In order to address the current inability of screen printing to monitor printing pressure online,an online printing pressure monitoring system applied to screen printing machines was designed in this study.In this stu...In order to address the current inability of screen printing to monitor printing pressure online,an online printing pressure monitoring system applied to screen printing machines was designed in this study.In this study,the consistency of printed electrodes was measured by using a confocal microscope and the pressure distribution detected by online pressure monitoring system was compared to investigate the relationship.The results demonstrated the relationship between printing pressure and the consistency of printed electrodes.As printing pressure increases,the ink layer at the corresponding position becomes thicker and that higher printing pressure enhances the consistency of the printed electrodes.The experiment confirms the feasibility of the online pressure monitoring system,which aids in predicting and controlling the consistency of printed electrodes,thereby improving their performance.展开更多
Optical coherence tomography(OCT)imaging technology has significant advantages in in situ and noninvasive monitoring of biological tissues.However,it still faces the following challenges:including data processing spee...Optical coherence tomography(OCT)imaging technology has significant advantages in in situ and noninvasive monitoring of biological tissues.However,it still faces the following challenges:including data processing speed,image quality,and improvements in three-dimensional(3D)visualization effects.OCT technology,especially functional imaging techniques like optical coherence tomography angiography(OCTA),requires a long acquisition time and a large data size.Despite the substantial increase in the acquisition speed of swept source optical coherence tomography(SS-OCT),it still poses significant challenges for data processing.Additionally,during in situ acquisition,image artifacts resulting from interface reflections or strong reflections from biological tissues and culturing containers present obstacles to data visualization and further analysis.Firstly,a customized frequency domainfilter with anti-banding suppression parameters was designed to suppress artifact noises.Then,this study proposed a graphics processing unit(GPU)-based real-time data processing pipeline for SS-OCT,achieving a measured line-process rate of 800 kHz for 3D fast and high-quality data visualization.Furthermore,a GPU-based realtime data processing for CC-OCTA was integrated to acquire dynamic information.Moreover,a vascular-like network chip was prepared using extrusion-based 3D printing and sacrificial materials,with sacrificial material being printed at the desired vascular network locations and then removed to form the vascular-like network.OCTA imaging technology was used to monitor the progression of sacrificial material removal and vascular-like network formation.Therefore,GPU-based OCT enables real-time processing and visualization with artifact suppression,making it particularly suitable for in situ noninvasive longitudinal monitoring of 3D bioprinting tissue and vascular-like networks in microfluidic chips.展开更多
The rapidly increasing demand for wearable electronic devices has motivated research in low-cost and flexible printed batteries with diverse form factors and architectures.In the past,technological achieve-ments in th...The rapidly increasing demand for wearable electronic devices has motivated research in low-cost and flexible printed batteries with diverse form factors and architectures.In the past,technological achieve-ments in the field have been emphasized,overlooking the industrial and market requirements.However,different applications require different battery chemistries and formats,that greatly impacts the manu-facturing process and competition landscape.These chemistries and formats should therefore be selected carefully to maximize the chances for commercial success.As some of these technologies are starting to be marketed for portable electronics,there is a pressing need to evaluate different printing technologies and compare them in terms of the processing constraints and product requirements of specific electronic devices.By evaluating the intrinsic strengths and current limitations of printed battery technologies,development pathways can be prioritized,and potential bottlenecks can be overcome to accelerate the path to market.展开更多
CQDs-doped TiO_(2)(C-TiO_(2))has drawn increased attention in recent because of its excellent catalytic performance.Understanding the transport of C-TiO_(2)in porous media is necessary for evaluating the environmental...CQDs-doped TiO_(2)(C-TiO_(2))has drawn increased attention in recent because of its excellent catalytic performance.Understanding the transport of C-TiO_(2)in porous media is necessary for evaluating the environmental process of this new nanomaterial.Column experiments were used in this study to investigate ionic strength(IS),dissolved organic matter(DOM)and sand grain size on the transport of C-TiO_(2).The mobility of C-TiO_(2)was inhibited by the increased IS and decreased sand grain size,but was promoted by the increased DOM concentration.The promotion efficiency of DOM ranked as humic acid(HA)>alginate(Alg)>bovine serum albumin(BSA),which was in the same order as their ability to change surface charges.The micromodels of pore network were prepared via 3D printing to further reveal the deposition mechanisms and spatial/temporal distribution of C-TiO_(2)in porous space.C-TiO_(2)mainly attached to the upstream region of collectors because of interception.The collector ripening was observed after long-time deposition.The existence of DOM caused visible decrease of C-TiO_(2)deposition in the pore network.HA caused the most remarkable reduce of deposition in the three types of DOM,which was consistent with the column experiment results.This research is helpful to predict the transport of C-TiO_(2)in natural porous media.展开更多
Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising techniqu...Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.展开更多
Gravure printing is a promising large-scale fabrication method for flexible organic solar cells(FOSCs)because it is compatible with two-dimension patternable roll-to-roll fabrication.However,the unsuitable rheological...Gravure printing is a promising large-scale fabrication method for flexible organic solar cells(FOSCs)because it is compatible with two-dimension patternable roll-to-roll fabrication.However,the unsuitable rheological property of ZnO nanoinks resulted in unevenness and looseness of the gravure-printed ZnO interfacial layer.Here we propose a strategy to manipulate the macroscopic and microscopic of the gravure-printed ZnO films through using mixed solvent and poly(vinylpyrrolidone)(PVP)additive.The regulation of drying speed effectively manipulates the droplets fusion and leveling process and eliminates the printing ribbing structure in the macroscopic morphology.The additive of PVP effectively regulates the rheological property and improves the microscopic compactness of the films.Following this method,large-area ZnO∶PVP films(28×9 cm^(2))with excellent uniformity,compactness,conductivity,and bending durability were fabricated.The power conversion efficiencies of FOSCs with gravure-printed AgNWs and ZnO∶PVP films reached 14.34%and 17.07%for the 1 cm^(2)PM6:Y6 and PM6∶L8-BO flexible devices.The efficiency of 17.07%is the highest value to date for the 1 cm^(2)FOSCs.The use of mixed solvent and PVP addition also significantly enlarged the printing window of ZnO ink,ensuring high-quality printed thin films with thicknesses varying from 30 to 100 nm.展开更多
Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern medicine.Nowadays,the increasing demand for personaliz...Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern medicine.Nowadays,the increasing demand for personalized medical devices poses a significant challenge to traditional manufacturing methods.The emerging manufacturing technology of three-dimensional(3D)printing as an alternative has shown exciting applications in the medical field and is an ideal method for manufacturing such personalized medical devices with complex structures.However,the application of this new technology has also brought new risks to medical devices,making 3D-printed devices face severe challenges due to insufficient regulation and the lack of standards to provide guidance to the industry.This review aims to summarize the current regulatory landscape and existing research on the standardization of 3D-printed medical devices in China,and provide ideas to address these challenges.We focus on the aspects concerned by the regulatory authorities in 3D-printed medical devices,highlighting the quality system of such devices,and discuss the guidelines that manufacturers should follow,as well as the current limitations and the feasible path of regulation and standardization work based on this perspective.The key points of the whole process quality control,performance evaluation methods and the concept of whole life cycle management of 3D-printed medical devices are emphasized.Furthermore,the significance of regulation and standardization is pointed out.Finally,aspects worthy of attention and future perspectives in this field are discussed.展开更多
The fabrication of multi-material medical phantoms with both patient-specificity and realistic mechanical properties is of great importance for the development of surgical planning and medical training.In this work,a ...The fabrication of multi-material medical phantoms with both patient-specificity and realistic mechanical properties is of great importance for the development of surgical planning and medical training.In this work,a 3D multi-material printing system for medical phantom manufacturing was developed.Rigid and elastomeric materials are firstly combined in such application for an accurate tactile feedback.The phantom is designed with multiple layers,where silicone ink,Thermoplastic Polyurethane(TPU),and Acrylonitrile Butadiene Styrene(ABS)were chosen as printing materials for skin,soft tissue,and bone,respectively.Then,the printed phantoms were utilized for the investigation of needle-phantom interaction by needle insertion experiments.The mechanical needle-phantom interaction was characterized by skin-soft tissue interfacial puncture force,puncture depth,and number of insertion force peaks.The experiments demonstrated that the manufacturing conditions,i.e.the silicone grease ratio,interfacial thickness and the infill rate,played effective roles in regulating mechanical needle-phantom interaction.Moreover,the influences of material properties,including interfacial thickness and ultimate stress,on needle-phantom interaction were studied by finite element simulation.Also,a patient-specific forearm phantom was printed,where the anatomical features were acquired from Computed Tomography(CT)data.This study provided a potential manufacturing method for multi-material medical phantoms with tunable mechanical properties and offered guidelines for better phantom design.展开更多
Reconstruction of severe bone defects in revision total knee arthroplasty(TKA)remains a challenge for orthopaedists.The progression of medical imaging and additive manufacturing technology has enabled the rapid manufa...Reconstruction of severe bone defects in revision total knee arthroplasty(TKA)remains a challenge for orthopaedists.The progression of medical imaging and additive manufacturing technology has enabled the rapid manufacture of custom-made implants,and 3D-printed augments with interconnected pore structures have become an alternative approach for the reconstruction of bone defects in revision TKA,especially in patients with complex bone defects.The size and location of the bone defect were determined by thin-layer computed tomography(CT;layer thickness is 1 mm)after reduction of artifacts.The 3D reconstruction models of the host bone were obtained based on thin-layer CT imaging.The custom-made augmentation was designed according to the 3D reconstruction bone model.The augmentation had an interconnected porous structure on the bone-implant interface to achieve biological fixation.After the design was complete,the 3D model of augment was exported in STL format,and augments were fabricated with Ti6Al4V powder using electron beam melting.Thin-layer CT and 3D reconstruction bone models are accurate methods for evaluating periprosthetic bone loss after artifact reduction.The 3D-printed augments perfectly match the bone defects during surgery.3D-printed augmentation is an effective approach for the reconstruction of bone defects in revision TKA.Thus,surgeons and engineers should carefully evaluate the bone defect during augment design to avoid a mismatch between the augment and host bone.展开更多
In order to research the feasibility of using the selective adsorption principle to achieve automatic shaping of nano patterns,in this study,using the liquid gallium as the conductive ink and graphene as the printing ...In order to research the feasibility of using the selective adsorption principle to achieve automatic shaping of nano patterns,in this study,using the liquid gallium as the conductive ink and graphene as the printing plate surface,by changing the surface wettability of patterned areas on the nanoscale of graphene printed boards,the automatic formation of liquid gallium patterns on the graphene printed plate surface was simulated.The results indicated that liquid gallium can achieve automatic patterning on the surface of graphene patterned areas;the greater the interaction energy between gallium and carbon atoms,the clearer the pattern;gallium liquid is prone to remain in complex local positions of the pattern,making it difficult to shape the pattern;if the spacing between adjacent pattern lines is too large or too small,it will result in residual gallium liquid between the lines;increasing the thickness of the gallium film will cause the pattern to expand beyond the boundary,but increasing the thickness of the gallium film can also enhance the thickness and uniformity of the pattern lines.In summary,the principle of selective adsorption can be used to achieve the automatic formation of nano patterns,and the pattern formation effect is influenced by factors such as atomic interaction energy and pattern configuration.展开更多
Developing biomimetic hydrogel-based scaffolds that can mimic the native anisotropic skeletal muscle tissue structure for inducing 3D aligned myogenic differentiation remains an on going challenge.Herein,we presented ...Developing biomimetic hydrogel-based scaffolds that can mimic the native anisotropic skeletal muscle tissue structure for inducing 3D aligned myogenic differentiation remains an on going challenge.Herein,we presented a method to 3D bioprint fibrinogen and GelMA via free printing into the support gel to engineer 3D oriented skeletal muscle scaffolds.A 3D aligned biomimetic scaffold based on this double-network hydrogel bioink was further 3D printed within the Carbopol supported gel by using a printing gel-in-gel strategy to mimic the native anisotropic structure of skeletal muscle tissue,and the cell cultivation experiment performed on myoblast-laden 3D bioprinted aligned biomimetic scaffolds indicated the material's ability to guide 3D myoblast alignment and elongation.展开更多
Introduction Mandibular segmental defects result in significant cosmetic and functional deficiencies.Meanwhile,the reconstruction of both the contour and function of the mandible is a challenging task.At present,autol...Introduction Mandibular segmental defects result in significant cosmetic and functional deficiencies.Meanwhile,the reconstruction of both the contour and function of the mandible is a challenging task.At present,autologous vascularized fibula transplantation is the most common method to reconstruct a mandible with long-span defects[1].展开更多
Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced ...Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced image acquisition techniques,image processing,and computer-aided design methods has enabled the precise design and additive manufacturing of anatomically correct and patient-specific implants and scaffolds.However,these sophisticated techniques can be timeconsuming,labor-intensive,and expensive.Moreover,the necessary imaging and manufacturing equipment may not be readily available when urgent treatment is needed for trauma patients.In this study,a novel design and AM methods are proposed for the development of modular and customizable scaffold blocks that can be adapted to fit the bone defect area of a patient.These modular scaffold blocks can be combined to quickly form any patient-specific scaffold directly from two-dimensional(2D)medical images when the surgeon lacks access to a 3D printer or cannot wait for lengthy 3D imaging,modeling,and 3D printing during surgery.The proposed method begins with developing a bone surface-modeling algorithm that reconstructs a model of the patient’s bone from 2D medical image measurements without the need for expensive 3D medical imaging or segmentation.This algorithm can generate both patient-specific and average bone models.Additionally,a biomimetic continuous path planning method is developed for the additive manufacturing of scaffolds,allowing porous scaffold blocks with the desired biomechanical properties to be manufactured directly from 2D data or images.The algorithms are implemented,and the designed scaffold blocks are 3D printed using an extrusion-based AM process.Guidelines and instructions are also provided to assist surgeons in assembling scaffold blocks for the self-repair of patient-specific large bone defects.展开更多
For effective anterior cruciate ligament(ACL)reconstruction,an interference screw(IFS)is employed to force transplantation of the ligament into the bone tunnel.In this study,IFSs were successfully designed and pre-par...For effective anterior cruciate ligament(ACL)reconstruction,an interference screw(IFS)is employed to force transplantation of the ligament into the bone tunnel.In this study,IFSs were successfully designed and pre-pared,and the top tooth width,thread depth,and drive structure were parameterized with a forming accuracy of 80.0±21.1μm using SLA-3D printing technology.To improve the initial stability of ACL reconstruction,a biomechanical model was established,and the results were optimized through insertion torque and tensile test-ing.Consequently,the IFS with the top tooth width of 0.4 mm,thread depth of 0.8 mm,and hexagon drive,matching with theΦ8 mm bone tunnel,exhibits the best mechanical properties(maximum insertion torque of 1.064±0.117 N m,ultimate load of 446.126±37.632 N,stiffness of 66.33±27.48 N/mm).Additionally,the ZrO_(2)/PDA/RGD/Zn^(2+)bioactive coating was found to significantly improve the surface bioactivity of zirconia IFS.In conclusion,this study has significant implications for ACL reconstruction.展开更多
Bioactive coating of ceramic scaffolds is an effective way to ameliorate osseointegration and attenuate implant-induced inflammatory responses,which should be biocompatible and possess suitable mechani-cal properties ...Bioactive coating of ceramic scaffolds is an effective way to ameliorate osseointegration and attenuate implant-induced inflammatory responses,which should be biocompatible and possess suitable mechani-cal properties to regulate cell adhesion and migration.In this study,a poly(ethylene glycol)diacry-late/tricalcium phosphate(PEGDA/TCP)ceramic scaffold was prepared using SLA-3D printing,and its com-pressive strength was 8.9±1.0 MPa.Chitosan(Chi)and chondroitin sulfate(CS)were assembled on the sur-face of the PEGDA/TCP scaffolds and crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide(EDC/NHS).Scanning electron microscope(SEM),Fourier transform infrared(FTIR),and laser scanning microscope were used to evaluate the surface modification of the PEGDA/TCP scaffolds.Cellu-lar tests showed that polyelectrolyte multilayers(PEMs)promoted cell adhesion and proliferation of osteoblasts relative to unmodified scaffolds.Furthermore,it can be demonstrated that the SLA-3D printed TCP scaffolds could meet the compressive requirements of trabecular bones,and the bioactivity of the bone scaffolds could be effectively improved by combining them with Chi/CS PEM.展开更多
Stretchable circuits based on liquid metals are promising for wearables but the lack of scalable processes for sintering of printed liquid metal dispersions constitutes a challenge for large-area and high-volume manuf...Stretchable circuits based on liquid metals are promising for wearables but the lack of scalable processes for sintering of printed liquid metal dispersions constitutes a challenge for large-area and high-volume manufacturing.In this work,materials and methods for fully screen printed stretchable liquid metal multilayer circuits have been developed.The ink is based on liquid metal droplets dispersed in the green solvent propylene glycol using the harmless dispersion agent polyvinylpyrrolidone.The development of a scalable water-spray sintering method in combination with ink optimization yielded highly conductive prints of≈7.3×10^(5)S/m.Interestingly,the printed conductors experienced a resistance increase of less than 10%during 50%strain cycling,which is far below the expected 125%increase due to the geometry factor.The process allows for printing of highperformance multilayer circuits,which is demonstrated by the development of printed stretchable near-field communication tags.展开更多
The field of tissue engineering has witnessed significant progress with the emergence of three-dimensional(3D)printing technologies.The ability to fabricate precise structures with complex geometries combined with the...The field of tissue engineering has witnessed significant progress with the emergence of three-dimensional(3D)printing technologies.The ability to fabricate precise structures with complex geometries combined with the in-tegration of two-dimensional(2D)materials,including graphene,graphene oxide,and transition metal dichalco-genides,has provided novel opportunities.This integration enables the fabrication of functional structures with tailored properties,leveraging the exceptional mechanical,electrical,and chemical characteristics of these mate-rials,in conjunction with the design flexibility offered by 3D printing.Herein,we review the recent advancements in the selection of appropriate 2D materials,diverse 3D printing methods employed for integration,and charac-terization techniques used to evaluate the performance of the resulting constructs.The successful integration of 3D printing and 2D materials holds immense potential for advancing tissue engineering and paving the way for personalized medicine,regenerative therapies,and point-of-care diagnostics.展开更多
Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely us...Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely used in fields such as injection molding,die casting,and stamping dies.Adding reinforcing particles into steel is an effective means to improve its performance.Nb/18Ni300 composites were fabricated by LPBF using two kinds of Nb powders with different particle sizes,and their microstructures and properties were studied.The results show that the unmelted Nb particles are uniformly distributed in the 18Ni300 matrix and the grains are refined,which is particularly pronounced with fine Nb particles.In addition,element diffusion occurs between the particles and the matrix.The main phases of the base alloy are α-Fe and a small amount of γ-Fe.With the addition of Nb,part of the α-Fe is transformed into γ-Fe,and unmelted Nb phases appear.The addition of Nb also enhances the hardness and wear resistance of the composites but slightly reduces their tensile properties.After aging treatment,the molten pools and grain boundaries become blurred,grains are further refined,and the interfaces around the particles are thinned.The aging treatment also promotes the formation of reverted austenite.The hardness,ultimate tensile strength,and volumetric wear rate of the base alloy reach 51.9 HRC,1704 MPa,and 17.8×10^(-6) mm^(3)/(N·m),respectively.In contrast,the sample added with fine Nb particles has the highest hardness(56.1 HRC),ultimate tensile strength(1892 MPa)and yield strength(1842 MPa),and the volume wear rate of the sample added with coarse Nb particles is reduced by 90%to 1.7×10^(-6) mm^(3)/(N·m).展开更多
The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solutio...The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solution were used to regulate the microstructure,mechanical properties,and corrosion properties of B_(4)C/TC4 composite.Results show that with the increase in temperature from 500℃to 800°C,partial lamellarα-Ti in the as-deposited sample is gradually transformed into equiaxedα-Ti,accompanied by the disappearance of basketweave microstructure.At 1100°C,a small portion of TiC phase suffers fusion.This composite exhibits the optimal combination of strength and plasticity after annealing at 500℃for 4 h followed by furnace cooling,which is attributed to the stress release effect and the refined basketweave microstructure.However,this composite shows a decline in corrosion resistance after various heat treatments due to grain coarsening and micro-galvanic corrosion.展开更多
Flexible and wearable sensors offer immense potential for rehabilitation medicine,but most rely solely on electrical signals,lacking real-time visual feedback and limiting trainee's interactivity.Inspired by the s...Flexible and wearable sensors offer immense potential for rehabilitation medicine,but most rely solely on electrical signals,lacking real-time visual feedback and limiting trainee's interactivity.Inspired by the structural coloration of Cyanocitta stelleri feathers,we developed a dual-mode sensor by utilizing black conductive polymer hydrogel(CPH)-enhanced structural color strategy.This sensor integrates a hydroxypropyl cellulose(HPC)-based structural color interface with a designed CPH sensing component.Highly visible light-absorbing CPH(absorption rate>88%)serves as the critical substrate for enhancing structural color performance.By absorbing incoherent scattered light and suppressing background interference,it significantly enhances the saturation of structural color,thereby achieving a high contrast index of 4.92.Unlike the faint and hardly visible structural colors on non-black substrates,the HPC on CPH displays vivid,highly perceptible colors and desirable mechanochromic behavior.Moreover,the CPH acts as a flexible sensing element,fortified by hydrogen and coordination bond networks,and exhibits exceptional electromechanical properties,including 867.1 kPa tensile strength,strain sensitivity(gauge factor of 4.24),and outstanding durability(over 4400 cycles).Compared to traditional single-mode sensors,the integrated sensor provides real-time visual and digital dual feedback,enhancing the accuracy and interactivity of rehabilitation assessments.This technology holds promise for advancing next-generation rehabilitation medicine.展开更多
文摘In order to address the current inability of screen printing to monitor printing pressure online,an online printing pressure monitoring system applied to screen printing machines was designed in this study.In this study,the consistency of printed electrodes was measured by using a confocal microscope and the pressure distribution detected by online pressure monitoring system was compared to investigate the relationship.The results demonstrated the relationship between printing pressure and the consistency of printed electrodes.As printing pressure increases,the ink layer at the corresponding position becomes thicker and that higher printing pressure enhances the consistency of the printed electrodes.The experiment confirms the feasibility of the online pressure monitoring system,which aids in predicting and controlling the consistency of printed electrodes,thereby improving their performance.
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1104600 and 2022YFA1200208)National Natural Science Foundation of China(No.31927801)Key Research and Development Foundation of Zhejiang Province(No.2022C01123).
文摘Optical coherence tomography(OCT)imaging technology has significant advantages in in situ and noninvasive monitoring of biological tissues.However,it still faces the following challenges:including data processing speed,image quality,and improvements in three-dimensional(3D)visualization effects.OCT technology,especially functional imaging techniques like optical coherence tomography angiography(OCTA),requires a long acquisition time and a large data size.Despite the substantial increase in the acquisition speed of swept source optical coherence tomography(SS-OCT),it still poses significant challenges for data processing.Additionally,during in situ acquisition,image artifacts resulting from interface reflections or strong reflections from biological tissues and culturing containers present obstacles to data visualization and further analysis.Firstly,a customized frequency domainfilter with anti-banding suppression parameters was designed to suppress artifact noises.Then,this study proposed a graphics processing unit(GPU)-based real-time data processing pipeline for SS-OCT,achieving a measured line-process rate of 800 kHz for 3D fast and high-quality data visualization.Furthermore,a GPU-based realtime data processing for CC-OCTA was integrated to acquire dynamic information.Moreover,a vascular-like network chip was prepared using extrusion-based 3D printing and sacrificial materials,with sacrificial material being printed at the desired vascular network locations and then removed to form the vascular-like network.OCTA imaging technology was used to monitor the progression of sacrificial material removal and vascular-like network formation.Therefore,GPU-based OCT enables real-time processing and visualization with artifact suppression,making it particularly suitable for in situ noninvasive longitudinal monitoring of 3D bioprinting tissue and vascular-like networks in microfluidic chips.
基金Financial support from the Cooperative Research Centres Projects (CRC-P) grantAustralian Research Council through its Linkage and Laureate Fellowship programs+3 种基金financial support from Advance Queensland Industry Research Fellowships (AQIRF) organized by the Queensland government, Australiafinancial support from the Research Training Program scholarship provided by the Australian government and the Research Higher Degree Top-up scholarship provided by the CRC-Pthe Dow Centre for Sustainable Engineering Innovationthe University of Queensland
文摘The rapidly increasing demand for wearable electronic devices has motivated research in low-cost and flexible printed batteries with diverse form factors and architectures.In the past,technological achieve-ments in the field have been emphasized,overlooking the industrial and market requirements.However,different applications require different battery chemistries and formats,that greatly impacts the manu-facturing process and competition landscape.These chemistries and formats should therefore be selected carefully to maximize the chances for commercial success.As some of these technologies are starting to be marketed for portable electronics,there is a pressing need to evaluate different printing technologies and compare them in terms of the processing constraints and product requirements of specific electronic devices.By evaluating the intrinsic strengths and current limitations of printed battery technologies,development pathways can be prioritized,and potential bottlenecks can be overcome to accelerate the path to market.
基金This work was supported by the National Natural Science Foundation of China(No.41773110)the National Natural Science Foundation of China-Shandong Joint Fund(No.U2006214)the Shenzhen Science and Technology Research and Development Funds,China(No.JCYJ20180301171357901).
文摘CQDs-doped TiO_(2)(C-TiO_(2))has drawn increased attention in recent because of its excellent catalytic performance.Understanding the transport of C-TiO_(2)in porous media is necessary for evaluating the environmental process of this new nanomaterial.Column experiments were used in this study to investigate ionic strength(IS),dissolved organic matter(DOM)and sand grain size on the transport of C-TiO_(2).The mobility of C-TiO_(2)was inhibited by the increased IS and decreased sand grain size,but was promoted by the increased DOM concentration.The promotion efficiency of DOM ranked as humic acid(HA)>alginate(Alg)>bovine serum albumin(BSA),which was in the same order as their ability to change surface charges.The micromodels of pore network were prepared via 3D printing to further reveal the deposition mechanisms and spatial/temporal distribution of C-TiO_(2)in porous space.C-TiO_(2)mainly attached to the upstream region of collectors because of interception.The collector ripening was observed after long-time deposition.The existence of DOM caused visible decrease of C-TiO_(2)deposition in the pore network.HA caused the most remarkable reduce of deposition in the three types of DOM,which was consistent with the column experiment results.This research is helpful to predict the transport of C-TiO_(2)in natural porous media.
文摘Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.
基金supported by the National Natural Science Foundation of China(22135001)Youth Innovation Promotion Association(2019317)+2 种基金the Young Cross Team Project of CAS(JCTD-2021-14)CAS-CSIRO joint project of Chinese Academy of Sciences(121E32KYSB20190021)Vacuum Interconnected Nanotech Workstation,Suzhou Institute of Nano-Tech and Nano-Bionics of Chinese Academy of Sciences(CAS)
文摘Gravure printing is a promising large-scale fabrication method for flexible organic solar cells(FOSCs)because it is compatible with two-dimension patternable roll-to-roll fabrication.However,the unsuitable rheological property of ZnO nanoinks resulted in unevenness and looseness of the gravure-printed ZnO interfacial layer.Here we propose a strategy to manipulate the macroscopic and microscopic of the gravure-printed ZnO films through using mixed solvent and poly(vinylpyrrolidone)(PVP)additive.The regulation of drying speed effectively manipulates the droplets fusion and leveling process and eliminates the printing ribbing structure in the macroscopic morphology.The additive of PVP effectively regulates the rheological property and improves the microscopic compactness of the films.Following this method,large-area ZnO∶PVP films(28×9 cm^(2))with excellent uniformity,compactness,conductivity,and bending durability were fabricated.The power conversion efficiencies of FOSCs with gravure-printed AgNWs and ZnO∶PVP films reached 14.34%and 17.07%for the 1 cm^(2)PM6:Y6 and PM6∶L8-BO flexible devices.The efficiency of 17.07%is the highest value to date for the 1 cm^(2)FOSCs.The use of mixed solvent and PVP addition also significantly enlarged the printing window of ZnO ink,ensuring high-quality printed thin films with thicknesses varying from 30 to 100 nm.
基金the National Natural Science Foundation of China(No.81827804,U1909218)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.T2121004).
文摘Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern medicine.Nowadays,the increasing demand for personalized medical devices poses a significant challenge to traditional manufacturing methods.The emerging manufacturing technology of three-dimensional(3D)printing as an alternative has shown exciting applications in the medical field and is an ideal method for manufacturing such personalized medical devices with complex structures.However,the application of this new technology has also brought new risks to medical devices,making 3D-printed devices face severe challenges due to insufficient regulation and the lack of standards to provide guidance to the industry.This review aims to summarize the current regulatory landscape and existing research on the standardization of 3D-printed medical devices in China,and provide ideas to address these challenges.We focus on the aspects concerned by the regulatory authorities in 3D-printed medical devices,highlighting the quality system of such devices,and discuss the guidelines that manufacturers should follow,as well as the current limitations and the feasible path of regulation and standardization work based on this perspective.The key points of the whole process quality control,performance evaluation methods and the concept of whole life cycle management of 3D-printed medical devices are emphasized.Furthermore,the significance of regulation and standardization is pointed out.Finally,aspects worthy of attention and future perspectives in this field are discussed.
基金This study was partially supported by the National Key Research and Development Program of China(Grant No.2018YFA0703000)the National Natural Science Foundation of China(Grant No.52075482)+1 种基金the Key Research and Development Program of Zhejiang Province(Grant No.2017CO1063)the National Natural Science Foundation of China(Grant No.51875518).
文摘The fabrication of multi-material medical phantoms with both patient-specificity and realistic mechanical properties is of great importance for the development of surgical planning and medical training.In this work,a 3D multi-material printing system for medical phantom manufacturing was developed.Rigid and elastomeric materials are firstly combined in such application for an accurate tactile feedback.The phantom is designed with multiple layers,where silicone ink,Thermoplastic Polyurethane(TPU),and Acrylonitrile Butadiene Styrene(ABS)were chosen as printing materials for skin,soft tissue,and bone,respectively.Then,the printed phantoms were utilized for the investigation of needle-phantom interaction by needle insertion experiments.The mechanical needle-phantom interaction was characterized by skin-soft tissue interfacial puncture force,puncture depth,and number of insertion force peaks.The experiments demonstrated that the manufacturing conditions,i.e.the silicone grease ratio,interfacial thickness and the infill rate,played effective roles in regulating mechanical needle-phantom interaction.Moreover,the influences of material properties,including interfacial thickness and ultimate stress,on needle-phantom interaction were studied by finite element simulation.Also,a patient-specific forearm phantom was printed,where the anatomical features were acquired from Computed Tomography(CT)data.This study provided a potential manufacturing method for multi-material medical phantoms with tunable mechanical properties and offered guidelines for better phantom design.
基金the 3D Snowball Project of Shanghai Jiao Tong University School of Medicine(No.GXQ202007)the Natural Science Foundation of Shanghai(No.20ZR1432000)+2 种基金the Project of Shanghai Collaborative Innovation Center for Translational Medicine(No.TM201814)the Clinical Research Program of the 9th People’s Hospital affiliated to Shanghai Jiao Tong University School of Medicine(No.JYLJ025)the National Natural Science Foundation of China(No.81772425)。
文摘Reconstruction of severe bone defects in revision total knee arthroplasty(TKA)remains a challenge for orthopaedists.The progression of medical imaging and additive manufacturing technology has enabled the rapid manufacture of custom-made implants,and 3D-printed augments with interconnected pore structures have become an alternative approach for the reconstruction of bone defects in revision TKA,especially in patients with complex bone defects.The size and location of the bone defect were determined by thin-layer computed tomography(CT;layer thickness is 1 mm)after reduction of artifacts.The 3D reconstruction models of the host bone were obtained based on thin-layer CT imaging.The custom-made augmentation was designed according to the 3D reconstruction bone model.The augmentation had an interconnected porous structure on the bone-implant interface to achieve biological fixation.After the design was complete,the 3D model of augment was exported in STL format,and augments were fabricated with Ti6Al4V powder using electron beam melting.Thin-layer CT and 3D reconstruction bone models are accurate methods for evaluating periprosthetic bone loss after artifact reduction.The 3D-printed augments perfectly match the bone defects during surgery.3D-printed augmentation is an effective approach for the reconstruction of bone defects in revision TKA.Thus,surgeons and engineers should carefully evaluate the bone defect during augment design to avoid a mismatch between the augment and host bone.
文摘In order to research the feasibility of using the selective adsorption principle to achieve automatic shaping of nano patterns,in this study,using the liquid gallium as the conductive ink and graphene as the printing plate surface,by changing the surface wettability of patterned areas on the nanoscale of graphene printed boards,the automatic formation of liquid gallium patterns on the graphene printed plate surface was simulated.The results indicated that liquid gallium can achieve automatic patterning on the surface of graphene patterned areas;the greater the interaction energy between gallium and carbon atoms,the clearer the pattern;gallium liquid is prone to remain in complex local positions of the pattern,making it difficult to shape the pattern;if the spacing between adjacent pattern lines is too large or too small,it will result in residual gallium liquid between the lines;increasing the thickness of the gallium film will cause the pattern to expand beyond the boundary,but increasing the thickness of the gallium film can also enhance the thickness and uniformity of the pattern lines.In summary,the principle of selective adsorption can be used to achieve the automatic formation of nano patterns,and the pattern formation effect is influenced by factors such as atomic interaction energy and pattern configuration.
文摘Developing biomimetic hydrogel-based scaffolds that can mimic the native anisotropic skeletal muscle tissue structure for inducing 3D aligned myogenic differentiation remains an on going challenge.Herein,we presented a method to 3D bioprint fibrinogen and GelMA via free printing into the support gel to engineer 3D oriented skeletal muscle scaffolds.A 3D aligned biomimetic scaffold based on this double-network hydrogel bioink was further 3D printed within the Carbopol supported gel by using a printing gel-in-gel strategy to mimic the native anisotropic structure of skeletal muscle tissue,and the cell cultivation experiment performed on myoblast-laden 3D bioprinted aligned biomimetic scaffolds indicated the material's ability to guide 3D myoblast alignment and elongation.
基金supported in part by grants from the Clinical Research for Crossing Item of Shandong University(No.2020SDUCRCB001)the Shandong Provincial Natural Science Foundation(No.ZR2020MH180)+1 种基金the Rongxiang Regeneration Medicine Fund of Shandong University(No.2019SDRX-11)the Science and Technology Development Plan of Jinan City(No.201805041)。
文摘Introduction Mandibular segmental defects result in significant cosmetic and functional deficiencies.Meanwhile,the reconstruction of both the contour and function of the mandible is a challenging task.At present,autologous vascularized fibula transplantation is the most common method to reconstruct a mandible with long-span defects[1].
文摘Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced image acquisition techniques,image processing,and computer-aided design methods has enabled the precise design and additive manufacturing of anatomically correct and patient-specific implants and scaffolds.However,these sophisticated techniques can be timeconsuming,labor-intensive,and expensive.Moreover,the necessary imaging and manufacturing equipment may not be readily available when urgent treatment is needed for trauma patients.In this study,a novel design and AM methods are proposed for the development of modular and customizable scaffold blocks that can be adapted to fit the bone defect area of a patient.These modular scaffold blocks can be combined to quickly form any patient-specific scaffold directly from two-dimensional(2D)medical images when the surgeon lacks access to a 3D printer or cannot wait for lengthy 3D imaging,modeling,and 3D printing during surgery.The proposed method begins with developing a bone surface-modeling algorithm that reconstructs a model of the patient’s bone from 2D medical image measurements without the need for expensive 3D medical imaging or segmentation.This algorithm can generate both patient-specific and average bone models.Additionally,a biomimetic continuous path planning method is developed for the additive manufacturing of scaffolds,allowing porous scaffold blocks with the desired biomechanical properties to be manufactured directly from 2D data or images.The algorithms are implemented,and the designed scaffold blocks are 3D printed using an extrusion-based AM process.Guidelines and instructions are also provided to assist surgeons in assembling scaffold blocks for the self-repair of patient-specific large bone defects.
基金supported by National Key Research and Development Program of China(Grant No.2022YFB4601400)Major Basic Research Projects of Shandong Province of China(Grant No.ZR2023ZD24).
文摘For effective anterior cruciate ligament(ACL)reconstruction,an interference screw(IFS)is employed to force transplantation of the ligament into the bone tunnel.In this study,IFSs were successfully designed and pre-pared,and the top tooth width,thread depth,and drive structure were parameterized with a forming accuracy of 80.0±21.1μm using SLA-3D printing technology.To improve the initial stability of ACL reconstruction,a biomechanical model was established,and the results were optimized through insertion torque and tensile test-ing.Consequently,the IFS with the top tooth width of 0.4 mm,thread depth of 0.8 mm,and hexagon drive,matching with theΦ8 mm bone tunnel,exhibits the best mechanical properties(maximum insertion torque of 1.064±0.117 N m,ultimate load of 446.126±37.632 N,stiffness of 66.33±27.48 N/mm).Additionally,the ZrO_(2)/PDA/RGD/Zn^(2+)bioactive coating was found to significantly improve the surface bioactivity of zirconia IFS.In conclusion,this study has significant implications for ACL reconstruction.
基金supported by National Key Research and Development Project of China(Grant.No.2022YFB4601403)National Natural Science Foundation of China(Grant.No.52175336).
文摘Bioactive coating of ceramic scaffolds is an effective way to ameliorate osseointegration and attenuate implant-induced inflammatory responses,which should be biocompatible and possess suitable mechani-cal properties to regulate cell adhesion and migration.In this study,a poly(ethylene glycol)diacry-late/tricalcium phosphate(PEGDA/TCP)ceramic scaffold was prepared using SLA-3D printing,and its com-pressive strength was 8.9±1.0 MPa.Chitosan(Chi)and chondroitin sulfate(CS)were assembled on the sur-face of the PEGDA/TCP scaffolds and crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide(EDC/NHS).Scanning electron microscope(SEM),Fourier transform infrared(FTIR),and laser scanning microscope were used to evaluate the surface modification of the PEGDA/TCP scaffolds.Cellu-lar tests showed that polyelectrolyte multilayers(PEMs)promoted cell adhesion and proliferation of osteoblasts relative to unmodified scaffolds.Furthermore,it can be demonstrated that the SLA-3D printed TCP scaffolds could meet the compressive requirements of trabecular bones,and the bioactivity of the bone scaffolds could be effectively improved by combining them with Chi/CS PEM.
基金supported by the Swedish Foundation for Strategic Research,the Swedish Research Council(2023-04694)the Knut and Alice Wallenberg Foundation(Wallenberg Academy Fellow)the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University(Faculty Grant SFO Mat LiU No 200900971).
文摘Stretchable circuits based on liquid metals are promising for wearables but the lack of scalable processes for sintering of printed liquid metal dispersions constitutes a challenge for large-area and high-volume manufacturing.In this work,materials and methods for fully screen printed stretchable liquid metal multilayer circuits have been developed.The ink is based on liquid metal droplets dispersed in the green solvent propylene glycol using the harmless dispersion agent polyvinylpyrrolidone.The development of a scalable water-spray sintering method in combination with ink optimization yielded highly conductive prints of≈7.3×10^(5)S/m.Interestingly,the printed conductors experienced a resistance increase of less than 10%during 50%strain cycling,which is far below the expected 125%increase due to the geometry factor.The process allows for printing of highperformance multilayer circuits,which is demonstrated by the development of printed stretchable near-field communication tags.
基金the ITB Research Fund 2023 scheme of the Institut Teknologi Bandung(PN-6-02-2023).
文摘The field of tissue engineering has witnessed significant progress with the emergence of three-dimensional(3D)printing technologies.The ability to fabricate precise structures with complex geometries combined with the in-tegration of two-dimensional(2D)materials,including graphene,graphene oxide,and transition metal dichalco-genides,has provided novel opportunities.This integration enables the fabrication of functional structures with tailored properties,leveraging the exceptional mechanical,electrical,and chemical characteristics of these mate-rials,in conjunction with the design flexibility offered by 3D printing.Herein,we review the recent advancements in the selection of appropriate 2D materials,diverse 3D printing methods employed for integration,and charac-terization techniques used to evaluate the performance of the resulting constructs.The successful integration of 3D printing and 2D materials holds immense potential for advancing tissue engineering and paving the way for personalized medicine,regenerative therapies,and point-of-care diagnostics.
基金Key-Area Research and Development Program of Guangdong Province(2023B0909020004)Project of Innovation Research Team in Zhongshan(CXTD2023006)+1 种基金Natural Science Foundation of Guangdong Province(2023A1515011573)Zhongshan Social Welfare Science and Technology Research Project(2024B2022)。
文摘Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely used in fields such as injection molding,die casting,and stamping dies.Adding reinforcing particles into steel is an effective means to improve its performance.Nb/18Ni300 composites were fabricated by LPBF using two kinds of Nb powders with different particle sizes,and their microstructures and properties were studied.The results show that the unmelted Nb particles are uniformly distributed in the 18Ni300 matrix and the grains are refined,which is particularly pronounced with fine Nb particles.In addition,element diffusion occurs between the particles and the matrix.The main phases of the base alloy are α-Fe and a small amount of γ-Fe.With the addition of Nb,part of the α-Fe is transformed into γ-Fe,and unmelted Nb phases appear.The addition of Nb also enhances the hardness and wear resistance of the composites but slightly reduces their tensile properties.After aging treatment,the molten pools and grain boundaries become blurred,grains are further refined,and the interfaces around the particles are thinned.The aging treatment also promotes the formation of reverted austenite.The hardness,ultimate tensile strength,and volumetric wear rate of the base alloy reach 51.9 HRC,1704 MPa,and 17.8×10^(-6) mm^(3)/(N·m),respectively.In contrast,the sample added with fine Nb particles has the highest hardness(56.1 HRC),ultimate tensile strength(1892 MPa)and yield strength(1842 MPa),and the volume wear rate of the sample added with coarse Nb particles is reduced by 90%to 1.7×10^(-6) mm^(3)/(N·m).
基金Tianjin Municipal Natural Science Foundation(23JCYBJC00040)National Natural Science Foundation of China(52175369)。
文摘The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solution were used to regulate the microstructure,mechanical properties,and corrosion properties of B_(4)C/TC4 composite.Results show that with the increase in temperature from 500℃to 800°C,partial lamellarα-Ti in the as-deposited sample is gradually transformed into equiaxedα-Ti,accompanied by the disappearance of basketweave microstructure.At 1100°C,a small portion of TiC phase suffers fusion.This composite exhibits the optimal combination of strength and plasticity after annealing at 500℃for 4 h followed by furnace cooling,which is attributed to the stress release effect and the refined basketweave microstructure.However,this composite shows a decline in corrosion resistance after various heat treatments due to grain coarsening and micro-galvanic corrosion.
基金supported by the Science and Technology Development Fund,Macao SAR(0065/2023/AFJ,0116/2022/A3)the National Natural Science Foundation of China(52402166)+4 种基金the Natural Science Foundation of Guangdong Province(2025A1515011120)the Australian Research Council(DE220100154)the financial support from the Science and Technology Development Fund(FDCT),Macao SAR(No.0149/2022/A),and(No.0046/2024/AFJ)Guangdong Science and Technology Department(2023QN10C305)for this workthe financial support from the National Natural Science Foundation of China(Grant No.22305185)。
文摘Flexible and wearable sensors offer immense potential for rehabilitation medicine,but most rely solely on electrical signals,lacking real-time visual feedback and limiting trainee's interactivity.Inspired by the structural coloration of Cyanocitta stelleri feathers,we developed a dual-mode sensor by utilizing black conductive polymer hydrogel(CPH)-enhanced structural color strategy.This sensor integrates a hydroxypropyl cellulose(HPC)-based structural color interface with a designed CPH sensing component.Highly visible light-absorbing CPH(absorption rate>88%)serves as the critical substrate for enhancing structural color performance.By absorbing incoherent scattered light and suppressing background interference,it significantly enhances the saturation of structural color,thereby achieving a high contrast index of 4.92.Unlike the faint and hardly visible structural colors on non-black substrates,the HPC on CPH displays vivid,highly perceptible colors and desirable mechanochromic behavior.Moreover,the CPH acts as a flexible sensing element,fortified by hydrogen and coordination bond networks,and exhibits exceptional electromechanical properties,including 867.1 kPa tensile strength,strain sensitivity(gauge factor of 4.24),and outstanding durability(over 4400 cycles).Compared to traditional single-mode sensors,the integrated sensor provides real-time visual and digital dual feedback,enhancing the accuracy and interactivity of rehabilitation assessments.This technology holds promise for advancing next-generation rehabilitation medicine.
