In order to improve the osseointegration and antibacterial activity of titanium alloys,micro/nano-structured ceramic coatings doped with antibacterial element F were prepared by plasma electrolytic oxidation(PEO)proce...In order to improve the osseointegration and antibacterial activity of titanium alloys,micro/nano-structured ceramic coatings doped with antibacterial element F were prepared by plasma electrolytic oxidation(PEO)process on Ti6Al4V alloy in NaF electrolyte.The influence of NaF concentration(0.15-0.50 mol/L)on the PEO process,microstructure,phase composition,corrosion resistance and thickness of the coatings was investigated using scanning/transmission electron microscopy,energy dispersive spectroscopy,atomic force microscopy,X-ray diffractometer,and potentiodynamic polarization.The results demonstrated that Ti6Al4V alloy had low PEO voltage(less than 200 V)in NaF electrolyte,which decreased further as the NaF concentration increased.A micro/nano-structured coating with 10-15μm pits and 200-800 nm pores was formed in NaF electrolyte;the morphology was different from the typical pancake structure obtained with other electrolytes.The coating formed in NaF electrolyte had low surface roughness and was thin(<4μm).The NaF concentration had a small effect on the phase transition from metastable anatase phase to stable rutile phase,but greatly affected the corrosion resistance.In general,as the NaF concentration increased,the surface roughness,phase(anatase and rutile)contents,corrosion resistance,and thickness of the coating first increased and then decreased,reaching the maximum values at 0.25 mol/L NaF.展开更多
Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of...Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.展开更多
In the present work, osteoblast behavior on a hierarchical micro-/nano-structured titanium surface was investigated. A hi- erarchical hybrid micro-/nano-structured titanium surface topography was produced via Electrol...In the present work, osteoblast behavior on a hierarchical micro-/nano-structured titanium surface was investigated. A hi- erarchical hybrid micro-/nano-structured titanium surface topography was produced via Electrolytic Etching （EE）. MG-63 cells were cultured on disks for 2 h to 7 days. The osteoblast response to the hierarchical hybrid micro-/nano-structured titanium surface was evaluated through the osteoblast cell morphology, attachment and proliferation. For comparison, MG-63 cells were also cultured on Sandblasted and Acid-etched （SEA） as well as Machined （M） surfaces respectively. The results show signifi- cant differences in the adhesion rates and proliferation levels of MG-63 cells on EE, SLA, and M surfaces. Both adhesion rate and proliferation level on EE surface are higher than those on SLA and M surfaces. Therefore, we may expect that, comparing with SLA and M surfaces, bone growth on EE surface could be accelerated and bone formation could be promoted at an early stage, which could be applied in the clinical practices for immediate and early-stage loadings.展开更多
There exist strong interests of developing nano-grained steels because of the outstanding properties including high strength/weight ratio, wear resistance, excellent toughness, and favorable cellular activity. This ar...There exist strong interests of developing nano-grained steels because of the outstanding properties including high strength/weight ratio, wear resistance, excellent toughness, and favorable cellular activity. This article reviews the main fabrication process and microstructural control of nano-structured steels over the last decades. Severe plastic deformation is considered as an effective route of obtaining the nano-grained microstructures. The process of cold-rolling and annealing of martensitic steel is a viable method to obtain bulk nano-structured low carbon steel, while the final thickness of the cold-rolling plate is limited. According to the theoretical results of the thermal simulation studies, a novel alloy design combined with the rapid transformation and rolling process is proposed to successfully fabricate nano-grained high strength bulk steel. The refinement mechanisms are expected to be taking advantage of increase in the transformation nucleation sites and inhibiting the grain coarsening. Moreover, corresponding mechanical properties are summarized.展开更多
A novel oxide-dispersion-strengthened(ODS)die steel was fabricated by mechanical alloying and hot consolidation.Annealing and quench-tempering treatments both obtained an ultra-fine grain structure(mean size:310-330 n...A novel oxide-dispersion-strengthened(ODS)die steel was fabricated by mechanical alloying and hot consolidation.Annealing and quench-tempering treatments both obtained an ultra-fine grain structure(mean size:310-330 nm)with an ultra-high density of ultra-fine Y-Al-O nano-oxides(number density:~(1-1.5)×10^(23)m^(−3),mean size:5.1-7.2 nm).Prolonged thermal exposure further induced the new,highly dense precipitation of ultra-fine Y-Zr-O nano-oxides.Both nano-oxides tended to be wrapped up with a B2-NiAl nano-shells.Although the quench-tempered sample showed much higher room-temperature strength(yield strength=1393±40 MPa and ultimate tensile strength=1774±11 MPa)and slightly lower elongation(elongation=13.6%±0.6%)than the annealed sample(YS=988±7 MPa,UTS=1490±12 MPa,and EL=15.2%±1.1%),both samples exhibited better strength-ductility synergy at room temperature and much higher thermal stabilities at high temperatures(600-700℃)than all those conventional hot-work die steels,which makes the new ODS steel highly promising for advanced hot-work mold and die applications at high temperatures above 600℃.展开更多
First-principles energetics analyses were performed to investigate the nucleation of(Y-Si-O)nano-clusters(NCs)in nanostructured ferritic alloys(NFAs).It was predicted that the nucleation of(Y-Si-O)NCs follows the same...First-principles energetics analyses were performed to investigate the nucleation of(Y-Si-O)nano-clusters(NCs)in nanostructured ferritic alloys(NFAs).It was predicted that the nucleation of(Y-Si-O)NCs follows the same general pathway as previously found for(Y-Ti/Al/Zr-O)NCs in NFAs:they all tend to begin with the(O-O)pairs and grow to(O-Y)-cores and further to larger NCs by attracting Y and other solute elements nearby.Nucleation of a hexa-atomic-[2Y-Si-3O]-cluster can reduce the total energy by 4.71 eV.Among various microalloying-induced NCs,the nucleation preference ordering was predicted as(Y-Zr-O)>(Y-Ti-O)>(Y-Al-O)>(Y-Si-O).The number densities and chemical compositions of NCs in multi-microalloyed NFAs would largely depend on the number availability of(O,Y)-cores,as well as the relative abundance and atomic diffusivities of microalloying solute elements nearby.展开更多
Micro-arc oxidized Cu-incorporated TiO2 coatings （Cu-TiO2） were prepared in the Ca, P, Cu-containing electrolyte to obtain an implant material with superior biological activity and antibacterial property. The surfac...Micro-arc oxidized Cu-incorporated TiO2 coatings （Cu-TiO2） were prepared in the Ca, P, Cu-containing electrolyte to obtain an implant material with superior biological activity and antibacterial property. The surface topography, phase, and element composition of the TiO2 and Cu-TiO2 coatings were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and energy-dispersive X-ray spectrometry （EDS）, respectively. Staphylococcus aureus （S. aureus） was selected to evaluate the antibacterial property of the Cu-TiO2 coatings, whereas osteoblastic MG63 cells were cultured on the coatings to investigate the biological activity. The obtained results demonstrated that Cu element was successfully incorporated into the porous nano-structured TiO2 coatings, which did not alter apparently the surface topography and phase composition of the coatings as compared to the Cu-free TiO2 coatings. Moreover, the antibacterial studies suggested that the Cu-incorporated TiO2 coatings could significantly inhibit the adhesion of S. aureus. In addition, the in vitro biological evaluation displayed that the adhesion, proliferation and differentiation of MG63 cells on the Cu-incorporated coatings were enhanced as compared to those on the Cu-free coatings and Ti plates. In conclusion, the innovative Cu-incorporated nano-structured TiO2 coatings on Ti substrate with excellent antibacterial property and biological activity are promising candidates for orthopedic implant.展开更多
Micro/nanoplastics(M/NPs)have become pervasive environmental pollutants,posing significant risks to human health through various exposure routes,including ingestion,inhalation,and direct contact.This review systematic...Micro/nanoplastics(M/NPs)have become pervasive environmental pollutants,posing significant risks to human health through various exposure routes,including ingestion,inhalation,and direct contact.This review systematically examined the potential impacts of M/NPs on ocular health,focusing on exposure pathways,toxicological mechanisms,and resultant damage to the eye.Ocular exposure to M/NPs can occur via direct contact and oral ingestion,with the latter potentially leading to the penetration of particles through ocular biological barriers into ocular tissues.The review highlighted that M/NPs can induce adverse effects on the ocular surface,elevate intraocular pressure,and cause abnormalities in the vitreous and retina.Mechanistically,oxidative stress and inflammation are central to M/NP-induced ocular damage,with smaller particles often exhibiting greater toxicity.Overall,this review underscored the potential risks of M/NPs to ocular health and emphasized the need for further research to elucidate exposure mechanisms,toxicological pathways,and mitigation strategies.展开更多
Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic condu...Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.展开更多
Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always...Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always struggle to balance mechanical properties and thermal insulation,resulting in their inability to meet the demands for both washing resistance and personal protection.Herein,inspired by the natural spring-like structures of cucumber tendrils,a superelastic and washable micro/nanofibrous sponge(MNFS)based on biomimetic helical fibers is directly prepared utilizing multiple-jet electrospinning technology for high-performance thermal insulation.By regulating the conductivity of polyvinylidene fluoride solution,multiple-jet ejection and multiple-stage whipping of jets are achieved,and further control of phase separation rates enables the rapid solidification of jets to form spring-like helical fibers,which are directly entangled to assemble MNFS.The resulting MNFS exhibits superelasticity that can withstand large tensile strain(200%),1000 cyclic tensile or compression deformations,and retain good resilience even in liquid nitrogen(-196℃).Furthermore,the MNFS shows efficient thermal insulation with low thermal conductivity(24.85 mW m^(-1)K^(-1)),close to the value of dry air,and remains structural stability even after cyclic washing.This work offers new possibilities for advanced fibrous sponges in transportation,environmental,and energy applications.展开更多
The deployment of flexible zinc-ion batteries is impeded by dendrite growth from random anode defects.Conventional defect-elimination strategies often compromise flexibility and fail to achieve uniform interfaces.We p...The deployment of flexible zinc-ion batteries is impeded by dendrite growth from random anode defects.Conventional defect-elimination strategies often compromise flexibility and fail to achieve uniform interfaces.We propose a paradigm shift:reconfiguring random defects into engineered,monodisperse artificial micro-curves to homogenize electric fields and guide aligned zinc(Zn)deposition.Using moisture-assisted flash heating,we transform zincophilic silver(Ag)coatings on carbon fibers into uniformly dispersed micro-curved particles(Ag Particles@CC),creating identical nucleation sites with optimal zinc ion(Zn^(2+))adsorption energetics.Theoretical simulations confirm these structures eliminate localized field concentrations,enabling homogeneous plating/stripping.This design demonstrates remarkable performance,with ultrastable 1500 cycles at 10 mA cm^(-2)(98.6%avg.Coulombic efficiency)and symmetric cell operation>650 h(57.7 mV hysteresis).Crucially,interparticle discontinuities preserve intrinsic flexibility,enabling flexible pouch cells(Ag Particles@CC-Zn//NaV_(3)O_(8)·1,5H_(2)O)to successfully power wearable devices such as smartwatches and smartphones.This work establishes defect reconfiguration via artificial micro-curvature engineering as a universal strategy toward dendritesuppressed,flexible energy storage.展开更多
Aluminum scandium nitride(AlScN),an emergingⅢ-nitride semiconductor material,has attracted significant atten-tion in recent years due to its exceptional piezoelectric properties,high thermal stability,tunable bandgap...Aluminum scandium nitride(AlScN),an emergingⅢ-nitride semiconductor material,has attracted significant atten-tion in recent years due to its exceptional piezoelectric properties,high thermal stability,tunable bandgap,and excellent com-patibility with micro/nano fabrication.This paper systematically reviews the crystal structure,fundamental properties,and prop-erty modulation mechanisms of AlScN.It also summarizes recent progress in micro/nano fabrication technologies,including deposition,etching,and device integration.Furthermore,the applications of AlScN in diverse fields such as micro-electrome-chanical systems(MEMS),RF communications,energy conversion,optoelectronics and sensors are discussed.Finally,current challenges and promising future research directions for AlScN are outlined.展开更多
Micro/nano devices(MNDs)are characterized by miniaturization,high precision,and multifunctional integration,making them highly suitable for use in areas such as microrobotics,biomedical devices and electronic sensors....Micro/nano devices(MNDs)are characterized by miniaturization,high precision,and multifunctional integration,making them highly suitable for use in areas such as microrobotics,biomedical devices and electronic sensors.Their fabrication requires exceptional precision in structural integrity,material control,and functional integration.Traditional micro/nano fabrication techniques face inherent limitations in constructing complex three-dimensional(3D)architectures and integrating multiple materials.While additive manufacturing(AM)provides flexibility,challenges remain in material alignment control,microstructural organization,and multifunctional integration.To overcome these limitations,field-assisted additive manufacturing(FAM)has emerged as a promising approach that combines magnetic,acoustic,or electric fields to regulate material alignment,microstructural organization,and spatial alignment.This capability improves fabrication precision,enhances material anisotropy and facilitates functional integration.This review systematically explores the mechanisms,fabrication process,and functional integration of FAM in the framework of nozzle-based and vat photopolymerization-based,while further exploring their applications in microrobotics,biomedical devices,and electronic sensors.Moreover,this review provides a comparative overview of different FAM approaches,highlighting their respective characteristics,typical applications,and unique advantages.In addition,the major challenges facing FAM research are comprehensively assessed and future directions are explored,including advances in spatial precision control capability,intelligent control for process integration,and multi-field coupling optimization.This review establishes a foundational theoretical framework that can serve as a systematic reference for micro/nano manufacturing researchers to promote the development of FAM for high-performance micro/nano device fabrication.展开更多
文摘In order to improve the osseointegration and antibacterial activity of titanium alloys,micro/nano-structured ceramic coatings doped with antibacterial element F were prepared by plasma electrolytic oxidation(PEO)process on Ti6Al4V alloy in NaF electrolyte.The influence of NaF concentration(0.15-0.50 mol/L)on the PEO process,microstructure,phase composition,corrosion resistance and thickness of the coatings was investigated using scanning/transmission electron microscopy,energy dispersive spectroscopy,atomic force microscopy,X-ray diffractometer,and potentiodynamic polarization.The results demonstrated that Ti6Al4V alloy had low PEO voltage(less than 200 V)in NaF electrolyte,which decreased further as the NaF concentration increased.A micro/nano-structured coating with 10-15μm pits and 200-800 nm pores was formed in NaF electrolyte;the morphology was different from the typical pancake structure obtained with other electrolytes.The coating formed in NaF electrolyte had low surface roughness and was thin(<4μm).The NaF concentration had a small effect on the phase transition from metastable anatase phase to stable rutile phase,but greatly affected the corrosion resistance.In general,as the NaF concentration increased,the surface roughness,phase(anatase and rutile)contents,corrosion resistance,and thickness of the coating first increased and then decreased,reaching the maximum values at 0.25 mol/L NaF.
基金supported by the Natural Science Foundation of Tianjin(General Program,No.18JCYBJC19500)the Independent Innovation Fund of Tianjin University(No.2019XZS-0014)the Research Grants Council of Hong Kong(No.HKUST615408).
文摘Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.
文摘In the present work, osteoblast behavior on a hierarchical micro-/nano-structured titanium surface was investigated. A hi- erarchical hybrid micro-/nano-structured titanium surface topography was produced via Electrolytic Etching （EE）. MG-63 cells were cultured on disks for 2 h to 7 days. The osteoblast response to the hierarchical hybrid micro-/nano-structured titanium surface was evaluated through the osteoblast cell morphology, attachment and proliferation. For comparison, MG-63 cells were also cultured on Sandblasted and Acid-etched （SEA） as well as Machined （M） surfaces respectively. The results show signifi- cant differences in the adhesion rates and proliferation levels of MG-63 cells on EE, SLA, and M surfaces. Both adhesion rate and proliferation level on EE surface are higher than those on SLA and M surfaces. Therefore, we may expect that, comparing with SLA and M surfaces, bone growth on EE surface could be accelerated and bone formation could be promoted at an early stage, which could be applied in the clinical practices for immediate and early-stage loadings.
文摘There exist strong interests of developing nano-grained steels because of the outstanding properties including high strength/weight ratio, wear resistance, excellent toughness, and favorable cellular activity. This article reviews the main fabrication process and microstructural control of nano-structured steels over the last decades. Severe plastic deformation is considered as an effective route of obtaining the nano-grained microstructures. The process of cold-rolling and annealing of martensitic steel is a viable method to obtain bulk nano-structured low carbon steel, while the final thickness of the cold-rolling plate is limited. According to the theoretical results of the thermal simulation studies, a novel alloy design combined with the rapid transformation and rolling process is proposed to successfully fabricate nano-grained high strength bulk steel. The refinement mechanisms are expected to be taking advantage of increase in the transformation nucleation sites and inhibiting the grain coarsening. Moreover, corresponding mechanical properties are summarized.
基金support from the National MCF Energy R&D Program of China(No.2018YFE0306100).
文摘A novel oxide-dispersion-strengthened(ODS)die steel was fabricated by mechanical alloying and hot consolidation.Annealing and quench-tempering treatments both obtained an ultra-fine grain structure(mean size:310-330 nm)with an ultra-high density of ultra-fine Y-Al-O nano-oxides(number density:~(1-1.5)×10^(23)m^(−3),mean size:5.1-7.2 nm).Prolonged thermal exposure further induced the new,highly dense precipitation of ultra-fine Y-Zr-O nano-oxides.Both nano-oxides tended to be wrapped up with a B2-NiAl nano-shells.Although the quench-tempered sample showed much higher room-temperature strength(yield strength=1393±40 MPa and ultimate tensile strength=1774±11 MPa)and slightly lower elongation(elongation=13.6%±0.6%)than the annealed sample(YS=988±7 MPa,UTS=1490±12 MPa,and EL=15.2%±1.1%),both samples exhibited better strength-ductility synergy at room temperature and much higher thermal stabilities at high temperatures(600-700℃)than all those conventional hot-work die steels,which makes the new ODS steel highly promising for advanced hot-work mold and die applications at high temperatures above 600℃.
基金financially suppor ted by the National MCF Energy R&D Program of China(Project No.2018YFE0306100)the National Natural Science Foundation of China(No.51971249)。
文摘First-principles energetics analyses were performed to investigate the nucleation of(Y-Si-O)nano-clusters(NCs)in nanostructured ferritic alloys(NFAs).It was predicted that the nucleation of(Y-Si-O)NCs follows the same general pathway as previously found for(Y-Ti/Al/Zr-O)NCs in NFAs:they all tend to begin with the(O-O)pairs and grow to(O-Y)-cores and further to larger NCs by attracting Y and other solute elements nearby.Nucleation of a hexa-atomic-[2Y-Si-3O]-cluster can reduce the total energy by 4.71 eV.Among various microalloying-induced NCs,the nucleation preference ordering was predicted as(Y-Zr-O)>(Y-Ti-O)>(Y-Al-O)>(Y-Si-O).The number densities and chemical compositions of NCs in multi-microalloyed NFAs would largely depend on the number availability of(O,Y)-cores,as well as the relative abundance and atomic diffusivities of microalloying solute elements nearby.
基金supported by the Shanghai Science and Technology R&D Fund(Nos.0952nm04400,07JC14057 and 08ZR1421600)the National Basic Research Fund(No. 2005CB623901)the National Natural Science Foundation of China(Nos.30700170,30973041 and 81271959)
文摘Micro-arc oxidized Cu-incorporated TiO2 coatings （Cu-TiO2） were prepared in the Ca, P, Cu-containing electrolyte to obtain an implant material with superior biological activity and antibacterial property. The surface topography, phase, and element composition of the TiO2 and Cu-TiO2 coatings were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and energy-dispersive X-ray spectrometry （EDS）, respectively. Staphylococcus aureus （S. aureus） was selected to evaluate the antibacterial property of the Cu-TiO2 coatings, whereas osteoblastic MG63 cells were cultured on the coatings to investigate the biological activity. The obtained results demonstrated that Cu element was successfully incorporated into the porous nano-structured TiO2 coatings, which did not alter apparently the surface topography and phase composition of the coatings as compared to the Cu-free TiO2 coatings. Moreover, the antibacterial studies suggested that the Cu-incorporated TiO2 coatings could significantly inhibit the adhesion of S. aureus. In addition, the in vitro biological evaluation displayed that the adhesion, proliferation and differentiation of MG63 cells on the Cu-incorporated coatings were enhanced as compared to those on the Cu-free coatings and Ti plates. In conclusion, the innovative Cu-incorporated nano-structured TiO2 coatings on Ti substrate with excellent antibacterial property and biological activity are promising candidates for orthopedic implant.
基金Supported by the Guangdong Provincial Natural Science Foundation(No.2114050001527).
文摘Micro/nanoplastics(M/NPs)have become pervasive environmental pollutants,posing significant risks to human health through various exposure routes,including ingestion,inhalation,and direct contact.This review systematically examined the potential impacts of M/NPs on ocular health,focusing on exposure pathways,toxicological mechanisms,and resultant damage to the eye.Ocular exposure to M/NPs can occur via direct contact and oral ingestion,with the latter potentially leading to the penetration of particles through ocular biological barriers into ocular tissues.The review highlighted that M/NPs can induce adverse effects on the ocular surface,elevate intraocular pressure,and cause abnormalities in the vitreous and retina.Mechanistically,oxidative stress and inflammation are central to M/NP-induced ocular damage,with smaller particles often exhibiting greater toxicity.Overall,this review underscored the potential risks of M/NPs to ocular health and emphasized the need for further research to elucidate exposure mechanisms,toxicological pathways,and mitigation strategies.
基金financially supported by the National Key Research and Development Program(2022YFE0127400)the National Natural Science Foundation of China(52172040,52202041,and U23B2077)+1 种基金Taishan Scholar Project of Shandong Province(tsqn202211086,ts202208832,tsqnz20221118)the Fundamental Research Funds for the Central Universities(23CX06055A).
文摘Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.
基金supported by Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2022QNRC001)the National Natural Science Foundation of China(No.52273053)the Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.21CGA41)。
文摘Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always struggle to balance mechanical properties and thermal insulation,resulting in their inability to meet the demands for both washing resistance and personal protection.Herein,inspired by the natural spring-like structures of cucumber tendrils,a superelastic and washable micro/nanofibrous sponge(MNFS)based on biomimetic helical fibers is directly prepared utilizing multiple-jet electrospinning technology for high-performance thermal insulation.By regulating the conductivity of polyvinylidene fluoride solution,multiple-jet ejection and multiple-stage whipping of jets are achieved,and further control of phase separation rates enables the rapid solidification of jets to form spring-like helical fibers,which are directly entangled to assemble MNFS.The resulting MNFS exhibits superelasticity that can withstand large tensile strain(200%),1000 cyclic tensile or compression deformations,and retain good resilience even in liquid nitrogen(-196℃).Furthermore,the MNFS shows efficient thermal insulation with low thermal conductivity(24.85 mW m^(-1)K^(-1)),close to the value of dry air,and remains structural stability even after cyclic washing.This work offers new possibilities for advanced fibrous sponges in transportation,environmental,and energy applications.
基金supported by the National Natural Science Foundation of China(52202218)the Fundamental Research Funds for the Central Universities(CUSF-DH-T-2023044)。
文摘The deployment of flexible zinc-ion batteries is impeded by dendrite growth from random anode defects.Conventional defect-elimination strategies often compromise flexibility and fail to achieve uniform interfaces.We propose a paradigm shift:reconfiguring random defects into engineered,monodisperse artificial micro-curves to homogenize electric fields and guide aligned zinc(Zn)deposition.Using moisture-assisted flash heating,we transform zincophilic silver(Ag)coatings on carbon fibers into uniformly dispersed micro-curved particles(Ag Particles@CC),creating identical nucleation sites with optimal zinc ion(Zn^(2+))adsorption energetics.Theoretical simulations confirm these structures eliminate localized field concentrations,enabling homogeneous plating/stripping.This design demonstrates remarkable performance,with ultrastable 1500 cycles at 10 mA cm^(-2)(98.6%avg.Coulombic efficiency)and symmetric cell operation>650 h(57.7 mV hysteresis).Crucially,interparticle discontinuities preserve intrinsic flexibility,enabling flexible pouch cells(Ag Particles@CC-Zn//NaV_(3)O_(8)·1,5H_(2)O)to successfully power wearable devices such as smartwatches and smartphones.This work establishes defect reconfiguration via artificial micro-curvature engineering as a universal strategy toward dendritesuppressed,flexible energy storage.
基金supported by the National Natural Science Foundation of China(General Program,No.52473331).
文摘Aluminum scandium nitride(AlScN),an emergingⅢ-nitride semiconductor material,has attracted significant atten-tion in recent years due to its exceptional piezoelectric properties,high thermal stability,tunable bandgap,and excellent com-patibility with micro/nano fabrication.This paper systematically reviews the crystal structure,fundamental properties,and prop-erty modulation mechanisms of AlScN.It also summarizes recent progress in micro/nano fabrication technologies,including deposition,etching,and device integration.Furthermore,the applications of AlScN in diverse fields such as micro-electrome-chanical systems(MEMS),RF communications,energy conversion,optoelectronics and sensors are discussed.Finally,current challenges and promising future research directions for AlScN are outlined.
基金financial support from the National Natural Science Foundation of China(Nos.52205590,52575652,52322502,52175009)State Key Laboratory of Robotics and Systems(HIT)(No.SKLRS-2024-KF11)+3 种基金the Natural Science Foundation of Jiangsu Province(No.BK20220834)the Taihu Lake Innovation Fund for the School of Future Technology of Southeast University,the Start-up Research Fund of Southeast University(No.RF1028623098)the National Heilongjiang Providence Nature Science Foundation of China(YQ2022E022)the European Research Council(ERC)under the European Union’s Horizon Europe research and innovation programme(I-BOT Project,Grant Agreement No.101162939)。
文摘Micro/nano devices(MNDs)are characterized by miniaturization,high precision,and multifunctional integration,making them highly suitable for use in areas such as microrobotics,biomedical devices and electronic sensors.Their fabrication requires exceptional precision in structural integrity,material control,and functional integration.Traditional micro/nano fabrication techniques face inherent limitations in constructing complex three-dimensional(3D)architectures and integrating multiple materials.While additive manufacturing(AM)provides flexibility,challenges remain in material alignment control,microstructural organization,and multifunctional integration.To overcome these limitations,field-assisted additive manufacturing(FAM)has emerged as a promising approach that combines magnetic,acoustic,or electric fields to regulate material alignment,microstructural organization,and spatial alignment.This capability improves fabrication precision,enhances material anisotropy and facilitates functional integration.This review systematically explores the mechanisms,fabrication process,and functional integration of FAM in the framework of nozzle-based and vat photopolymerization-based,while further exploring their applications in microrobotics,biomedical devices,and electronic sensors.Moreover,this review provides a comparative overview of different FAM approaches,highlighting their respective characteristics,typical applications,and unique advantages.In addition,the major challenges facing FAM research are comprehensively assessed and future directions are explored,including advances in spatial precision control capability,intelligent control for process integration,and multi-field coupling optimization.This review establishes a foundational theoretical framework that can serve as a systematic reference for micro/nano manufacturing researchers to promote the development of FAM for high-performance micro/nano device fabrication.
