired design of ceramic lattice structure with pores at multiple length scales,ranging from few nanometers to hundreds of micrometers,is proposed in the present work.These ceramic lattices with hierarchical porous structures were successfully fabricated via 3D cryogenic printing.Under quasi-static compressions,the printed ceramic lattices showed unprecedented long plateau strain(∼60%)and a specific energy absorption of∼10 kJ·kg^(−1) with a porosity of∼90%.The resulting energy absorption capability was comparable with most composites and metals,thus overcoming the brittle nature of traditional porous ceramics.This was attributed to the delayed destruction of the lattice structure,as well as the gradual collapse of pores at multiple length scales.Similar trends have also been observed under split Hopkinson pressure bar(SHPB)tests,indicating excellent energy absorption under high strain-rate impacts.The proposed 3D printing technique that produces hierarchical pores was also demonstrated to apply to other functional materials,such as silicon carbide,barium titanate,hydroxyapatite,and even titanium alloy,thus opening up new possibilities for fabricating bioinspired hierarchical porous structures.展开更多
Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shape...Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shaped ceramic cores.In this study,silica-based ceramic cores incorporating nano-3YSZ(3mol.% yttria stabilised zirconia)and micron-sized Y_(2)O_(3) were prepared via SL 3D printing ceramic technology to promote the formation of cristobalite and ZrSiO_(4),thereby improving the high-temperature properties.The flexural strength at 25℃ and 1,500℃,deflection at 1,500℃,shrinkage rate,and porosity of the core samples sintered at different temperatures(1,170℃,1,185℃,1,200℃,1,215℃,and 1,230℃)were tested and investigated.The mechanism underlying the high temperature performance of the cores was elucidated through analysis of cross-sectional morphology,element distribution,and phase constitution of the samples.As the sintering temperature increases,the shrinkage and flexural strength at 25℃ of the core rise,while the open porosity and deflection at 1,500℃ decrease.When the sintering temperature reaches 1,200℃ or higher,the 1,500℃ flexural strength can be measured,which increases as the sintering temperature rises.The core exhibits excellent creep resistance when sintered at temperatures of 1,200℃ and above.Considering the comprehensive performance requirements for the core,the sintering temperature of 1,200℃ was selected.At the sintering temperature of 1,200℃,the core exhibits shrinkage rates of 3.76%(X),3.38%(Y),and 3.95%(Z),alongside a flexural strength of 9.01 MPa at 25℃ and 32.15 MPa at 1,500℃,and an open porosity of 26.39%.The deflection of the core at 1,500℃ is 0.15 mm,which helps to maintain the dimensional stability of the ceramic core during casting.XRD results indicate that samples fractured after 25℃ flexural strength test still contain amorphous quartz glass,alongside substantial quantities of yttria stabilized zirconia and Y_(2)O_(3).Samples fractured after 1,500℃ flexural strength test exhibit significant crystallisation of amorphous quartz glass into cristobalite,with silica and 3YSZ combining to form ZrSiO_(4).Y_(2)O_(3) as a network modifier of the glass network destroys the bridging oxygen in the silica-oxygen bond,thereby reducing the energy required for glass crystallisation and promoting the crystallisation reaction of quartz glass to form cristobalite.In addition,nano-3YSZ combines with SiO_(2) at high temperatures to form ZrSiO_(4).Since cristobalite and ZrSiO_(4) are crystals,both of them have strong creep resistance,thus improving the high temperature flexural strength and deformation resistance of the ceramic cores.展开更多
Hierarchical porous structure,which include macropores,minor pores,and micropores in scaffolds,are essential in the multiple biological functions of bone repair and regeneration.In this study,patientcustomized calcium...Hierarchical porous structure,which include macropores,minor pores,and micropores in scaffolds,are essential in the multiple biological functions of bone repair and regeneration.In this study,patientcustomized calcium-deficient hydroxyapatite(CDHA)scaffolds with three-level hierarchical porous structure were fabricated by indirect 3D printing technology and particulate leaching method.The sacrificial template scaffolds were fabricated using a photo-curing 3D printer,which provided a prerequisite for the integral structure and interconnected macropores of CDHA scaffolds.Additionally,20 wt%pore former was incorporated into the slurry to enhance the content of smaller pores within the CDHA-2 scaffolds,and then the CDHA-2 scaffolds were sintered to remove the sacrificial template scaffolds and pore former.The obtained CDHA-2 scaffolds exhibited interconnected macropores(300-400μm),minor pores(∼10-100μm),and micropores(<10μm)distributed throughout the scaffolds,which could promote bone tissue ingrowth,increase surface roughness,and enhance protein adsorption of scaffolds.In vitro studies identified that CDHA-2 scaffolds had nanocrystal grains,high specific surface area,and outstanding protein adsorption capacity,which could provide a microenvironment for cell adhesion,spreading,and proliferation.In addition,the murine intramuscular implantation experiment suggested that CDHA-2 scaffolds exhibited excellent osteoinductivity and were superior to traditional BCP ceramics under conditions without the addition of live cells and exogenous growth factors.The rabbit calvarial defect repair results indicated that CDHA-2 scaffolds could enhance in situ bone regeneration.In conclusion,these findings demonstrated that the hierarchical porous structure of CDHA scaffolds was a pivotal factor in modulating osteoinductivity and bone regeneration,and CDHA-2 scaffolds were potential candidates for bone regeneration.展开更多
The complex ceramic core used for hollow turbine blades requires a high porosity and a high fiexural strength. For a better balance between porosity and fiexural strength, ceramic materials with porous structures are ...The complex ceramic core used for hollow turbine blades requires a high porosity and a high fiexural strength. For a better balance between porosity and fiexural strength, ceramic materials with porous structures are preferred. In order to achieve the transition from disordered pore formation to ordered pore formation, Al_(2)O_(3) ceramic cores with triply periodic minimal surface(TPMS) micro lattice structures with different structural configurations(gyroid, diamond, and neovius) and different volume fractions of lattice structures(30, 40, and 50, vol.%) were designed and prepared by vat photopolymerization 3D printing. The effects of structural configuration and volume fraction of the lattice structure on the following structural shrinkage, microstructure, and flexural strength were investigated. The shrinkage relationship of the three lattice configurations is: neovius>diamond>gyroid. Besides, it is found that with an increase in the volume fraction of the 3D printed Al_(2)O_(3) ceramic micro lattice structures, their fiexural strength correspondingly increases ranging from 54.95 MPa to 139.1 MPa. The maximum average fiexural strength of the 3D printed Al_(2)O_(3) ceramic micro lattice structures is obtained when the structural configuration is diamond and with a volume fraction of 50vol.%, which is 139.1 MPa. Even when the volume fraction of the lattice structure is 30vol.%, that is to say the porosity is 70%, the fiexural strength is as high as 50-70 MPa, which can still be maintained at a high level. In addition, when the volume fraction of the lattice structure is a certain value, the sample with diamond configuration has a higher strength. The internal pore morphology, pore size, and porosity of the cores are precisely controlled, achieving both a high porosity and a high strength. Therefore, this study maintains high porosity and high strength simultaneously, providing a new lattice structure design idea for 3D printed ceramic cores.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 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 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 National Natural Science Foundation of China(Grant Nos.52375348,52175331)National Natural Science Foundation of Shandong Province(Grant Nos.ZR2022ME014,ZR2020ZD04).
文摘Specially shaped permanent magnet structures can satisfy the requirements of equipment with limited space or unique shapes.Thereby,these optimize the distribution of magnetic fields.However,traditional manufacturing methods are limited by the mold design and insufficient material utilization.In this study,a polymer-based Nd_(2)Fe_(14)B(NdFeB)magnetic slurry was developed based on direct ink writing(DIW)3D printing technology.A rapidly volatilizable magnetic slurry was used to achieve 3D oriented controllable layering,thus realizing the direct molding fabrication of NdFeB permanent magnets with complex structures.By exploring and optimizing the 3D printing process parameters,specially shaped bonded NdFeB permanent magnet structures with high precision and shape fidelity were prepared.The test results indicated that the remnant magnetization of the printed magnets was proportional to the NdFeB content in the slurry,the coercivity closely matched that of the original powder,and the mechanical properties of the printed magnets were favorable.Building on this,a magnetically driven helical-structure robot was designed and printed to achieve stable motion in low-Reynolds-number fluids.This paper presents a new,low-cost solution for the room-temperature preparation of shape-bonded NdFeB permanent magnets.
基金supported by National Natural Science Foundation of China(Grant No.52205413)National Key Research and Development Program(Grant No.2022YFB3806101)+1 种基金K C Wong Education FoundationThe Youth Innovation Team of Shaanxi Universities。
文摘In-space 3D printing is transforming the manufacturing paradigm of space structures from ground-based production to in-situ space manufacturing,effectively addressing the challenges of high costs,long response times,and structural size limitations associated with traditional rocket launches.This technology enables rapid on-orbit emergency repairs and significantly expands the geometric dimensions of space structures.High-performance polymers and their composites are widely used in in-space 3D printing,yet their implementation faces complex challenges posed by extreme space environmental conditions and limited energy or resources.This paper reviews the state-of-the-art in 3D printing of polymer and composites for on-orbit structure manufacturing.Based on existing research activities,the review focuses on three key aspects including the impact of extreme space environments on forming process and performance,innovative design and manufacturing methods for space structures,and on-orbit recycling and remanufacturing of raw materials.Some experiments that have already been conducted on-orbit and simulated experiments completed on the ground are systematically analyzed to provide a more comprehensive understanding of the constraints and objectives for on-orbit structure manufacturing.Furthermore,several perspectives requiring further research in future are proposed to facilitate the development of new in-space 3D printing technologies and space structures,thereby supporting increasingly advanced space exploration activities.
基金supported by the National Natural Science Fund of China(Nos.82202726,82370929)the National Clinical Research Center for Geriatrics,West China Hospital,Sichuan University(No.Z20192013)+5 种基金Key research and development project of Sichuan Science and Technology Department(No.2023YFG0219)"Zeroto One" Innovation Research Project of Sichuan University(No.2022SCUH0014)Frontiers Medical Center,Tianfu Jincheng Laboratory Foundation(No.TFJC2023010001)Sichuan Science and Technology Program(No.2022NSFSC0002)Sichuan Province Youth Science and Technology Innovation Team(No.2022JDTD0021)Research and Develop Program,West China Hospital of Stomatology Sichuan University(Nos.RD03202302,RCDWJS2024-1)。
文摘The technology of three dimensional(3D) printing,also known as additive manufacturing,is a cuttingedge type of fabrication method that utilizes a computer-aided design platform and employs layer-bylayer stacking to construct objects with exceptional flexibility.Due to its capacity to produce a substantial quantity of products within a short period of time,3D printing has emerged as one of the most significant manufacturing technology.Over the past two decades,remarkable advancements have been made in the application of 3D printing technology in the realm of bone tissue engineering.This review presents an innovative and systematic discussion on the potential application of 3D printing technology in bone tissue engineering,particularly in the treatment of infected bone defects.It comprehensively evaluates the materials utilized in 3D printing,highlights the interplay between cells and bone regeneration,and addresses and resolves challenges associated with current 3D printing technology.These challenges include material selection,fabrication of intricate 3D structures,integration of different cell types,streamlining design processes and material selection procedures,enhancing the clinical translational potential of 3D printing technology,and ultimately exploring future applications of four dimensional(4D) printing technology.The 3D printing technology has demonstrated significant potential in the synthesis of bone substitutes,offering consistent mechanical properties and ease of use.It has found extensive applications in personalized implant customization,prosthetic limb manufacturing,surgical tool production,tissue engineering,biological modeling,and cell diagnostics.Simultaneously,3D bioprinting provides an effective solution to address the issue of organ donor shortage.However,challenges still exist in material selection,management of structural complexity,integration of different cell types,and construction of functionally mature tissues.With advancements in multi-material printing techniques as well as bioprinting and 4D printing technologies emerging on the horizon;3D printing holds immense prospects for revolutionizing the means by which infectious bone defects are repaired.
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financially supported by the National Natural Science Foundation of China(22225902,U22A20436,22209185)the National Key Research&Development Program of China(2022YFE0115900,2021YFA1501500)+2 种基金the China National Postdoctoral Program for Innovative Talents(BX20230365)the China Postdoctoral Science Foundation(2023M743494)Self-Deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(CXZX-2023-JQ08)。
文摘The rapid advancement of energy storage technologies highlights the urgent need for innovative electrochemical energy storage(EES)systems featuring complex geometries.Three-dimensional(3D)printing has emerged as a groundbreaking solution,enabling the fabrication of customized,high-performance electrodes with precise structural control.This approach enhances accuracy,convenience,and facilitates improved ion and electron transport.In this review,we systematically summarize recent advancements in leveraging 3D printing techniques for lithium-ion and sodium-ion batteries.We begin by comparing the unique capabilities of various 3D printing methods against traditional fabrication techniques for producing tailored electrodes.We then address critical challenges across different battery module architectures-cathodes,anodes,electrolytes,and integrated systems-highlighting breakthroughs in material selection,ink formulation,and post-processing.Finally,we explore the future potential of 3Dprinted batteries in next-generation EES devices,emphasizing their role in advancing customizable,high-efficiency solutions.The insights provided herein illuminate how 3D printing can significantly accelerate the development of advanced battery materials,fostering innovation in energy storage technology.
基金supported by the National Natural Science Foundation of China(Grant No.52305359)the startup funding from the Huazhong University of Science and Technology,the Opening fund of the State Key Laboratory of Nonlinear Mechanics and Natural Science Foundation of Hubei Province(No.2023AFB141)。
文摘Fabricating damage tolerant porous ceramics with efficient energy absorption and impact-resistant capability has been a challenge because of the brittle nature of ceramic materials.In nature,mineralized tissues or organisms such as cuttlebones and diatoms have evolved with hierarchical porous structures to overcome this difficulty.A bioinspired design of ceramic lattice structure with pores at multiple length scales,ranging from few nanometers to hundreds of micrometers,is proposed in the present work.These ceramic lattices with hierarchical porous structures were successfully fabricated via 3D cryogenic printing.Under quasi-static compressions,the printed ceramic lattices showed unprecedented long plateau strain(∼60%)and a specific energy absorption of∼10 kJ·kg^(−1) with a porosity of∼90%.The resulting energy absorption capability was comparable with most composites and metals,thus overcoming the brittle nature of traditional porous ceramics.This was attributed to the delayed destruction of the lattice structure,as well as the gradual collapse of pores at multiple length scales.Similar trends have also been observed under split Hopkinson pressure bar(SHPB)tests,indicating excellent energy absorption under high strain-rate impacts.The proposed 3D printing technique that produces hierarchical pores was also demonstrated to apply to other functional materials,such as silicon carbide,barium titanate,hydroxyapatite,and even titanium alloy,thus opening up new possibilities for fabricating bioinspired hierarchical porous structures.
基金financially supported by the Liaoning Province Science and Technology Plan Joint Program(2023JH2/101700037).
文摘Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shaped ceramic cores.In this study,silica-based ceramic cores incorporating nano-3YSZ(3mol.% yttria stabilised zirconia)and micron-sized Y_(2)O_(3) were prepared via SL 3D printing ceramic technology to promote the formation of cristobalite and ZrSiO_(4),thereby improving the high-temperature properties.The flexural strength at 25℃ and 1,500℃,deflection at 1,500℃,shrinkage rate,and porosity of the core samples sintered at different temperatures(1,170℃,1,185℃,1,200℃,1,215℃,and 1,230℃)were tested and investigated.The mechanism underlying the high temperature performance of the cores was elucidated through analysis of cross-sectional morphology,element distribution,and phase constitution of the samples.As the sintering temperature increases,the shrinkage and flexural strength at 25℃ of the core rise,while the open porosity and deflection at 1,500℃ decrease.When the sintering temperature reaches 1,200℃ or higher,the 1,500℃ flexural strength can be measured,which increases as the sintering temperature rises.The core exhibits excellent creep resistance when sintered at temperatures of 1,200℃ and above.Considering the comprehensive performance requirements for the core,the sintering temperature of 1,200℃ was selected.At the sintering temperature of 1,200℃,the core exhibits shrinkage rates of 3.76%(X),3.38%(Y),and 3.95%(Z),alongside a flexural strength of 9.01 MPa at 25℃ and 32.15 MPa at 1,500℃,and an open porosity of 26.39%.The deflection of the core at 1,500℃ is 0.15 mm,which helps to maintain the dimensional stability of the ceramic core during casting.XRD results indicate that samples fractured after 25℃ flexural strength test still contain amorphous quartz glass,alongside substantial quantities of yttria stabilized zirconia and Y_(2)O_(3).Samples fractured after 1,500℃ flexural strength test exhibit significant crystallisation of amorphous quartz glass into cristobalite,with silica and 3YSZ combining to form ZrSiO_(4).Y_(2)O_(3) as a network modifier of the glass network destroys the bridging oxygen in the silica-oxygen bond,thereby reducing the energy required for glass crystallisation and promoting the crystallisation reaction of quartz glass to form cristobalite.In addition,nano-3YSZ combines with SiO_(2) at high temperatures to form ZrSiO_(4).Since cristobalite and ZrSiO_(4) are crystals,both of them have strong creep resistance,thus improving the high temperature flexural strength and deformation resistance of the ceramic cores.
基金supported by the National Key Research and Development Program of China(No.2019YFA0110600)the Science and Technology Support Program of Sichuan Province(No.2019YJ0161).
文摘Hierarchical porous structure,which include macropores,minor pores,and micropores in scaffolds,are essential in the multiple biological functions of bone repair and regeneration.In this study,patientcustomized calcium-deficient hydroxyapatite(CDHA)scaffolds with three-level hierarchical porous structure were fabricated by indirect 3D printing technology and particulate leaching method.The sacrificial template scaffolds were fabricated using a photo-curing 3D printer,which provided a prerequisite for the integral structure and interconnected macropores of CDHA scaffolds.Additionally,20 wt%pore former was incorporated into the slurry to enhance the content of smaller pores within the CDHA-2 scaffolds,and then the CDHA-2 scaffolds were sintered to remove the sacrificial template scaffolds and pore former.The obtained CDHA-2 scaffolds exhibited interconnected macropores(300-400μm),minor pores(∼10-100μm),and micropores(<10μm)distributed throughout the scaffolds,which could promote bone tissue ingrowth,increase surface roughness,and enhance protein adsorption of scaffolds.In vitro studies identified that CDHA-2 scaffolds had nanocrystal grains,high specific surface area,and outstanding protein adsorption capacity,which could provide a microenvironment for cell adhesion,spreading,and proliferation.In addition,the murine intramuscular implantation experiment suggested that CDHA-2 scaffolds exhibited excellent osteoinductivity and were superior to traditional BCP ceramics under conditions without the addition of live cells and exogenous growth factors.The rabbit calvarial defect repair results indicated that CDHA-2 scaffolds could enhance in situ bone regeneration.In conclusion,these findings demonstrated that the hierarchical porous structure of CDHA scaffolds was a pivotal factor in modulating osteoinductivity and bone regeneration,and CDHA-2 scaffolds were potential candidates for bone regeneration.
基金supported by the National Natural Science Foundation of China (Grant No. 52275310)。
文摘The complex ceramic core used for hollow turbine blades requires a high porosity and a high fiexural strength. For a better balance between porosity and fiexural strength, ceramic materials with porous structures are preferred. In order to achieve the transition from disordered pore formation to ordered pore formation, Al_(2)O_(3) ceramic cores with triply periodic minimal surface(TPMS) micro lattice structures with different structural configurations(gyroid, diamond, and neovius) and different volume fractions of lattice structures(30, 40, and 50, vol.%) were designed and prepared by vat photopolymerization 3D printing. The effects of structural configuration and volume fraction of the lattice structure on the following structural shrinkage, microstructure, and flexural strength were investigated. The shrinkage relationship of the three lattice configurations is: neovius>diamond>gyroid. Besides, it is found that with an increase in the volume fraction of the 3D printed Al_(2)O_(3) ceramic micro lattice structures, their fiexural strength correspondingly increases ranging from 54.95 MPa to 139.1 MPa. The maximum average fiexural strength of the 3D printed Al_(2)O_(3) ceramic micro lattice structures is obtained when the structural configuration is diamond and with a volume fraction of 50vol.%, which is 139.1 MPa. Even when the volume fraction of the lattice structure is 30vol.%, that is to say the porosity is 70%, the fiexural strength is as high as 50-70 MPa, which can still be maintained at a high level. In addition, when the volume fraction of the lattice structure is a certain value, the sample with diamond configuration has a higher strength. The internal pore morphology, pore size, and porosity of the cores are precisely controlled, achieving both a high porosity and a high strength. Therefore, this study maintains high porosity and high strength simultaneously, providing a new lattice structure design idea for 3D printed ceramic cores.
