Ceramic slurry of 78 mass%solid loading was prepared using photosensitive acrylic resin and dispersant SP-710 as the liquid phase,Al_(2)O_(3) powder(d50=2.38μm)and TiO_(2) powder additive as the solid phase.Alumina c...Ceramic slurry of 78 mass%solid loading was prepared using photosensitive acrylic resin and dispersant SP-710 as the liquid phase,Al_(2)O_(3) powder(d50=2.38μm)and TiO_(2) powder additive as the solid phase.Alumina ceramics were prepared by DLP,sintering for 4 h at 1450,1500,1550 or 1600℃,respectively.The effects of the TiO_(2) addition(0,1%,2%,3%and 5%,by mass)on the properties of the ceramics were studied.The results show that the addition of TiO_(2) can improve the sintering of Al_(2)O_(3) ceramics,significantly improve the densification,and reduce the sintering temperature.With the optimum TiO_(2) addition of 3%and the optimum sintering temperature of 1600℃,the obtained Al_(2)O_(3) ceramics have shrinkage of 15.7%,15.8%and 23.8%at the x axis,the y axis,and the z axis,respectively,the porosity of 2.4%,the bulk density of 3.74 g·cm-3 and the three-point bending strength of 251.1 MPa.Compared with the undoped alumina ceramics,the doped alumina ceramic has increased bulk density by 0.56 g·cm-3,decreased apparent porosity from 20.2%to 2.4%,and the three-point bending strength increases by 2.5 times.Therefore,the density and the strength of DLP prepared ceramics can be improved effectively by adding an appropriate amount of TiO_(2),and the performance of the DLP prepared ceramics is close to that of the pressed samples.Thus,it is hopeful to apply DLP in refractories field.展开更多
Osteoid plays a crucial role in directing cell behavior and osteogenesis through its unique characteristics,including viscoelasticity and liquid crystal(LC)state.Thus,integrating osteoid-like features into 3D printing...Osteoid plays a crucial role in directing cell behavior and osteogenesis through its unique characteristics,including viscoelasticity and liquid crystal(LC)state.Thus,integrating osteoid-like features into 3D printing scaffolds proves to be a promising approach for personalized bone repair.Despite extensive research on viscoelasticity,the role of LC state in bone repair has been largely overlooked due to the scarcity of suitable LC materials.Moreover,the intricate interplay between LC state and viscoelasticity in osteogenesis remains poorly understood.Here,we developed innovative hydrogel scaffolds with osteoid-like LC state and viscoelasticity using digital light processing with a custom LC ink.By utilizing these LC scaffolds as 3D research models,we discovered that LC state mediates high protein clustering to expose accessible RGD motifs to trigger cell-protein interactions and osteogenic differentiation,while viscoelasticity operates via mechanotransduction pathways.Additionally,our investigation revealed a synergistic effect between LC state and viscoelasticity,amplifying cellprotein interactions and osteogenic mechanotransduction processes.Furthermore,the interesting mechanochromic response observed in the LC hydrogel scaffolds suggests their potential application in mechanosensing.Our findings shed light on the mechanisms and synergistic effects of LC state and viscoelasticity in osteoid on osteogenesis,offering valuable insights for the biomimetic design of bone repair scaffolds.展开更多
We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investig...We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.展开更多
The soft robotics display huge advantages over their rigid counterparts when interacting with living organisms and fragile objects.As one of the most efficient actuators toward soft robotics,the soft pneumatic actuato...The soft robotics display huge advantages over their rigid counterparts when interacting with living organisms and fragile objects.As one of the most efficient actuators toward soft robotics,the soft pneumatic actuator(SPA)can produce large,complex responses with utilizing pressure as the only input source.In this work,a new approach that combines digital light processing(DLP)and injection-assisted post-curing is proposed to create SPAs that can realize different functionalities.To enable this,we develop a new class of photo-cross linked elastomers with tunable mechanical properties,good stretchability,and rapid curing speed.By carefully designing the geometry of the cavities embedded in the actuators,the resulting actuators can realize contracting,expanding,flapping,and twisting motions.In addition,we successfully fabricate a soft self-sensing bending actuator by injecting conductive liquids into the three-dimensional(3D)printed actuator,demonstrating that the present method has the potential to be used to manufacture intelligent soft robotic systems.展开更多
Fabricating SiC ceramics via the digital light processing(DLP)technology is of great challenge due to strong light absorption and high refractive index of deep-colored SiC powders,which highly differ from those of res...Fabricating SiC ceramics via the digital light processing(DLP)technology is of great challenge due to strong light absorption and high refractive index of deep-colored SiC powders,which highly differ from those of resin,and thus significantly affect the curing performance of the photosensitive SiC slurry.In this paper,a thin silicon oxide(SiO_(2))layer was in-situ formed on the surface of SiC powders by pre-oxidation treatment.This method was proven to effectively improve the curing ability of SiC slurry.The SiC photosensitive slurry was fabricated with solid content of 55 vol%and viscosity of 7.77 Pa·s(shear rate of 30 s^(−1)).The curing thickness was 50μm with exposure time of only 5 s.Then,a well-designed sintering additive was added to completely convert low-strength SiO_(2) into mullite reinforcement during sintering.Complexshaped mullite-bond SiC ceramics were successfully fabricated.The flexural strength of SiC ceramics sintered at 1550℃in air reached 97.6 MPa with porosity of 39.2 vol%,as high as those prepared by spark plasma sintering(SPS)techniques.展开更多
Three-dimensional(3D)printing is an emerging technique that has shown promising success in engineering human tissues in recent years.Further development of vatphotopolymerization printing modalities has significantly ...Three-dimensional(3D)printing is an emerging technique that has shown promising success in engineering human tissues in recent years.Further development of vatphotopolymerization printing modalities has significantly enhanced the complexity level for 3D printing of various functional structures and components.Similarly,the development of microfluidic chip systems is an emerging research sector with promising medical applications.This work demonstrates the coupling of a digital light processing(DLP)printing procedure with a microfluidic chip system to produce size-tunable,3D-printable porosities with narrow pore size distributions within a gelatin methacryloyl(GelMA)hydrogel matrix.It is found that the generation of size-tunable gas bubbles trapped within an aqueous GelMA hydrogel-precursor can be controlled with high precision.Furthermore,the porosities are printed in two-dimensional(2D)as well as in 3D using the DLP printer.In addition,the cytocompatibility of the printed porous scaffolds is investigated using fibroblasts,where high cell viabilities as well as cell proliferation,spreading,and migration are confirmed.It is anticipated that the strategy is widely applicable in a range of application areas such as tissue engineering and regenerative medicine,among others.展开更多
Sic-based composites are widely used as electromagnetic wave absorbers due to their excellent dielectric properties.However,the constraints associated with structural design and the intricacies of the preparation proc...Sic-based composites are widely used as electromagnetic wave absorbers due to their excellent dielectric properties.However,the constraints associated with structural design and the intricacies of the preparation process hinder their broader application.In this study,novel mullite anti-gyroid/SiC gyroid metastructures are designed to integrate the mechanical and electromagnetic wave(EMW)absorption properties of composite materials.Mullite anti-gyroid/SiC gyroid composites are fabricated utilizing a combination of digital light processing(DLP)three-dimensional(3D)printing and precursor infiltration and pyrolysis(PiP)processes.Through the modulation of structural units,the electromagnetic parameters can be effectively regulated,thus improving the impedance matching characteristics of the composites.The structural composites show outstanding EMW absorption properties,with a minimum reflection loss of-54 dB at a thickness of 1.9 mm and an effective absorption bandwidth of 3.20 GHz at a thickness of 2.2 mm.Furthermore,the PIP process significantly enhances the mechanical properties of the composites;compared with those of the mullite/SiC ceramics,the flexural strength of the composites is improved by 3.69-5.85 times(13.28±1.15 MPa vs.(49.05±1.07)-(77.78±3.72)MPa),and the compressive strength is improved by 4.59-13.58 times(8.55±0.90 MPa vs.(39.02±1.63)-(116.13±2.58)MPa).This approach offers a novel and effective method for fabricating structural composites with an expanded range of higher electromagnetic wave absorption properties and improved mechanical properties.展开更多
The rise of antibiotic resistance as one of the most serious global public health threats has necessitated the timely clinical diagnosis and precise treatment of deadly bacterial infections.To identify which types and...The rise of antibiotic resistance as one of the most serious global public health threats has necessitated the timely clinical diagnosis and precise treatment of deadly bacterial infections.To identify which types and doses of antibiotics remain effective for fighting against multi-drug-resistant pathogens,the development of rapid and accurate antibiotic-susceptibility testing(AST)is of primary importance.Conventional methods for AST in well-plate formats with disk diffusion or broth dilution are both labor-intensive and operationally tedious.The microfluidic chip provides a versatile tool for evaluating bacterial AST and resistant behaviors.In this paper,we develop an operationally simple,3D-printed microfluidic chip for AST which automatically deploys antibiotic concentration gradients and fluorescence intensity-based reporting to ideally reduce the report time for AST to within 5 h.By harnessing a commercially available,digital light processing(DLP)3D printing method that offers a rapid,high-precision microfluidic chip-manufacturing capability,we design and realize the accurate generation of on-chip antibiotic concentration gradients based on flow resistance and diffusion mechanisms.We further demonstrate the employment of the microfluidic chip for the AST of E.coli to representative clinical antibiotics of three classes:ampicillin,chloramphenicol,and kanamycin.The determined minimum inhibitory concentration values are comparable to those reported by conventional well-plate methods.Our proposed method demonstrates a promising approach for realizing robust,convenient,and automatable AST of clinical bacterial pathogens.展开更多
Fabrication of silicon carbide(SiC)ceramics by digital light processing(DLP)technology is difficult owing to high refractive index and high ultraviolet(UV)absorptivity of SiC powders.The surface of the SiC powders can...Fabrication of silicon carbide(SiC)ceramics by digital light processing(DLP)technology is difficult owing to high refractive index and high ultraviolet(UV)absorptivity of SiC powders.The surface of the SiC powders can be coated with silicon oxide(SiO_(2))with low refractive index and low UV absorptivity via high-temperature oxidation,reducing the loss of UV energy in the DLP process and realizing the DLP preparation of the SiC ceramics.However,it is necessary to explore a high-temperature modification process to obtain a better modification effect of the SiC powders.Therefore,the high-temperature modification behavior of the SiC powders is thoroughly investigated in this paper.The results show that nano-scale oxide film is formed on the surface of the SiC powders by short-time high-temperature oxidation,effectively reducing the UV absorptivity and the surface refractive index(nʹ)of the SiC powders.When the oxidation temperature is 1300℃,compared with that of unoxidized SiC powders,the UV absorptivity of oxidized SiC powders decreases from 0.5065 to 0.4654,and a curing depth of SiC slurry increases from 22±4 to 59±4μm.Finally,SiC green bodies are successfully prepared by the DLP with the the oxidized powders,and flexural strength of SiC sintered parts reaches 47.9±2.3 MPa after 3 h of atmospheric sintering at 2000℃without any sintering aid.展开更多
The suitable lenticular lens for large panel autostereoscopic display was designed,and its optical transmission property was analyzed.The location of the best viewing zones and the relationship between screen size and...The suitable lenticular lens for large panel autostereoscopic display was designed,and its optical transmission property was analyzed.The location of the best viewing zones and the relationship between screen size and the optimum viewing distance were proposed.On the basis of the original monitor,rear projection screen material suitable for large panel three-dimensional(3D) monitor and splicing method for 3D display wall were studied.Close to 150-inch-large panel stereo display wall was achieved.展开更多
The geometry of the phase interface in co-continuous piezoelectric composites is critical in improving their piezo-electric properties.However,conventional co-continuous piezoelectric composites are mostly simple stru...The geometry of the phase interface in co-continuous piezoelectric composites is critical in improving their piezo-electric properties.However,conventional co-continuous piezoelectric composites are mostly simple structures such as wood stacks or honeycombs,which are prone to stress concentrations at the joints,thus reducing the fatigue service performance and force-electric conversion efficiency of piezoelectric composites.Such simple structures limit further improvements in the overall performance of co-continuous piezoelectric composites.In this study,based on the digital light processing 3D printing method,we investigated the influence of three dif-ferent structures-the gyroid,diamond,and woodpile interfaces-on the piezoelectric and mechanical properties of co-continuous ceramic/polymer piezoelectric composites.These findings demonstrate that the gyroid and di-amond interfaces outperformed the ceramic skeleton of the woodpile interface in terms of both mechanical and electrical properties.When the ceramic volume percentage was 50%,the piezo-composite of the gyroid surface exhibited the greatest hydrostatic figure of merit(HFOM),reaching 4.23×10^(−12) Pa^(−1),and its piezoelectric coeffi-cient(d_(33))and relative dielectric constant(εr)reached 115 pC/N and 748,respectively.The research results lay the foundation for the application of co-continuous piezoelectric composites in underwater communication and detection.展开更多
Hydroponic farming is a viable and economical farming method,which can produce safe and healthy greens and vegetables conveniently and at a relatively low cost.It is essential to provide supplemental lighting for crop...Hydroponic farming is a viable and economical farming method,which can produce safe and healthy greens and vegetables conveniently and at a relatively low cost.It is essential to provide supplemental lighting for crops grown in greenhouses to meet the daily light requirement,Daily Light Integral(DLI).The present paper investigates how effectively and efficiently LEDs can be used as a light source in hydroponics.It is important for a hydroponic grower to assess the requirement of photo synthetically active radiation(PAR)or the Photosynthetic Photon Flux Density(PPFD),in a greenhouse,and adjust the quality and quantity of supplemental lighting accordingly.A Quantum sensor(or PAR sensor)can measure PAR more accurately than a digital light meter,which measures the light intensity or illuminance in the SI unit Lux,but a PAR sensor is relatively expensive and normally not affordable by an ordinary farmer.Therefore,based on the present investigation and experimental results,a very simple way to convert light intensity measured with a Lux meter into PAR is proposed,using a simple conversion factor(41.75 according to the present work).This allows a small-scale hydroponic farmer to use a simple and inexpensive technique to assess the day to day DLI values of PAR in a greenhouse accurately using just an inexpensive light meter.The present paper also proposes a more efficient way of using LED light panels in a hydroponic system.By moving the LED light panels closer to the crop,LED light source can use a fewer number of LEDs to produce the same required daily light requirement and can increase the efficiency of the power usage to more than 80%.Specifically,the present work has determined that it is important to design more efficient vertically movable LED light panels with capabilities of switching individual LEDs on and off,for the use in greenhouses.This allows a user to control the number of LEDs that can be lit at a particular time,as required.By doing so it is possible to increase the efficiency of a LED lighting system by reducing its cost of the electricity usage.展开更多
Digital light processing(DLP)of structurally complex poly(ethylene glycol)(PEG)hydrogels with high mechanical toughness represents a long-standing challenge in thefield of 3D printing.Here,we report a 3D printing appro...Digital light processing(DLP)of structurally complex poly(ethylene glycol)(PEG)hydrogels with high mechanical toughness represents a long-standing challenge in thefield of 3D printing.Here,we report a 3D printing approach for the high-resolution manufacturing of structurally complex and mechanically strong PEG hydrogels via heat-assisted DLP.Instead of using aqueous solutions of photo-crosslinkable monomers,PEG macromonomer melts werefirst printed in the absence of water,resulting in bulk PEG networks.Then,post-printing swelling of the printed networks was achieved in water,producing high-fidelity 3D hydrogels with complex structures.By employing a dual-macromonomer resin containing a PEG-based four-arm macrophotoinitiator,“all-PEG”hydrogel constructs were pro-duced with compressive toughness up to 1.3 MJ m^(-3).By this approach,porous 3D hydrogel scaffolds with trabecular-like architecture were fabricated,and the scaf-fold surface supported cell attachment and the formation of a monolayer mimicking bone-lining cells.This study highlights the promises of heat-assisted DLP of PEG photopolymers for hydrogel fabrication,which may accelerate the development of 3D tissue-like constructs for regenerative medicine.展开更多
Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular trend.Among various manufacturing technologies,magnetic-assis...Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular trend.Among various manufacturing technologies,magnetic-assisted digital light processing(DLP)stands out because it enables precise manufacturing of macro-scale structures and micro-scale distributions with the assistance of an external magnetic field.Current research on manufacturing magnetic flexible actuators mostly employs single materials,which limits the magnetic driving performance to some extent.Based on these characterizations,we propose a multi-material magnetic field-assisted DLP technology to produce flexible actuators with an accuracy of 200μm.The flexible actuators are printed using two materials with different mechanical and magnetic properties.Considering the interface connectivity of multi-material printing,the effect of interfaces on mechanical properties is also explored.Experimental results indicate good chemical affinity between the two materials we selected.The overlap or connection length of the interface moderately improves the tensile strength of multi-material structures.In addition,we investigate the influence of the volume fraction of the magnetic part on deformation.Simulation and experimental results indicate that increasing the volume ratio(20%to 50%)of the magnetic structure can enhance the responsiveness of the actuator(more than 50%).Finally,we successfully manufacture two multi-material flexible actuators with specific magnetic arrangements:a multi-legged crawling robot and a flexible gripper capable of crawling and grasping actions.These results confirm that this method will pave the way for further research on the precise fabrication of magnetic flexible actuators with diverse functionalities.展开更多
Mechanically strong magnesium-doped Ca-silicate bioceramic scaffolds have many advantages in repairing large segmental bone defects.Herein we combine β-TCP with 6 mol%magnesium-doped calcium silicate(Mg6)at three dif...Mechanically strong magnesium-doped Ca-silicate bioceramic scaffolds have many advantages in repairing large segmental bone defects.Herein we combine β-TCP with 6 mol%magnesium-doped calcium silicate(Mg6)at three different ratios(TCP,TCP+15%Mg6,TCP+85%Mg6)to find an appropriate ratio which can exert considerable influence on bone regeneration.In this study,the bioceramic scaffolds were assessed for mechanical strength,bioactive ion release,biocompatibility,and osteogenic capacity through in vitro testing.Additionally,the potential for promoting bone regeneration was investigated through in vivo implantation of porous tube-like scaffolds.The results showed that the compressive strength increased with the augmentation of Mg6 component.Especially the compressive strength of the TCP+85%Mg6 group reached 38.1±3.8 MPa,three times that of the other two groups.Furthermore,extensive in vivo investigations revealed that the TCP+85%Mg6 bioceramic scaffolds were particularly beneficial for the osteogenic capacity of critical-sized femoral defects(20 mm in length).Altogether,magnesium doping in bioceramic implants is a promising strategy to provide stronger mechanical support and enhance osteogenesis to accelerate the repair of large defects.展开更多
Hydroxyapatite(HA)bioceramic scaffolds were fabricated by using digital light processing(DLP)based additive manufacturing.Key issues on the HA bioceramic scaffolds,including dispersion,DLP fabrication,sintering,mechan...Hydroxyapatite(HA)bioceramic scaffolds were fabricated by using digital light processing(DLP)based additive manufacturing.Key issues on the HA bioceramic scaffolds,including dispersion,DLP fabrication,sintering,mechanical properties,and biocompatibility were discussed in detail.Firstly,the ffects of dispersant dosage,solid loading,and sintering temperature were studied.The optimal dispersant dosage,solid loading,and sintering temperature were 2wt%,50vol%,and 1250℃,respectively.Then,the mechanical properties and biocompatibility of the HA bioceramic scaffolds were investigated.The DLP-prepared porous HA bioceramic scaffold was found to exhibit excellent mechanical properties and degradation behavior.From this study,DLP technique shows good potential for manufacturing HA bioceramic scaffolds.展开更多
High performance hydroxyapatite(HA)ceramics with excellent densification and mechanical properties were successfully fabricated by digital light processing(DLP)three-dimensional(3D)printing technology.It was found tha...High performance hydroxyapatite(HA)ceramics with excellent densification and mechanical properties were successfully fabricated by digital light processing(DLP)three-dimensional(3D)printing technology.It was found that the sintering atmosphere of wet C02 can dramatically improve the densification process and thus lead to better mechanical properties.HA ceramics with a relative density of 97.12%and a three-point bending strength of 92.4 MPa can be achieved at a sintering temperature of 1300℃,which makes a solid foundation for application in bone engineering.Furthermore,a relatively high compressive strength of 4.09 MPa can be also achieved for a DLP-printed p-cell triply periodic minimum surface(TPMS)structure with a porosity of 74%,which meets the requirement of cancellous bone substitutes.A further cell proliferation test demonstrated that the sintering atmosphere of wet CO2 led to improve cell vitality after 7 days of cell culture Moreover,with the possible benefit from the bio-inspired structure,the 3D-printed TPMS structure significantly improved the cell vitality,which is crucial for early osteogenesis and osteointegration.展开更多
Digital light processing(DLP)-based 3D printing technique holds promise in fabricating scaffolds with high precision.Here raw calcium phosphate(CaP)powders were modified by 5.5%monoalcohol ethoxylate phosphate(MAEP)to...Digital light processing(DLP)-based 3D printing technique holds promise in fabricating scaffolds with high precision.Here raw calcium phosphate(CaP)powders were modified by 5.5%monoalcohol ethoxylate phosphate(MAEP)to ensure high solid loading and low viscosity.The rheological tests found that photocurable slurries composed of 50wt%modified CaP powders and 2wt%toners were suitable for DLP printing.Based on geometric models designed by computer-aided design(CAD)system,three printed CaP ceramics with distinct macroporous structures were prepared,including simple cube,octet-truss and inverse face-centered cube(fcc),which presented the similar phase composition and microstructure,but the different macropore geometries.Inverse fcc group showed the highest porosity and compressive strength.The in vitro and in vivo biological evaluations were performed to compare the bioactivity of three printed CaP ceramics,and the traditional foamed ceramic was used as control.It suggested that all CaP ceramics exhibited good biocompatibility,as evidence by an even bone-like apatite layer formation on the surface,and the good cell proliferation and spreading.A mouse intramuscular implantation model found that all of CaP ceramics could induce ectopic bone formation,and foam group had the strongest osteoinduction,followed by inverse fcc,while cube and octet-truss had the weakest one.It indicated that macropore geometry was of great importance to affect the osteoinductivity of scaffolds,and spherical,concave macropores facilitated osteogenesis.These findings provide a strategy to design and fabricate high-performance orthopedic grafts with proper pore geometry and desired biological performance via DLP-based 3D printing technique.展开更多
Bone scaffolds require both good bioactivity and mechanical properties to keep shape and promote bone repair.In this work,T-ZnO_(w) enhanced biphasic calcium phosphate(BCP)scaffolds with triply periodic minimal surfac...Bone scaffolds require both good bioactivity and mechanical properties to keep shape and promote bone repair.In this work,T-ZnO_(w) enhanced biphasic calcium phosphate(BCP)scaffolds with triply periodic minimal surface(TPMS)-based double-layer porous structure were fabricated by digital light processing(DLP)with high precision.Property of suspension was first discussed to obtain better printing quality.After sintering,T-ZnO_(w) reacts with b-tricalcium phosphate(β-TCP)to form Ca_(19)Zn_(2)(PO_(4))14,and inhibits the phase transition toα-TCP.With the content of T-ZnO_(w) increasing from 0 to 2 wt%,the flexural strength increases from 40.9 to 68.5 MPa because the four-needle whiskers can disperse stress,and have the effect of pulling out as well as fracture toughening.However,excessive whiskers will reduce the cure depth,and cause more printing defects,thus reducing the mechanical strength.Besides,T-ZnO_(w) accelerates the deposition of apatite,and the sample with 2 wt%T-ZnO_(w) shows the fastest mineralization rate.The good biocompatibility has been proved by cell proliferation test.Results confirmed that doping T-ZnO_(w) can improve the mechanical strength of BCP scaffolds,and keep good biological property,which provides a new strategy for better bone repair.展开更多
An integrated method based on optical and digital image processing is presented to suppress speckle in digital holography. A spatial light modulator is adopted to introduce random phases to the illuminating beam. Mult...An integrated method based on optical and digital image processing is presented to suppress speckle in digital holography. A spatial light modulator is adopted to introduce random phases to the illuminating beam. Multiple holograms are reconstructed and superimposed, and the intensity is averaged to smooth the noise. The adaptive algorithm based on the nonlocal means is designed to further suppress the speckle. The presented method is compared with other methods reduction is improved, and the proposed method is effective The experimental results show that speckle and feasible.展开更多
文摘Ceramic slurry of 78 mass%solid loading was prepared using photosensitive acrylic resin and dispersant SP-710 as the liquid phase,Al_(2)O_(3) powder(d50=2.38μm)and TiO_(2) powder additive as the solid phase.Alumina ceramics were prepared by DLP,sintering for 4 h at 1450,1500,1550 or 1600℃,respectively.The effects of the TiO_(2) addition(0,1%,2%,3%and 5%,by mass)on the properties of the ceramics were studied.The results show that the addition of TiO_(2) can improve the sintering of Al_(2)O_(3) ceramics,significantly improve the densification,and reduce the sintering temperature.With the optimum TiO_(2) addition of 3%and the optimum sintering temperature of 1600℃,the obtained Al_(2)O_(3) ceramics have shrinkage of 15.7%,15.8%and 23.8%at the x axis,the y axis,and the z axis,respectively,the porosity of 2.4%,the bulk density of 3.74 g·cm-3 and the three-point bending strength of 251.1 MPa.Compared with the undoped alumina ceramics,the doped alumina ceramic has increased bulk density by 0.56 g·cm-3,decreased apparent porosity from 20.2%to 2.4%,and the three-point bending strength increases by 2.5 times.Therefore,the density and the strength of DLP prepared ceramics can be improved effectively by adding an appropriate amount of TiO_(2),and the performance of the DLP prepared ceramics is close to that of the pressed samples.Thus,it is hopeful to apply DLP in refractories field.
基金supported by the National Natural Science Foundation of China(31771047)Guangdong Provincial Natural Science Foundation of China(2022A1515010592and 2023A1515010107)+2 种基金Guangdong Provincial Key Areas R&D Programs(2022B1111080007)the Key Areas Research and Development Program of Guangzhou(202103030003)the Outstanding Innovative Talents Cultivation Funded Programs for Doctoral Students of Jinan University(2023CXB013).
文摘Osteoid plays a crucial role in directing cell behavior and osteogenesis through its unique characteristics,including viscoelasticity and liquid crystal(LC)state.Thus,integrating osteoid-like features into 3D printing scaffolds proves to be a promising approach for personalized bone repair.Despite extensive research on viscoelasticity,the role of LC state in bone repair has been largely overlooked due to the scarcity of suitable LC materials.Moreover,the intricate interplay between LC state and viscoelasticity in osteogenesis remains poorly understood.Here,we developed innovative hydrogel scaffolds with osteoid-like LC state and viscoelasticity using digital light processing with a custom LC ink.By utilizing these LC scaffolds as 3D research models,we discovered that LC state mediates high protein clustering to expose accessible RGD motifs to trigger cell-protein interactions and osteogenic differentiation,while viscoelasticity operates via mechanotransduction pathways.Additionally,our investigation revealed a synergistic effect between LC state and viscoelasticity,amplifying cellprotein interactions and osteogenic mechanotransduction processes.Furthermore,the interesting mechanochromic response observed in the LC hydrogel scaffolds suggests their potential application in mechanosensing.Our findings shed light on the mechanisms and synergistic effects of LC state and viscoelasticity in osteoid on osteogenesis,offering valuable insights for the biomimetic design of bone repair scaffolds.
基金Supported by the Natural Science Foundation of Beijing under Grant Nos 2162033 and 7182091the National Natural Science Foundation of China under Grant No 21627813
文摘We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.
基金the National Natural Science Foundation of China(Nos.11572002 and 12002032)the China Postdoctoral Science Foundation(Nos.BX20200056 and 2020M670149)。
文摘The soft robotics display huge advantages over their rigid counterparts when interacting with living organisms and fragile objects.As one of the most efficient actuators toward soft robotics,the soft pneumatic actuator(SPA)can produce large,complex responses with utilizing pressure as the only input source.In this work,a new approach that combines digital light processing(DLP)and injection-assisted post-curing is proposed to create SPAs that can realize different functionalities.To enable this,we develop a new class of photo-cross linked elastomers with tunable mechanical properties,good stretchability,and rapid curing speed.By carefully designing the geometry of the cavities embedded in the actuators,the resulting actuators can realize contracting,expanding,flapping,and twisting motions.In addition,we successfully fabricate a soft self-sensing bending actuator by injecting conductive liquids into the three-dimensional(3D)printed actuator,demonstrating that the present method has the potential to be used to manufacture intelligent soft robotic systems.
基金supported by Shandong University−MSEA International Institute for Materials Genome Joint Innovation Center for Advanced Ceramics,and the Key Research and Development Projects of Shaanxi Province(Nos.2018ZDCXLGY-09-06 and 2021ZDLGY14-06).
文摘Fabricating SiC ceramics via the digital light processing(DLP)technology is of great challenge due to strong light absorption and high refractive index of deep-colored SiC powders,which highly differ from those of resin,and thus significantly affect the curing performance of the photosensitive SiC slurry.In this paper,a thin silicon oxide(SiO_(2))layer was in-situ formed on the surface of SiC powders by pre-oxidation treatment.This method was proven to effectively improve the curing ability of SiC slurry.The SiC photosensitive slurry was fabricated with solid content of 55 vol%and viscosity of 7.77 Pa·s(shear rate of 30 s^(−1)).The curing thickness was 50μm with exposure time of only 5 s.Then,a well-designed sintering additive was added to completely convert low-strength SiO_(2) into mullite reinforcement during sintering.Complexshaped mullite-bond SiC ceramics were successfully fabricated.The flexural strength of SiC ceramics sintered at 1550℃in air reached 97.6 MPa with porosity of 39.2 vol%,as high as those prepared by spark plasma sintering(SPS)techniques.
基金National Science Centre Poland(NCN),Grant/Award Number:2020/37/B/ST8/02167European Union’s Horizon 2020 research and innovation program,Grant/Award Number:813786+2 种基金National Institutes of Health,Grant/Award Number:R21EB025270National Science Foundation,Grant/Award Number:CBET-EBMS-1936105Brigham Research Institute。
文摘Three-dimensional(3D)printing is an emerging technique that has shown promising success in engineering human tissues in recent years.Further development of vatphotopolymerization printing modalities has significantly enhanced the complexity level for 3D printing of various functional structures and components.Similarly,the development of microfluidic chip systems is an emerging research sector with promising medical applications.This work demonstrates the coupling of a digital light processing(DLP)printing procedure with a microfluidic chip system to produce size-tunable,3D-printable porosities with narrow pore size distributions within a gelatin methacryloyl(GelMA)hydrogel matrix.It is found that the generation of size-tunable gas bubbles trapped within an aqueous GelMA hydrogel-precursor can be controlled with high precision.Furthermore,the porosities are printed in two-dimensional(2D)as well as in 3D using the DLP printer.In addition,the cytocompatibility of the printed porous scaffolds is investigated using fibroblasts,where high cell viabilities as well as cell proliferation,spreading,and migration are confirmed.It is anticipated that the strategy is widely applicable in a range of application areas such as tissue engineering and regenerative medicine,among others.
基金The authors gratefully acknowledged the financial support provided by the National Key R&D Program of China(No.2021YFB3701500)the Program of Shanghai Academic/Technology Research Leader(No.22XD1404000).
文摘Sic-based composites are widely used as electromagnetic wave absorbers due to their excellent dielectric properties.However,the constraints associated with structural design and the intricacies of the preparation process hinder their broader application.In this study,novel mullite anti-gyroid/SiC gyroid metastructures are designed to integrate the mechanical and electromagnetic wave(EMW)absorption properties of composite materials.Mullite anti-gyroid/SiC gyroid composites are fabricated utilizing a combination of digital light processing(DLP)three-dimensional(3D)printing and precursor infiltration and pyrolysis(PiP)processes.Through the modulation of structural units,the electromagnetic parameters can be effectively regulated,thus improving the impedance matching characteristics of the composites.The structural composites show outstanding EMW absorption properties,with a minimum reflection loss of-54 dB at a thickness of 1.9 mm and an effective absorption bandwidth of 3.20 GHz at a thickness of 2.2 mm.Furthermore,the PIP process significantly enhances the mechanical properties of the composites;compared with those of the mullite/SiC ceramics,the flexural strength of the composites is improved by 3.69-5.85 times(13.28±1.15 MPa vs.(49.05±1.07)-(77.78±3.72)MPa),and the compressive strength is improved by 4.59-13.58 times(8.55±0.90 MPa vs.(39.02±1.63)-(116.13±2.58)MPa).This approach offers a novel and effective method for fabricating structural composites with an expanded range of higher electromagnetic wave absorption properties and improved mechanical properties.
基金the National Natural Science Foundation of China(No.51908467)and by institutional funds from the Westlake University。
文摘The rise of antibiotic resistance as one of the most serious global public health threats has necessitated the timely clinical diagnosis and precise treatment of deadly bacterial infections.To identify which types and doses of antibiotics remain effective for fighting against multi-drug-resistant pathogens,the development of rapid and accurate antibiotic-susceptibility testing(AST)is of primary importance.Conventional methods for AST in well-plate formats with disk diffusion or broth dilution are both labor-intensive and operationally tedious.The microfluidic chip provides a versatile tool for evaluating bacterial AST and resistant behaviors.In this paper,we develop an operationally simple,3D-printed microfluidic chip for AST which automatically deploys antibiotic concentration gradients and fluorescence intensity-based reporting to ideally reduce the report time for AST to within 5 h.By harnessing a commercially available,digital light processing(DLP)3D printing method that offers a rapid,high-precision microfluidic chip-manufacturing capability,we design and realize the accurate generation of on-chip antibiotic concentration gradients based on flow resistance and diffusion mechanisms.We further demonstrate the employment of the microfluidic chip for the AST of E.coli to representative clinical antibiotics of three classes:ampicillin,chloramphenicol,and kanamycin.The determined minimum inhibitory concentration values are comparable to those reported by conventional well-plate methods.Our proposed method demonstrates a promising approach for realizing robust,convenient,and automatable AST of clinical bacterial pathogens.
基金supported by grants from the Key Project Fund for Science and Technology Development of Guangdong Province (2020B090924003)the National Natural Science Foundation of China (51975230)Major Special Projects of Technological Innovation in Hubei Province (2019AAA002).
文摘Fabrication of silicon carbide(SiC)ceramics by digital light processing(DLP)technology is difficult owing to high refractive index and high ultraviolet(UV)absorptivity of SiC powders.The surface of the SiC powders can be coated with silicon oxide(SiO_(2))with low refractive index and low UV absorptivity via high-temperature oxidation,reducing the loss of UV energy in the DLP process and realizing the DLP preparation of the SiC ceramics.However,it is necessary to explore a high-temperature modification process to obtain a better modification effect of the SiC powders.Therefore,the high-temperature modification behavior of the SiC powders is thoroughly investigated in this paper.The results show that nano-scale oxide film is formed on the surface of the SiC powders by short-time high-temperature oxidation,effectively reducing the UV absorptivity and the surface refractive index(nʹ)of the SiC powders.When the oxidation temperature is 1300℃,compared with that of unoxidized SiC powders,the UV absorptivity of oxidized SiC powders decreases from 0.5065 to 0.4654,and a curing depth of SiC slurry increases from 22±4 to 59±4μm.Finally,SiC green bodies are successfully prepared by the DLP with the the oxidized powders,and flexural strength of SiC sintered parts reaches 47.9±2.3 MPa after 3 h of atmospheric sintering at 2000℃without any sintering aid.
基金Key Project of Shanghai Science and Technology Commission,China (No. 075115002)
文摘The suitable lenticular lens for large panel autostereoscopic display was designed,and its optical transmission property was analyzed.The location of the best viewing zones and the relationship between screen size and the optimum viewing distance were proposed.On the basis of the original monitor,rear projection screen material suitable for large panel three-dimensional(3D) monitor and splicing method for 3D display wall were studied.Close to 150-inch-large panel stereo display wall was achieved.
基金supported by National Key Research and Develop-ment Plan of China(Grant.No.2021YFB3703100)National Natural Science Foundation of China(Grant.No.52202066)+3 种基金Joint Fund of Min-istry of China Education for Pre-Research of Equipment(Grant.No.8091B032105)Hubei High Value Patent Cultivation Project of China(Grant.No.2021pm0012)Wuhan Knowledge Innovation Project-Dawn Plan‘JD’Technology Research Project in Hubei Province of China(2023BAA023).
文摘The geometry of the phase interface in co-continuous piezoelectric composites is critical in improving their piezo-electric properties.However,conventional co-continuous piezoelectric composites are mostly simple structures such as wood stacks or honeycombs,which are prone to stress concentrations at the joints,thus reducing the fatigue service performance and force-electric conversion efficiency of piezoelectric composites.Such simple structures limit further improvements in the overall performance of co-continuous piezoelectric composites.In this study,based on the digital light processing 3D printing method,we investigated the influence of three dif-ferent structures-the gyroid,diamond,and woodpile interfaces-on the piezoelectric and mechanical properties of co-continuous ceramic/polymer piezoelectric composites.These findings demonstrate that the gyroid and di-amond interfaces outperformed the ceramic skeleton of the woodpile interface in terms of both mechanical and electrical properties.When the ceramic volume percentage was 50%,the piezo-composite of the gyroid surface exhibited the greatest hydrostatic figure of merit(HFOM),reaching 4.23×10^(−12) Pa^(−1),and its piezoelectric coeffi-cient(d_(33))and relative dielectric constant(εr)reached 115 pC/N and 748,respectively.The research results lay the foundation for the application of co-continuous piezoelectric composites in underwater communication and detection.
文摘Hydroponic farming is a viable and economical farming method,which can produce safe and healthy greens and vegetables conveniently and at a relatively low cost.It is essential to provide supplemental lighting for crops grown in greenhouses to meet the daily light requirement,Daily Light Integral(DLI).The present paper investigates how effectively and efficiently LEDs can be used as a light source in hydroponics.It is important for a hydroponic grower to assess the requirement of photo synthetically active radiation(PAR)or the Photosynthetic Photon Flux Density(PPFD),in a greenhouse,and adjust the quality and quantity of supplemental lighting accordingly.A Quantum sensor(or PAR sensor)can measure PAR more accurately than a digital light meter,which measures the light intensity or illuminance in the SI unit Lux,but a PAR sensor is relatively expensive and normally not affordable by an ordinary farmer.Therefore,based on the present investigation and experimental results,a very simple way to convert light intensity measured with a Lux meter into PAR is proposed,using a simple conversion factor(41.75 according to the present work).This allows a small-scale hydroponic farmer to use a simple and inexpensive technique to assess the day to day DLI values of PAR in a greenhouse accurately using just an inexpensive light meter.The present paper also proposes a more efficient way of using LED light panels in a hydroponic system.By moving the LED light panels closer to the crop,LED light source can use a fewer number of LEDs to produce the same required daily light requirement and can increase the efficiency of the power usage to more than 80%.Specifically,the present work has determined that it is important to design more efficient vertically movable LED light panels with capabilities of switching individual LEDs on and off,for the use in greenhouses.This allows a user to control the number of LEDs that can be lit at a particular time,as required.By doing so it is possible to increase the efficiency of a LED lighting system by reducing its cost of the electricity usage.
基金financial support(Sinergia No.177178 and research project No.315230_197644/1)financial support from the Swiss National Science Foundation(No.190345,188522 and 206501)financial support from China Scholarship Council(CSC,No.202006790027).
文摘Digital light processing(DLP)of structurally complex poly(ethylene glycol)(PEG)hydrogels with high mechanical toughness represents a long-standing challenge in thefield of 3D printing.Here,we report a 3D printing approach for the high-resolution manufacturing of structurally complex and mechanically strong PEG hydrogels via heat-assisted DLP.Instead of using aqueous solutions of photo-crosslinkable monomers,PEG macromonomer melts werefirst printed in the absence of water,resulting in bulk PEG networks.Then,post-printing swelling of the printed networks was achieved in water,producing high-fidelity 3D hydrogels with complex structures.By employing a dual-macromonomer resin containing a PEG-based four-arm macrophotoinitiator,“all-PEG”hydrogel constructs were pro-duced with compressive toughness up to 1.3 MJ m^(-3).By this approach,porous 3D hydrogel scaffolds with trabecular-like architecture were fabricated,and the scaf-fold surface supported cell attachment and the formation of a monolayer mimicking bone-lining cells.This study highlights the promises of heat-assisted DLP of PEG photopolymers for hydrogel fabrication,which may accelerate the development of 3D tissue-like constructs for regenerative medicine.
基金support from the National Natural Science Foundation of China(Grant No.52205424)the Natural Science Foundation of Zhejiang Province for Distinguished Young Scholars of China(Grant No.LR22E050002)+1 种基金the“Pioneer”and“Leading Goose”R&D Program of Zhejiang Province of China(Grant No.2023C01170)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LY23A020001).
文摘Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular trend.Among various manufacturing technologies,magnetic-assisted digital light processing(DLP)stands out because it enables precise manufacturing of macro-scale structures and micro-scale distributions with the assistance of an external magnetic field.Current research on manufacturing magnetic flexible actuators mostly employs single materials,which limits the magnetic driving performance to some extent.Based on these characterizations,we propose a multi-material magnetic field-assisted DLP technology to produce flexible actuators with an accuracy of 200μm.The flexible actuators are printed using two materials with different mechanical and magnetic properties.Considering the interface connectivity of multi-material printing,the effect of interfaces on mechanical properties is also explored.Experimental results indicate good chemical affinity between the two materials we selected.The overlap or connection length of the interface moderately improves the tensile strength of multi-material structures.In addition,we investigate the influence of the volume fraction of the magnetic part on deformation.Simulation and experimental results indicate that increasing the volume ratio(20%to 50%)of the magnetic structure can enhance the responsiveness of the actuator(more than 50%).Finally,we successfully manufacture two multi-material flexible actuators with specific magnetic arrangements:a multi-legged crawling robot and a flexible gripper capable of crawling and grasping actions.These results confirm that this method will pave the way for further research on the precise fabrication of magnetic flexible actuators with diverse functionalities.
基金support from the Medical Science and Technology Project of Zhejiang Province (2022+ZDXK-04)Zhejiang Provincial Basic Research for Public Welfare Funds (LGF20H060016,LGF21H060006,LGF22E030002)+1 种基金National Natural Science Foundation of China (82172419,82101649)Zheiang Provincial Natural Science Foundation of China (LZ22E020002).
文摘Mechanically strong magnesium-doped Ca-silicate bioceramic scaffolds have many advantages in repairing large segmental bone defects.Herein we combine β-TCP with 6 mol%magnesium-doped calcium silicate(Mg6)at three different ratios(TCP,TCP+15%Mg6,TCP+85%Mg6)to find an appropriate ratio which can exert considerable influence on bone regeneration.In this study,the bioceramic scaffolds were assessed for mechanical strength,bioactive ion release,biocompatibility,and osteogenic capacity through in vitro testing.Additionally,the potential for promoting bone regeneration was investigated through in vivo implantation of porous tube-like scaffolds.The results showed that the compressive strength increased with the augmentation of Mg6 component.Especially the compressive strength of the TCP+85%Mg6 group reached 38.1±3.8 MPa,three times that of the other two groups.Furthermore,extensive in vivo investigations revealed that the TCP+85%Mg6 bioceramic scaffolds were particularly beneficial for the osteogenic capacity of critical-sized femoral defects(20 mm in length).Altogether,magnesium doping in bioceramic implants is a promising strategy to provide stronger mechanical support and enhance osteogenesis to accelerate the repair of large defects.
基金This study is mainly financially supported by the Beijing Natural Science Foundation(2182064)hosted by Prof.Rujie He.Prof.Rujie He also thanks the support from the National Natural Science Foundation of China(51772028)+2 种基金Prof.M i n Xia thanks the support from the Fundamental Research Funds for the Central Universities(3052017010)Prof.Xinxin Jin thanks the support from the National Natural Science Foundation of China(51602082)Dr.Keqiang Zhang thanks the support from the Graduate Technology Innovation Project of Beijing Institute of Technology(No.2019CX10020).
文摘Hydroxyapatite(HA)bioceramic scaffolds were fabricated by using digital light processing(DLP)based additive manufacturing.Key issues on the HA bioceramic scaffolds,including dispersion,DLP fabrication,sintering,mechanical properties,and biocompatibility were discussed in detail.Firstly,the ffects of dispersant dosage,solid loading,and sintering temperature were studied.The optimal dispersant dosage,solid loading,and sintering temperature were 2wt%,50vol%,and 1250℃,respectively.Then,the mechanical properties and biocompatibility of the HA bioceramic scaffolds were investigated.The DLP-prepared porous HA bioceramic scaffold was found to exhibit excellent mechanical properties and degradation behavior.From this study,DLP technique shows good potential for manufacturing HA bioceramic scaffolds.
基金the National Key R&D Program of China(2017YFB1103500,2017YFB1103502).
文摘High performance hydroxyapatite(HA)ceramics with excellent densification and mechanical properties were successfully fabricated by digital light processing(DLP)three-dimensional(3D)printing technology.It was found that the sintering atmosphere of wet C02 can dramatically improve the densification process and thus lead to better mechanical properties.HA ceramics with a relative density of 97.12%and a three-point bending strength of 92.4 MPa can be achieved at a sintering temperature of 1300℃,which makes a solid foundation for application in bone engineering.Furthermore,a relatively high compressive strength of 4.09 MPa can be also achieved for a DLP-printed p-cell triply periodic minimum surface(TPMS)structure with a porosity of 74%,which meets the requirement of cancellous bone substitutes.A further cell proliferation test demonstrated that the sintering atmosphere of wet CO2 led to improve cell vitality after 7 days of cell culture Moreover,with the possible benefit from the bio-inspired structure,the 3D-printed TPMS structure significantly improved the cell vitality,which is crucial for early osteogenesis and osteointegration.
基金sponsored by the National Key Research and Development Program of China(2017YFB0702600)National Natural Science Foundation of China(31971283,31670985)Sichuan Science and Technology Programs(2019JDTD0008,2021YFS0032).
文摘Digital light processing(DLP)-based 3D printing technique holds promise in fabricating scaffolds with high precision.Here raw calcium phosphate(CaP)powders were modified by 5.5%monoalcohol ethoxylate phosphate(MAEP)to ensure high solid loading and low viscosity.The rheological tests found that photocurable slurries composed of 50wt%modified CaP powders and 2wt%toners were suitable for DLP printing.Based on geometric models designed by computer-aided design(CAD)system,three printed CaP ceramics with distinct macroporous structures were prepared,including simple cube,octet-truss and inverse face-centered cube(fcc),which presented the similar phase composition and microstructure,but the different macropore geometries.Inverse fcc group showed the highest porosity and compressive strength.The in vitro and in vivo biological evaluations were performed to compare the bioactivity of three printed CaP ceramics,and the traditional foamed ceramic was used as control.It suggested that all CaP ceramics exhibited good biocompatibility,as evidence by an even bone-like apatite layer formation on the surface,and the good cell proliferation and spreading.A mouse intramuscular implantation model found that all of CaP ceramics could induce ectopic bone formation,and foam group had the strongest osteoinduction,followed by inverse fcc,while cube and octet-truss had the weakest one.It indicated that macropore geometry was of great importance to affect the osteoinductivity of scaffolds,and spherical,concave macropores facilitated osteogenesis.These findings provide a strategy to design and fabricate high-performance orthopedic grafts with proper pore geometry and desired biological performance via DLP-based 3D printing technique.
基金This work was supported by the financial support from the Major Special Projects of Technological Innovation in Hubei Province(2019AAA002)the National Key R&D Program of China(2018YFB1105503)Fundamental Research Funds for the Central Universities(2019kfyXMPY020,2020kfyFPZX003,2018KFYYXJJ030,and 2019kfyXKJC011).
文摘Bone scaffolds require both good bioactivity and mechanical properties to keep shape and promote bone repair.In this work,T-ZnO_(w) enhanced biphasic calcium phosphate(BCP)scaffolds with triply periodic minimal surface(TPMS)-based double-layer porous structure were fabricated by digital light processing(DLP)with high precision.Property of suspension was first discussed to obtain better printing quality.After sintering,T-ZnO_(w) reacts with b-tricalcium phosphate(β-TCP)to form Ca_(19)Zn_(2)(PO_(4))14,and inhibits the phase transition toα-TCP.With the content of T-ZnO_(w) increasing from 0 to 2 wt%,the flexural strength increases from 40.9 to 68.5 MPa because the four-needle whiskers can disperse stress,and have the effect of pulling out as well as fracture toughening.However,excessive whiskers will reduce the cure depth,and cause more printing defects,thus reducing the mechanical strength.Besides,T-ZnO_(w) accelerates the deposition of apatite,and the sample with 2 wt%T-ZnO_(w) shows the fastest mineralization rate.The good biocompatibility has been proved by cell proliferation test.Results confirmed that doping T-ZnO_(w) can improve the mechanical strength of BCP scaffolds,and keep good biological property,which provides a new strategy for better bone repair.
基金supported by the National Natural Science Foundation of China(No.61177018)the Program for New Century Excellent Talents in University(No.NECT-11-0596)+1 种基金the Key Program of Beijing Sci-ence and Technology Plan(No.D121100004812001)Beijing Nova Program(No.2011066)
文摘An integrated method based on optical and digital image processing is presented to suppress speckle in digital holography. A spatial light modulator is adopted to introduce random phases to the illuminating beam. Multiple holograms are reconstructed and superimposed, and the intensity is averaged to smooth the noise. The adaptive algorithm based on the nonlocal means is designed to further suppress the speckle. The presented method is compared with other methods reduction is improved, and the proposed method is effective The experimental results show that speckle and feasible.
