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
Drug development and precision therapy are core technologies in the biopharmaceutical field.In the traditional paradigm,new drug development relies on validation through animal testing and clinical trials-a process th...Drug development and precision therapy are core technologies in the biopharmaceutical field.In the traditional paradigm,new drug development relies on validation through animal testing and clinical trials-a process that requires a decade of testing and costs over two billion dollars[1].Although animal testing has long served as the standard approach for evaluating drug efficacy and toxicity,its predictive accuracy for human responses remains limited due to translational barriers arising from interspecies physiological differences[2].Despite passing animal testing,only about 12%of drug candidates proceed to preclinical trials,and fewer than 11.7%gain final approval[3].展开更多
The inherent complexities of excitable cardiac,nervous,and skeletal muscle tissues pose great challenges in constructing artificial counterparts that closely resemble their natural bioelectrical,structural,and mechani...The inherent complexities of excitable cardiac,nervous,and skeletal muscle tissues pose great challenges in constructing artificial counterparts that closely resemble their natural bioelectrical,structural,and mechanical properties.Recent advances have increasingly revealed the beneficial impact of bioelectrical microenvironments on cellular behaviors,tissue regeneration,and therapeutic efficacy for excitable tissues.This review aims to unveil the mechanisms by which electrical microenvironments enhance the regeneration and functionality of excitable cells and tissues,considering both endogenous electrical cues from electroactive biomaterials and exogenous electrical stimuli from external electronic systems.We explore the synergistic effects of these electrical microenvironments,combined with structural and mechanical guidance,on the regeneration of excitable tissues using tissue engineering scaffolds.Additionally,the emergence of micro/nanoscale bioelectronics has significantly broadened this field,facilitating intimate interactions between implantable bioelectronics and excitable tissues across cellular,tissue,and organ levels.These interactions enable precise data acquisition and localized modulation of cell and tissue functionalities through intricately designed electronic components according to physiological needs.The integration of tissue engineering and bioelectronics promises optimal outcomes,highlighting a growing trend in developing living tissue construct-bioelectronic hybrids for restoring and monitoring damaged excitable tissues.Furthermore,we envision critical challenges in engineering the next-generation hybrids,focusing on integrated fabrication strategies,the development of ionic conductive biomaterials,and their convergence with biosensors.展开更多
Brain,the material foundation of human intelligence,is the most complex tissue in the human body.Brain diseases are among the leading threats to human life,yet our understanding of their pathogenic mechanisms and drug...Brain,the material foundation of human intelligence,is the most complex tissue in the human body.Brain diseases are among the leading threats to human life,yet our understanding of their pathogenic mechanisms and drug development remains limited,largely due to the lack of accurate brain-like tissue models that replicate its complex structure and functions.Therefore,constructing brain-like models—both in morphology and function—possesses significant scientific value for advancing brain science and pathological pharmacology research,representing the frontiers in the biomanufacturing field.This review outlines the primary requirements and challenges in biomanufacturing brain-like tissue,addressing its complex structures,functions,and environments.Also,the existing biomanufacturing technologies,strategies,and characteristics for brain-like models are depicted,and cutting-edge developments in biomanufacturing central neural repair prosthetics,brain development models,brain disease models,and brain-inspired biocomputing models are systematically reviewed.Finally,the paper concludes with future perspectives on the biomanufacturing of brain-like tissue transitioning from structural manufacturing to intelligent functioning.展开更多
The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is ha...The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical properties.This study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation system.The combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK implants.Moreover,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after implantation.In conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.展开更多
In the background of carbon neutrality,monolithic ceramic catalysts are universally used in energy conversion and chemical catalysis due to the high heat and mass transfer efficiencies,low bed pressures,and scalabilit...In the background of carbon neutrality,monolithic ceramic catalysts are universally used in energy conversion and chemical catalysis due to the high heat and mass transfer efficiencies,low bed pressures,and scalability through modular design.However,traditional manufacturing processes are limited by mold dependence,organic solvent toxicity,and insufficient molding capability for complex structures,resulting in difficulty achieving precise regulation of cross-scale pores.Additive manufacturing(AM)technology employs a digital layered molding strategy to achieve the cross-scale structural regulation of catalysts from macroscopic flow channels to mesopores and micropores.This paper summarizes recent advances in the structural design of monolithic catalysts enabled by AM technologies and highlights their emerging applications in catalytic processes.Structurally,AM-fabricated monoliths have been effectively employed in key chemical reactions such as fuel reforming,CO_(2)conversion,biofuel synthesis.Strategies such as geometrical topology optimization,multi-scale pore synergy,biomimetic structural design,and functional gradient integration have been utilized to enhance heat and mass transport,reduce pressure drops,and improve overall catalytic performance.By overcoming the limitations of traditional catalysts,AM technologies create a new paradigm for addressing the longstanding challenge of coupling mass transfer with reaction kinetics.This approach provides a feasible pathway for driving both theoretical innovation and practical implementation of high-efficiency catalytic systems.展开更多
Solid propellants are essential energy sources for rockets and other aerospace vehicles,and improvements in their performance have significant implications for the aerospace industry.The application of additive manufa...Solid propellants are essential energy sources for rockets and other aerospace vehicles,and improvements in their performance have significant implications for the aerospace industry.The application of additive manufacturing(AM)in the production of solid propellants promises a substantial leap in the design and fabrication of solid propellant grains.This review summarizes recent research on AM techniques for solid propellant manufacturing,evaluates current applications,and explores development trends.This review highlights that AM technology for solid propellants offers unparalleled advantages in terms of propellant design flexibility and functional gradient loading compared with traditional processes.This study presents a new perspective for the future manufacturing of intelligent and controllable solid propulsion systems.展开更多
Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping cap...Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping capabilities based on photopolymerization.However,owing to differences in the curing behavior and physical properties of different materials,multimaterial DLP 3D printing faces challenges such as insufficient interfacial bonding strength and unstable mechanical properties.In this study,two resins were integrated by multimaterial DLP 3D printing technology,and the effects of different layer thicknesses and exposure times on the interfacial bonding strength and morphology of the multimaterials were systematically investigated.The interfacial bonding mechanisms of the two resins was analyzed.It was found that increasing the exposure time can improve the interfacial bonding strength between materials,but certain limitations exist.A mathematical model relating the interfacial bonding strength to the exposure time and layer thickness was developed,and optimal process parameters were determined using optimization algorithms.A variable-parameter printing strategy for the interface was proposed to further improve the performance of printed parts.The maximum tensile strength of the multimaterial samples(44.43 MPa)using this strategy reached that of single-material parts(45 MPa),validating the feasibility of this strategy.This provides guidance for multimaterial DLP 3D printing processes and offers valuable insights for the future additive manufacturing of high-performance multimaterial components.展开更多
Variable material screw-based material extrusion(S-MEX)3D printing technology provides a novel approach for fabricating composites with continuous material gradients.Nevertheless,achieving precise alignment between th...Variable material screw-based material extrusion(S-MEX)3D printing technology provides a novel approach for fabricating composites with continuous material gradients.Nevertheless,achieving precise alignment between the process parameters and material compositions is challenging because of fluctuations in the melt rheological state caused by material variations.In this study,an invertible extrusion prediction model for 0-40 wt% short carbon fiber reinforced polyether-ether-ketone(SCF/PEEK)in the S-MEX process was established using an invertible neural network(INN)that demonstrated the capabilities of forward flow rate prediction and inverse process optimization with accuracies of 0.852 and 0.877,respectively.Moreover,a strategy for adjusting the screw speeds using process parameters obtained from the INN was developed to maintain a consistent flow rate during the variable material printing process.Benefiting from uniform flow,the linewidth accuracy was improved by 77%,and the surface roughness was reduced by 51%.Adjusting the process parameters by using an INN offers significant potential for flow rate control and the enhancement of the overall performance of variable material 3D printing.展开更多
Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resol...Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resolution of conventional bioprinting techniques such as extrusion-and inkjet-based printing.Recently,an electrohydrodynamic(EHD)bioprinting strategy was reported for the precise deposition of well-organized cell-laden constructs with microscale filament size,whereas few studies have been devoted to developing bioinks that can be applied for EHD bioprinting and simultaneously support cell spreading.This study describes functionalized alginate-based bioinks for microscale EHD bioprinting using peptide grafting and fibrin incorporation,which leads to high cell viability(>90%)and cell spreading.The printed filaments can be further refined to as small as 30μm by incorporating polyoxyethylene and remained stable over one week when exposed to an aqueous environment.By utilizing the presented alginate-based bioinks,layer-specific cell alignment along the printing struts could be observed inside the EHD-printed microscale filaments,which allows fabricating living constructs with cell-scale filament resolution for guided cellular orientation.展开更多
3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fa...3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fabrication,and resource constraints.Despite the obstacles posed by microgravity and extreme environments,continual advancements underscore the pivotal role of 3D printing in aerospace science.Beyond its primary function of producing space structures,3D printing contributes significantly to progress in electronics,biomedicine,and resource optimization.This perspective delves into the technological advantages,environmental challenges,development status,and opportunities of 3D printing in space.Envisioning its crucial impact,we anticipate that 3D printing will unlock innovative solutions,reshape manufacturing practices,and foster self-sufficiency in future space endeavors.展开更多
Three-dimensional(3D) printing provides a promising way to fabricate biodegradable scaffolds with designer architectures for the regeneration of various tissues.However,the existing3D-printed scaffolds commonly suffer...Three-dimensional(3D) printing provides a promising way to fabricate biodegradable scaffolds with designer architectures for the regeneration of various tissues.However,the existing3D-printed scaffolds commonly suffer from weak cell-scaffold interactions and insufficient cell organizations due to the limited resolution of the 3D-printed features.Here,composite scaffolds with mechanically-robust frameworks and aligned nanofibrous architectures are presented and hybrid manufactured by combining techniques of 3D printing,electrospinning,and unidirectional freeze-casting.It was found that the composite scaffolds provided volume-stable environments and enabled directed cellular infiltration for tissue regeneration.In particular,the nanofibrous architectures with aligned micropores served as artificial extracellular matrix materials and improved the attachment,proliferation,and infiltration of cells.The proposed scaffolds can also support the adipogenic maturation of adipose-derived stem cells(ADSCs)in vitro.Moreover,the composite scaffolds were found to guide directed tissue infiltration and promote nearby neovascularization when implanted into a subcutaneous model of rats,and the addition of ADSCs further enhanced their adipogenic potential.The presented hybrid manufacturing strategy might provide a promising way to produce additional topological cues within 3D-printed scaffolds for better tissue regeneration.展开更多
The shortage of skin for grafting continues to be a major problem in the treatment of serious skin injuries.3D bioprinting provides a new way to solve this problem.However,current 3D printed skin is less effective in ...The shortage of skin for grafting continues to be a major problem in the treatment of serious skin injuries.3D bioprinting provides a new way to solve this problem.However,current 3D printed skin is less effective in treatment of large wounds because of severe shrinkage and scarring.In this study,bionically designed bilayer skin was fabricated using an extrusion-based bioprinter and a gelatin/sodium alginate/gelatin methacrylate hydrogel with excellent physical and biological properties.Full-thickness skin wounds were created in the back of nude mice and treated with bioprinted skin or hydrogel.Bioprinted skin accelerated wound healing,reduced wound contraction and scarring,and facilitated wound skin epithelialization compared with the bioprinted hydrogel or untreated wound.The skin from the wound was collected 28 days after grafting for histology and immunofluorescence analysis.The thickness of the dermis and epidermis of the bioprinted skin was similar to that of nude mice.Microvascular formation in the dermis and dense keratinocytes in the epidermis of the bioprinted skin were observed.This study provides a potential treatment strategy for reducing skin contraction and scar in large skin wounds.展开更多
Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor ...Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor cells.This study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I collagen.It also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and migration.Finally,it compares two-dimensional(2D)and 3D cultures.For comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D model.Besides,the two models yielded significantly different cell morphologies.Finally,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D model.These results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture systems.The developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.展开更多
Improvement of fabrication efficiency and part performance was the main challenge for the large-scale powder bed fusion(PBF)process.In this study,a dynamic monitoring and feedback system of powder bed temperature fiel...Improvement of fabrication efficiency and part performance was the main challenge for the large-scale powder bed fusion(PBF)process.In this study,a dynamic monitoring and feedback system of powder bed temperature field using an infrared thermal imager has been established and integrated into a four-laser PBF equipment with a working area of 2000 mm×2000 mm.The heat-affected zone(HAZ)temperature field has been controlled by adjusting the scanning speed dynamically.Simultaneously,the relationship among spot size,HAZ temperature,and part performance has been established.The fluctuation of the HAZ temperature in four-laser scanning areas was decreased from 30.85℃to 17.41℃.Thus,the consistency of the sintering performance of the produced large component has been improved.Based on the controllable temperature field,a dynamically adjusting strategy for laser spot size was proposed,by which the fabrication efficiency was improved up to 65.38%.The current research results were of great significance to the further industrial applications of large-scale PBF equipment.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
Porous designs effectively reduce stress shielding in metallic orthopedic implants.However,current porous structures often fail to adequately meet the needs of patients with osteoporosis and low-modulus body regions.T...Porous designs effectively reduce stress shielding in metallic orthopedic implants.However,current porous structures often fail to adequately meet the needs of patients with osteoporosis and low-modulus body regions.This study proposes a sinusoidal-based lattice structure for an ultralow and widely tunable modulus design,aiming to match diverse bone tissue requirements and enhance biomechanical compatibility.Parametric modeling and finite element analysis were used to evaluate the performance of this structure.Results show that,within the design range suitable for bone growth,the elastic modulus of this lattice structure is tunable over a wide range,from 0.09 to 32.67 GPa,outperforming existing porous structures.The lowest value closely matched the minimum mechanical properties of human cancellous bone among porous structures.Moreover,the structure exhibited distinct anisotropic characteristics,allowing for directional design based on mechanical requirements.The structure’s permeability ranged from 1.19×10^(-8) m^(2) to 2.3×10^(-7) m^(2),making it highly compatible with human cancellous bone and meeting the requirements of orthopedic implants.Samples with porosities ranging from 46% to 87% were successfully fabricated using powder bed fusion additive manufacturing,validating the simulation predictions.This tunable low-modulus lattice structure provides a novel approach for developing personalized orthopedic implants,particularly for patients with specialized needs such as osteoporosis,and can potentially enhance biomechanical compatibility and long-term stability.展开更多
In engineering,the demand for high energy absorption by structures subjected to impact loads is increasing.Balancing the limited space,manufacturing feasibility,and energy absorption capabilities is a key point in the...In engineering,the demand for high energy absorption by structures subjected to impact loads is increasing.Balancing the limited space,manufacturing feasibility,and energy absorption capabilities is a key point in the design of many enclosed structures with energy absorption requirements.To achieve a lightweight design and controllable energy absorption by the structures,within a limited space,this study proposes a bio-inspired double-layer impact-resistant structure that can be manufactured by an additive manufacturing method(powder bed fusion),inspired by the microstructure of a woodpecker’s head.The structure is composed of two basic structural units:a quasi-circular ring and an oblique cylinder.The controllable energy absorption capabilities of the structure were studied through a combination of theoretical analyses,numerical simulations,and physical experiments.The results showed that,for the quasi-circular ring structure,the specific energy absorption range of 13-72 J/g could be effectively regulated by adjusting the structural parameters.The specific energy absorption range of 11-137 J/g could be effectively regulated for oblique cylindrical structures.Finally,the structure was applied to the design of engineering impact-resistant devices,proving the effectiveness of the controllable energy absorption of the structure.Moreover,the design process of the structure was optimized,laying a foundation for the structure to better serve engineering design applications.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
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 Program of the National Natural Science Foundation of China(Grant Nos.:52435006,and 52275291)the Program for Innovation Team of Shaanxi Province The work was supported by the Program of the National Natural Science Foundation of China(Grant Nos.:52435006,and 52275291)the Program for Innovation Team of Shaanxi Province。
文摘Drug development and precision therapy are core technologies in the biopharmaceutical field.In the traditional paradigm,new drug development relies on validation through animal testing and clinical trials-a process that requires a decade of testing and costs over two billion dollars[1].Although animal testing has long served as the standard approach for evaluating drug efficacy and toxicity,its predictive accuracy for human responses remains limited due to translational barriers arising from interspecies physiological differences[2].Despite passing animal testing,only about 12%of drug candidates proceed to preclinical trials,and fewer than 11.7%gain final approval[3].
基金financially supported by the National Natural Science Foundation of China(Nos.52125501,52405325)the Key Research Project of Shaanxi Province(Nos.2021LLRH-08,2024SF2-GJHX-34)+5 种基金the Program for Innovation Team of Shaanxi Province(No.2023-CX-TD17)the Postdoctoral Fellowship Program of CPSF(No.GZB20230573)the Postdoctoral Project of Shaanxi Province(No.2023BSHYDZZ30)the Basic Research Program of Natural Science in Shaanxi Province(No.2021JQ-906)the China Postdoctoral Science Foundationthe Fundamental Research Funds for the Central Universities。
文摘The inherent complexities of excitable cardiac,nervous,and skeletal muscle tissues pose great challenges in constructing artificial counterparts that closely resemble their natural bioelectrical,structural,and mechanical properties.Recent advances have increasingly revealed the beneficial impact of bioelectrical microenvironments on cellular behaviors,tissue regeneration,and therapeutic efficacy for excitable tissues.This review aims to unveil the mechanisms by which electrical microenvironments enhance the regeneration and functionality of excitable cells and tissues,considering both endogenous electrical cues from electroactive biomaterials and exogenous electrical stimuli from external electronic systems.We explore the synergistic effects of these electrical microenvironments,combined with structural and mechanical guidance,on the regeneration of excitable tissues using tissue engineering scaffolds.Additionally,the emergence of micro/nanoscale bioelectronics has significantly broadened this field,facilitating intimate interactions between implantable bioelectronics and excitable tissues across cellular,tissue,and organ levels.These interactions enable precise data acquisition and localized modulation of cell and tissue functionalities through intricately designed electronic components according to physiological needs.The integration of tissue engineering and bioelectronics promises optimal outcomes,highlighting a growing trend in developing living tissue construct-bioelectronic hybrids for restoring and monitoring damaged excitable tissues.Furthermore,we envision critical challenges in engineering the next-generation hybrids,focusing on integrated fabrication strategies,the development of ionic conductive biomaterials,and their convergence with biosensors.
基金supported by the Program of the National Natural Science Foundation of China(52275291)(52435006)the Program for Innovation Team of Shaanxi Province(2023CX-TD-17)the Fundamental Research Funds for the Central Universities。
文摘Brain,the material foundation of human intelligence,is the most complex tissue in the human body.Brain diseases are among the leading threats to human life,yet our understanding of their pathogenic mechanisms and drug development remains limited,largely due to the lack of accurate brain-like tissue models that replicate its complex structure and functions.Therefore,constructing brain-like models—both in morphology and function—possesses significant scientific value for advancing brain science and pathological pharmacology research,representing the frontiers in the biomanufacturing field.This review outlines the primary requirements and challenges in biomanufacturing brain-like tissue,addressing its complex structures,functions,and environments.Also,the existing biomanufacturing technologies,strategies,and characteristics for brain-like models are depicted,and cutting-edge developments in biomanufacturing central neural repair prosthetics,brain development models,brain disease models,and brain-inspired biocomputing models are systematically reviewed.Finally,the paper concludes with future perspectives on the biomanufacturing of brain-like tissue transitioning from structural manufacturing to intelligent functioning.
基金supported by the National Key R&D Program of China(No.2023YFB4603500)the Program for Innovation Team of Shaanxi Province(No.2023-CX-TD-17)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Shaanxi Province Qinchuangyuan“Scientist+Engineer”Team Construction Project(No.2022KXJ-106).
文摘The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical properties.This study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation system.The combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK implants.Moreover,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after implantation.In conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.
基金supported by the National Natural Science Foundation of China(Grant No.52405414)the China Postdoctoral Science Foundation(Grant No.2024M762580)+1 种基金Young Talent Fund of Xi'an Association for Science and Technology(Grant No.0959202513033)the Youth Innovation Team of Shaanxi Universities,and the Fundamental Research Funds for Central Universities.The authors gratefully acknowledge the support by the Instrumental Analysis Center of Xi’an Jiaotong University for sample characterization.
文摘In the background of carbon neutrality,monolithic ceramic catalysts are universally used in energy conversion and chemical catalysis due to the high heat and mass transfer efficiencies,low bed pressures,and scalability through modular design.However,traditional manufacturing processes are limited by mold dependence,organic solvent toxicity,and insufficient molding capability for complex structures,resulting in difficulty achieving precise regulation of cross-scale pores.Additive manufacturing(AM)technology employs a digital layered molding strategy to achieve the cross-scale structural regulation of catalysts from macroscopic flow channels to mesopores and micropores.This paper summarizes recent advances in the structural design of monolithic catalysts enabled by AM technologies and highlights their emerging applications in catalytic processes.Structurally,AM-fabricated monoliths have been effectively employed in key chemical reactions such as fuel reforming,CO_(2)conversion,biofuel synthesis.Strategies such as geometrical topology optimization,multi-scale pore synergy,biomimetic structural design,and functional gradient integration have been utilized to enhance heat and mass transport,reduce pressure drops,and improve overall catalytic performance.By overcoming the limitations of traditional catalysts,AM technologies create a new paradigm for addressing the longstanding challenge of coupling mass transfer with reaction kinetics.This approach provides a feasible pathway for driving both theoretical innovation and practical implementation of high-efficiency catalytic systems.
基金supported by National Key Research and Development Program of China(Grant.No.2022YFB4603102)Insight Action(Grant.No.AA5F41D0).
文摘Solid propellants are essential energy sources for rockets and other aerospace vehicles,and improvements in their performance have significant implications for the aerospace industry.The application of additive manufacturing(AM)in the production of solid propellants promises a substantial leap in the design and fabrication of solid propellant grains.This review summarizes recent research on AM techniques for solid propellant manufacturing,evaluates current applications,and explores development trends.This review highlights that AM technology for solid propellants offers unparalleled advantages in terms of propellant design flexibility and functional gradient loading compared with traditional processes.This study presents a new perspective for the future manufacturing of intelligent and controllable solid propulsion systems.
基金supported by National Key R&D Program of China(Grant No.2022YFB4600103)National Youth Talent Support Program,China Postdoctoral Science Foundation(Grant No.2021M692555)+1 种基金Shaanxi Province Qinchuangyuan'Scientists+Engineers'Team Building Project(Grant No.2023KXJ-266)Fundamental Research Funds for the Central Universities(Grant No.xzy012023145)。
文摘Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping capabilities based on photopolymerization.However,owing to differences in the curing behavior and physical properties of different materials,multimaterial DLP 3D printing faces challenges such as insufficient interfacial bonding strength and unstable mechanical properties.In this study,two resins were integrated by multimaterial DLP 3D printing technology,and the effects of different layer thicknesses and exposure times on the interfacial bonding strength and morphology of the multimaterials were systematically investigated.The interfacial bonding mechanisms of the two resins was analyzed.It was found that increasing the exposure time can improve the interfacial bonding strength between materials,but certain limitations exist.A mathematical model relating the interfacial bonding strength to the exposure time and layer thickness was developed,and optimal process parameters were determined using optimization algorithms.A variable-parameter printing strategy for the interface was proposed to further improve the performance of printed parts.The maximum tensile strength of the multimaterial samples(44.43 MPa)using this strategy reached that of single-material parts(45 MPa),validating the feasibility of this strategy.This provides guidance for multimaterial DLP 3D printing processes and offers valuable insights for the future additive manufacturing of high-performance multimaterial components.
基金supported by National Natural Science Foundation of China(Grant Nos.12202547,62461160259)Shaanxi Province Qingchuangyuan“Scientist and Engineering”Team Construction Project(Grant Nos.2022KXJ-102,2022KXJ-106)+1 种基金Fundamental Research Funds for the Central UniversitiesProgram for Innovation Team of Shaanxi Province(Grant No.2023-CX-TD-17).
文摘Variable material screw-based material extrusion(S-MEX)3D printing technology provides a novel approach for fabricating composites with continuous material gradients.Nevertheless,achieving precise alignment between the process parameters and material compositions is challenging because of fluctuations in the melt rheological state caused by material variations.In this study,an invertible extrusion prediction model for 0-40 wt% short carbon fiber reinforced polyether-ether-ketone(SCF/PEEK)in the S-MEX process was established using an invertible neural network(INN)that demonstrated the capabilities of forward flow rate prediction and inverse process optimization with accuracies of 0.852 and 0.877,respectively.Moreover,a strategy for adjusting the screw speeds using process parameters obtained from the INN was developed to maintain a consistent flow rate during the variable material printing process.Benefiting from uniform flow,the linewidth accuracy was improved by 77%,and the surface roughness was reduced by 51%.Adjusting the process parameters by using an INN offers significant potential for flow rate control and the enhancement of the overall performance of variable material 3D printing.
基金This work was financially supported by the National Key Research and Development Program of China(No.2018YFA0703003)the National Natural Science Foundation of China(No.52125501)+1 种基金the Key Research Project of Shaanxi Province(Nos.2021LLRH-08,2020GXLH-Y-021,and 2021GXLH-Z-028)the Youth InnovationTeam of Shaanxi Universities and the Fundamental Research Funds for the Central Universities.
文摘Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resolution of conventional bioprinting techniques such as extrusion-and inkjet-based printing.Recently,an electrohydrodynamic(EHD)bioprinting strategy was reported for the precise deposition of well-organized cell-laden constructs with microscale filament size,whereas few studies have been devoted to developing bioinks that can be applied for EHD bioprinting and simultaneously support cell spreading.This study describes functionalized alginate-based bioinks for microscale EHD bioprinting using peptide grafting and fibrin incorporation,which leads to high cell viability(>90%)and cell spreading.The printed filaments can be further refined to as small as 30μm by incorporating polyoxyethylene and remained stable over one week when exposed to an aqueous environment.By utilizing the presented alginate-based bioinks,layer-specific cell alignment along the printing struts could be observed inside the EHD-printed microscale filaments,which allows fabricating living constructs with cell-scale filament resolution for guided cellular orientation.
基金supported by the National Natural Science Foundation of China(52125501 and 52205317)the Key Research Project of Shaanxi Province(2021LLRH-08)+4 种基金the Program for Innovation Team of Shaanxi Province(2023-CX-TD-17)the Natural Science Basis Research Plan in Shaanxi Province of China(2022JQ-523)the High-Level Talent Recruitment Program of Shaanxi Provincethe Fundamental Research Funds for the Central UniversitiesChina Postdoctoral Science Foundation。
文摘3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fabrication,and resource constraints.Despite the obstacles posed by microgravity and extreme environments,continual advancements underscore the pivotal role of 3D printing in aerospace science.Beyond its primary function of producing space structures,3D printing contributes significantly to progress in electronics,biomedicine,and resource optimization.This perspective delves into the technological advantages,environmental challenges,development status,and opportunities of 3D printing in space.Envisioning its crucial impact,we anticipate that 3D printing will unlock innovative solutions,reshape manufacturing practices,and foster self-sufficiency in future space endeavors.
基金financially supported by the National Key Research and Development Program of China(2018YFA0703003)the National Natural Science Foundation of China (52125501)+2 种基金the Key Research Project of Shaanxi Province (2021LLRH-08,2021GXLH-Z-028)the Program for Innovation Team of Shaanxi Province (2023-CX-TD-17)the Fundamental Research Funds for the Central Universities。
文摘Three-dimensional(3D) printing provides a promising way to fabricate biodegradable scaffolds with designer architectures for the regeneration of various tissues.However,the existing3D-printed scaffolds commonly suffer from weak cell-scaffold interactions and insufficient cell organizations due to the limited resolution of the 3D-printed features.Here,composite scaffolds with mechanically-robust frameworks and aligned nanofibrous architectures are presented and hybrid manufactured by combining techniques of 3D printing,electrospinning,and unidirectional freeze-casting.It was found that the composite scaffolds provided volume-stable environments and enabled directed cellular infiltration for tissue regeneration.In particular,the nanofibrous architectures with aligned micropores served as artificial extracellular matrix materials and improved the attachment,proliferation,and infiltration of cells.The proposed scaffolds can also support the adipogenic maturation of adipose-derived stem cells(ADSCs)in vitro.Moreover,the composite scaffolds were found to guide directed tissue infiltration and promote nearby neovascularization when implanted into a subcutaneous model of rats,and the addition of ADSCs further enhanced their adipogenic potential.The presented hybrid manufacturing strategy might provide a promising way to produce additional topological cues within 3D-printed scaffolds for better tissue regeneration.
基金This work was supported by the National Key R&D Program of China(No.2018YFE0207900)the Development projects of Key research of People’s Liberation Army(No.BWS17J036,18-163-13-ZT-003-011-01)the National Natural Science Foundation of China(51835010 and 51375371)。
文摘The shortage of skin for grafting continues to be a major problem in the treatment of serious skin injuries.3D bioprinting provides a new way to solve this problem.However,current 3D printed skin is less effective in treatment of large wounds because of severe shrinkage and scarring.In this study,bionically designed bilayer skin was fabricated using an extrusion-based bioprinter and a gelatin/sodium alginate/gelatin methacrylate hydrogel with excellent physical and biological properties.Full-thickness skin wounds were created in the back of nude mice and treated with bioprinted skin or hydrogel.Bioprinted skin accelerated wound healing,reduced wound contraction and scarring,and facilitated wound skin epithelialization compared with the bioprinted hydrogel or untreated wound.The skin from the wound was collected 28 days after grafting for histology and immunofluorescence analysis.The thickness of the dermis and epidermis of the bioprinted skin was similar to that of nude mice.Microvascular formation in the dermis and dense keratinocytes in the epidermis of the bioprinted skin were observed.This study provides a potential treatment strategy for reducing skin contraction and scar in large skin wounds.
基金supported by the National Natural Science Foundation of China (No. 52275291)the Fundamental Research Funds for the Central Universitiesthe Program for Innovation Team of Shaanxi Province,China (No. 2023-CX-TD-17)
文摘Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor cells.This study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I collagen.It also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and migration.Finally,it compares two-dimensional(2D)and 3D cultures.For comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D model.Besides,the two models yielded significantly different cell morphologies.Finally,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D model.These results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture systems.The developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.
基金Supported by National High Technology Research and Development Program of China(863 Program,Grant No.2015AA042503)K.C.Wong Education Foundation.
文摘Improvement of fabrication efficiency and part performance was the main challenge for the large-scale powder bed fusion(PBF)process.In this study,a dynamic monitoring and feedback system of powder bed temperature field using an infrared thermal imager has been established and integrated into a four-laser PBF equipment with a working area of 2000 mm×2000 mm.The heat-affected zone(HAZ)temperature field has been controlled by adjusting the scanning speed dynamically.Simultaneously,the relationship among spot size,HAZ temperature,and part performance has been established.The fluctuation of the HAZ temperature in four-laser scanning areas was decreased from 30.85℃to 17.41℃.Thus,the consistency of the sintering performance of the produced large component has been improved.Based on the controllable temperature field,a dynamically adjusting strategy for laser spot size was proposed,by which the fabrication efficiency was improved up to 65.38%.The current research results were of great significance to the further industrial applications of large-scale PBF equipment.
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 R&D Program of China(Grant No.2022YFB4600500)Fundamental Research Funds for the Central Universities,and the Program for Innovation Team of Shaanxi Province(Grant No.2023-CX-TD-17).
文摘Porous designs effectively reduce stress shielding in metallic orthopedic implants.However,current porous structures often fail to adequately meet the needs of patients with osteoporosis and low-modulus body regions.This study proposes a sinusoidal-based lattice structure for an ultralow and widely tunable modulus design,aiming to match diverse bone tissue requirements and enhance biomechanical compatibility.Parametric modeling and finite element analysis were used to evaluate the performance of this structure.Results show that,within the design range suitable for bone growth,the elastic modulus of this lattice structure is tunable over a wide range,from 0.09 to 32.67 GPa,outperforming existing porous structures.The lowest value closely matched the minimum mechanical properties of human cancellous bone among porous structures.Moreover,the structure exhibited distinct anisotropic characteristics,allowing for directional design based on mechanical requirements.The structure’s permeability ranged from 1.19×10^(-8) m^(2) to 2.3×10^(-7) m^(2),making it highly compatible with human cancellous bone and meeting the requirements of orthopedic implants.Samples with porosities ranging from 46% to 87% were successfully fabricated using powder bed fusion additive manufacturing,validating the simulation predictions.This tunable low-modulus lattice structure provides a novel approach for developing personalized orthopedic implants,particularly for patients with specialized needs such as osteoporosis,and can potentially enhance biomechanical compatibility and long-term stability.
基金supported by National Key R&D Program of China(Grant No.2022YFB4600500)Fundamental Research Funds for the Central Universitiesthe Program for Innovation Team of Shaanxi Province of China(Grant No.2023-CX-TD-17).
文摘In engineering,the demand for high energy absorption by structures subjected to impact loads is increasing.Balancing the limited space,manufacturing feasibility,and energy absorption capabilities is a key point in the design of many enclosed structures with energy absorption requirements.To achieve a lightweight design and controllable energy absorption by the structures,within a limited space,this study proposes a bio-inspired double-layer impact-resistant structure that can be manufactured by an additive manufacturing method(powder bed fusion),inspired by the microstructure of a woodpecker’s head.The structure is composed of two basic structural units:a quasi-circular ring and an oblique cylinder.The controllable energy absorption capabilities of the structure were studied through a combination of theoretical analyses,numerical simulations,and physical experiments.The results showed that,for the quasi-circular ring structure,the specific energy absorption range of 13-72 J/g could be effectively regulated by adjusting the structural parameters.The specific energy absorption range of 11-137 J/g could be effectively regulated for oblique cylindrical structures.Finally,the structure was applied to the design of engineering impact-resistant devices,proving the effectiveness of the controllable energy absorption of the structure.Moreover,the design process of the structure was optimized,laying a foundation for the structure to better serve engineering design applications.
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.
