In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing （SPRB） and grain refinement mechanism, the microstructure characteristics and mat...In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing （SPRB） and grain refinement mechanism, the microstructure characteristics and material properties of sample at various depths from the topmost surface were investigated by SEM, TEM, XRD, OM etc. The experimental results show that the gradient nano/micro-structure was introduced into the surface layer of over 100μm in thickness. The remarkable increase in hardness near the topmost surface was mainly attributed to the reduced grain size. The equiaxed nano-sized grains were in random orientation and the most of their boundaries were low-angle grain boundaries （LAGBs）. The coarse grains are refined into the few micro-sized grains by dislocation activities;deformation twinning was found to be the primary form for the formation of submicron grains;the formation of nanostructure was dominated by dislocation activities accompanied with rotation of grains in local region.展开更多
In order to enhance electrochemical properties of LiFePO4 （LFP） cathode materials, spherical porous nano/micro structured LFP/C cathode materials were synthesized by spray drying, followed by calcination. The result...In order to enhance electrochemical properties of LiFePO4 （LFP） cathode materials, spherical porous nano/micro structured LFP/C cathode materials were synthesized by spray drying, followed by calcination. The results show that the spherical precursors with the sizes of 0.5-5 μm can be completely converted to LFP/C when the calcination temperature is higher than 500 ℃. The LFP/C microspheres obtained at calcination temperature of 700 ℃ are composed of numerous particles with sizes of -20 nm, and have well-developed interconnected pore structure and large specific surface area of 28.77 mE/g. The specific discharge capacities of the LFP/C obtained at 700 ℃ are 162.43, 154.35 and 144.03 mA.h/g at 0.5C, 1C and 2C, respectively. Meanwhile, the capacity retentions can reach up to 100% after 50 cycles. The improved electrochemical properties of the materials are ascribed to a small Li＋ diffusion resistance and special structure of LFP/C microspheres.展开更多
In this paper, the effect of van der Waals （vdW） force on the pull-in behavior of electrostatically actuated nano/micromirrors is investigated. First, the minimum po- tential energy principle is utilized to find the...In this paper, the effect of van der Waals （vdW） force on the pull-in behavior of electrostatically actuated nano/micromirrors is investigated. First, the minimum po- tential energy principle is utilized to find the equation gov- erning the static behavior of nano/micromirror under electro- static and vdW forces. Then, the stability of static equilib- rium points is analyzed using the energy method. It is found that when there exist two equilibrium points, the smaller one is stable and the larger one is unstable. The effects of dif- ferent design parameters on the mirror＇s pull-in angle and pull-in voltage are studied and it is found that vdW force can considerably reduce the stability limit of the mirror. At the end, the nonlinear equilibrium equation is solved numer- ically and analytically using homotopy perturbation method （HPM）. It is observed that a sixth order perturbation approx- imation can precisely model the mirror＇s behavior. The re- suits of this paper can be used for stable operation design and safe fabrication of torsional nano/micro actuators.展开更多
This research reviews the application of computational mechanics on the properties of nano/micro scaled thin films,in which the application of different computational methods is included.The concept and fundamental th...This research reviews the application of computational mechanics on the properties of nano/micro scaled thin films,in which the application of different computational methods is included.The concept and fundamental theories of concerned applications,material behavior estimations,interfacial delamination behavior,strain engineering,and multilevel modeling are thoroughly discussed.Moreover,an example of an interfacial adhesion estimation is presented to systematically estimate the related mechanical reliability issue in the microelectronic industry.The presented results show that the peeled mode fracture is the dominant delamination behavior of layered material system,with high stiffness along the bonding interface.However,the shear mode fracture being dominated as the polymer cover plate with low moduli is considered.The occurrence of crack advance is also significantly influenced by the interfacial crack length and applied loading.Therefore,this paper could serve as a guideline of several engineering cases with the assistance of computational mechanics.展开更多
A three-dimensional dynamic model for nano/micro-fabrications of silicon was presented. With the developed model, the fabrication process of silicon on nothing（SON） structure was quantitatively investigated. We empl...A three-dimensional dynamic model for nano/micro-fabrications of silicon was presented. With the developed model, the fabrication process of silicon on nothing（SON） structure was quantitatively investigated. We employ a diffuse interface model that incorporates the mechanism of surface diffusion. The mechanism of the fabrication is systematically integrated for high reliability of computational analysis. A semi-implicit Fourier spectral scheme is applied for high efficiency and numerical stability. Moreover, the theoretical analysis provides the guidance that is ordered by the fundamental geometrical design parameters to guide different fabrications of SON structures. The performed simulations suggest a substantial potential of the presented model for a reliable design technology of nano/micro-fabrications.展开更多
The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost ...The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost toxic cyanotoxin,microcystin-LR(MC-LR)enter soil via runoff,irrigated surface water and sewage,and the application of cyanobacterial biofertilizers as part of the sustainable agricultural practice.Earthworms in such remediation systems must sustain the potential risk from both nZVI and MC-LR.In the present study,earthworms(Eisenia fetida)were exposed up to 14 days to MC-LR and nZVI(individually and inmixture),and the toxicity was investigated at both the organismal andmetabolic levels,including growth,tissue damage,oxidative stress,metabolic response and gut microbiota.Results showed that co-exposure of MC-LR and nZVI is less potent to earthworms than that of separate exposure.Histological observations in the co-exposure group revealed only minor epidermal brokenness,and KEGG enrichment analysis showed that co-exposure induced earthworms to regulate glutathione biosynthesis for detoxification and reduced adverse effects from MC-LR.The combined use of nZVI promoted the growth and reproduction of soil and earthworm gut bacteria(e.g.,Sphingobacterium and Acinetobacter)responsible for the degradation of MC-LR,whichmight explain the observed antagonism between nZVI and MC-LR in earthworm microcosm.Our study suggests the beneficial use of nZVI to detoxify pollutants in earthworm-based vermiremediation systems where freshwater containing cyanobacterial blooms is frequently used to irrigate soil and supply water for the growth and metabolism of earthworms.展开更多
Micro/nano hierarchical structures could endow materials with various surface functions.However,the multilayer and multiscale characteristics of micro/nano hierarchical structures bring difficulties for their one step...Micro/nano hierarchical structures could endow materials with various surface functions.However,the multilayer and multiscale characteristics of micro/nano hierarchical structures bring difficulties for their one step and controllable fabrication.Accordingly,based on tip-based fabrication techniques,this study proposed a micro-amplitude vibration-assisted scratching method by introducing a periodic backward displacement into the conventional scratching process,which enabled the synchronous creation of the microscale V-groove and nanoscale ripples,i.e.a typical micro/nano hierarchical structure.The experiments and finite element modeling were employed to explore the formation process and mechanism of the micro/nano hierarchical structures.Being different from conventional cutting,this method was mainly based on the plow mechanism,and it could accurately replicate the shape of the indenter on the material surface.The microscale V-groove was formed due to the scratching action,and the nanoscale ripple was formed due to the extrusion action of the indenter on the microscale V-groove’s surface.Furthermore,the relationships between the processing parameters and the dimensions of the micro/nano hierarchical structures were established through experiments,and optimized processing parameters were determined to achieve regular micro/nano hierarchical structures.By this method,complex patterns constructed by various micro/nano hierarchical structures were fabricated on both flat and curved surfaces,achieving diverse surface structural colors.展开更多
Over the past three decades,micro/nano science and technology have experienced rapid advancements as new materials and advanced devices have increasingly evolved towards high levels of integration and miniaturization....Over the past three decades,micro/nano science and technology have experienced rapid advancements as new materials and advanced devices have increasingly evolved towards high levels of integration and miniaturization.In this context,mechanical properties have emerged as critical parameters for evaluating the operational performance and longevity of materials and devices at the micro/nanoscale.展开更多
Micro(nano)plastics,as an emerging environmental pollutant,are gradually discovered in hyporheic zones and groundwaterworldwide.Recent studies have focused on the origin and spatial/temporal distribution of micro(nano...Micro(nano)plastics,as an emerging environmental pollutant,are gradually discovered in hyporheic zones and groundwaterworldwide.Recent studies have focused on the origin and spatial/temporal distribution of micro(nano)plastics in regional groundwater,together with the influence of their properties and effects of environmental factors on their transport.However,the transport of micro(nano)plastics in the whole hyporheic zone-groundwater system and the behavior of co-existing substances still lack a complete theoretical interpretation.To provide systematic theoretical support for that,this review summarizes the current pollution status of micro(nano)plastics in the hyporheic zone-groundwater system,provides a comprehensive introduction of their sources and fate,and classifies the transport mechanisms into mechanical transport,physicochemical transport and biological processes assisted transport fromthe perspectives ofmechanical stress,physicochemical reactions,and bioturbation,respectively.Ultimately,this review proposes to advance the understanding of the multi-dimensional hydrosphere transport of micro(nano)plastics centered on groundwater,themicroorganisms-mediated synergistic transformation and co-transport involving the intertidal circulation.Overall,this review systematically dissects the presence and transport cycles of micro(nano)plastics within the hyporheic zone-groundwater system and proposes prospects for future studies based on the limitations of current studies.展开更多
The rapid evolution of laser micro/nano-manufacturing techniques has transformed precision manufacturing,enabling the creation of complex micro/nano-structures.These techniques are crucial for multiple industries,incl...The rapid evolution of laser micro/nano-manufacturing techniques has transformed precision manufacturing,enabling the creation of complex micro/nano-structures.These techniques are crucial for multiple industries,including electronics,photonics,and biomedical engineering,owing to their unmatched precision and versatility.The ability to manipulate materials at such scales has unlocked new possibilities for innovation,thereby facilitating the development of advanced components and devices with enhanced performance and functionalities.展开更多
Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-formi...Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-forming three-dimensional(3D)microscale functional devices and inducing fascinating and unique physical or chemical phenomena have granted this technology powerful versatility that no other technology can match.As this technology advances rapidly in various fields of application,some key challenges have emerged and remain to be urgently addressed.This review firstly introduces the fundamental principles for understanding how fs laser pulses interact with materials and the associated unique phenomena in section 2.Then micro/nano-fabrication in transparent materials by fs laser processing is presented in section 3.Thereafter,several high efficiency/throughput fabrication methods as well as pulse-shaping techniques are listed in sections 4 and 5 reviews four-dimensional(4D)and nanoscale printing realized by fs laser processing technology.Special attention is paid to the heterogeneous integration(HI)of functional materials enabled by fs laser processing in section 6.Several intriguing examples of 3D functional micro-devices created by fs laser-based manufacturing methods such as microfluidics,lab-on-chip,micro-optics,micro-mechanics,micro-electronics,micro-bots and micro-biodevices are reviewed in section 7.Finally,a summary of the review and a perspective are proposed to explore the challenges and future opportunities for further betterment of fs laser micro/nano processing technology.展开更多
Enzyme-powered micro/nanomotors(MNMs)(EMNMs)use natural enzymes to facilitate the decomposition of fuels,including hydrogen peroxide(H2O2),glucose,triglycerides,and urea to provide power.EMNMs can achieve self-propuls...Enzyme-powered micro/nanomotors(MNMs)(EMNMs)use natural enzymes to facilitate the decomposition of fuels,including hydrogen peroxide(H2O2),glucose,triglycerides,and urea to provide power.EMNMs can achieve self-propulsion through the in situ utilization of biofuels without additional fuels,exhibiting excellent biocompatibility and significant potential for application in the biomedical field.Compared with H_(2)O_(2),which may cause oxidative damage to the body,urea exhibits superior biosafety characteristics.Presently,urease-powered MNMs(UMNMs)have made notable progress in their applications in the biomedical field and have garnered considerable attention from researchers.In this review,we present the latest advancements in the biomedical field of UMNMs,primarily focusing on:1)diverse materials used for constructing the fundamental framework of motors;2)control of motor movement through the regulation of enzymatic reaction rates;and 3)research directions for the clinical application of motors,including in vivo imaging,biomarker detection,cancer treatment,optical therapy,overcoming biological barriers,antibacterial interventions,antithrombotic strategies,and gastric disease management.Despite showing immense potential in biomedical applications,there are still several challenges impeding its practical implementation,such as maintaining activity in the in vivo environment while accurately targeting specific sites to achieve the desired clinical therapeutic effects.展开更多
Micro/nanorobots have exhibited excellent application potential in the biomedical field,such as drug delivery,minimally invasive surgery,and bio-sensing.Furthermore,in order to achieve practical application,it is esse...Micro/nanorobots have exhibited excellent application potential in the biomedical field,such as drug delivery,minimally invasive surgery,and bio-sensing.Furthermore,in order to achieve practical application,it is essential for swimming micro/nanorobots to navigate towards specific targets or adjust their speed and morphology in complete environments.The navigation of swimming micro/nanorobots with temporal and spatial precision is critical for fulfilling the demand of applications.Here,we introduced a fully integrated wearable control system for micro/nanorobots navigation and manipulation,which is composed of a multifunctional sensor array,an artificial intelligence(AI)planner,and a magnetic field generator.The sensor array could perceive real-time changes in gestures,wrist rotation,and acoustic signals.AI planner based on machine learning offers adaptive path planning in response to dynamically changing signals to generate magnetic fields for the on-demand manipulation of micro/nanorobots.Such a novel,feasible control strategy was validated in the biological experiment in which cancer cells were targeted and killed by photothermal therapy using micro/nanorobots and integrated control platform.This wearable control system could play a crucial role in future intelligent medical applications and could be easily reconfigured toward other medical robots’control.展开更多
The designing and manufacturing of micro/nanoscale tools for delivery,diagnostic,and therapeutic are essential for their multiscale integration in the precision medicine field.Conventional three-dimensional(3D)printin...The designing and manufacturing of micro/nanoscale tools for delivery,diagnostic,and therapeutic are essential for their multiscale integration in the precision medicine field.Conventional three-dimensional(3D)printing approaches are not suitable for such kind of tools due to the accuracy limitation.Multiphoton polymerization(MPP)-based micro/nanomanufacturing is a noncontact,high-precision molding technology that has been widely used in the micro/nano field is a promising tool for micro/nanoscale related precision medicine.In this article the fundamentals of MPP-based technology and the required materials in precision medicine are overviewed.The biomedical applications in various scenarios are then summarized and categorized as delivery systems,microtissue modeling,surgery,and diagnosis.Finally,the existing challenges and future perspectives on MPP-based micro/nanomanufacturing for precision medicine are discussed,focusing on material design,process optimization,and practical applications to overcome its current limitations.展开更多
Sn-based solder is a widely used interconnection material in the field of electronic packaging;however,the performance requirements for these solders are becoming increasingly demanding owing to the rapid development ...Sn-based solder is a widely used interconnection material in the field of electronic packaging;however,the performance requirements for these solders are becoming increasingly demanding owing to the rapid development in this area.In recent years,the addition of micro/nanoreinforcement phases to Sn-based solders has provided a solution to improve the intrinsic properties of the solders.This paper reviews the progress in Sn-based micro/nanoreinforced composite solders over the past decade.The types of reinforcement particles,preparation methods of the composite solders,and strengthening effects on the microstructure,wettability,melting point,mechanical properties,and corrosion resistance under different particle-addition levels are discussed and summarized.The mechanisms of performance enhancement are summarized based on material-strengthening effects such as grain refinement and second-phase dispersion strengthening.In addition,we discuss the current shortcomings of such composite solders and possible future improvements,thereby establishing a theoretical foundation for the future development of Sn-based solders.展开更多
Micro/nanoscale robots(MNRs)have attracted significant interest in various fields because of their flexible design,physically controlled maneuvering,and barrier targeting.The execution of specific functions using MNRs...Micro/nanoscale robots(MNRs)have attracted significant interest in various fields because of their flexible design,physically controlled maneuvering,and barrier targeting.The execution of specific functions using MNRs relies on precise propulsion methods.Among the diverse propulsion techniques,physical propulsion is widely used owing to its noninvasive,safe,and convenient attributes.This review provides an analysis of the propulsion mechanisms in the magnetic,electric,thermal,and ultrasound fields and presents a comprehensive summary of the structures,movements,and applications of various MNRs while also examining their advantages and shortcomings associated with various physical propulsion methods.Finally,challenges and perspectives associated with the future development of MNRs are presented.The content of this review can serve as a multidisciplinary science reference for physicists,bioengineers,clinicians,roboticists,and chemists involved in pharmaceutical design and clinical therapy research.展开更多
Hierarchical micro/nanograting structures have attracted increasing attention owing to their significant applications in the fields of structural coloring,anti-counterfeiting,and decoration.Thus,the fabrication of hie...Hierarchical micro/nanograting structures have attracted increasing attention owing to their significant applications in the fields of structural coloring,anti-counterfeiting,and decoration.Thus,the fabrication of hierarchical micro/nanograting structures is important for these applications.In this study,a strategy for machining hierarchical micro/nanograting structures is developed by controlling the tool movement trajectory.A coupling Euler-Lagrange finite element model is established to simulate the machining process.The effect of the machining methods on the nanograting formation is demonstrated,and a suitable machining method for reducing the cutting force is obtained.The height of the nanograting decreases with an increase in the tool edge radius.Furthermore,optical variable devices(OVDs)are machined using an array overlap machining approach.Coding schemes for the parallel column unit crossover and column unit in the groove crossover are designed to achieve high-quality machining of OVDs.The coloring of the logo of the Harbin Institute of Technology and the logo of the centennial anniversary of the Harbin Institute of Technology on the surface of metal samples,such as aluminum alloys,is realized.The findings of this study provide a method for the fabrication of hierarchical micro/nanograting structures that can be used to prepare OVDs.展开更多
The poor corrosion resistance of magnesium(Mg)and its alloys limits their application in various fields.Micro arc oxidation(MAO)coatings can improve the corrosion resistance,but the pore defects and low surface hardne...The poor corrosion resistance of magnesium(Mg)and its alloys limits their application in various fields.Micro arc oxidation(MAO)coatings can improve the corrosion resistance,but the pore defects and low surface hardness make them susceptible to wear and accelerated corrosion during usage.In this study,a ZrO_(2)nanoparticles doped-MAO coating is prepared on the ZK61 Mg alloy by utilizing an MgF_(2)passivation layer to prevent ablation.The ZrO_(2)nanoparticles re-melt and precipitate due to local discharging,which produces evenly dispersed nanocrystals in the MAO coating.As a result,the hardness of the MAO coating with the appropriate ZrO_(2)concentration increases by over 10 times,while the wear rate decreases and corrosion resistance increases.With increasing ZrO_(2)concentrations,the corrosion potentials increase from−1.528 V of the bare ZK61 Mg alloy to−1.184 V,the corrosion current density decreases from 1.065×10^(–4)A cm^(–2)to 3.960×10^(–8)A cm^(–2),and the charge transfer resistance increases from 3.41×10^(2)Ωcm^(2)to 6.782×10^(5)Ωcm^(2).Immersion tests conducted in a salt solution for 28 d reveal minimal corrosion in contrast to severe corrosion on the untreated ZK61 Mg alloy.ZrO_(2)nanoparticles improve the corrosion resistance of MAO coatings by sealing pores and secondary strengthening of the corrosion product layer.展开更多
基金Project(50975095)supported by the National Natural Science Foundation of ChinaProject(2012ZM0048)supported by the Fundamental Research Funds for the Central Universities,China
文摘In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing （SPRB） and grain refinement mechanism, the microstructure characteristics and material properties of sample at various depths from the topmost surface were investigated by SEM, TEM, XRD, OM etc. The experimental results show that the gradient nano/micro-structure was introduced into the surface layer of over 100μm in thickness. The remarkable increase in hardness near the topmost surface was mainly attributed to the reduced grain size. The equiaxed nano-sized grains were in random orientation and the most of their boundaries were low-angle grain boundaries （LAGBs）. The coarse grains are refined into the few micro-sized grains by dislocation activities;deformation twinning was found to be the primary form for the formation of submicron grains;the formation of nanostructure was dominated by dislocation activities accompanied with rotation of grains in local region.
基金Project(2013AA050901)supported by the National High-tech Research and Development Program of China
文摘In order to enhance electrochemical properties of LiFePO4 （LFP） cathode materials, spherical porous nano/micro structured LFP/C cathode materials were synthesized by spray drying, followed by calcination. The results show that the spherical precursors with the sizes of 0.5-5 μm can be completely converted to LFP/C when the calcination temperature is higher than 500 ℃. The LFP/C microspheres obtained at calcination temperature of 700 ℃ are composed of numerous particles with sizes of -20 nm, and have well-developed interconnected pore structure and large specific surface area of 28.77 mE/g. The specific discharge capacities of the LFP/C obtained at 700 ℃ are 162.43, 154.35 and 144.03 mA.h/g at 0.5C, 1C and 2C, respectively. Meanwhile, the capacity retentions can reach up to 100% after 50 cycles. The improved electrochemical properties of the materials are ascribed to a small Li＋ diffusion resistance and special structure of LFP/C microspheres.
文摘In this paper, the effect of van der Waals （vdW） force on the pull-in behavior of electrostatically actuated nano/micromirrors is investigated. First, the minimum po- tential energy principle is utilized to find the equation gov- erning the static behavior of nano/micromirror under electro- static and vdW forces. Then, the stability of static equilib- rium points is analyzed using the energy method. It is found that when there exist two equilibrium points, the smaller one is stable and the larger one is unstable. The effects of dif- ferent design parameters on the mirror＇s pull-in angle and pull-in voltage are studied and it is found that vdW force can considerably reduce the stability limit of the mirror. At the end, the nonlinear equilibrium equation is solved numer- ically and analytically using homotopy perturbation method （HPM）. It is observed that a sixth order perturbation approx- imation can precisely model the mirror＇s behavior. The re- suits of this paper can be used for stable operation design and safe fabrication of torsional nano/micro actuators.
文摘This research reviews the application of computational mechanics on the properties of nano/micro scaled thin films,in which the application of different computational methods is included.The concept and fundamental theories of concerned applications,material behavior estimations,interfacial delamination behavior,strain engineering,and multilevel modeling are thoroughly discussed.Moreover,an example of an interfacial adhesion estimation is presented to systematically estimate the related mechanical reliability issue in the microelectronic industry.The presented results show that the peeled mode fracture is the dominant delamination behavior of layered material system,with high stiffness along the bonding interface.However,the shear mode fracture being dominated as the polymer cover plate with low moduli is considered.The occurrence of crack advance is also significantly influenced by the interfacial crack length and applied loading.Therefore,this paper could serve as a guideline of several engineering cases with the assistance of computational mechanics.
基金the National Natural Science Foundation of China(No.51775154)the ZheJiang Provincial Natural Science Foundation of China(No.LZ15E050004)
文摘A three-dimensional dynamic model for nano/micro-fabrications of silicon was presented. With the developed model, the fabrication process of silicon on nothing（SON） structure was quantitatively investigated. We employ a diffuse interface model that incorporates the mechanism of surface diffusion. The mechanism of the fabrication is systematically integrated for high reliability of computational analysis. A semi-implicit Fourier spectral scheme is applied for high efficiency and numerical stability. Moreover, the theoretical analysis provides the guidance that is ordered by the fundamental geometrical design parameters to guide different fabrications of SON structures. The performed simulations suggest a substantial potential of the presented model for a reliable design technology of nano/micro-fabrications.
基金supported by the National Natural Science Foundation of China(No.21777139)the National Key Research and Development Program of China(No.2017YFA0207003).
文摘The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost toxic cyanotoxin,microcystin-LR(MC-LR)enter soil via runoff,irrigated surface water and sewage,and the application of cyanobacterial biofertilizers as part of the sustainable agricultural practice.Earthworms in such remediation systems must sustain the potential risk from both nZVI and MC-LR.In the present study,earthworms(Eisenia fetida)were exposed up to 14 days to MC-LR and nZVI(individually and inmixture),and the toxicity was investigated at both the organismal andmetabolic levels,including growth,tissue damage,oxidative stress,metabolic response and gut microbiota.Results showed that co-exposure of MC-LR and nZVI is less potent to earthworms than that of separate exposure.Histological observations in the co-exposure group revealed only minor epidermal brokenness,and KEGG enrichment analysis showed that co-exposure induced earthworms to regulate glutathione biosynthesis for detoxification and reduced adverse effects from MC-LR.The combined use of nZVI promoted the growth and reproduction of soil and earthworm gut bacteria(e.g.,Sphingobacterium and Acinetobacter)responsible for the degradation of MC-LR,whichmight explain the observed antagonism between nZVI and MC-LR in earthworm microcosm.Our study suggests the beneficial use of nZVI to detoxify pollutants in earthworm-based vermiremediation systems where freshwater containing cyanobacterial blooms is frequently used to irrigate soil and supply water for the growth and metabolism of earthworms.
基金supported by the Jilin Province Key Research and Development Plan Project(20240302066GX)the National Natural Science Foundation of China(Grant No.52075221)the Fundamental Research Funds for the Central Universities(2023-JCXK-02)。
文摘Micro/nano hierarchical structures could endow materials with various surface functions.However,the multilayer and multiscale characteristics of micro/nano hierarchical structures bring difficulties for their one step and controllable fabrication.Accordingly,based on tip-based fabrication techniques,this study proposed a micro-amplitude vibration-assisted scratching method by introducing a periodic backward displacement into the conventional scratching process,which enabled the synchronous creation of the microscale V-groove and nanoscale ripples,i.e.a typical micro/nano hierarchical structure.The experiments and finite element modeling were employed to explore the formation process and mechanism of the micro/nano hierarchical structures.Being different from conventional cutting,this method was mainly based on the plow mechanism,and it could accurately replicate the shape of the indenter on the material surface.The microscale V-groove was formed due to the scratching action,and the nanoscale ripple was formed due to the extrusion action of the indenter on the microscale V-groove’s surface.Furthermore,the relationships between the processing parameters and the dimensions of the micro/nano hierarchical structures were established through experiments,and optimized processing parameters were determined to achieve regular micro/nano hierarchical structures.By this method,complex patterns constructed by various micro/nano hierarchical structures were fabricated on both flat and curved surfaces,achieving diverse surface structural colors.
文摘Over the past three decades,micro/nano science and technology have experienced rapid advancements as new materials and advanced devices have increasingly evolved towards high levels of integration and miniaturization.In this context,mechanical properties have emerged as critical parameters for evaluating the operational performance and longevity of materials and devices at the micro/nanoscale.
基金supported by the National Natural Science Foundation of China(Nos.22036001,42342057,and 22236006).
文摘Micro(nano)plastics,as an emerging environmental pollutant,are gradually discovered in hyporheic zones and groundwaterworldwide.Recent studies have focused on the origin and spatial/temporal distribution of micro(nano)plastics in regional groundwater,together with the influence of their properties and effects of environmental factors on their transport.However,the transport of micro(nano)plastics in the whole hyporheic zone-groundwater system and the behavior of co-existing substances still lack a complete theoretical interpretation.To provide systematic theoretical support for that,this review summarizes the current pollution status of micro(nano)plastics in the hyporheic zone-groundwater system,provides a comprehensive introduction of their sources and fate,and classifies the transport mechanisms into mechanical transport,physicochemical transport and biological processes assisted transport fromthe perspectives ofmechanical stress,physicochemical reactions,and bioturbation,respectively.Ultimately,this review proposes to advance the understanding of the multi-dimensional hydrosphere transport of micro(nano)plastics centered on groundwater,themicroorganisms-mediated synergistic transformation and co-transport involving the intertidal circulation.Overall,this review systematically dissects the presence and transport cycles of micro(nano)plastics within the hyporheic zone-groundwater system and proposes prospects for future studies based on the limitations of current studies.
文摘The rapid evolution of laser micro/nano-manufacturing techniques has transformed precision manufacturing,enabling the creation of complex micro/nano-structures.These techniques are crucial for multiple industries,including electronics,photonics,and biomedical engineering,owing to their unmatched precision and versatility.The ability to manipulate materials at such scales has unlocked new possibilities for innovation,thereby facilitating the development of advanced components and devices with enhanced performance and functionalities.
基金supported by National Key R&D Program of China(Grant Nos.2021YFB2802000 and 2022YFB2804300)Science and Technology Commission of Shanghai Municipality(Grant No.21DZ1100500)+3 种基金Shanghai Municipal Science and Technology Major Projectthe Shanghai Frontiers Science Center Program(2021-2025 No.20)National Natural Science Foundation of China(Grant No.61975123)Shanghai Scienceand Technology Innovation Action Plan(Grant No.23JC1403100)。
文摘Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-forming three-dimensional(3D)microscale functional devices and inducing fascinating and unique physical or chemical phenomena have granted this technology powerful versatility that no other technology can match.As this technology advances rapidly in various fields of application,some key challenges have emerged and remain to be urgently addressed.This review firstly introduces the fundamental principles for understanding how fs laser pulses interact with materials and the associated unique phenomena in section 2.Then micro/nano-fabrication in transparent materials by fs laser processing is presented in section 3.Thereafter,several high efficiency/throughput fabrication methods as well as pulse-shaping techniques are listed in sections 4 and 5 reviews four-dimensional(4D)and nanoscale printing realized by fs laser processing technology.Special attention is paid to the heterogeneous integration(HI)of functional materials enabled by fs laser processing in section 6.Several intriguing examples of 3D functional micro-devices created by fs laser-based manufacturing methods such as microfluidics,lab-on-chip,micro-optics,micro-mechanics,micro-electronics,micro-bots and micro-biodevices are reviewed in section 7.Finally,a summary of the review and a perspective are proposed to explore the challenges and future opportunities for further betterment of fs laser micro/nano processing technology.
基金supported by the National Natural Science Foundation of China(Grant No.:82372102).
文摘Enzyme-powered micro/nanomotors(MNMs)(EMNMs)use natural enzymes to facilitate the decomposition of fuels,including hydrogen peroxide(H2O2),glucose,triglycerides,and urea to provide power.EMNMs can achieve self-propulsion through the in situ utilization of biofuels without additional fuels,exhibiting excellent biocompatibility and significant potential for application in the biomedical field.Compared with H_(2)O_(2),which may cause oxidative damage to the body,urea exhibits superior biosafety characteristics.Presently,urease-powered MNMs(UMNMs)have made notable progress in their applications in the biomedical field and have garnered considerable attention from researchers.In this review,we present the latest advancements in the biomedical field of UMNMs,primarily focusing on:1)diverse materials used for constructing the fundamental framework of motors;2)control of motor movement through the regulation of enzymatic reaction rates;and 3)research directions for the clinical application of motors,including in vivo imaging,biomarker detection,cancer treatment,optical therapy,overcoming biological barriers,antibacterial interventions,antithrombotic strategies,and gastric disease management.Despite showing immense potential in biomedical applications,there are still several challenges impeding its practical implementation,such as maintaining activity in the in vivo environment while accurately targeting specific sites to achieve the desired clinical therapeutic effects.
基金supported by the National Key Research and Development Program(2022YFB4701700)National Excellent Youth Science Fund Project of the National Natural Science Foundation of China(52322502)+6 种基金the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(52025054)National Natural Science Foundation of China(52175009),Postdoctoral Fellowship Program of CPSF(GZC20232498)Postdoctoral Innovative Talents in Shandong Province(SDBX2023011)China Postdoctoral Science Foundation Grant(2023M733341)Key R&D Program of Shandong Province,China(2021ZLGX04)National Heilongjiang Providence Nature Science Foundation of China(YQ2022E022)Fundamental Research Funds for the Central Universities。
文摘Micro/nanorobots have exhibited excellent application potential in the biomedical field,such as drug delivery,minimally invasive surgery,and bio-sensing.Furthermore,in order to achieve practical application,it is essential for swimming micro/nanorobots to navigate towards specific targets or adjust their speed and morphology in complete environments.The navigation of swimming micro/nanorobots with temporal and spatial precision is critical for fulfilling the demand of applications.Here,we introduced a fully integrated wearable control system for micro/nanorobots navigation and manipulation,which is composed of a multifunctional sensor array,an artificial intelligence(AI)planner,and a magnetic field generator.The sensor array could perceive real-time changes in gestures,wrist rotation,and acoustic signals.AI planner based on machine learning offers adaptive path planning in response to dynamically changing signals to generate magnetic fields for the on-demand manipulation of micro/nanorobots.Such a novel,feasible control strategy was validated in the biological experiment in which cancer cells were targeted and killed by photothermal therapy using micro/nanorobots and integrated control platform.This wearable control system could play a crucial role in future intelligent medical applications and could be easily reconfigured toward other medical robots’control.
基金the National Natural Science Foundation of China(52275294)the National Key Research and Development Program of China(2018YFA0703000).
文摘The designing and manufacturing of micro/nanoscale tools for delivery,diagnostic,and therapeutic are essential for their multiscale integration in the precision medicine field.Conventional three-dimensional(3D)printing approaches are not suitable for such kind of tools due to the accuracy limitation.Multiphoton polymerization(MPP)-based micro/nanomanufacturing is a noncontact,high-precision molding technology that has been widely used in the micro/nano field is a promising tool for micro/nanoscale related precision medicine.In this article the fundamentals of MPP-based technology and the required materials in precision medicine are overviewed.The biomedical applications in various scenarios are then summarized and categorized as delivery systems,microtissue modeling,surgery,and diagnosis.Finally,the existing challenges and future perspectives on MPP-based micro/nanomanufacturing for precision medicine are discussed,focusing on material design,process optimization,and practical applications to overcome its current limitations.
基金financially supported by the State Key Laboratory for Mechanical Behavior of Materials,China(No.202325012)the National Natural Science Foundation of China(No.U21A20128).
文摘Sn-based solder is a widely used interconnection material in the field of electronic packaging;however,the performance requirements for these solders are becoming increasingly demanding owing to the rapid development in this area.In recent years,the addition of micro/nanoreinforcement phases to Sn-based solders has provided a solution to improve the intrinsic properties of the solders.This paper reviews the progress in Sn-based micro/nanoreinforced composite solders over the past decade.The types of reinforcement particles,preparation methods of the composite solders,and strengthening effects on the microstructure,wettability,melting point,mechanical properties,and corrosion resistance under different particle-addition levels are discussed and summarized.The mechanisms of performance enhancement are summarized based on material-strengthening effects such as grain refinement and second-phase dispersion strengthening.In addition,we discuss the current shortcomings of such composite solders and possible future improvements,thereby establishing a theoretical foundation for the future development of Sn-based solders.
基金the National Natural Science Foundation of China(Nos.U2130128 and 12102376)Yanzhao Young Scientist Project from Natural Science Foundation of Hebei Province(No.B2023205040)+6 种基金Basic Research Cooperation Special Foundation of Beijing-Tianjin-Hebei Region(Nos.H2022205047,22JCZXJC00060,and E3B33911DF)Central Government Guiding Local Science and Technology Development Project(No.216Z4302G)Hebei Administration for Market Supervision Science and Technology Project List(No.2023ZC03)Innovation Capability Improvement Plan Project of Hebei Province(No.22567604H)Ph.D Scientific Research Start-up Fund(No.L2023B18)College Student’s Innovation and Entrepreneurship Training Plan Program(No.S202410094046)of Hebei Normal Universitythe Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011592).
文摘Micro/nanoscale robots(MNRs)have attracted significant interest in various fields because of their flexible design,physically controlled maneuvering,and barrier targeting.The execution of specific functions using MNRs relies on precise propulsion methods.Among the diverse propulsion techniques,physical propulsion is widely used owing to its noninvasive,safe,and convenient attributes.This review provides an analysis of the propulsion mechanisms in the magnetic,electric,thermal,and ultrasound fields and presents a comprehensive summary of the structures,movements,and applications of various MNRs while also examining their advantages and shortcomings associated with various physical propulsion methods.Finally,challenges and perspectives associated with the future development of MNRs are presented.The content of this review can serve as a multidisciplinary science reference for physicists,bioengineers,clinicians,roboticists,and chemists involved in pharmaceutical design and clinical therapy research.
基金Supported by National Natural Science Foundation of China(Grant Nos.52035004,52105434).
文摘Hierarchical micro/nanograting structures have attracted increasing attention owing to their significant applications in the fields of structural coloring,anti-counterfeiting,and decoration.Thus,the fabrication of hierarchical micro/nanograting structures is important for these applications.In this study,a strategy for machining hierarchical micro/nanograting structures is developed by controlling the tool movement trajectory.A coupling Euler-Lagrange finite element model is established to simulate the machining process.The effect of the machining methods on the nanograting formation is demonstrated,and a suitable machining method for reducing the cutting force is obtained.The height of the nanograting decreases with an increase in the tool edge radius.Furthermore,optical variable devices(OVDs)are machined using an array overlap machining approach.Coding schemes for the parallel column unit crossover and column unit in the groove crossover are designed to achieve high-quality machining of OVDs.The coloring of the logo of the Harbin Institute of Technology and the logo of the centennial anniversary of the Harbin Institute of Technology on the surface of metal samples,such as aluminum alloys,is realized.The findings of this study provide a method for the fabrication of hierarchical micro/nanograting structures that can be used to prepare OVDs.
基金supported by the Postdoctoral Fellowship Program of CPSF(No.GZC20231545)the China Postdoctoral Science Foundation(Nos.2024T170557 and 2023M742224)+6 种基金the Shanghai Post-doctoral Excellence Program(No.2023440)the National Natural Science Foundation of China(Nos.52127801,52401101,and 22205012)the Shenzhen Basic Research Project(Nos.JCYJ20210324120001003,JCYJ20200109144608205)the Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515011301 and 2021A1515012246)the IER Foundation(Nos.IERF202201 andIERF202202),the City University of Hong Kong Donation Research(No.DON-RMG 9229021)the Hong Kong PDFS-RGC Postdoctoral Fellowship Scheme(Nos.PDFS2122–1S08 and CityU 9061014)the Hong Kong HMRF(Health and Medical Research Fund)(Nos.2120972 and CityU 9211320).
文摘The poor corrosion resistance of magnesium(Mg)and its alloys limits their application in various fields.Micro arc oxidation(MAO)coatings can improve the corrosion resistance,but the pore defects and low surface hardness make them susceptible to wear and accelerated corrosion during usage.In this study,a ZrO_(2)nanoparticles doped-MAO coating is prepared on the ZK61 Mg alloy by utilizing an MgF_(2)passivation layer to prevent ablation.The ZrO_(2)nanoparticles re-melt and precipitate due to local discharging,which produces evenly dispersed nanocrystals in the MAO coating.As a result,the hardness of the MAO coating with the appropriate ZrO_(2)concentration increases by over 10 times,while the wear rate decreases and corrosion resistance increases.With increasing ZrO_(2)concentrations,the corrosion potentials increase from−1.528 V of the bare ZK61 Mg alloy to−1.184 V,the corrosion current density decreases from 1.065×10^(–4)A cm^(–2)to 3.960×10^(–8)A cm^(–2),and the charge transfer resistance increases from 3.41×10^(2)Ωcm^(2)to 6.782×10^(5)Ωcm^(2).Immersion tests conducted in a salt solution for 28 d reveal minimal corrosion in contrast to severe corrosion on the untreated ZK61 Mg alloy.ZrO_(2)nanoparticles improve the corrosion resistance of MAO coatings by sealing pores and secondary strengthening of the corrosion product layer.
