Background As the global population increases,the demand for protein sources is expected to increase,driving the demand for cell-based cultivated meat.This study aimed to enhance the productivity of cultivated meat th...Background As the global population increases,the demand for protein sources is expected to increase,driving the demand for cell-based cultivated meat.This study aimed to enhance the productivity of cultivated meat through optimization of the cell source and organization process.Results We engineered fibroblasts into myogenic cells via non-viral introduction of the MYOD1 gene,avoiding viral methods for safety.After confirming the stable derivation of myogenic cells,we combined knockout(KO)of MSTN,a negative regulator of myogenesis,with MYOD1-mediated myogenesis to improve cultivated meat production.Primary cells from MSTN KO cattle exhibited enhanced myogenic potential.Additionally,when tested in immortalized fibroblasts,myostatin treatment reduced MYOD1-induced myogenesis in two-dimensional cultures,while MSTN knockout increased it.To achieve muscle-like cell alignment,we employed digital light processing(DLP)-based three-dimensional(3D)bioprinting to organize cells into 3D groove-shaped hydrogels.These bioactive hydrogels supported stable cell proliferation and significantly improved muscle cell alignment.Upon differentiation into myotubes,the cells demonstrated an ordered alignment,particularly the MSTN KO cells,which showed highly efficient differentiation.Conclusions The integration of genetic modification and advanced DLP 3D bioprinting with groove-patterned hydrogels provides an effective strategy for producing high-quality,muscle-aligned cultivated meat.展开更多
Introduction It is necessary for an ideal bioceramic scaffold to have a suitable structure.The structure can affect the mechanical properties of the scaffold(i.e.,elastic modulus and compressive strength)and the biolo...Introduction It is necessary for an ideal bioceramic scaffold to have a suitable structure.The structure can affect the mechanical properties of the scaffold(i.e.,elastic modulus and compressive strength)and the biological properties of the scaffold(i.e.,degradability and cell growth rate).Lattice structure is a kind of periodic porous structure,which has some advantages of light weight and high strength,and is widely used in the preparation of bioceramic scaffolders.For the structure of the scaffold,high porosity and large pore size are important for bone growth,bone integration and promoting good mechanical interlocking between neighboring bones and the scaffold.However,scaffolds with a high porosity often lack mechanical strength.In addition,different parts of the bone have different structural requirements.In this paper,scaffolds with a non-uniform structure or a hierarchical structure were designed,with loose and porous exterior to facilitate cell adhesion,osteogenic differentiation and vascularization as well as relatively dense interior to provide sufficient mechanical support for bone repair.Methods In this work,composite ceramics scaffolds with 10%akermanite content were prepared by DLP technology.The scaffold had a high porosity outside to promote the growth of bone tissue,and a low porosity inside to withstand external forces.The compressive strength,fracture form,in-vitro degradation performance and bioactivity of graded bioceramic scaffolds were investigated.The models of scaffolds were imported into the DLP printer with a 405 nm light.The samples were printed with the intensity of 8 mJ/cm^(2)and a layer thickness of 50μm.Finally,the ceramic samples were sintered at 1100℃.The degradability of the hierarchical gyroid bioceramic scaffolds was evaluated through immersion in Tris-HCl solution and SBF solution at a ratio of 200 mL/g.The bioactivity of bioceramic was obtained via immersing them in SBF solution for two weeks.The concentrations of calcium,phosphate,silicon,and magnesium ions in the soaking solution were determined by an inductively coupled plasma optical emission spectrometer.Results and discussion In this work,a hierarchical Gyroid structure HA-AK10 scaffold(sintered at 1100℃)with a radial internal porosity of 50%and an external porosity of 70%is prepared,and the influence of structural form on the compressive strength and degradation performance of the scaffold is investigated.The biological activity of the bioceramics in vitro is also verified.The mechanical simulation results show that the stress distribution corresponds to the porosity distribution of the structure,and the low porosity is larger and the overall stress concentration phenomenon does not appear.After soaking in SBF solution,Si—OH is firstly formed on the surface of bioceramics,and then silicon gel layer is produced due to the presence of calcium and silicon ions.The silicon gel layer is dissociated into negatively charged groups under alkaline environment secondary adsorption of calcium ions and phosphate ions,forming amorphous calcium phosphate,and finally amorphous calcium phosphate crystals and adsorption of carbonate ions,forming carbonate hydroxyapatite.This indicates that the composite bioceramics have a good biological activity in-vitro and can provide a good environment for the growth of bone cells.A hierarchical Gyroid ceramic scaffold with a bone geometry is prepared via applying the hierarchical structure to the bone contour scaffold.The maximum load capacity of the hierarchical Gyroid ceramic scaffold is 8 times that of the uniform structure.Conclusions The hierarchical structure scaffold designed had good overall compressive performance,good degradation performance,and still maintained a good mechanical stability during degradation.In addition,in-vitro biological experimental results showed that the surface graded composite scaffold could have a good in-vitro biological activity and provide a good environment for bone cells.Compared to the heterosexual structure,the graded scaffold had greater mechanical properties.展开更多
Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resul...Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resulted in lengthy molding durations but also compromised the mechanical strength.In this work,silica(SiO--_2)ceramic cores,with fine complex geometric shapes,were fabricated using 65vol.%ceramic slurry by digital light processing(DLP)with different printing angles.Printing angles significantly impact the surface accuracy,shrinkage,printing efficiency of green bodies,as well as the microstructure and mechanical properties of sintered ceramic core samples.As the printing angle in the green body increases,the bonding area decreases,surface roughness on the XY plane worsens,shrinkage in the Z direction becomes more pronounced,and the printing efficiency declines.Similarly,an increase in the printing angle in the sintered body leads to a reduction in bending strength.At a printing angle of 30°,the printing time is reduced to half of that at 90°,which improves the molding efficiency.Meanwhile,the obtained bulk density of 1.71 g·cm~(-3),open porosity of 24%,and fiexural strength of 10.6±1 MPa can meet the requirements of sintered ceramic cores.Therefore,designing and optimizing the printing angles can achieve the balance between shrinkage,printing efficiency,and fiexural strength.展开更多
Electronic 3D printing possesses a remarkable molding ability and convenience in integrated circuits,flexible wearables,and individual automobile requirements.However,traditional 3D printing technology still struggles...Electronic 3D printing possesses a remarkable molding ability and convenience in integrated circuits,flexible wearables,and individual automobile requirements.However,traditional 3D printing technology still struggles to meet the demands of high precision and high efficiency in the process of fabricating a curved surface circuit,particularly achieving precise silver circuit molding on irregular substrates.Here,a high-precision and muti-scaled conformal manufacturing method for silver circuits is presented through the digital light processing(DLP)of ultraviolet-curable silver paste(UV-SP)with adjustable photocuring properties,enabling the successful preparation of micro-scaled conductive structure on the sharply skewed hook face.The minimum modeling depth and width of the cured silver paste can be well controlled to 10 and 88µm,respectively.Compared with traditional printing technology,the printing efficiency of complex patterns has increased by over 70%.The printed silver circuit demonstrates an exceptionally high electrical conductivity,reaching as high as 1.16×10^(7) S/m.Additionally,the UV-SP exhibits significant manufacturing efficiency and superior molding resolution compared to conventional direct ink writing and inkjet printing techniques,thereby contributing to the attainment of high precision and efficiency of conformal and micro-molding manufacturing in sensors,communication antennas,and other electronic devices based on curved substrates.展开更多
Digital light processing(DLP)is widely used in ceramic additive manufacturing.However,it remains unexplored for metals.In this study,the regulatory mechanisms of the microstructure and mechanical properties of AISI 31...Digital light processing(DLP)is widely used in ceramic additive manufacturing.However,it remains unexplored for metals.In this study,the regulatory mechanisms of the microstructure and mechanical properties of AISI 316L stainless steel were investigated by optimizing a DLP-compatible metal slurry formulation and sintering process.A photosensitive resin system(mass ratio of 5:1:2:2 for U600,LA,ACMO,and HDDA,respectively)with 88 wt%solid content is designed to achieve a slurry with balanced rheology,photocurability,and low pyrolysis residue.Compared to vacuum sintering,which leads to brittle fracture of material,the Ar/H2 mixed gas(5%H2)effectively reduces carbon and oxygen impurities via reduction,mitigating carbide and oxide segregation at grain boundaries and within grains,thereby enhancing strength-ductility.In addition,the prolonged high-temperature sintering inducesδ-ferrite precipitation at grain boundaries,which fills residual pores to improve densification obviously.Under optimized sintering conditions(Ar/H2,1380°C,6 h),the material achieves 96.2%relative density with tensile strength and fracture elongation of 543.5 MPa and 58.7%,respectively,exhibiting uniform dimple-dominated fracture morphology.This synergistic optimization of the slurry formulation and sintering parameters improves the strength-ductility balance in DLP-fabricated metal materials,offering theoretical and technical insights for the additive manufacturing of complex high-performance metal components.展开更多
4D-printable shape memory polymers(SMPs)hold great promise for fabricating shape morphing biomedical devices,but most existing printed polymers either require harsh activation conditions or lack sufficient mechanical ...4D-printable shape memory polymers(SMPs)hold great promise for fabricating shape morphing biomedical devices,but most existing printed polymers either require harsh activation conditions or lack sufficient mechanical strength for vascular implantation.Here,we report a dual-stimuli-responsive shape memory polymer system enhanced by acrylated Pluronic F127(PF127-DA)micelles,which can be fabricated using digital light processing(DLP)based 3D printing.The PF127-DA based nanoscale micelles,which are formed via self-assembly in the hydrogel ink for 3D printing,act as crosslinkers to improve mechanical strength,fatigue resistance and elastic recovery.After drying the printed hydrogel,the obtained SMPs exhibit excellent shape recovery behaviour under mild physiological conditions—specifically body temperature(37℃)and aqueous swelling—resulting in recovery stress up to about 150?k Pa.This swelling-assisted actuation enables effective radial support,making the printed constructs suitable for vascular use.In vitro cytocompatibility assays with NIH/3T3 fibroblasts confirmed the suitable biocompatibility.Furthermore,the self-expanding behavior of the printed stents was validated in an occluded vessel model under physiological conditions.These results demonstrate the feasibility of 4D printed micelle-enhanced SMP for patient-specific,minimally invasive vascular stents and other soft implantable devices requiring high recovery force under physiological stimulation.展开更多
Background:The shortage of donor corneas is a severe global issue,and hence the development of corneal alternatives is imperative and urgent.Although attempts to produce artificial cornea substitutes by tissue enginee...Background:The shortage of donor corneas is a severe global issue,and hence the development of corneal alternatives is imperative and urgent.Although attempts to produce artificial cornea substitutes by tissue engineering have made some positive progress,many problems remain that hamper their clinical application worldwide.For example,the curvature of tissue-engineered cornea substitutes cannot be designed to fit the bulbus oculi of patients.Objective:To overcome these limitations,in this paper,we present a novel integrated three-dimensional(3 D) bioprintingbased cornea substitute fabrication strategy to realize design,customized fabrication,and evaluation of multi-layer hollow structures with complicated surfaces.Methods:The key rationale for this method is to combine digital light processing(DLP) and extrusion bioprinting into an integrated 3 D cornea bioprinting system.A designable and personalized corneal substitute was designed based on mathematical modelling and a computer tomography scan of a natural cornea.The printed corneal substitute was evaluated based on biomechanical analysis,weight,structural integrity,and fit.Results:The results revealed that the fabrication of high water content and highly transparent curved films with geometric features designed according to the natural human cornea can be achieved using a rapid,simple,and low-cost manufacturing process with a high repetition rate and quality.Conclusions:This study demonstrated the feasibility of customized design,analysis,and fabrication of a corneal substitute.The programmability of this method opens up the possibility of producing substitutes for other cornea-like shell structures with different scale and geometry features,such as the glomerulus,atrium,and oophoron.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
The emergence of additive manufacturing(AM)enables ceramics to be fabricated with customized geometry,and polymer-derived ceramics(PDCs)has attracted growing attention owing to their irreplaceable advantages.The combi...The emergence of additive manufacturing(AM)enables ceramics to be fabricated with customized geometry,and polymer-derived ceramics(PDCs)has attracted growing attention owing to their irreplaceable advantages.The combination of 3D printing and PDCs endows the resultant ceramics with both precision and performance.However,AM of ceramics from preceramic polymers is still challenging,and insufficient investigation of functionality also limits the versatility of precursor and its derived ceramics.Herein,we propose a novel paradigm for 3D printing dense silicon carbonitride ceramic and study its electrical semiconducting properties.The formulated photosensitive precursor inks could achieve self-polymerization and cross-linking under the radiation of UV light(405 nm).The green body with intricate structures is fabricated by digital light processing(DLP).Lightweight(1.79-2.08 g cm^(-3))and low porosity(<5%)amorphous ceramics were obtained after thermal treatments.Processes of cross-linking,decomposition,and ceramization are monitored and analyzed.Furthermore,the semi-conducting behaviors of resultant ceramics are identified where the conductivity(10^(-5)-10^(-1)S m^(-1))has a monotonic correspondence with the testing temperatures(25-1000℃).The numerical relationship is fitted by exponential functions,and its conducting mechanism could be interpreted by the band tail hopping(BTH)model.This work could provide alternative solutions for the fabrication of PDCs and potentials for sensing applications.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
This review provides a comprehensive overview of the various three-dimensional printing techniques for area exposure additive manufacturing using the patterned control of optical devices.Additive manufacturing techniq...This review provides a comprehensive overview of the various three-dimensional printing techniques for area exposure additive manufacturing using the patterned control of optical devices.Additive manufacturing techniques can be broadly categorized into low-power exposure and high-power melting,both of which involve innovative patterning and light-sourcing methods.The working principles and accompanying auxiliary devices of core technologies including the digital micromirror device,liquid crystal display,liquid crystal on silicon mask,and optically addressable light valve are summarized.The discussed techniques and devices have played critical roles in advancing both vat photopolymerization and powder bed fusion additive manufacturing processes and can be applied to markedly enhance printing efficiency.The advances discussed in this review hold significant promise in fields such as biomedicine,robotics,and sensing.The associated challenges and opportunities faced by the considered techniques and devices are summarized accordingly.展开更多
Flexible piezoresistive sensors based on carbon nanomaterials have attracted significant attention with regard to their application to wearable electronics.The enhanced performance of these sensors is primarily due to...Flexible piezoresistive sensors based on carbon nanomaterials have attracted significant attention with regard to their application to wearable electronics.The enhanced performance of these sensors is primarily due to the integration of microstructures and conductive coatings.In this study,a flexible sandwich-shaped piezoresistive pressure sensor is fabricated by adopting microstructured electrodes and a porous sensing layer of carbon nanocomposite.The microtextured electrodes are obtained from a template by three-dimensional printing using digital light processing(DLP),and the porous structure is obtained by scarification of an NaCl crystal template.Multiwalled carbon nanotubes(MWCNTs)and graphene nanoparticles(GNPs),composited with polydimethylsiloxane and silica(ESSIL 296),are used to fabricate the functional structures,including the upper and lower electrode layers and a sandwiched porous sensing layer.The sensor exhibits a rapid response and recovery speed(-80 ms),a high sensitivity(0.437 kPa^(−1))within a range of 0–1.08 kPa,and excellent stability.In addition,such sensors demonstrate potential applications for finger motion monitoring and information encryption.展开更多
Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures ...Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures were prepared through digital light processing(DLP)3D printing,polymer-derived ceramics(PDCs),chemical vapor infiltration(CVI),and oxidation technologies.The incorporation of the CVISiC phase effectively increases the dissipation capability,while the synergistic interaction between the gyroid structure and SiO_(2)phase significantly improves impedance matching performance.The SiOC/SiC/SiO_(2)composite achieved a minimum reflection loss(RL min)of-62.2 d B at 4.3 mm,and the effective absorption bandwidth(EAB)covered the X-band,with a thickness range of 4.1 mm-4.65 mm.The CST simulation results explain the broadband and low-frequency absorption characteristics,with an EAB of 8.4 GHz(9.6-18 GHz)and an RL min of-21.5 dB at 5 GHz.The excellent EM wave attenuation performance is associated primarily with polarization loss,conduction loss,the gyroid structure's enhancement of multiple reflections and scattering of EM waves,and the resonance effect between the structural units.The SiOC/SiC/SiO_(2)composite also demonstrated strong mechanical properties,with a maximum compressive failure strength of 31.6 MPa in the height direction.This work opens novel prospects for the development of multifunctional structural wave-absorbing materials suitable for broadband microwave absorption and load-bearing properties.展开更多
Flexible devices are increasingly crucial in various aspects of our lives,including healthcare devices and humanmachine interface systems,revolutionizing human life.As technology evolves rapidly,there is a high demand...Flexible devices are increasingly crucial in various aspects of our lives,including healthcare devices and humanmachine interface systems,revolutionizing human life.As technology evolves rapidly,there is a high demand for innovative manufacturing methods that enable rapid prototyping of custom and multifunctional flexible devices with high quality.Recently,digital light processing(DLP)3D printing has emerged as a promising manufacturing approach due to its capabilities of creating intricate customized structures,high fabrication speed,low-cost technology and widespread adoption.This review provides a state-of-the-art overview of the recent advances in the creation of flexible devices using DLP printing,with a focus on soft actuators,flexible sensors and flexible energy devices.We emphasize how DLP printing and the development of DLP printable materials enhance the structural design,sensitivity,mechanical performance,and overall functionality of these devices.Finally,we discuss the challenges and perspectives associated with DLP-printed flexible devices.We anticipate that the continued advancements in DLP printing will foster the development of smarter flexible devices,shortening the design-to-manufacturing cycles.展开更多
Digital light processing(DLP)is a high-speed,high-precision 3-dimensional(3D)printing technique gaining traction in the fabrication of ceramic composites.However,when printing 0-3 composites containing lead zirconate ...Digital light processing(DLP)is a high-speed,high-precision 3-dimensional(3D)printing technique gaining traction in the fabrication of ceramic composites.However,when printing 0-3 composites containing lead zirconate titanate(PZT)particles,a widely used piezoelectric ceramic,severe density and refractive index mismatches between the 2 phases pose challenges for ink synthesis and the printing process.Here,we systematically and quantitatively optimized DLP printing of PZT composites,streamlining process development and providing a solid theoretical and experimental foundation for broader applications of DLP technology.PZT particles were pretreated with air plasma to improve slurry uniformity and enhance stress transfer at the composite interface,leading to improved chemical modification,mechanical strength,and piezoelectric properties.We investigated the effects of key process parameters on printability and accuracy by analyzing the curing behavior of PZT–polymer composites.A quantitative model of the DLP curing process was introduced.Unlike stereolithography(SLA),DLP curing depth was found to depend on energy dose and light intensity,with higher intensities proving more favorable for printing 0-3 PZT composites.From depth/width–energy curves,optimal process parameters were determined.We designed and fabricated a soft piezoelectric metamaterial-based touch sensor using these parameters,achieving a customized output profile.This work offers critical insights into optimizing DLP for functional materials and expands the potential of 3D-printed piezoelectric composites.展开更多
Advancements in additive manufacturing(AM)are revolutionizing 3D part production,making 3D printing crucial for creating optical devices like lenses and waveguides.This study employs vat photopolymerization(VPP)to fab...Advancements in additive manufacturing(AM)are revolutionizing 3D part production,making 3D printing crucial for creating optical devices like lenses and waveguides.This study employs vat photopolymerization(VPP)to fabricate adaptive 4D printed smart Fresnel lenses with photochromic properties using digital light processing(DLP).These lenses are fabricated with precise optical performance and geometric dimensions.Photochromic powders enable dynamic color changes upon UV exposure.The lenses were optically evaluated in both inactive and active states,demonstrating excellent UV and blue light blocking when inactive.Upon UV activation,the lenses darken and absorb parts of the visible light spectrum,with the degree of absorption and color change dependent on the photochromic material and its concentration.The lenses show minimal focal length errors,maintaining high precision and UV responsiveness even at low concentrations.This research highlights the lenses’precision,UV responsiveness,blue light filtering capabilities,and stability after multiple UV exposure cycles.These findings underscore the potential of 4D printing in developing smart optical devices tailored for applications that demand dynamic light modulation and UV filtering,highlighting a combination of innovative manufacturing techniques and functional optics.展开更多
CONSPECTUS:Recent years have witnessed a surge in efforts to integrate electrically conductive nanomaterials into photopolymerbased additive manufacturing(AM),driven by the growing demand for multifunctional 3D-printi...CONSPECTUS:Recent years have witnessed a surge in efforts to integrate electrically conductive nanomaterials into photopolymerbased additive manufacturing(AM),driven by the growing demand for multifunctional 3D-printing.While several AM techniques have been adapted to process conductive composites,Digital Light Processing(DLP)stands out for its high-resolution and fast-curing capabilities.However,it poses a central limitation:the requirement for optical transparency in the printing resin,which is compromised by the incorporation of conventional conductive fillers.This Account highlights the advances in overcoming three fundamental challenges in the field:(i)How can conductive nanocomposites be printed by DLP without compromising resolution?(ii)How can high electrical conductivity be achieved at low filler content?(iii)What is the origin of anisotropic conductivity in printed objects,and how can it be mitigated?To address the first question,the authors introduced a strategy based on UV-transparent precursors,specifically monolayer graphene oxide(GO).GO’s minimal UV absorption allows its use as a printable nanofiller at weight fractions up to 0.35 vol%,preserving the curing depth and optical clarity required for DLP.Postprinting thermal reduction of GO into reduced graphene oxide(rGO)yields nanocomposites with conductivities up to 10^(-2)S m^(-1)-comparable to conventional carbon nanotube(CNT)systems but achieved without high UV attenuation.To tackle the second question,the authors explored the use of single-walled carbon nanotubes(SWCNTs),which,due to their high aspect ratio and intrinsic conductivity,exhibit ultralow percolation thresholds(<0.01 vol%).At these concentrations,UV interference is negligible.However,the need for surfactant-assisted dispersion introduces contact resistance,limiting conductivity.To overcome this,this Account presents a hybrid formulation in which GO serves as both dispersant and conductive additive,enhancing internanotube contacts upon reduction.This approach achieves conductivities up to 0.3 S m^(-1),with a total filler content below 0.15 vol%,representing a significant leap in performance without sacrificing resolution.To resolve the third question regarding electrical anisotropy,the study employs polarized Raman spectroscopy,conclusively showing that nanotube alignment is not responsible for the observed directional conductivity differences.Instead,the anisotropy arises from interfacial contact resistance between printed layers,an intrinsic artifact of the layer-by-layer DLP process.Mitigation strategies such as delayed UV curing and temperature-controlled printing were shown to significantly reduce this resistance and improve isotropy.Beyond addressing these scientific questions,this Account highlights the practical impact of these materials.Notably,hybrid nanocomposites exhibited strong potential in microwave absorption,reaching broadband reflection losses below-10 dB at low filler loadings,due to combined ohmic and dielectric losses.These outcomes demonstrate that high-resolution,fast DLP printing of conductive materials is not only feasible but also tunable and scalable for applications in sensors,soft robotics,and electromagnetic shielding.By answering these key questions,the work establishes a foundation for the rational design of printable conductive nanocomposites,balancing optical compatibility,conductivity,and mechanical precision-paving the way for next-generation functional devices fabricated through vat photopolymerization.展开更多
Porous oil-containing materials achieve self-lubrication through pore-stored oil,making them suitable for demanding applications such as vacuum,high-speed and maintenance-free systems.While 3D printing combines the ad...Porous oil-containing materials achieve self-lubrication through pore-stored oil,making them suitable for demanding applications such as vacuum,high-speed and maintenance-free systems.While 3D printing combines the advantages of complex structure fabrication and performance regulation,research on its application in porous metal fabrication remains limited.This study integrates digital light processing(DLP)3D printing with vacuum impregnation to fabricate porous AISI 316L stainless steel materials impregnated with PAO10 oil.By adjusting the slurry solid loading(82 wt.%-88 wt.%)and sintering temperature(1200℃-1350℃),12 groups of materials with controlled porosity were fabricated.DLP technology enables precise regulation of oil impregnation rate(10 wt.%-40 wt.%)and achieves high open porosity exceeding 80%.The mechanical properties improve progressively with elevated process parameters,accompanied by fracture morphology evolution from interparticle fractures to dimple-dominated ductile fractures.Both oil impregnation rate and mechanical strength are critical to self-lubricating performance,showing a notable synergistic effect.Optimal self-lubricating performance requires a tensile strength of 250 MPa and an oil impregnation rate of 15%.S1-1350°C sample demonstrates the best performance,with a friction coefficient of 0.09 and an ultralow wear rate of 3.30×10-6mm3/(N m)under a 30 N load and 0.04 m/s sliding speed against Si3N4counterpart.These results will provide valuable insights for advancing the digital design and precision manufacturing of self-lubricating porous materials.展开更多
The anisotropic setae structures of geckos demonstrate a natural anisotropic response to external forces,thereby enabling rapid and repeated attachment and detachment.Considering this biological mechanism,this study p...The anisotropic setae structures of geckos demonstrate a natural anisotropic response to external forces,thereby enabling rapid and repeated attachment and detachment.Considering this biological mechanism,this study proposes an innovative process that harnesses the overcuring of resins in digital light processing(DLP)3D printing to emulate setae structures.The proposed method facilitates the spontaneous fabrication of anisotropic shapes from isotropically modeled geometries.Furthermore,it reduces the number of hierarchical structures typically produced in conventional 3D printing and creates smooth surfaces,thereby enhancing the structural stability for directional adhesion and detachment.The anisotropic structures were processed into functional surfaces through a double-casting method,exhibiting an adhesive strength akin to that of gecko-setae structures while maintaining easy detachment capabilities.Finally,a simple mechanical module was fabricated to directly demonstrate the detachment effect.This study introduces a novel approach to DLP printing for fabricating enhanced anisotropic structures that can be seamlessly integrated with existing 3D printing techniques.By strategically utilizing overcuring,a phenomenon often perceived as a limitation,this study demonstrated its potential to expand the boundaries of next-generation 3D printing technologies.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
基金financially supported by the Korea Institute of Planning and Evaluation for Technology in Food,Agriculture and Forestry(IPET-RS-2024–00402320)by the Meterials/Parts Technology Development Pro-gram(1415187291,Development of composite formulation with a sustained release(gene)for the treatment of companion animal sarcopenia)funded By the Ministry of Trade,Industry&Energy(MOTIE,Korea)。
文摘Background As the global population increases,the demand for protein sources is expected to increase,driving the demand for cell-based cultivated meat.This study aimed to enhance the productivity of cultivated meat through optimization of the cell source and organization process.Results We engineered fibroblasts into myogenic cells via non-viral introduction of the MYOD1 gene,avoiding viral methods for safety.After confirming the stable derivation of myogenic cells,we combined knockout(KO)of MSTN,a negative regulator of myogenesis,with MYOD1-mediated myogenesis to improve cultivated meat production.Primary cells from MSTN KO cattle exhibited enhanced myogenic potential.Additionally,when tested in immortalized fibroblasts,myostatin treatment reduced MYOD1-induced myogenesis in two-dimensional cultures,while MSTN knockout increased it.To achieve muscle-like cell alignment,we employed digital light processing(DLP)-based three-dimensional(3D)bioprinting to organize cells into 3D groove-shaped hydrogels.These bioactive hydrogels supported stable cell proliferation and significantly improved muscle cell alignment.Upon differentiation into myotubes,the cells demonstrated an ordered alignment,particularly the MSTN KO cells,which showed highly efficient differentiation.Conclusions The integration of genetic modification and advanced DLP 3D bioprinting with groove-patterned hydrogels provides an effective strategy for producing high-quality,muscle-aligned cultivated meat.
文摘Introduction It is necessary for an ideal bioceramic scaffold to have a suitable structure.The structure can affect the mechanical properties of the scaffold(i.e.,elastic modulus and compressive strength)and the biological properties of the scaffold(i.e.,degradability and cell growth rate).Lattice structure is a kind of periodic porous structure,which has some advantages of light weight and high strength,and is widely used in the preparation of bioceramic scaffolders.For the structure of the scaffold,high porosity and large pore size are important for bone growth,bone integration and promoting good mechanical interlocking between neighboring bones and the scaffold.However,scaffolds with a high porosity often lack mechanical strength.In addition,different parts of the bone have different structural requirements.In this paper,scaffolds with a non-uniform structure or a hierarchical structure were designed,with loose and porous exterior to facilitate cell adhesion,osteogenic differentiation and vascularization as well as relatively dense interior to provide sufficient mechanical support for bone repair.Methods In this work,composite ceramics scaffolds with 10%akermanite content were prepared by DLP technology.The scaffold had a high porosity outside to promote the growth of bone tissue,and a low porosity inside to withstand external forces.The compressive strength,fracture form,in-vitro degradation performance and bioactivity of graded bioceramic scaffolds were investigated.The models of scaffolds were imported into the DLP printer with a 405 nm light.The samples were printed with the intensity of 8 mJ/cm^(2)and a layer thickness of 50μm.Finally,the ceramic samples were sintered at 1100℃.The degradability of the hierarchical gyroid bioceramic scaffolds was evaluated through immersion in Tris-HCl solution and SBF solution at a ratio of 200 mL/g.The bioactivity of bioceramic was obtained via immersing them in SBF solution for two weeks.The concentrations of calcium,phosphate,silicon,and magnesium ions in the soaking solution were determined by an inductively coupled plasma optical emission spectrometer.Results and discussion In this work,a hierarchical Gyroid structure HA-AK10 scaffold(sintered at 1100℃)with a radial internal porosity of 50%and an external porosity of 70%is prepared,and the influence of structural form on the compressive strength and degradation performance of the scaffold is investigated.The biological activity of the bioceramics in vitro is also verified.The mechanical simulation results show that the stress distribution corresponds to the porosity distribution of the structure,and the low porosity is larger and the overall stress concentration phenomenon does not appear.After soaking in SBF solution,Si—OH is firstly formed on the surface of bioceramics,and then silicon gel layer is produced due to the presence of calcium and silicon ions.The silicon gel layer is dissociated into negatively charged groups under alkaline environment secondary adsorption of calcium ions and phosphate ions,forming amorphous calcium phosphate,and finally amorphous calcium phosphate crystals and adsorption of carbonate ions,forming carbonate hydroxyapatite.This indicates that the composite bioceramics have a good biological activity in-vitro and can provide a good environment for the growth of bone cells.A hierarchical Gyroid ceramic scaffold with a bone geometry is prepared via applying the hierarchical structure to the bone contour scaffold.The maximum load capacity of the hierarchical Gyroid ceramic scaffold is 8 times that of the uniform structure.Conclusions The hierarchical structure scaffold designed had good overall compressive performance,good degradation performance,and still maintained a good mechanical stability during degradation.In addition,in-vitro biological experimental results showed that the surface graded composite scaffold could have a good in-vitro biological activity and provide a good environment for bone cells.Compared to the heterosexual structure,the graded scaffold had greater mechanical properties.
基金the Youth Innovation Promotion Association of Chinese Academy of Science(No.2021160)the National Natural Science Foundation of China(No.51802319)the Technology and Engineering Center for Space(No.CSU-QZKT-2019-04)。
文摘Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resulted in lengthy molding durations but also compromised the mechanical strength.In this work,silica(SiO--_2)ceramic cores,with fine complex geometric shapes,were fabricated using 65vol.%ceramic slurry by digital light processing(DLP)with different printing angles.Printing angles significantly impact the surface accuracy,shrinkage,printing efficiency of green bodies,as well as the microstructure and mechanical properties of sintered ceramic core samples.As the printing angle in the green body increases,the bonding area decreases,surface roughness on the XY plane worsens,shrinkage in the Z direction becomes more pronounced,and the printing efficiency declines.Similarly,an increase in the printing angle in the sintered body leads to a reduction in bending strength.At a printing angle of 30°,the printing time is reduced to half of that at 90°,which improves the molding efficiency.Meanwhile,the obtained bulk density of 1.71 g·cm~(-3),open porosity of 24%,and fiexural strength of 10.6±1 MPa can meet the requirements of sintered ceramic cores.Therefore,designing and optimizing the printing angles can achieve the balance between shrinkage,printing efficiency,and fiexural strength.
基金supported by the National Natural Science Foundation of China(Nos.51972079 and 52302062)the National Key Research and Development Program of China(Nos.2022YFB370630202 and 2022YFB3706305).
文摘Electronic 3D printing possesses a remarkable molding ability and convenience in integrated circuits,flexible wearables,and individual automobile requirements.However,traditional 3D printing technology still struggles to meet the demands of high precision and high efficiency in the process of fabricating a curved surface circuit,particularly achieving precise silver circuit molding on irregular substrates.Here,a high-precision and muti-scaled conformal manufacturing method for silver circuits is presented through the digital light processing(DLP)of ultraviolet-curable silver paste(UV-SP)with adjustable photocuring properties,enabling the successful preparation of micro-scaled conductive structure on the sharply skewed hook face.The minimum modeling depth and width of the cured silver paste can be well controlled to 10 and 88µm,respectively.Compared with traditional printing technology,the printing efficiency of complex patterns has increased by over 70%.The printed silver circuit demonstrates an exceptionally high electrical conductivity,reaching as high as 1.16×10^(7) S/m.Additionally,the UV-SP exhibits significant manufacturing efficiency and superior molding resolution compared to conventional direct ink writing and inkjet printing techniques,thereby contributing to the attainment of high precision and efficiency of conformal and micro-molding manufacturing in sensors,communication antennas,and other electronic devices based on curved substrates.
基金supported by National Natural Science Foundation of China(Grant Nos.52205231,52205196)Taishan Scholars Program,and Research Project of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(Grant Nos.AMGM0613,AMGM0620).
文摘Digital light processing(DLP)is widely used in ceramic additive manufacturing.However,it remains unexplored for metals.In this study,the regulatory mechanisms of the microstructure and mechanical properties of AISI 316L stainless steel were investigated by optimizing a DLP-compatible metal slurry formulation and sintering process.A photosensitive resin system(mass ratio of 5:1:2:2 for U600,LA,ACMO,and HDDA,respectively)with 88 wt%solid content is designed to achieve a slurry with balanced rheology,photocurability,and low pyrolysis residue.Compared to vacuum sintering,which leads to brittle fracture of material,the Ar/H2 mixed gas(5%H2)effectively reduces carbon and oxygen impurities via reduction,mitigating carbide and oxide segregation at grain boundaries and within grains,thereby enhancing strength-ductility.In addition,the prolonged high-temperature sintering inducesδ-ferrite precipitation at grain boundaries,which fills residual pores to improve densification obviously.Under optimized sintering conditions(Ar/H2,1380°C,6 h),the material achieves 96.2%relative density with tensile strength and fracture elongation of 543.5 MPa and 58.7%,respectively,exhibiting uniform dimple-dominated fracture morphology.This synergistic optimization of the slurry formulation and sintering parameters improves the strength-ductility balance in DLP-fabricated metal materials,offering theoretical and technical insights for the additive manufacturing of complex high-performance metal components.
基金Natural Science Basic Research Program of Shaanxi(No.2025JC-YBMS-358)the Fundamental Research Funds for the Central Universities(No.D5000250307)。
文摘4D-printable shape memory polymers(SMPs)hold great promise for fabricating shape morphing biomedical devices,but most existing printed polymers either require harsh activation conditions or lack sufficient mechanical strength for vascular implantation.Here,we report a dual-stimuli-responsive shape memory polymer system enhanced by acrylated Pluronic F127(PF127-DA)micelles,which can be fabricated using digital light processing(DLP)based 3D printing.The PF127-DA based nanoscale micelles,which are formed via self-assembly in the hydrogel ink for 3D printing,act as crosslinkers to improve mechanical strength,fatigue resistance and elastic recovery.After drying the printed hydrogel,the obtained SMPs exhibit excellent shape recovery behaviour under mild physiological conditions—specifically body temperature(37℃)and aqueous swelling—resulting in recovery stress up to about 150?k Pa.This swelling-assisted actuation enables effective radial support,making the printed constructs suitable for vascular use.In vitro cytocompatibility assays with NIH/3T3 fibroblasts confirmed the suitable biocompatibility.Furthermore,the self-expanding behavior of the printed stents was validated in an occluded vessel model under physiological conditions.These results demonstrate the feasibility of 4D printed micelle-enhanced SMP for patient-specific,minimally invasive vascular stents and other soft implantable devices requiring high recovery force under physiological stimulation.
基金Project supported by the National Natural Science Foundation of China(Nos.51875518 and 51475419)the Key Research and Development Projects of Zhejiang Province(Nos.2017C01054 and2018C03062)the Fundamental Research Funds for the Central Universities(No.2019FZA4002),China
文摘Background:The shortage of donor corneas is a severe global issue,and hence the development of corneal alternatives is imperative and urgent.Although attempts to produce artificial cornea substitutes by tissue engineering have made some positive progress,many problems remain that hamper their clinical application worldwide.For example,the curvature of tissue-engineered cornea substitutes cannot be designed to fit the bulbus oculi of patients.Objective:To overcome these limitations,in this paper,we present a novel integrated three-dimensional(3 D) bioprintingbased cornea substitute fabrication strategy to realize design,customized fabrication,and evaluation of multi-layer hollow structures with complicated surfaces.Methods:The key rationale for this method is to combine digital light processing(DLP) and extrusion bioprinting into an integrated 3 D cornea bioprinting system.A designable and personalized corneal substitute was designed based on mathematical modelling and a computer tomography scan of a natural cornea.The printed corneal substitute was evaluated based on biomechanical analysis,weight,structural integrity,and fit.Results:The results revealed that the fabrication of high water content and highly transparent curved films with geometric features designed according to the natural human cornea can be achieved using a rapid,simple,and low-cost manufacturing process with a high repetition rate and quality.Conclusions:This study demonstrated the feasibility of customized design,analysis,and fabrication of a corneal substitute.The programmability of this method opens up the possibility of producing substitutes for other cornea-like shell structures with different scale and geometry features,such as the glomerulus,atrium,and oophoron.
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the National Natural Science Foundation of China(No.12090034).
文摘The emergence of additive manufacturing(AM)enables ceramics to be fabricated with customized geometry,and polymer-derived ceramics(PDCs)has attracted growing attention owing to their irreplaceable advantages.The combination of 3D printing and PDCs endows the resultant ceramics with both precision and performance.However,AM of ceramics from preceramic polymers is still challenging,and insufficient investigation of functionality also limits the versatility of precursor and its derived ceramics.Herein,we propose a novel paradigm for 3D printing dense silicon carbonitride ceramic and study its electrical semiconducting properties.The formulated photosensitive precursor inks could achieve self-polymerization and cross-linking under the radiation of UV light(405 nm).The green body with intricate structures is fabricated by digital light processing(DLP).Lightweight(1.79-2.08 g cm^(-3))and low porosity(<5%)amorphous ceramics were obtained after thermal treatments.Processes of cross-linking,decomposition,and ceramization are monitored and analyzed.Furthermore,the semi-conducting behaviors of resultant ceramics are identified where the conductivity(10^(-5)-10^(-1)S m^(-1))has a monotonic correspondence with the testing temperatures(25-1000℃).The numerical relationship is fitted by exponential functions,and its conducting mechanism could be interpreted by the band tail hopping(BTH)model.This work could provide alternative solutions for the fabrication of PDCs and potentials for sensing applications.
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.
文摘This review provides a comprehensive overview of the various three-dimensional printing techniques for area exposure additive manufacturing using the patterned control of optical devices.Additive manufacturing techniques can be broadly categorized into low-power exposure and high-power melting,both of which involve innovative patterning and light-sourcing methods.The working principles and accompanying auxiliary devices of core technologies including the digital micromirror device,liquid crystal display,liquid crystal on silicon mask,and optically addressable light valve are summarized.The discussed techniques and devices have played critical roles in advancing both vat photopolymerization and powder bed fusion additive manufacturing processes and can be applied to markedly enhance printing efficiency.The advances discussed in this review hold significant promise in fields such as biomedicine,robotics,and sensing.The associated challenges and opportunities faced by the considered techniques and devices are summarized accordingly.
基金supported by the Science and Technology Cooperation and Exchange Special Project of Shanxi Province(Grant No.202204041101006)the Shanxi Provincial Patent Transformation Special Plan Project(Grant No.202403003)+4 种基金a research project supported by the Shanxi Scholarship Council of China(Grant No.2023-130)the Aeronautical Science Foundation of China(Grant No.2023Z0560U0001)the Fundamental Research Program of Shanxi Province(Grant No.202203021222077)the Science and Technology Project of the North University of China(Grant No.20231914)the National Natural Science Foundation of China(Grant Nos.52405633 and 62404208).
文摘Flexible piezoresistive sensors based on carbon nanomaterials have attracted significant attention with regard to their application to wearable electronics.The enhanced performance of these sensors is primarily due to the integration of microstructures and conductive coatings.In this study,a flexible sandwich-shaped piezoresistive pressure sensor is fabricated by adopting microstructured electrodes and a porous sensing layer of carbon nanocomposite.The microtextured electrodes are obtained from a template by three-dimensional printing using digital light processing(DLP),and the porous structure is obtained by scarification of an NaCl crystal template.Multiwalled carbon nanotubes(MWCNTs)and graphene nanoparticles(GNPs),composited with polydimethylsiloxane and silica(ESSIL 296),are used to fabricate the functional structures,including the upper and lower electrode layers and a sandwiched porous sensing layer.The sensor exhibits a rapid response and recovery speed(-80 ms),a high sensitivity(0.437 kPa^(−1))within a range of 0–1.08 kPa,and excellent stability.In addition,such sensors demonstrate potential applications for finger motion monitoring and information encryption.
基金financially supported by National Natural Science Foundation of China(Grant Nos.12141203,52202083,W2421013)the Natural Science Foundation Project of Shaanxi Province(Grant No.2024JC-YBMS-450)+1 种基金the Sichuan Science and Technology Program(Grant No.2024YFHZ0265)the Open Project of High-end Equipment Advanced Materials and Manufacturing Technology Laboratory(Grant No.2023KFKT0005)。
文摘Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures were prepared through digital light processing(DLP)3D printing,polymer-derived ceramics(PDCs),chemical vapor infiltration(CVI),and oxidation technologies.The incorporation of the CVISiC phase effectively increases the dissipation capability,while the synergistic interaction between the gyroid structure and SiO_(2)phase significantly improves impedance matching performance.The SiOC/SiC/SiO_(2)composite achieved a minimum reflection loss(RL min)of-62.2 d B at 4.3 mm,and the effective absorption bandwidth(EAB)covered the X-band,with a thickness range of 4.1 mm-4.65 mm.The CST simulation results explain the broadband and low-frequency absorption characteristics,with an EAB of 8.4 GHz(9.6-18 GHz)and an RL min of-21.5 dB at 5 GHz.The excellent EM wave attenuation performance is associated primarily with polarization loss,conduction loss,the gyroid structure's enhancement of multiple reflections and scattering of EM waves,and the resonance effect between the structural units.The SiOC/SiC/SiO_(2)composite also demonstrated strong mechanical properties,with a maximum compressive failure strength of 31.6 MPa in the height direction.This work opens novel prospects for the development of multifunctional structural wave-absorbing materials suitable for broadband microwave absorption and load-bearing properties.
基金supported by the Science and Technology Development Fund,Macao SAR(0119/2022/A3 and 0009/2023/ITP1)the Research Grant from the University of Macao and the University of Macao Development Foundation(SRG2022-00038-FST and MYRG-GRG2023-00225-FST-UMDF).
文摘Flexible devices are increasingly crucial in various aspects of our lives,including healthcare devices and humanmachine interface systems,revolutionizing human life.As technology evolves rapidly,there is a high demand for innovative manufacturing methods that enable rapid prototyping of custom and multifunctional flexible devices with high quality.Recently,digital light processing(DLP)3D printing has emerged as a promising manufacturing approach due to its capabilities of creating intricate customized structures,high fabrication speed,low-cost technology and widespread adoption.This review provides a state-of-the-art overview of the recent advances in the creation of flexible devices using DLP printing,with a focus on soft actuators,flexible sensors and flexible energy devices.We emphasize how DLP printing and the development of DLP printable materials enhance the structural design,sensitivity,mechanical performance,and overall functionality of these devices.Finally,we discuss the challenges and perspectives associated with DLP-printed flexible devices.We anticipate that the continued advancements in DLP printing will foster the development of smarter flexible devices,shortening the design-to-manufacturing cycles.
基金supported by the National Natural Science Foundation of China(grant no.12072143)the Science,Technology and Innovation Commission of Shenzhen Municipality(grant no.ZDSYS20210623092005017)the Stable Support Plan Program of Shenzhen Natural Science Fund(grant no.20200925155345003).
文摘Digital light processing(DLP)is a high-speed,high-precision 3-dimensional(3D)printing technique gaining traction in the fabrication of ceramic composites.However,when printing 0-3 composites containing lead zirconate titanate(PZT)particles,a widely used piezoelectric ceramic,severe density and refractive index mismatches between the 2 phases pose challenges for ink synthesis and the printing process.Here,we systematically and quantitatively optimized DLP printing of PZT composites,streamlining process development and providing a solid theoretical and experimental foundation for broader applications of DLP technology.PZT particles were pretreated with air plasma to improve slurry uniformity and enhance stress transfer at the composite interface,leading to improved chemical modification,mechanical strength,and piezoelectric properties.We investigated the effects of key process parameters on printability and accuracy by analyzing the curing behavior of PZT–polymer composites.A quantitative model of the DLP curing process was introduced.Unlike stereolithography(SLA),DLP curing depth was found to depend on energy dose and light intensity,with higher intensities proving more favorable for printing 0-3 PZT composites.From depth/width–energy curves,optimal process parameters were determined.We designed and fabricated a soft piezoelectric metamaterial-based touch sensor using these parameters,achieving a customized output profile.This work offers critical insights into optimizing DLP for functional materials and expands the potential of 3D-printed piezoelectric composites.
基金We acknowledge Khalifa University for the research funding,in the form of Advanced Digital&Additive Manufacturing(ADAM)Group(Award No.RCII-2019-003),in support of this research.
文摘Advancements in additive manufacturing(AM)are revolutionizing 3D part production,making 3D printing crucial for creating optical devices like lenses and waveguides.This study employs vat photopolymerization(VPP)to fabricate adaptive 4D printed smart Fresnel lenses with photochromic properties using digital light processing(DLP).These lenses are fabricated with precise optical performance and geometric dimensions.Photochromic powders enable dynamic color changes upon UV exposure.The lenses were optically evaluated in both inactive and active states,demonstrating excellent UV and blue light blocking when inactive.Upon UV activation,the lenses darken and absorb parts of the visible light spectrum,with the degree of absorption and color change dependent on the photochromic material and its concentration.The lenses show minimal focal length errors,maintaining high precision and UV responsiveness even at low concentrations.This research highlights the lenses’precision,UV responsiveness,blue light filtering capabilities,and stability after multiple UV exposure cycles.These findings underscore the potential of 4D printing in developing smart optical devices tailored for applications that demand dynamic light modulation and UV filtering,highlighting a combination of innovative manufacturing techniques and functional optics.
基金the AID(Agence Innovation Défense)and the Nouvelle Aquitaine Region。
文摘CONSPECTUS:Recent years have witnessed a surge in efforts to integrate electrically conductive nanomaterials into photopolymerbased additive manufacturing(AM),driven by the growing demand for multifunctional 3D-printing.While several AM techniques have been adapted to process conductive composites,Digital Light Processing(DLP)stands out for its high-resolution and fast-curing capabilities.However,it poses a central limitation:the requirement for optical transparency in the printing resin,which is compromised by the incorporation of conventional conductive fillers.This Account highlights the advances in overcoming three fundamental challenges in the field:(i)How can conductive nanocomposites be printed by DLP without compromising resolution?(ii)How can high electrical conductivity be achieved at low filler content?(iii)What is the origin of anisotropic conductivity in printed objects,and how can it be mitigated?To address the first question,the authors introduced a strategy based on UV-transparent precursors,specifically monolayer graphene oxide(GO).GO’s minimal UV absorption allows its use as a printable nanofiller at weight fractions up to 0.35 vol%,preserving the curing depth and optical clarity required for DLP.Postprinting thermal reduction of GO into reduced graphene oxide(rGO)yields nanocomposites with conductivities up to 10^(-2)S m^(-1)-comparable to conventional carbon nanotube(CNT)systems but achieved without high UV attenuation.To tackle the second question,the authors explored the use of single-walled carbon nanotubes(SWCNTs),which,due to their high aspect ratio and intrinsic conductivity,exhibit ultralow percolation thresholds(<0.01 vol%).At these concentrations,UV interference is negligible.However,the need for surfactant-assisted dispersion introduces contact resistance,limiting conductivity.To overcome this,this Account presents a hybrid formulation in which GO serves as both dispersant and conductive additive,enhancing internanotube contacts upon reduction.This approach achieves conductivities up to 0.3 S m^(-1),with a total filler content below 0.15 vol%,representing a significant leap in performance without sacrificing resolution.To resolve the third question regarding electrical anisotropy,the study employs polarized Raman spectroscopy,conclusively showing that nanotube alignment is not responsible for the observed directional conductivity differences.Instead,the anisotropy arises from interfacial contact resistance between printed layers,an intrinsic artifact of the layer-by-layer DLP process.Mitigation strategies such as delayed UV curing and temperature-controlled printing were shown to significantly reduce this resistance and improve isotropy.Beyond addressing these scientific questions,this Account highlights the practical impact of these materials.Notably,hybrid nanocomposites exhibited strong potential in microwave absorption,reaching broadband reflection losses below-10 dB at low filler loadings,due to combined ohmic and dielectric losses.These outcomes demonstrate that high-resolution,fast DLP printing of conductive materials is not only feasible but also tunable and scalable for applications in sensors,soft robotics,and electromagnetic shielding.By answering these key questions,the work establishes a foundation for the rational design of printable conductive nanocomposites,balancing optical compatibility,conductivity,and mechanical precision-paving the way for next-generation functional devices fabricated through vat photopolymerization.
基金supported by the Special Research Assistant Project of the Chinese Academy of Sciences(Grant No.E1ZL0295)the National Natural Science Foundation of China(Grant Nos.52205231,52205196)+1 种基金the Taishan Scholars Programthe Research Project of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(Grant Nos.AMGM0613,AMGM0620)。
文摘Porous oil-containing materials achieve self-lubrication through pore-stored oil,making them suitable for demanding applications such as vacuum,high-speed and maintenance-free systems.While 3D printing combines the advantages of complex structure fabrication and performance regulation,research on its application in porous metal fabrication remains limited.This study integrates digital light processing(DLP)3D printing with vacuum impregnation to fabricate porous AISI 316L stainless steel materials impregnated with PAO10 oil.By adjusting the slurry solid loading(82 wt.%-88 wt.%)and sintering temperature(1200℃-1350℃),12 groups of materials with controlled porosity were fabricated.DLP technology enables precise regulation of oil impregnation rate(10 wt.%-40 wt.%)and achieves high open porosity exceeding 80%.The mechanical properties improve progressively with elevated process parameters,accompanied by fracture morphology evolution from interparticle fractures to dimple-dominated ductile fractures.Both oil impregnation rate and mechanical strength are critical to self-lubricating performance,showing a notable synergistic effect.Optimal self-lubricating performance requires a tensile strength of 250 MPa and an oil impregnation rate of 15%.S1-1350°C sample demonstrates the best performance,with a friction coefficient of 0.09 and an ultralow wear rate of 3.30×10-6mm3/(N m)under a 30 N load and 0.04 m/s sliding speed against Si3N4counterpart.These results will provide valuable insights for advancing the digital design and precision manufacturing of self-lubricating porous materials.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2023-00260527).
文摘The anisotropic setae structures of geckos demonstrate a natural anisotropic response to external forces,thereby enabling rapid and repeated attachment and detachment.Considering this biological mechanism,this study proposes an innovative process that harnesses the overcuring of resins in digital light processing(DLP)3D printing to emulate setae structures.The proposed method facilitates the spontaneous fabrication of anisotropic shapes from isotropically modeled geometries.Furthermore,it reduces the number of hierarchical structures typically produced in conventional 3D printing and creates smooth surfaces,thereby enhancing the structural stability for directional adhesion and detachment.The anisotropic structures were processed into functional surfaces through a double-casting method,exhibiting an adhesive strength akin to that of gecko-setae structures while maintaining easy detachment capabilities.Finally,a simple mechanical module was fabricated to directly demonstrate the detachment effect.This study introduces a novel approach to DLP printing for fabricating enhanced anisotropic structures that can be seamlessly integrated with existing 3D printing techniques.By strategically utilizing overcuring,a phenomenon often perceived as a limitation,this study demonstrated its potential to expand the boundaries of next-generation 3D printing technologies.
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.
