The pursuit of simultaneously high wear resistance and excellent lubrication in multi‐principal element alloy(MPEA)composites is often hindered by a fundamental trade‐off,which is exacerbated by the agglomeration of...The pursuit of simultaneously high wear resistance and excellent lubrication in multi‐principal element alloy(MPEA)composites is often hindered by a fundamental trade‐off,which is exacerbated by the agglomeration of high‐content graphene reinforcements.This compromise becomes particularly severe in composites with high‐content graphene reinforcements,whose agglomeration leads to embrittlement and lubrication failure.Here,a flake powder-metallurgy strategy is developed to construct a self‐assembled lamellar structure in graphene/CoCrNi MPEA composites(Gr/MPEA_(AL)).This approach enables the uniform dispersion of a high graphene content(3.0 wt%),which is unattainable by conventional methods.The resulting composite exhibits a rare dual enhancement in performance:an order‐of‐magnitude improvement in wear resistance coupled with a low coefficient of friction.Intriguingly,the tribological behavior shows significant anisotropy,with optimal performance observed when sliding perpendicular to the lamellae.Through a multi‐scale methodology combining molecular dynamics simulations,finite element analysis,and systematic experiments,it is revealed that this exceptional performance stems from the synergy of high‐density deformation nanotwins,efficient strain delocalization,and abundant graphene‐derived lubricating sites.This work establishes a general paradigm for designing composite architectures that reconcile traditionally incompatible properties,offering broad implications for developing next‐generation structural materials with integrated mechanical robustness and surface functionality for safety‐critical applications.展开更多
The microscopic Bouligand-type architectures of fish scales demonstrate a notable efficiency in enhancing the damage tolerance of materials;nevertheless,it is challenging to reproduce in metals.Here bioinspired tungst...The microscopic Bouligand-type architectures of fish scales demonstrate a notable efficiency in enhancing the damage tolerance of materials;nevertheless,it is challenging to reproduce in metals.Here bioinspired tungsten-copper composites with different Bouligand-type architectures mimicking fish scales were fabricated by infiltrating a copper melt into woven contextures of tungsten fibers.These composites exhibit a synergetic enhancement in both strength and ductility at room temperature along with an improved resistance to high-temperature oxidization.The strengths were interpreted by adapting the classical laminate theory to incorporate the characteristics of Bouligand-type architectures.In particular,under load the tungsten fibers can reorient adaptively within the copper matrix by their straightening,stretching,interfacial sliding with the matrix,and the cooperative kinking deformation of fiber grids,representing a successful implementation of the optimizing mechanisms of the Bouligand-type architectures to enhance strength and toughness.This study may serve to promote the development of new high-performance tungsten-copper composites for applications,e.g.,as electrical contacts or heat sinks,and offer a viable approach for constructing bioinspired architectures in metallic materials.展开更多
Over the past two decades,superhydrophobic surfaces that are easily created have aroused considerable attention for their superior performances in various applications at room temperature.Nowadays,there is a growing d...Over the past two decades,superhydrophobic surfaces that are easily created have aroused considerable attention for their superior performances in various applications at room temperature.Nowadays,there is a growing demand in special fields for the development of surfaces that can resist wetting by high-temperature molten droplets(>1200°C)using facile design and fabrication strategies.Herein,bioinspired directional structures(BDSs)were prepared on Y2O3-stabilized ZrO2(YSZ)surfaces using femtosecond laser ablation.Benefiting from the anisotropic energy barriers,the BDSs featured with no additional modifiers showed a remarkable increase from 9.2°to 60°in the contact angle of CaO–MgO–Al2O3–SiO2(CMAS)melt and a 70.1%reduction in the spreading area of CMAS at 1250°C,compared with polished super-CMAS-melt-philic YSZ surfaces.Moreover,the BDSs demonstrated exceptional wetting inhibition even at 1400°C,with an increase from 3.3°to 31.3°in contact angle and a 67.9%decrease in spreading area.This work provides valuable insight and a facile preparation strategy for effectively inhibiting the wetting of molten droplets on super-melt-philic surfaces at extremely high temperatures.展开更多
Fabricating damage tolerant porous ceramics with efficient energy absorption and impact-resistant capability has been a challenge because of the brittle nature of ceramic materials.In nature,mineralized tissues or org...Fabricating damage tolerant porous ceramics with efficient energy absorption and impact-resistant capability has been a challenge because of the brittle nature of ceramic materials.In nature,mineralized tissues or organisms such as cuttlebones and diatoms have evolved with hierarchical porous structures to overcome this difficulty.A bioinspired design of ceramic lattice structure with pores at multiple length scales,ranging from few nanometers to hundreds of micrometers,is proposed in the present work.These ceramic lattices with hierarchical porous structures were successfully fabricated via 3D cryogenic printing.Under quasi-static compressions,the printed ceramic lattices showed unprecedented long plateau strain(∼60%)and a specific energy absorption of∼10 kJ·kg^(−1) with a porosity of∼90%.The resulting energy absorption capability was comparable with most composites and metals,thus overcoming the brittle nature of traditional porous ceramics.This was attributed to the delayed destruction of the lattice structure,as well as the gradual collapse of pores at multiple length scales.Similar trends have also been observed under split Hopkinson pressure bar(SHPB)tests,indicating excellent energy absorption under high strain-rate impacts.The proposed 3D printing technique that produces hierarchical pores was also demonstrated to apply to other functional materials,such as silicon carbide,barium titanate,hydroxyapatite,and even titanium alloy,thus opening up new possibilities for fabricating bioinspired hierarchical porous structures.展开更多
This paper presents the development of a bioinspired multifunctional flexible optical sensor(BioMFOS)as an ultrasensitive tool for force(intensity and location)and orientation sensing.The sensor structure is bioinspir...This paper presents the development of a bioinspired multifunctional flexible optical sensor(BioMFOS)as an ultrasensitive tool for force(intensity and location)and orientation sensing.The sensor structure is bioinspired in orb webs,which are multifunctional devices for prey capturing and vibration transmission.The multifunctional feature of the structure is achieved by using transparent resins that present both mechanical and optical properties for structural integrity and strain/deflection transmission as well as the optical signal transmission properties with core/cladding configuration of a waveguide.In this case,photocurable and polydimethylsiloxane(PDMS)resins are used for the core and cladding,respectively.The optical transmission,tensile tests,and dynamic mechanical analysis are performed in the resins and show the possibility of light transmission at the visible wavelength range in conjunction with high flexibility and a dynamic range up to 150 Hz,suitable for wearable applications.The BioMFOS has small dimensions(around 2 cm)and lightweight(0.8 g),making it suitable for wearable application and clothing integration.Characterization tests are performed in the structure by means of applying forces at different locations of the structure.The results show an ultra-high sensitivity and resolution,where forces in theμN range can be detected and the location of the applied force can also be detected with a sub-millimeter spatial resolution.Then,the BioMFOS is tested on the orientation detection in 3D plane,where a correlation coefficient higher than 0.9 is obtained when compared with a gold-standard inertial measurement unit(IMU).Furthermore,the device also shows its capabilities on the movement analysis and classification in two protocols:finger position detection(with the BioMFOS positioned on the top of the hand)and trunk orientation assessment(with the sensor integrated on the clothing).In both cases,the sensor is able of classifying the movement,especially when analyzed in conjunction with preprocessing and clustering techniques.As another wearable application,the respiratory rate is successfully estimated with the BioMFOS integrated into the clothing.Thus,the proposed multifunctional device opens new avenues for novel bioinspired photonic devices and can be used in many applications of biomedical,biomechanics,and micro/nanotechnology.展开更多
Bioinspired active camber morphing is an innovative solution for the aerodynamic performance enhancement of flight vehicles such as Micro Aerial Vehicles(MAVs)and Unmanned Aerial Vehicles(UAVs).In the present article,...Bioinspired active camber morphing is an innovative solution for the aerodynamic performance enhancement of flight vehicles such as Micro Aerial Vehicles(MAVs)and Unmanned Aerial Vehicles(UAVs).In the present article,a bio-inspired Fish Bone Active Camber(FishBAC)corrugated rib design concept with and without a spine for an Unmanned Aerial Vehicle(UAV)is proposed.The wing model is composed of multiple corrugated ribs and a splitted spar for connecting each rib.The rib geometry is subjected to static structural analysis using ANSYS Finite Element Analysis(FEA)module under the unit load conditions.The deformation modes are first extracted from the solution of the wind tunnel test and the elastically deformed NACA 4412 profile will be used to perform Fluid-Structure Interaction(FSI)studies as a partly coupled analysis.FishBAC corrugated rib with spine design is a stable structure as inspired from nature species that can withstand elastic and inertial loads.Computational fluid dynamics(CFD)simulation is performed to compute the coefficient of lift(Cl),coefficient of drag(Cd)at different Angle of Attack(AoA)for a modified NACA 4412 airfoil and the pressure loads acting on the deformed shape is extracted.The Cl obtained for the modified airfoil at lower AoA is about 60–80%higher and the maximum Cl(Clmax)is 62%higher than the baseline airfoil.The Cd of modified airfoil is reduced about 20%at the AoAα=3°as compared with the baseline model.The proposed corrugated rib structure has been successfully 3D printed with Polylactic Acid plus(PLA+)material and the wind tunnel testing is done to validate the Cl,Cd values obtained through CFD simulations and the results are presented.展开更多
Hybrid-driven technology,which can improve the sailing performance of underwater gliders(UGs),has been successfully used in ocean observation.However,a hybrid-driven UG(HUG)with an added tail propeller is still unable...Hybrid-driven technology,which can improve the sailing performance of underwater gliders(UGs),has been successfully used in ocean observation.However,a hybrid-driven UG(HUG)with an added tail propeller is still unable to achieve backward and turning motion with a body length radius,and the hydrodynamic pitch moment acting on the HUG that is mainly caused by the fixed-wing makes it difficult to achieve high-precision attitude control during fixed-depth navigation.To solve this problem,a two-degree-of-freedom bioinspired controllable wing mechanism(CWM)is proposed to improve the maneuverability and cruising ability of HUGs.The CWM can realize five motion modes:modifying the dihedral angle or anhedral angle,changing the frontal area of the wing,switching the wing from horizontal to be a vertical rudder,flapping the wing as propulsion,and rotating the wing as a vector propeller.First,the design process of the CWM is provided,and hydrodynamic forces in each motion mode of three CWMs with different trailing edge sweepback angles(TESA)and attitude angles are analyzed through computational fluid dynamics simulation.The relationship between hydrodynamics and the attitude angles or TESA of the CWM is analyzed.Then,experiments are conducted to measure the hydrodynamics of the CWM when it is in a flapping wing mode and rotating the wing as a vector propeller,respectively.The hydrodynamic forces obtained from the simulation are consistent with data measured by a force sensor,proving the credibility of the simulated hydrodynamics.Subsequently,by applying the results of the hydrodynamic force in this study,the flapping trajectory of the wingtip is planned using the cubic spline interpolation method.Furthermore,two underwater demo vehicles with a pair of CWMs are developed,and experiments are conducted in a water tank,further validating and demonstrating the feasibility of the proposed CWM.展开更多
Intermediate filaments are one of the key components of the cytoskeleton in eukaryotic cells, and their mechanical properties are found to be equally important for physiological function and disease. While the mechani...Intermediate filaments are one of the key components of the cytoskeleton in eukaryotic cells, and their mechanical properties are found to be equally important for physiological function and disease. While the mechanical properties of single full length filaments have been studied, how the mechanical properties of crosslinks affect the mechanical property of the intermediate filament network is not well understood. This paper applies a mesoscopic model of the intermediate network with varied crosslink strengths to investigate its failure mechanism under the extreme mechanical loading. It finds that relatively weaker crosslinks lead to a more flaw tolerant intermediate filament network that is also 23% stronger than the one with strong crosslinks. These findings suggest that the mechanical properties of interfacial components are critical for bioinspired designs which provide intriguing mechanical properties.展开更多
Radiative cooling passively emits heat to outer space without energy input,offering promise for energy-efficient thermal management.It is an important solution to promote the low-carbon environmental protection strate...Radiative cooling passively emits heat to outer space without energy input,offering promise for energy-efficient thermal management.It is an important solution to promote the low-carbon environmental protection strategy.With the continuous development of radiative cooling technologies,the material selection,preparation process,structural design,and applica-tion fields have also made more diverse progress.Therefore,this review aims to systematically introduce the fundamental concepts and underlying principles of radiative cooling.A summary of the commonly used materials for radiative cooling is provided.In addition,the advanced fabrication processes and structural designs of radiative cooling materials are further explored and discussed.Subsequently,the unique functions of radiative cooling materials are highlighted to enhance their applicability and usefulness across various fields.An overview of combining radiative cooling materials with different fields is also provided.In reality,these applications hold the potential to improve thermal management across a range of fields.Finally,it summarizes the shortcomings and great potential of radiative cooling materials in various fields.It also looks forward to the future,aiming to promote the progress and widespread adoption of radiative cooling technologies.展开更多
Solar-driven interfacial desalination has been considered a promising and green technology for relieving worldwide water shortage because of its zero carbon emission.However,salt accumulation during evaporation result...Solar-driven interfacial desalination has been considered a promising and green technology for relieving worldwide water shortage because of its zero carbon emission.However,salt accumulation during evaporation results in a significant reduction in solar evaporation performance and sustained service life.High-performance and long-term salt-rejecting solar evaporators are urgently desirable.Inspired by the rapid water transfer driven by leaf transpiration and the capillary pressure in woody plants,we developed electrospun polyacrylonitrile@carbon nanotubes nanofiber/cotton core-spun yarn(PCCS yarn)based solar evaporator enabled by the multi-branch microchannels and sub-microchannels for ultra-efficient and durable high-salinity brine desalination.The optimal PCCS yarn-based solar evaporator exhibits a record-high evaporation rate of 3.46 kg m^(-2)h^(-1)under one sun illumination among 2D evaporators.Meanwhile,an excellent and stable brine desalination rate of∼2.75 kg m^(-2)h^(-1)for 100 h continuous solar irradiation is achieved even in 20wt%NaCl solution.The above results are attributed to the massive micro evaporation surfaces formed between nanofibers,rapid water replenishment in the radius direction,and orientational fast water transport by Laplace pressure along and across the PCCS yarn.In addition,the continuous preparation of the core-spun yarn by the conjugated electrospinning technology and the complete fabric production process in the textile industry make it possible for the practical application of the PCCS yarn-based solar evaporator.This work promotes the development of high-performance,long-term and scalable solar desalination devices.展开更多
Engineering biomaterials that actively interface with and instruct their biological milieu have given rise to a new generation of platforms for tissue repair and companion diagnostics.Among them,aerogel scaffolds,with...Engineering biomaterials that actively interface with and instruct their biological milieu have given rise to a new generation of platforms for tissue repair and companion diagnostics.Among them,aerogel scaffolds,with their ultra-porous architecture,ultralow density,tunable mechanics,and versatile chemistries,have emerged as transformative candidates capable of emulating and interpreting extracellular environments.This review highlights up-to-date advances shaping the landscape of aerogel-based scaffolds in tissue repair and diagnostic applications.We first summarize emerging fabrication and assembly strategies,including sol-gel processing,freeze-drying,electrospinning,and 3D printing,which unlock hierarchical morphologies and bioinspired features.The recent implementations of intelligent aerogels for tissue repair and neuroregeneration are then highlighted,together with related applications in bioactive functionalization,immune modulation,wound healing,sustained drug delivery,and moist repair dressings.Meanwhile,we outline aerogel-based disease diagnosis regarding genotypic physiological cues,focusing on faithfully detecting nucleic acids,tumor biopsy,virus antigen testing of infectious disease,and state-of-the-art demos with innovative signal transduction mechanisms.Data-driven strategies powered by machine learning are also reviewed,alongside integration into smart wearables for self-adapting,responsive platforms.Finally,persisting challenges and present perspective of aerogel scaffolds in medicine research and practice are also discussed.展开更多
Biomimetics has an immense potential to drive the next generation of technologies forward by propounding competent solutions from nature.For decades,the nonsmooth topography of most living creatures has been critical ...Biomimetics has an immense potential to drive the next generation of technologies forward by propounding competent solutions from nature.For decades,the nonsmooth topography of most living creatures has been critical to their existence and survival.Contrary to human-made smooth surfaces,when adapted for fluid flow applications,nonsmooth surfaces can enhance the overall aerodynamic performance by reducing the drag force.Recently,the bioinspired scale structure of fish has been identified as a key biomimetic derivative for improving the aerodynamic efficiency in various cross-domain applications.This study investigates the aerodynamics of a fish scale array(FSA)NACA 0021 model at a specific Reynolds number(Re)of approximately 2.46×105 that is meant for laminar flow conditions using Computational Fluid Dynamics(CFD)tools and a subsonic wind tunnel facility.A 3D printed biomimetic FSA film is developed and affixed on the NACA 0021 wing profile for the experimental investigation,followed by flow visualization through the smoke tunnel facility.As proved qualitatively under specific aerodynamic conditions,the creation of velocity streaks has a major role in the drag reduction process.To obtain a clear perspective of flow across the overlapping fish scale structures,the results are focused on the central and overlapping regions of the FSA structure.The experiment has proved the existence of a combined formation of low and high velocity streaks in central and overlapping regions.The FSA 0021 model showed a maximum drag reduction of 9.57%,which was attributed to the streak formation phenomenon observed in the overlapping FSA configuration.展开更多
基金supported by Guangdong Basic and Applied Basic Research Foundation(No.2024A1515012378)Natural Science Foundation of China(Nos.52471093,52274367)+3 种基金fund of the State Key Laboratory of Solidification Processing in NPU(No.2025‐QZ‐03)the Practice and Innovation Funds for Graduate Students of Northwestern Polytechnical University(No.PF2025041)Fundamental Research Projects of Science&Technology Innovation and development Plan in Yantai City(No.2024JCYJ099)project(No.ZR2024QE213)supported by Shandong Provincial Natural Science Foundation.
文摘The pursuit of simultaneously high wear resistance and excellent lubrication in multi‐principal element alloy(MPEA)composites is often hindered by a fundamental trade‐off,which is exacerbated by the agglomeration of high‐content graphene reinforcements.This compromise becomes particularly severe in composites with high‐content graphene reinforcements,whose agglomeration leads to embrittlement and lubrication failure.Here,a flake powder-metallurgy strategy is developed to construct a self‐assembled lamellar structure in graphene/CoCrNi MPEA composites(Gr/MPEA_(AL)).This approach enables the uniform dispersion of a high graphene content(3.0 wt%),which is unattainable by conventional methods.The resulting composite exhibits a rare dual enhancement in performance:an order‐of‐magnitude improvement in wear resistance coupled with a low coefficient of friction.Intriguingly,the tribological behavior shows significant anisotropy,with optimal performance observed when sliding perpendicular to the lamellae.Through a multi‐scale methodology combining molecular dynamics simulations,finite element analysis,and systematic experiments,it is revealed that this exceptional performance stems from the synergy of high‐density deformation nanotwins,efficient strain delocalization,and abundant graphene‐derived lubricating sites.This work establishes a general paradigm for designing composite architectures that reconcile traditionally incompatible properties,offering broad implications for developing next‐generation structural materials with integrated mechanical robustness and surface functionality for safety‐critical applications.
基金the financial support by the National Key R&D Program of China under grant number 2020YFA0710404the National Natural Science Foundation of China under grant number 51871216+5 种基金the KC Wong Education Foundation(GJTD-2020-09)the Liao Ning Revitalization Talents Programthe State Key Laboratory for Modification of Chemical Fibers and Polymer Materials at Donghua Universitythe Opening Project of Jiangsu Province Key Laboratory of High-End Structural Materials under grant number hsm1801the Youth Innovation Promotion Association CASsupport from the Multidisciplinary University Research Initiative to University of California Riverside,funded by the Air Force Office of Scientific Research(AFOSR-FA9550–15–1–0009)and subcontracted to the University of California Berkeley。
文摘The microscopic Bouligand-type architectures of fish scales demonstrate a notable efficiency in enhancing the damage tolerance of materials;nevertheless,it is challenging to reproduce in metals.Here bioinspired tungsten-copper composites with different Bouligand-type architectures mimicking fish scales were fabricated by infiltrating a copper melt into woven contextures of tungsten fibers.These composites exhibit a synergetic enhancement in both strength and ductility at room temperature along with an improved resistance to high-temperature oxidization.The strengths were interpreted by adapting the classical laminate theory to incorporate the characteristics of Bouligand-type architectures.In particular,under load the tungsten fibers can reorient adaptively within the copper matrix by their straightening,stretching,interfacial sliding with the matrix,and the cooperative kinking deformation of fiber grids,representing a successful implementation of the optimizing mechanisms of the Bouligand-type architectures to enhance strength and toughness.This study may serve to promote the development of new high-performance tungsten-copper composites for applications,e.g.,as electrical contacts or heat sinks,and offer a viable approach for constructing bioinspired architectures in metallic materials.
基金This work was supported by National Natural Science Foundation of China(No.52105212)Sichuan Science and Technology Program(No.2023NSFSC0863)China Postdoctoral Science Foundation(No.2021M702712).
文摘Over the past two decades,superhydrophobic surfaces that are easily created have aroused considerable attention for their superior performances in various applications at room temperature.Nowadays,there is a growing demand in special fields for the development of surfaces that can resist wetting by high-temperature molten droplets(>1200°C)using facile design and fabrication strategies.Herein,bioinspired directional structures(BDSs)were prepared on Y2O3-stabilized ZrO2(YSZ)surfaces using femtosecond laser ablation.Benefiting from the anisotropic energy barriers,the BDSs featured with no additional modifiers showed a remarkable increase from 9.2°to 60°in the contact angle of CaO–MgO–Al2O3–SiO2(CMAS)melt and a 70.1%reduction in the spreading area of CMAS at 1250°C,compared with polished super-CMAS-melt-philic YSZ surfaces.Moreover,the BDSs demonstrated exceptional wetting inhibition even at 1400°C,with an increase from 3.3°to 31.3°in contact angle and a 67.9%decrease in spreading area.This work provides valuable insight and a facile preparation strategy for effectively inhibiting the wetting of molten droplets on super-melt-philic surfaces at extremely high temperatures.
基金supported by the National Natural Science Foundation of China(Grant No.52305359)the startup funding from the Huazhong University of Science and Technology,the Opening fund of the State Key Laboratory of Nonlinear Mechanics and Natural Science Foundation of Hubei Province(No.2023AFB141)。
文摘Fabricating damage tolerant porous ceramics with efficient energy absorption and impact-resistant capability has been a challenge because of the brittle nature of ceramic materials.In nature,mineralized tissues or organisms such as cuttlebones and diatoms have evolved with hierarchical porous structures to overcome this difficulty.A bioinspired design of ceramic lattice structure with pores at multiple length scales,ranging from few nanometers to hundreds of micrometers,is proposed in the present work.These ceramic lattices with hierarchical porous structures were successfully fabricated via 3D cryogenic printing.Under quasi-static compressions,the printed ceramic lattices showed unprecedented long plateau strain(∼60%)and a specific energy absorption of∼10 kJ·kg^(−1) with a porosity of∼90%.The resulting energy absorption capability was comparable with most composites and metals,thus overcoming the brittle nature of traditional porous ceramics.This was attributed to the delayed destruction of the lattice structure,as well as the gradual collapse of pores at multiple length scales.Similar trends have also been observed under split Hopkinson pressure bar(SHPB)tests,indicating excellent energy absorption under high strain-rate impacts.The proposed 3D printing technique that produces hierarchical pores was also demonstrated to apply to other functional materials,such as silicon carbide,barium titanate,hydroxyapatite,and even titanium alloy,thus opening up new possibilities for fabricating bioinspired hierarchical porous structures.
基金FAPES(320/2020 and 84336650)CNPq(304049/2019-0 and 427054/2018-4)+2 种基金Fundação para a Ciência e a Tecnologia(FCT)through the DigiAqua project-PTDC/EEIEEE/0415/2021.C.FCT through the CEECIND/00034/2018(iFish project)developed within the scope of the project i3N,UIDB/50025/2020&UIDP/50025/2020financed by national funds through the FCT/MEC.
文摘This paper presents the development of a bioinspired multifunctional flexible optical sensor(BioMFOS)as an ultrasensitive tool for force(intensity and location)and orientation sensing.The sensor structure is bioinspired in orb webs,which are multifunctional devices for prey capturing and vibration transmission.The multifunctional feature of the structure is achieved by using transparent resins that present both mechanical and optical properties for structural integrity and strain/deflection transmission as well as the optical signal transmission properties with core/cladding configuration of a waveguide.In this case,photocurable and polydimethylsiloxane(PDMS)resins are used for the core and cladding,respectively.The optical transmission,tensile tests,and dynamic mechanical analysis are performed in the resins and show the possibility of light transmission at the visible wavelength range in conjunction with high flexibility and a dynamic range up to 150 Hz,suitable for wearable applications.The BioMFOS has small dimensions(around 2 cm)and lightweight(0.8 g),making it suitable for wearable application and clothing integration.Characterization tests are performed in the structure by means of applying forces at different locations of the structure.The results show an ultra-high sensitivity and resolution,where forces in theμN range can be detected and the location of the applied force can also be detected with a sub-millimeter spatial resolution.Then,the BioMFOS is tested on the orientation detection in 3D plane,where a correlation coefficient higher than 0.9 is obtained when compared with a gold-standard inertial measurement unit(IMU).Furthermore,the device also shows its capabilities on the movement analysis and classification in two protocols:finger position detection(with the BioMFOS positioned on the top of the hand)and trunk orientation assessment(with the sensor integrated on the clothing).In both cases,the sensor is able of classifying the movement,especially when analyzed in conjunction with preprocessing and clustering techniques.As another wearable application,the respiratory rate is successfully estimated with the BioMFOS integrated into the clothing.Thus,the proposed multifunctional device opens new avenues for novel bioinspired photonic devices and can be used in many applications of biomedical,biomechanics,and micro/nanotechnology.
文摘Bioinspired active camber morphing is an innovative solution for the aerodynamic performance enhancement of flight vehicles such as Micro Aerial Vehicles(MAVs)and Unmanned Aerial Vehicles(UAVs).In the present article,a bio-inspired Fish Bone Active Camber(FishBAC)corrugated rib design concept with and without a spine for an Unmanned Aerial Vehicle(UAV)is proposed.The wing model is composed of multiple corrugated ribs and a splitted spar for connecting each rib.The rib geometry is subjected to static structural analysis using ANSYS Finite Element Analysis(FEA)module under the unit load conditions.The deformation modes are first extracted from the solution of the wind tunnel test and the elastically deformed NACA 4412 profile will be used to perform Fluid-Structure Interaction(FSI)studies as a partly coupled analysis.FishBAC corrugated rib with spine design is a stable structure as inspired from nature species that can withstand elastic and inertial loads.Computational fluid dynamics(CFD)simulation is performed to compute the coefficient of lift(Cl),coefficient of drag(Cd)at different Angle of Attack(AoA)for a modified NACA 4412 airfoil and the pressure loads acting on the deformed shape is extracted.The Cl obtained for the modified airfoil at lower AoA is about 60–80%higher and the maximum Cl(Clmax)is 62%higher than the baseline airfoil.The Cd of modified airfoil is reduced about 20%at the AoAα=3°as compared with the baseline model.The proposed corrugated rib structure has been successfully 3D printed with Polylactic Acid plus(PLA+)material and the wind tunnel testing is done to validate the Cl,Cd values obtained through CFD simulations and the results are presented.
基金the National Key R&D Program of China(Grant No.2016YFC0301101)the National Natural Science Foundation of China(Grant No.51721003)+1 种基金the Natural Science Foundation of Tianjin City(Grant No.18JCJQJC46400)the Aoshan Talent Cultivation Program of QNLM(Grant Nos.2017ASTCP-OS05 and 2017ASTCP-OE01)。
文摘Hybrid-driven technology,which can improve the sailing performance of underwater gliders(UGs),has been successfully used in ocean observation.However,a hybrid-driven UG(HUG)with an added tail propeller is still unable to achieve backward and turning motion with a body length radius,and the hydrodynamic pitch moment acting on the HUG that is mainly caused by the fixed-wing makes it difficult to achieve high-precision attitude control during fixed-depth navigation.To solve this problem,a two-degree-of-freedom bioinspired controllable wing mechanism(CWM)is proposed to improve the maneuverability and cruising ability of HUGs.The CWM can realize five motion modes:modifying the dihedral angle or anhedral angle,changing the frontal area of the wing,switching the wing from horizontal to be a vertical rudder,flapping the wing as propulsion,and rotating the wing as a vector propeller.First,the design process of the CWM is provided,and hydrodynamic forces in each motion mode of three CWMs with different trailing edge sweepback angles(TESA)and attitude angles are analyzed through computational fluid dynamics simulation.The relationship between hydrodynamics and the attitude angles or TESA of the CWM is analyzed.Then,experiments are conducted to measure the hydrodynamics of the CWM when it is in a flapping wing mode and rotating the wing as a vector propeller,respectively.The hydrodynamic forces obtained from the simulation are consistent with data measured by a force sensor,proving the credibility of the simulated hydrodynamics.Subsequently,by applying the results of the hydrodynamic force in this study,the flapping trajectory of the wingtip is planned using the cubic spline interpolation method.Furthermore,two underwater demo vehicles with a pair of CWMs are developed,and experiments are conducted in a water tank,further validating and demonstrating the feasibility of the proposed CWM.
文摘Intermediate filaments are one of the key components of the cytoskeleton in eukaryotic cells, and their mechanical properties are found to be equally important for physiological function and disease. While the mechanical properties of single full length filaments have been studied, how the mechanical properties of crosslinks affect the mechanical property of the intermediate filament network is not well understood. This paper applies a mesoscopic model of the intermediate network with varied crosslink strengths to investigate its failure mechanism under the extreme mechanical loading. It finds that relatively weaker crosslinks lead to a more flaw tolerant intermediate filament network that is also 23% stronger than the one with strong crosslinks. These findings suggest that the mechanical properties of interfacial components are critical for bioinspired designs which provide intriguing mechanical properties.
基金National Natural Science Foundation of China Excellent Youth Fund(No.52222509)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)+3 种基金National Key Research and Development Program of China(No.2018YFA0703300)National Natural Science Foundation of China(No.52105298)Science and Technology Development Program of Jilin Province(No.SKL202402005)"Fundamental Research Funds for the Central Universities".
文摘Radiative cooling passively emits heat to outer space without energy input,offering promise for energy-efficient thermal management.It is an important solution to promote the low-carbon environmental protection strategy.With the continuous development of radiative cooling technologies,the material selection,preparation process,structural design,and applica-tion fields have also made more diverse progress.Therefore,this review aims to systematically introduce the fundamental concepts and underlying principles of radiative cooling.A summary of the commonly used materials for radiative cooling is provided.In addition,the advanced fabrication processes and structural designs of radiative cooling materials are further explored and discussed.Subsequently,the unique functions of radiative cooling materials are highlighted to enhance their applicability and usefulness across various fields.An overview of combining radiative cooling materials with different fields is also provided.In reality,these applications hold the potential to improve thermal management across a range of fields.Finally,it summarizes the shortcomings and great potential of radiative cooling materials in various fields.It also looks forward to the future,aiming to promote the progress and widespread adoption of radiative cooling technologies.
基金supported by the National Natural Science Foundation of China(51973027,52003044,52373069,52373032)the Fundamental Research Funds for the Central Universities(2232020A-08)+5 种基金International Cooperation Fund of Science and Technology Commission of Shanghai Municipality(21130750100)Major Scientific and Technological Innovation Projects of Shandong Province(2021CXGC011004)supported by the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-0003-E00023)to Prof.Xiaohong QinYoung Elite Scientists Sponsorship Program by CAST,State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(KF2216)DHU Distinguished Young Professor Program to Profthe Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(CUSF-DH-D-2022039)to Mantang He.
文摘Solar-driven interfacial desalination has been considered a promising and green technology for relieving worldwide water shortage because of its zero carbon emission.However,salt accumulation during evaporation results in a significant reduction in solar evaporation performance and sustained service life.High-performance and long-term salt-rejecting solar evaporators are urgently desirable.Inspired by the rapid water transfer driven by leaf transpiration and the capillary pressure in woody plants,we developed electrospun polyacrylonitrile@carbon nanotubes nanofiber/cotton core-spun yarn(PCCS yarn)based solar evaporator enabled by the multi-branch microchannels and sub-microchannels for ultra-efficient and durable high-salinity brine desalination.The optimal PCCS yarn-based solar evaporator exhibits a record-high evaporation rate of 3.46 kg m^(-2)h^(-1)under one sun illumination among 2D evaporators.Meanwhile,an excellent and stable brine desalination rate of∼2.75 kg m^(-2)h^(-1)for 100 h continuous solar irradiation is achieved even in 20wt%NaCl solution.The above results are attributed to the massive micro evaporation surfaces formed between nanofibers,rapid water replenishment in the radius direction,and orientational fast water transport by Laplace pressure along and across the PCCS yarn.In addition,the continuous preparation of the core-spun yarn by the conjugated electrospinning technology and the complete fabric production process in the textile industry make it possible for the practical application of the PCCS yarn-based solar evaporator.This work promotes the development of high-performance,long-term and scalable solar desalination devices.
基金supported by National Natural Science Foundation of China(22577094,22307098,and 12375334)Key Projects of Wenzhou Science and Technology Bureau(ZN2024009)+1 种基金the Key program of WIUCASQD2021012 from Wenzhou Institute,University of Chinese Academy of SciencesJoint Research Centre on Medicine,Wenzhou Institute,University of Chinese Academy of Sciences Xiangshan Hospital of Wenzhou Medical University(XSZD2024006).
文摘Engineering biomaterials that actively interface with and instruct their biological milieu have given rise to a new generation of platforms for tissue repair and companion diagnostics.Among them,aerogel scaffolds,with their ultra-porous architecture,ultralow density,tunable mechanics,and versatile chemistries,have emerged as transformative candidates capable of emulating and interpreting extracellular environments.This review highlights up-to-date advances shaping the landscape of aerogel-based scaffolds in tissue repair and diagnostic applications.We first summarize emerging fabrication and assembly strategies,including sol-gel processing,freeze-drying,electrospinning,and 3D printing,which unlock hierarchical morphologies and bioinspired features.The recent implementations of intelligent aerogels for tissue repair and neuroregeneration are then highlighted,together with related applications in bioactive functionalization,immune modulation,wound healing,sustained drug delivery,and moist repair dressings.Meanwhile,we outline aerogel-based disease diagnosis regarding genotypic physiological cues,focusing on faithfully detecting nucleic acids,tumor biopsy,virus antigen testing of infectious disease,and state-of-the-art demos with innovative signal transduction mechanisms.Data-driven strategies powered by machine learning are also reviewed,alongside integration into smart wearables for self-adapting,responsive platforms.Finally,persisting challenges and present perspective of aerogel scaffolds in medicine research and practice are also discussed.
文摘Biomimetics has an immense potential to drive the next generation of technologies forward by propounding competent solutions from nature.For decades,the nonsmooth topography of most living creatures has been critical to their existence and survival.Contrary to human-made smooth surfaces,when adapted for fluid flow applications,nonsmooth surfaces can enhance the overall aerodynamic performance by reducing the drag force.Recently,the bioinspired scale structure of fish has been identified as a key biomimetic derivative for improving the aerodynamic efficiency in various cross-domain applications.This study investigates the aerodynamics of a fish scale array(FSA)NACA 0021 model at a specific Reynolds number(Re)of approximately 2.46×105 that is meant for laminar flow conditions using Computational Fluid Dynamics(CFD)tools and a subsonic wind tunnel facility.A 3D printed biomimetic FSA film is developed and affixed on the NACA 0021 wing profile for the experimental investigation,followed by flow visualization through the smoke tunnel facility.As proved qualitatively under specific aerodynamic conditions,the creation of velocity streaks has a major role in the drag reduction process.To obtain a clear perspective of flow across the overlapping fish scale structures,the results are focused on the central and overlapping regions of the FSA structure.The experiment has proved the existence of a combined formation of low and high velocity streaks in central and overlapping regions.The FSA 0021 model showed a maximum drag reduction of 9.57%,which was attributed to the streak formation phenomenon observed in the overlapping FSA configuration.
