Carbon nanotube(CNT),particularly single-walled CNT,possesses exceptional properties,and can be utilized in many high-end applications including high-performance electronics.However,the atomic arrangement of a CNT det...Carbon nanotube(CNT),particularly single-walled CNT,possesses exceptional properties,and can be utilized in many high-end applications including high-performance electronics.However,the atomic arrangement of a CNT determines its band structure,making the atomic-precision fabrication one of most important topics for the development of this material.In this perspective,the author gives a personal summary on the history,current status of the atomic-precision fabrication of CNT and outlines the remaining challenges as well as the possible paths that may lead the production of atomically precise CNTs from‘fabrication’to‘manufacturing’.展开更多
This paper presents the design, development, and control of a large range beam flexure-based nano servo system for the micro-stereolithography （MSL） process. As a key enabler of high accuracy in this process, a comp...This paper presents the design, development, and control of a large range beam flexure-based nano servo system for the micro-stereolithography （MSL） process. As a key enabler of high accuracy in this process, a compact desktop-size beam flexure-based nanopositioner was designed with millimeter range and nanometric motion quality. This beam flexure-based motion system is highly suitable for harsh operation conditions, as no assembly or maintenance is required during the operation. From a mechanism design viewpoint, a mirror-symmetric arrangement and appropriate redundant constraints are crucial to reduce undesired parasitic motion. Detailed finite element analysis （FEA） was conducted and showed satisfactory mechanical features. With the identified dynamic models of the nanopositioner, real-time control strategies were designed and implemented into the monolithically fabricated prototype system, demonstrating the enhanced tracking capability of the MSL process. The servo system has both a millimeter operating range and a root mean square （RMS） tracking error of about 80 nm for a circular traiectorv.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
The development of robust anode-electrolyte interfaces(AEI)with enhanced compatibility and mechanical strength is critical for regulating zinc-ion nucleation kinetics,suppressing dendrite formation,and advancing zinc-...The development of robust anode-electrolyte interfaces(AEI)with enhanced compatibility and mechanical strength is critical for regulating zinc-ion nucleation kinetics,suppressing dendrite formation,and advancing zinc-ion battery commercialization.To address persistent interface degradation during battery cycling,we propose a novel manufacturing strategy utilizing digital-light-processing(DLP)3D printing.This approach enables programmable regulation of gel-polymer electrolyte(GPE)structures through layer-by-layer photopolymerization,achieving precision regulation of macro-microstructures and interfacial stresses.The DLP-manufactured GPEs feature cross-scale structures combining dense porous networks with smooth surface topography,providing abundant electrochemical active sites and stable interfacial contact.Multiphase-field simulations integrated with in-situ/ex-situ characterizations reveal stress-enhanced zinc deposition mechanisms,where optimized interfacial stress eliminates AEI contact instability,ensuring rapid mass transfer between electrode and electrolyte.Under regulated interface stress,the symmetrical cell demonstrates stability exceeding 2000 hours,and the full cell retains 91.72%capacity after 8000 ultralong cycles,with reliable operation under extreme temperature conditions(-10℃/60℃).The precise regulation of interfacial stresses establishes stable AEI configurations,demonstrating a transformative approach to durable zinc-ion battery design.展开更多
The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film coo...The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film cooling holes.It has been demonstrated that conventional long-pulse lasers are incapable of meeting the elevated quality surface finish requirements for these holes,a consequence of the severe thermal defects.The employment of backside water-assisted laser drilling technology confers a number of distinct advantages in terms of mitigating laser thermal damage,thus representing a highly promising solution to this challenge.However,significant accumulation of bubbles and machining products during the backside water-assisted laser drilling process has been demonstrated to have a detrimental effect on laser transmission and machining stability,thereby reducing machining quality.In order to surmount these challenges,a novel method has been proposed,namely an ultrasonic shock water flow-assisted picosecond laser drilling technique.Numerical models for ultrasonic acoustic streaming and particle tracking for machining product transport have been established to investigate the mechanism.The simulation results demonstrated that the majority of the machining products could rapidly move away from the machining area because of the action of acoustic streaming,thereby avoiding the accumulation of bubbles and products.Subsequent analysis,comparing the process performance in micro-hole machining,confirmed that the ultrasonic field could effectively eliminate bubble and chip accumulation,thus significantly improving micro-hole quality.Furthermore,the impact of ultrasonic and laser parameters on micro-hole quality under varying machining methods was thoroughly investigated.The findings demonstrated that the novel methodology outlined in this study yielded superior-quality micro-holes at elevated ultrasonic and laser power levels,in conjunction with reduced laser frequency and scanning velocity.The taper of the micro-holes produced by the new method was reduced by more than 25%compared with the other conventional methods.展开更多
High precision manufacturing, e.g. milling and grinding, which have manufacturing tolerances in the range of <10 μm require microscopic measurement techniques for the inspection of the manufactured components. The...High precision manufacturing, e.g. milling and grinding, which have manufacturing tolerances in the range of <10 μm require microscopic measurement techniques for the inspection of the manufactured components. These measurement techniques are very sensitive to cooling liquids and lubricants which are essential for many manufacturing processes. Therefore, the measurement of the components is usually conducted in separate and clean laboratories and not directly in the manufacturing machine. This approach has some major drawbacks, e.g. high time consumption and no possibility for online process monitoring. In this article, a novel concept for the integration of high precision optical topography measurement systems into the manufacturing machine is introduced and compared to other concepts. The introduced concept uses a reservoir with cooling liquid in which the measurement object is immersed during the measurement. Thereby, measurement disturbance by splashing cooling liquids and lubricants can effectively be avoided.展开更多
To explore a proof-of-concept for atomically precise manufacturing(APM)using scanning probe microscopy(SPM),first principle theoretical calculations of atom-by-atom transfer from the apex of an SPM tip to an individua...To explore a proof-of-concept for atomically precise manufacturing(APM)using scanning probe microscopy(SPM),first principle theoretical calculations of atom-by-atom transfer from the apex of an SPM tip to an individual radical on a surfacebound organic molecule have been performed.Atom transfer is achieved by spatially controlled motion of a gold terminated tip to the radical.Two molecular tools for SPM-based APM have been designed and investigated,each comprising an adamantane core,a radical end group,and trithiol linkers to enable strong chemisorption on the Au(111)surface:ethynyl-adamantanetrithiol and adamantyl-trithiol.We demonstrate the details of controlled Au atom abstraction during tip approach toward and retraction from the radical species.Upon approach of the tip,the apical Au atom undergoes a transfer toward the carbon radical at a clearly defined threshold separation.This atomic displacement is accompanied by a net energy gain of the system in the range−0.5 to−1.5 eV,depending on the radical structure.In the case of a triangular pyramidal apex model,two tip configurations are possible after the tip atom displacement:(1)an Au atom is abstracted from the tip and bound to the C radical,not bound to the tip base anymore,and(2)apical tip atoms rearrange to form a continuous neck between the tip and radical.In the second case,subsequent tip retraction leads to the same final configuration as the first,with the abstracted Au atom bound to radical carbon atom of the molecular tool.For the less reactive adamantyl-trithiol radical molecular tool,Au atom transfer is less energetically favored,but this has the advantage of avoiding other apex gold atoms from rearrangement.展开更多
Electroforming is a specialised electroplating process for the manufacture of precision metal parts and mold tooling. Because it can simplify technical process and shorten molding cycles, electroforming is also a rapi...Electroforming is a specialised electroplating process for the manufacture of precision metal parts and mold tooling. Because it can simplify technical process and shorten molding cycles, electroforming is also a rapid manufacturing technology. Compared with direct and unipolar pulse current, bipolar pulse current in electroforming can obtain fine structure and grain size as well as surface leveling, resulting in better precision and surface finish. In this paper, bipolar pulse current electroforming is introduced. The influencing parameters such as electrolyte parameter, additives, current density, pH, temperature, and pulse parameters have been studied by experiments. Experiments on nickel electroforming in molds and dies have been done. The results indicated that bipolar pulse current electroforming could improve the quality and precision further, while reducing internal stress.展开更多
Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth.However,it is still a challenge to widely tune str...Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth.However,it is still a challenge to widely tune structure parameters of scaffolds by conventional methods because of inevitable pore geometrical deformation and poor pore interconnectivity.Here,the long-term in vivo biological performances of nonstoichiometric bioceramic scaffolds with different pore dimensions were assessed in critical-size femoral bone defect model.The 6%Mg-substituted wollastonite(CSi-Mg6)powders were prepared via wet-chemical precipitation and the scaffolds elaborately printed by ceramic stereolithography,displaying designed constant pore strut and tailorable pore height(200,320,450,600μm),were investigated thoroughly in the bone regeneration process.Together with detailed structural stability and mechanical properties were collaboratively outlined.BothμCT and histological analyses indicated that bone tissue ingrowth was retarded in 200μm scaffolds in the whole stage(2-16 weeks)but the 320μm scaffolds showed appreciable bone tissue in the center of porous constructs at 6-10 weeks and matured bone tissue were uniformly invaded in the whole pore networks at 16 weeks.Interestingly,the neo-tissue ingrowth was facilitated in the 450μm and 600μm scaffolds after 2 weeks and higher extent of bone regeneration and remodeling at the later stage.These new findings provide critical information on how engineered porous architecture impact bone regeneration in vivo.Simultaneously,this study shows important implications for optimizing the porous scaffolds design by advanced additive manufacture technique to match the clinical translation with high performance.展开更多
Pore architecture in bioceramic scaffolds plays an important role in facilitating vascularization efficiency during bone repair or orbital reconstruction.Many investigations have explored this relationship but lack in...Pore architecture in bioceramic scaffolds plays an important role in facilitating vascularization efficiency during bone repair or orbital reconstruction.Many investigations have explored this relationship but lack integrating pore architectural features in a scaffold,hindering optimization of architectural parameters(geometry,size and curvature)to improve vascularization and consequently clinical outcomes.To address this challenge,we have developed an integrating design strategy to fabricate different pore architectures(cube,gyroid and hexagon)with different pore dimensions(-350,500 and 650 lm)in the silicate-based bioceramic scaffolds via digital light processing technique.The sintered scaffolds maintained high-fidelity pore architectures similar to the printing model.The hexagon-and gyroid-pore scaffolds exhibited the highest and lowest compressive strength(from 15 to 55MPa),respectively,but the cube-pore scaffolds showed appreciable elastic modulus.Moreover,the gyroid-pore architecture contributed on a faster ion dissolution and mass decay in vitro.It is interesting that bothμCT and histological analyses indicate vascularization efficiency was challenged even in the 650-μm pore region of hexagon-pore scaffolds within 2weeks in rabbit models,but the gyroid-pore constructs indicated appreciable blood vessel networks even in the 350-μm pore region at 2weeks and high-density blood vessels were uniformly invaded in the 500-and 650-μm pore at 4weeks.Angiogenesis was facilitated in the cube-pore scaffolds in comparison with the hexagon-pore ones within 4weeks.These studies demonstrate that the continuous pore wall curvature feature in gyroid-pore architecture is an important implication for biodegradation,vascular cell migration and vessel ingrowth in porous bioceramic scaffolds.展开更多
基金supported by JSPS KAKENHI(Grant Nos.JP18H05329,JP19H02543,JP20H00220,and JP20KK0114)by JST,CREST Grant No.JPMJCR20B5,Japansupported by the‘Nanotechnology Platform’of the MEXT,Japan,Grant Nos.JPMXP09A20UT0063 and JPMXP09A21UT0050.
文摘Carbon nanotube(CNT),particularly single-walled CNT,possesses exceptional properties,and can be utilized in many high-end applications including high-performance electronics.However,the atomic arrangement of a CNT determines its band structure,making the atomic-precision fabrication one of most important topics for the development of this material.In this perspective,the author gives a personal summary on the history,current status of the atomic-precision fabrication of CNT and outlines the remaining challenges as well as the possible paths that may lead the production of atomically precise CNTs from‘fabrication’to‘manufacturing’.
基金The authors would like to acknowledge support from the Open Foundation of the State Key Laboratory of Tribology ＆ Institute of Manufacturing Engineering （SKL2016B05）, and the National Natural Science Foundation of China （NSFC） （61327003）.
文摘This paper presents the design, development, and control of a large range beam flexure-based nano servo system for the micro-stereolithography （MSL） process. As a key enabler of high accuracy in this process, a compact desktop-size beam flexure-based nanopositioner was designed with millimeter range and nanometric motion quality. This beam flexure-based motion system is highly suitable for harsh operation conditions, as no assembly or maintenance is required during the operation. From a mechanism design viewpoint, a mirror-symmetric arrangement and appropriate redundant constraints are crucial to reduce undesired parasitic motion. Detailed finite element analysis （FEA） was conducted and showed satisfactory mechanical features. With the identified dynamic models of the nanopositioner, real-time control strategies were designed and implemented into the monolithically fabricated prototype system, demonstrating the enhanced tracking capability of the MSL process. The servo system has both a millimeter operating range and a root mean square （RMS） tracking error of about 80 nm for a circular traiectorv.
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 Natural Science Foundation of China(U22A20193)National Key Research and Development Program of China(2024YFB3409000)+1 种基金TCL science and technology innovation fund(20231751)Fundamental Research Funds for the Central Universities(No.2024ZYGXZR066)。
文摘The development of robust anode-electrolyte interfaces(AEI)with enhanced compatibility and mechanical strength is critical for regulating zinc-ion nucleation kinetics,suppressing dendrite formation,and advancing zinc-ion battery commercialization.To address persistent interface degradation during battery cycling,we propose a novel manufacturing strategy utilizing digital-light-processing(DLP)3D printing.This approach enables programmable regulation of gel-polymer electrolyte(GPE)structures through layer-by-layer photopolymerization,achieving precision regulation of macro-microstructures and interfacial stresses.The DLP-manufactured GPEs feature cross-scale structures combining dense porous networks with smooth surface topography,providing abundant electrochemical active sites and stable interfacial contact.Multiphase-field simulations integrated with in-situ/ex-situ characterizations reveal stress-enhanced zinc deposition mechanisms,where optimized interfacial stress eliminates AEI contact instability,ensuring rapid mass transfer between electrode and electrolyte.Under regulated interface stress,the symmetrical cell demonstrates stability exceeding 2000 hours,and the full cell retains 91.72%capacity after 8000 ultralong cycles,with reliable operation under extreme temperature conditions(-10℃/60℃).The precise regulation of interfacial stresses establishes stable AEI configurations,demonstrating a transformative approach to durable zinc-ion battery design.
基金supported by the National Natural Science Foundation of China(No.52205468,No.52275431,No.52375186)China Postdoctoral Science Foundation(No.2025M771349)Zhejiang Province Natural Science Foundation(No.LD22E050001)。
文摘The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film cooling holes.It has been demonstrated that conventional long-pulse lasers are incapable of meeting the elevated quality surface finish requirements for these holes,a consequence of the severe thermal defects.The employment of backside water-assisted laser drilling technology confers a number of distinct advantages in terms of mitigating laser thermal damage,thus representing a highly promising solution to this challenge.However,significant accumulation of bubbles and machining products during the backside water-assisted laser drilling process has been demonstrated to have a detrimental effect on laser transmission and machining stability,thereby reducing machining quality.In order to surmount these challenges,a novel method has been proposed,namely an ultrasonic shock water flow-assisted picosecond laser drilling technique.Numerical models for ultrasonic acoustic streaming and particle tracking for machining product transport have been established to investigate the mechanism.The simulation results demonstrated that the majority of the machining products could rapidly move away from the machining area because of the action of acoustic streaming,thereby avoiding the accumulation of bubbles and products.Subsequent analysis,comparing the process performance in micro-hole machining,confirmed that the ultrasonic field could effectively eliminate bubble and chip accumulation,thus significantly improving micro-hole quality.Furthermore,the impact of ultrasonic and laser parameters on micro-hole quality under varying machining methods was thoroughly investigated.The findings demonstrated that the novel methodology outlined in this study yielded superior-quality micro-holes at elevated ultrasonic and laser power levels,in conjunction with reduced laser frequency and scanning velocity.The taper of the micro-holes produced by the new method was reduced by more than 25%compared with the other conventional methods.
文摘High precision manufacturing, e.g. milling and grinding, which have manufacturing tolerances in the range of <10 μm require microscopic measurement techniques for the inspection of the manufactured components. These measurement techniques are very sensitive to cooling liquids and lubricants which are essential for many manufacturing processes. Therefore, the measurement of the components is usually conducted in separate and clean laboratories and not directly in the manufacturing machine. This approach has some major drawbacks, e.g. high time consumption and no possibility for online process monitoring. In this article, a novel concept for the integration of high precision optical topography measurement systems into the manufacturing machine is introduced and compared to other concepts. The introduced concept uses a reservoir with cooling liquid in which the measurement object is immersed during the measurement. Thereby, measurement disturbance by splashing cooling liquids and lubricants can effectively be avoided.
基金the National Science Foundation of China for Distinguished Young Scholars(51925505)led by Yingguang Lifunding was obtained from the National Natural Science Foundation of China(52175467 and 51775278)led by Changqing Liu.
基金funded by the US Department of Energy,Office of Energy Efficiency and Renewable Energy under Award Number DE-EE0008308funded by the Extreme Science and Engineering Discovery Environment(XSEDE)which is supported by National Science Foundation Grant Number TG-CHE170060.25 Specifically,it used the Bridges,Bridges-2(Pittsburgh Supercomputing Center(PSC)),and SDSC Expanse compute systems.
文摘To explore a proof-of-concept for atomically precise manufacturing(APM)using scanning probe microscopy(SPM),first principle theoretical calculations of atom-by-atom transfer from the apex of an SPM tip to an individual radical on a surfacebound organic molecule have been performed.Atom transfer is achieved by spatially controlled motion of a gold terminated tip to the radical.Two molecular tools for SPM-based APM have been designed and investigated,each comprising an adamantane core,a radical end group,and trithiol linkers to enable strong chemisorption on the Au(111)surface:ethynyl-adamantanetrithiol and adamantyl-trithiol.We demonstrate the details of controlled Au atom abstraction during tip approach toward and retraction from the radical species.Upon approach of the tip,the apical Au atom undergoes a transfer toward the carbon radical at a clearly defined threshold separation.This atomic displacement is accompanied by a net energy gain of the system in the range−0.5 to−1.5 eV,depending on the radical structure.In the case of a triangular pyramidal apex model,two tip configurations are possible after the tip atom displacement:(1)an Au atom is abstracted from the tip and bound to the C radical,not bound to the tip base anymore,and(2)apical tip atoms rearrange to form a continuous neck between the tip and radical.In the second case,subsequent tip retraction leads to the same final configuration as the first,with the abstracted Au atom bound to radical carbon atom of the molecular tool.For the less reactive adamantyl-trithiol radical molecular tool,Au atom transfer is less energetically favored,but this has the advantage of avoiding other apex gold atoms from rearrangement.
基金Supported by the China Postdoctoral Science Foundation (No. 20070410797)the National High-Tech Research Development (863) Program of China (No. 2008AA042501)
文摘Electroforming is a specialised electroplating process for the manufacture of precision metal parts and mold tooling. Because it can simplify technical process and shorten molding cycles, electroforming is also a rapid manufacturing technology. Compared with direct and unipolar pulse current, bipolar pulse current in electroforming can obtain fine structure and grain size as well as surface leveling, resulting in better precision and surface finish. In this paper, bipolar pulse current electroforming is introduced. The influencing parameters such as electrolyte parameter, additives, current density, pH, temperature, and pulse parameters have been studied by experiments. Experiments on nickel electroforming in molds and dies have been done. The results indicated that bipolar pulse current electroforming could improve the quality and precision further, while reducing internal stress.
基金support from the National Key Research and Development Program of China(2017YFE0117700,2018YC1105401)National Natural Science Foundation of China(81772311,81871775)the Science and Technology Department of Zhejiang Province Foundation(LGF18E020001,LGF20H060016).
文摘Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth.However,it is still a challenge to widely tune structure parameters of scaffolds by conventional methods because of inevitable pore geometrical deformation and poor pore interconnectivity.Here,the long-term in vivo biological performances of nonstoichiometric bioceramic scaffolds with different pore dimensions were assessed in critical-size femoral bone defect model.The 6%Mg-substituted wollastonite(CSi-Mg6)powders were prepared via wet-chemical precipitation and the scaffolds elaborately printed by ceramic stereolithography,displaying designed constant pore strut and tailorable pore height(200,320,450,600μm),were investigated thoroughly in the bone regeneration process.Together with detailed structural stability and mechanical properties were collaboratively outlined.BothμCT and histological analyses indicated that bone tissue ingrowth was retarded in 200μm scaffolds in the whole stage(2-16 weeks)but the 320μm scaffolds showed appreciable bone tissue in the center of porous constructs at 6-10 weeks and matured bone tissue were uniformly invaded in the whole pore networks at 16 weeks.Interestingly,the neo-tissue ingrowth was facilitated in the 450μm and 600μm scaffolds after 2 weeks and higher extent of bone regeneration and remodeling at the later stage.These new findings provide critical information on how engineered porous architecture impact bone regeneration in vivo.Simultaneously,this study shows important implications for optimizing the porous scaffolds design by advanced additive manufacture technique to match the clinical translation with high performance.
基金financial support from the National Key Research and Development Program of China(2017YFE0117700)the National Natural Science Foundation of China(81871775,81902225,81772311)+1 种基金Zhejiang Provincial Natural Science Foundation of China(LBY21H060001,LGF21H060002,Z22E029971)the Medical and Health Research Project of Zhejiang Province(2020KY929,2020RC115).
文摘Pore architecture in bioceramic scaffolds plays an important role in facilitating vascularization efficiency during bone repair or orbital reconstruction.Many investigations have explored this relationship but lack integrating pore architectural features in a scaffold,hindering optimization of architectural parameters(geometry,size and curvature)to improve vascularization and consequently clinical outcomes.To address this challenge,we have developed an integrating design strategy to fabricate different pore architectures(cube,gyroid and hexagon)with different pore dimensions(-350,500 and 650 lm)in the silicate-based bioceramic scaffolds via digital light processing technique.The sintered scaffolds maintained high-fidelity pore architectures similar to the printing model.The hexagon-and gyroid-pore scaffolds exhibited the highest and lowest compressive strength(from 15 to 55MPa),respectively,but the cube-pore scaffolds showed appreciable elastic modulus.Moreover,the gyroid-pore architecture contributed on a faster ion dissolution and mass decay in vitro.It is interesting that bothμCT and histological analyses indicate vascularization efficiency was challenged even in the 650-μm pore region of hexagon-pore scaffolds within 2weeks in rabbit models,but the gyroid-pore constructs indicated appreciable blood vessel networks even in the 350-μm pore region at 2weeks and high-density blood vessels were uniformly invaded in the 500-and 650-μm pore at 4weeks.Angiogenesis was facilitated in the cube-pore scaffolds in comparison with the hexagon-pore ones within 4weeks.These studies demonstrate that the continuous pore wall curvature feature in gyroid-pore architecture is an important implication for biodegradation,vascular cell migration and vessel ingrowth in porous bioceramic scaffolds.
