Structural connections between components are often weak areas in engineering applications.In nature,many biological materials with remarkablemechanical performance possess flexible and creative sutures.In this work,w...Structural connections between components are often weak areas in engineering applications.In nature,many biological materials with remarkablemechanical performance possess flexible and creative sutures.In this work,we propose a novel bioinspired interlocking tab considering both the geometry of the tab head and neck,and demonstrate a new approach to optimize the bio-inspired interlocking structures based on machine learning.Artificial neural networks for different optimization objectives are developed and trained using a database of thousands of interlocking structures generated through finite element analysis.Results show that the proposed method is able to achieve accurate prediction of the mechanical response of any given interlocking tab.The optimized designs with different optimization objectives,such as strength,stiffness,and toughness,are obtained efficiently and precisely.The optimum design predicted by machine learning is approximately 7.98 times stronger and 2.98 times tougher than the best design in the training set,which are validated through additive manufacturing and experimental testing.The machine learning-based optimization approach developed here can aid in the exploration of the intricate mechanism behind biological materials and the discovery of new material designs boasting orders of magnitude increase in computational efficacy over conventional methods.展开更多
Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-...Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-layered nanosheets tend to agglomerate owing to van der Waals forces,which obstruct internal nanoscale transport channels,resulting in low electrochemical activity and restricting their use for sensing purposes.Here,a hybrid MXene/rGO aerogel with a three-dimensional(3D)interlocked network was fabricated via a freeze-drying method.The porous MXene/rGO aerogel has a lightweight and hierarchical porous architecture,which can be compressed and expanded several times without breaking.Additionally,a flexible pressure sensor that uses the aerogel as the sensitive layer has a wide response range of approximately 0-40 kPa and a considerable response within this range,averaging approximately 61.49 kPa^(-1).The excellent sensing performance endows it with a broad range of applications,including human-computer interfaces and human health monitoring.展开更多
An interlocked M_(4) L_(8) coordination cage was synthesized by coordination-driven self-assembly of palladium(Ⅱ)ions with aromatic amide bidentate ligands.The reaction of the ligand and the metal at 2:1 ratio led to...An interlocked M_(4) L_(8) coordination cage was synthesized by coordination-driven self-assembly of palladium(Ⅱ)ions with aromatic amide bidentate ligands.The reaction of the ligand and the metal at 2:1 ratio led to the monomeric M_(2) L_(4) cage as the kinetic product,while the thermodynamic product M_(4) L_(8) cage was obtained by prolongating the reaction.This conve rsion and the interlocked structure was clearly revealed by using~1 H NMR,mass spectrometry and X-ray crystallography.The driving force of interlocking was mainly attributed to the interactions(hydrogen bonding,aromatic stacking and electrostatic interaction)arising from the aptitude of flexibility of the amide ligand.展开更多
The mechanics of structural ceramics,especially the toughness,are crucial to their service reliability and need to be continuously optimized.Inspired by the“brick-mortar”structure and further adjusting the microstru...The mechanics of structural ceramics,especially the toughness,are crucial to their service reliability and need to be continuously optimized.Inspired by the“brick-mortar”structure and further adjusting the microstructure of“mortar”on the interface,ceramic with strength and toughness up to 444.16 MPa and 13.79 MPa⋅m^(1/2) is constructed by hot pressed sintering with alumina(Al_(2)O_(3))as brick and vertical graphene(VG)with active atomic edges as mortar.Relying on the covalent interface between VG grown in-situ and Al_(2)O_(3),the sliding of Al_(2)O_(3)links the shear-deformation process of the crosslinked and interlocked nanointerface formed by VG,making the VG-enhanced Al_(2)O_(3)ceramics(AVG)obtain super toughness.Moreover,the structure of interlocked VG-nanointerface exhibits an excellent high-temperature resistance,which makes AVG still show the excellent strength of 437.66 MPa and toughness of 11.16 MPa⋅m^(1/2)after heat treatment at 1500℃for 100 h and they are respective 2.51 times and 3.18 times higher than Al_(2)O_(3)in the same condition.This work provides a new thought for the preparation of high-strength,ultra-tough and high-temperature mechanical stable ceramics.展开更多
The inverse relationship between the tribological and mechanical properties of environmentally friendly selflubricant films,induced by the addition of soft lubricant agents that can diffuse quickly at elevated tempera...The inverse relationship between the tribological and mechanical properties of environmentally friendly selflubricant films,induced by the addition of soft lubricant agents that can diffuse quickly at elevated temperatures,has hindered the widespread use of these materials in industrial applications.This paper took this challenge to break through the above established relationship by developing novel nacrelike multilayered Mo_(2)N–SiN_(x)/Ag–SiN_(x)self-lubricant films via an radio frequency(RF)magnetron sputtering system for real applications where harsh conditions at elevated temperatures exist.The multilayered films,deposited by alternating deposition of Mo_(2)N–SiN_(x)and Ag–SiN_(x)modulation layers,exhibited three phases of face-centered cubic(fcc)Mo_(2)N,fcc Ag and SiN_(x),where SiN_(x)encapsulated the nano-crystalline Mo_(2)N and Ag phases in each layer to successfully induce a“brick and mortar”nacre-like microstructure(in the area without the coherent structure).The epitaxy growth of the Ag–SiN_(x)layers with thickness below 6 nm on the Mo_(2)N template resulted in an extraordinary increase in both the hardness and elastic modulus,which was able to prevent severe degradation of the mechanical properties caused by the addition of Ag.The room-temperature anti-friction property could be enhanced by increasing the Ag–SiN_(x)layer thickness due to the excellent lubricant nature of Ag,which acts in synergy with Mo_(2)N,while the wear rate below 4×10^(−8)mm^(3)/(N·mm)was due to the high mechanical strength.The tribological properties at 600℃also benefited from the interlocked multilayered architecture,which allowed an extreme low friction coefficient of~0.12 and a negligible wear rate(WR).This behavior was attributed to the synergism between the lubricant action of Ag and Mo_(2)N and the tribo-phase transformation from Ag_(2)Mo_(4)O_(13)to Ag_(2)MoO_(4).展开更多
Smart electromagnetic functional devices prepared based on electromagnetic wave responsive materials will provide more convenience for human life in the future.Here,we prepare oriented magnetic liquid metal droplet-fi...Smart electromagnetic functional devices prepared based on electromagnetic wave responsive materials will provide more convenience for human life in the future.Here,we prepare oriented magnetic liquid metal droplet-filled polydimethylsiloxane films with micropillar array patterned surfaces,and further assemble them into bilayer films with interlocked structures.Once compressed,the increase in conductivity of the film due to the tunneling effect between microarrays and the elongation of liquid metal droplets leads to a rapid increase in electromagnetic interference shielding performance.Accordingly,a tunable electromagnetic interference shielding material with high sensitivity and wide control range is obtained,which has potential applications in electromagnetic wave control systems and intelligent electromagnetic protection systems.Meanwhile,we assemble a strain sensor and a magnetic sensor,which can precisely sense pressure and magnetic field according to changes in electromagnetic signal and electrical signal,respectively.展开更多
基金supported by the National Natural Science Foundation of China,Grant No.51875440.
文摘Structural connections between components are often weak areas in engineering applications.In nature,many biological materials with remarkablemechanical performance possess flexible and creative sutures.In this work,we propose a novel bioinspired interlocking tab considering both the geometry of the tab head and neck,and demonstrate a new approach to optimize the bio-inspired interlocking structures based on machine learning.Artificial neural networks for different optimization objectives are developed and trained using a database of thousands of interlocking structures generated through finite element analysis.Results show that the proposed method is able to achieve accurate prediction of the mechanical response of any given interlocking tab.The optimized designs with different optimization objectives,such as strength,stiffness,and toughness,are obtained efficiently and precisely.The optimum design predicted by machine learning is approximately 7.98 times stronger and 2.98 times tougher than the best design in the training set,which are validated through additive manufacturing and experimental testing.The machine learning-based optimization approach developed here can aid in the exploration of the intricate mechanism behind biological materials and the discovery of new material designs boasting orders of magnitude increase in computational efficacy over conventional methods.
基金financial support from the National Natural Science Foundation of China(NSFC Grant No.61625404,61888102,62174152)Young Elite Scientists Sponsorship Program by CAST(2018QNRC001)+1 种基金the Strategic Priority Program of the Chinese Academy of Sciences,Grant No XDA16021100the Science and Technology Development Plan of Jilin Province(20210101168JC).
文摘Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-layered nanosheets tend to agglomerate owing to van der Waals forces,which obstruct internal nanoscale transport channels,resulting in low electrochemical activity and restricting their use for sensing purposes.Here,a hybrid MXene/rGO aerogel with a three-dimensional(3D)interlocked network was fabricated via a freeze-drying method.The porous MXene/rGO aerogel has a lightweight and hierarchical porous architecture,which can be compressed and expanded several times without breaking.Additionally,a flexible pressure sensor that uses the aerogel as the sensitive layer has a wide response range of approximately 0-40 kPa and a considerable response within this range,averaging approximately 61.49 kPa^(-1).The excellent sensing performance endows it with a broad range of applications,including human-computer interfaces and human health monitoring.
基金supported by the National Natural Science Foundation of China(No.21871101)the Natural Science Foundation of Hubei Scientific Committee(Nos.2017CFA036,2019ACA125)。
文摘An interlocked M_(4) L_(8) coordination cage was synthesized by coordination-driven self-assembly of palladium(Ⅱ)ions with aromatic amide bidentate ligands.The reaction of the ligand and the metal at 2:1 ratio led to the monomeric M_(2) L_(4) cage as the kinetic product,while the thermodynamic product M_(4) L_(8) cage was obtained by prolongating the reaction.This conve rsion and the interlocked structure was clearly revealed by using~1 H NMR,mass spectrometry and X-ray crystallography.The driving force of interlocking was mainly attributed to the interactions(hydrogen bonding,aromatic stacking and electrostatic interaction)arising from the aptitude of flexibility of the amide ligand.
基金supported by the National Natural Science Foundation of China under Grant Nos.52222204,52172103,52293371,52072304,and Natural Science Basic Research Program in Shaanxi(2022JC-25).
文摘The mechanics of structural ceramics,especially the toughness,are crucial to their service reliability and need to be continuously optimized.Inspired by the“brick-mortar”structure and further adjusting the microstructure of“mortar”on the interface,ceramic with strength and toughness up to 444.16 MPa and 13.79 MPa⋅m^(1/2) is constructed by hot pressed sintering with alumina(Al_(2)O_(3))as brick and vertical graphene(VG)with active atomic edges as mortar.Relying on the covalent interface between VG grown in-situ and Al_(2)O_(3),the sliding of Al_(2)O_(3)links the shear-deformation process of the crosslinked and interlocked nanointerface formed by VG,making the VG-enhanced Al_(2)O_(3)ceramics(AVG)obtain super toughness.Moreover,the structure of interlocked VG-nanointerface exhibits an excellent high-temperature resistance,which makes AVG still show the excellent strength of 437.66 MPa and toughness of 11.16 MPa⋅m^(1/2)after heat treatment at 1500℃for 100 h and they are respective 2.51 times and 3.18 times higher than Al_(2)O_(3)in the same condition.This work provides a new thought for the preparation of high-strength,ultra-tough and high-temperature mechanical stable ceramics.
基金supported by projects granted by the National Natural Science Foundation of China(Nos.52171071 and 51801081)national funds through FCT of Portugal-Fundação para a Ciência e a Tecnologia,under a scientific contract of 2021.04115.CEECIND,2023.06224.CEECIND+3 种基金the projects of UIDB/00285/2020,and LA/0112/2020,MCTool21-ref.“POCI-01-0247-FEDER-045940”co-financed via FEDER and FCTFundação para a Ciência e a Tecnologia(COMPETE)The projects of UIDB/00285/2020,and LA/0112/2020The Slovenian Research Agency ARIS under the Research Core Funding Programme No.P2-0231 and the project MSCA-COFUND-5100-237/2023-9supported by the Outstanding University Young Teachers of“Qing Lan Project”of Jiangsu Province of China and the Excellent Talents of“Shenlan Project”of Jiangsu University of Science of China.
文摘The inverse relationship between the tribological and mechanical properties of environmentally friendly selflubricant films,induced by the addition of soft lubricant agents that can diffuse quickly at elevated temperatures,has hindered the widespread use of these materials in industrial applications.This paper took this challenge to break through the above established relationship by developing novel nacrelike multilayered Mo_(2)N–SiN_(x)/Ag–SiN_(x)self-lubricant films via an radio frequency(RF)magnetron sputtering system for real applications where harsh conditions at elevated temperatures exist.The multilayered films,deposited by alternating deposition of Mo_(2)N–SiN_(x)and Ag–SiN_(x)modulation layers,exhibited three phases of face-centered cubic(fcc)Mo_(2)N,fcc Ag and SiN_(x),where SiN_(x)encapsulated the nano-crystalline Mo_(2)N and Ag phases in each layer to successfully induce a“brick and mortar”nacre-like microstructure(in the area without the coherent structure).The epitaxy growth of the Ag–SiN_(x)layers with thickness below 6 nm on the Mo_(2)N template resulted in an extraordinary increase in both the hardness and elastic modulus,which was able to prevent severe degradation of the mechanical properties caused by the addition of Ag.The room-temperature anti-friction property could be enhanced by increasing the Ag–SiN_(x)layer thickness due to the excellent lubricant nature of Ag,which acts in synergy with Mo_(2)N,while the wear rate below 4×10^(−8)mm^(3)/(N·mm)was due to the high mechanical strength.The tribological properties at 600℃also benefited from the interlocked multilayered architecture,which allowed an extreme low friction coefficient of~0.12 and a negligible wear rate(WR).This behavior was attributed to the synergism between the lubricant action of Ag and Mo_(2)N and the tribo-phase transformation from Ag_(2)Mo_(4)O_(13)to Ag_(2)MoO_(4).
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51971008,U1832138,51731002,and 51671010)Natural Science Foundation of Beijing Municipality(No.2212033).
文摘Smart electromagnetic functional devices prepared based on electromagnetic wave responsive materials will provide more convenience for human life in the future.Here,we prepare oriented magnetic liquid metal droplet-filled polydimethylsiloxane films with micropillar array patterned surfaces,and further assemble them into bilayer films with interlocked structures.Once compressed,the increase in conductivity of the film due to the tunneling effect between microarrays and the elongation of liquid metal droplets leads to a rapid increase in electromagnetic interference shielding performance.Accordingly,a tunable electromagnetic interference shielding material with high sensitivity and wide control range is obtained,which has potential applications in electromagnetic wave control systems and intelligent electromagnetic protection systems.Meanwhile,we assemble a strain sensor and a magnetic sensor,which can precisely sense pressure and magnetic field according to changes in electromagnetic signal and electrical signal,respectively.
