In this paper,the nonlinear parametric vibration of fluid-conveying pipes flexibly restrained at both ends and subjected to the pulsation flow excitation is investigated.The nonlinear equation of motion is derived usi...In this paper,the nonlinear parametric vibration of fluid-conveying pipes flexibly restrained at both ends and subjected to the pulsation flow excitation is investigated.The nonlinear equation of motion is derived using Hamilton^principle by considering the Kevin-Voigt viscoelastic damping,the geometric nonlinearity and the translational and rotational springs supported at the ends.The mode functions and eigen-frequencies are determined by the assumed mode method according to the elastic boundary conditions.The Galerkin method is implemented to obtain the natural frequencies and mode shapes of the pipe conveying fluid with different flow velocities.The effects of flexibly restrained conditions on stability of the pipe are analyzed.The nonlinear responses of the pipe under pulsating flow excitation are solved by the direct numerical method.The vibration behaviors are discussed in details,such as time history,frequency spectrum,phase-plane portrait,Poincare map and motion trajectory.The results show that the responses of sub-harmonic resonance and combination resonance can also be reflected in the rigidly supported pipes.The 1/5,1/8 and 1/13 sub-harmonic resonances can occur at certain excitation frequencies of the nonlinear parametric vibration system.The steady-state response amplitudes increase by a large margin and significantly affect the stability of the pipe.The effects of different spring stiffness coefficients on the parametric resonance responses are presented.For larger translational springs and rotational stiffness coefficients,the resonance frequencies shift to higher regions and the resonance amplitudes may reduce by a certain extent in accordance with the rigid-body motion.This study can provide helpful guidance on the analysis and design of piping systems subject to vibrations.展开更多
Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior a...Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior and mechanical property of molecular crystals simultaneously via supramolecular salt strategy is rarely reported,which is very important to improve their photophysical behavior and softness for the fabrication of flexible light-emitting device.Herein,supramolecular salt approach has been successfully applied to synthesize two elastic organic fluorescent crystals(CMOH-Py-Cl and CMOH-Py-Br)derived from non-emissive and brittle pyridine-substituted coumarin derivative(CMOH-Py).Their elastic properties can be attributed to the prevalent presence of numerous weak interactions introduced by halogen atoms,which are beneficial to the absorption and release of mechanical energy.Furthermore,density functional theory(DFT)calculations demonstrated a narrowing of the HOMO-LUMO energy gaps from CMOH-Py to CMOH-Py-Cl/CMOH-Py-Br via supramolecular salt approach.Finally,the application of flexible crystal materials in the field of optical waveguides has been investigated.The transformation of crystals in terms of photophysical and mechanical properties,achieved by the supramolecular salt approach,offers novel insights into the design and construction of flexible crystalline materials,providing a new path for the development of next-generation smart materials.展开更多
Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limita...Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limitations due to size constraints and mechanical inflexibility. To address these challenges, this study develops a hybrid composite structure— polycrystalline powder(PCP) matrix(PCPM)—by strategically homogenizing 20 μm PCPs within a poly(methyl methacrylate) matrix. Such a configuration enables the formation of densely packed PCP microstructures while maintaining electric conductivity and mechanical flexibility. In the single-photon regime, responsivity(R) and external quantum efficiency(EQE) decline by 50%, with concurrent 3–4-fold enhancements in the On/Off ratio and 12–16-fold improvements in specific detectivity(D), compared with those of SC counterparts. Notably, in the two-photon regime, R and EQE exhibit a 2–3-fold increase, and the On/Off ratio and D exhibit 12–16-fold improvements. The PCPM configuration enables the high-repetitionrate wafer-scale fabrication of active layers for imaging PDs and provides exceptional mechanical flexibility and self-recovery. These findings establish PCPMs as a scalable platform for next-generation perovskite wearable electronics.展开更多
The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precis...The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.展开更多
Since the first design of tactile sensors was proposed by Harmon in 1982,tactile sensors have evolved through four key phases:industrial applications(1980s,basic pressure detection),miniaturization via MEMS(1990s),fle...Since the first design of tactile sensors was proposed by Harmon in 1982,tactile sensors have evolved through four key phases:industrial applications(1980s,basic pressure detection),miniaturization via MEMS(1990s),flexible electronics(2010s,stretchable materials),and intelligent systems(2020s-present,AI-driven multimodal sensing).With the innovation of material,processing techniques,and multimodal fusion of stimuli,the application of tactile sensors has been continuously expanding to a diversity of areas,including but not limited to medical care,aerospace,sports and intelligent robots.Currently,researchers are dedicated to develop tactile sensors with emerging mechanisms and structures,pursuing high-sensitivity,high-resolution,and multimodal characteristics and further constructing tactile systems which imitate and approach the performance of human organs.However,challenges in the combination between the theoretical research and the practical applications are still significant.There is a lack of comprehensive understanding in the state of the art of such knowledge transferring from academic work to technical products.Scaled-up production of laboratory materials faces fatal challenges like high costs,small scale,and inconsistent quality.Ambient factors,such as temperature,humidity,and electromagnetic interference,also impair signal reliability.Moreover,tactile sensors must operate across a wide pressure range(0.1 k Pa to several or even dozens of MPa)to meet diverse application needs.Meanwhile,the existing algorithms,data models and sensing systems commonly reveal insufficient precision as well as undesired robustness in data processing,and there is a realistic gap between the designed and the demanded system response speed.In this review,oriented by the design requirements of intelligent tactile sensing systems,we summarize the common sensing mechanisms,inspired structures,key performance,and optimizing strategies,followed by a brief overview of the recent advances in the perspectives of system integration and algorithm implementation,and the possible roadmap of future development of tactile sensors,providing a forward-looking as well as critical discussions in the future industrial applications of flexible tactile sensors.展开更多
A novel siphon-based divide-and-conquer(SbDaC)policy is presented in this paper for the synthesis of Petri net(PN)based liveness-enforcing supervisors(LES)for flexible manufacturing systems(FMS)prone to deadlocks or l...A novel siphon-based divide-and-conquer(SbDaC)policy is presented in this paper for the synthesis of Petri net(PN)based liveness-enforcing supervisors(LES)for flexible manufacturing systems(FMS)prone to deadlocks or livelocks.The proposed method takes an uncontrolled and bounded PN model(UPNM)of the FMS.Firstly,the reduced PNM(RPNM)is obtained from the UPNM by using PN reduction rules to reduce the computation burden.Then,the set of strict minimal siphons(SMSs)of the RPNM is computed.Next,the complementary set of SMSs is computed from the set of SMSs.By the union of these two sets,the superset of SMSs is computed.Finally,the set of subnets of the RPNM is obtained by applying the PN reduction rules to the superset of SMSs.All these subnets suffer from deadlocks.These subnets are then ordered from the smallest one to the largest one based on a criterion.To enforce liveness on these subnets,a set of control places(CPs)is computed starting from the smallest subnet to the largest one.Once all subnets are live,this process provides the LES,consisting of a set of CPs to be used for the UPNM.The live controlled PN model(CPNM)is constructed by merging the LES with the UPNM.The SbDaC policy is applicable to all classes of PNs related to FMS prone to deadlocks or livelocks.Several FMS examples are considered from the literature to highlight the applicability of the SbDaC policy.In particular,three examples are utilized to emphasize the importance,applicability and effectiveness of the SbDaC policy to realistic FMS with very large state spaces.展开更多
Flexible energy storage and harvesting devices,as core components of the flexible electronic system,have driven the transformation of electronic system from“external power supply”to“self-powering”and from“fixed f...Flexible energy storage and harvesting devices,as core components of the flexible electronic system,have driven the transformation of electronic system from“external power supply”to“self-powering”and from“fixed forms”to“adaptive configurations”,thus playing an important role in the advancement of wearable technology,the internet of things,and other related fields.MXenes,a class of two-dimensional transition metal carbides,nitrides,and carbonitrides,emerge as promising candidates for flexible energy storage and harvesting devices,attributed to their excellent conductivity,mechanical flexibility,and tunable interfacial characteristics.Specifically,the interfacial characteristics of MXenes,including surface energy,surface terminations,and interlayer spacing,have a decisive influence on the performance of MXene-based energy devices.This review summarizes the influence of microcosmic interfacial characteristics on macroscopic properties,the interfacial regulation strategies,and applications in flexible energy storage and harvesting of MXenes,concluding with current challenges and perspectives to guide the design of high-performance MXene-based energy devices.展开更多
The new RE 6 EL from KARL MAYER brings a breath of fresh air to raschel fabric production.Nowadays textile companies increasingly need to produce small production runs and respond to market changes with instantaneous ...The new RE 6 EL from KARL MAYER brings a breath of fresh air to raschel fabric production.Nowadays textile companies increasingly need to produce small production runs and respond to market changes with instantaneous pattern changes in order to operate profitably–meaning they require machines that offer maximum flexibility,reliability and cost efficiency.KARL MAYER understands the challenges of the market and is launching its new RE 6 EL.The Raschel machine offers the core strengths of the classic RSE 6 EL and essentially the same performance parameters,but has been further cost-optimised largely due to local production advantages.This makes the newcomer an efficiency champion in production,especially when it comes to frequent pattern changes.展开更多
The development of high-performance transparent substrates is critical for next-generation flexible electronic devices.Herein,we designed two novel meta-substituted diamines incorporating trifluoromethyl(―CF_(3))and ...The development of high-performance transparent substrates is critical for next-generation flexible electronic devices.Herein,we designed two novel meta-substituted diamines incorporating trifluoromethyl(―CF_(3))and methyl(―CH_(3))groups to synthesize colorless copolyimide(CPI)films via copolymerization with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)/3,3′,4,4′-biphenyltetracarboxylic dianhydride(BPDA).The combination of meta-substituted architecture and substituents enables the simultaneous attainment of an ultralow dielectric constant(D_k)and high transparency.The meta-substitution geometry and electronic effects of―CF_(3)/―CH_(3) effectively suppressed charge-transfer complex(CTC)formation,expanded fractional free volume(FFV),and restricted π-electron conjugation,as validated by DFT calculations and wide-angle X-ray diffraction(WAXD)analysis.The optimized CPI film(PIA_(1)-6FDA/BPDA(10/0))achieved outstanding transmittance(T_(450)=88.15%),ultralow dielectric constant(D_(k)=2.08 at 1 k Hz),and minimal dielectric loss(D_(f)=0.0012),while maintaining robust thermal stability(T_(d5%)>523℃)and mechanical strength(σ=87.5 MPa).This work establishes a molecular engineering strategy to concurrently enhance the optical and dielectric properties,positioning meta-substituted CPIs as promising candidates for transparent flexible devices.展开更多
Reed membrane,a natural cellulosic material traditionally used in musical instruments,holds promise in flexible electronics due to its abundance,low cost,and excellent biocompatibility.However,its native form contains...Reed membrane,a natural cellulosic material traditionally used in musical instruments,holds promise in flexible electronics due to its abundance,low cost,and excellent biocompatibility.However,its native form contains water-soluble ions and lipid-soluble waxes that hinder performance in acoustic and electronics by compromising electrical insulation and mechanical stability.Here,supercritical fluid superposition purification(SCSP-WA)is introduced,which utilizes supercritical CO_(2)with water and acetone as bipolar co-solvents to selectively remove these impurities.Post-SCSP-WA treatment,the reed membrane exhibits significant enhancements in mechanical strength and electrical insulation,achieving a 4-fold increase in elongation at break,improved tensile strength and Young’s modulus,and a 98.5%reduction in leakage current,all while maintaining low and stable capacitance.These improvements stem from the restructuring of the fibrous network into a porous,interconnected microstructure.Material characterization(X-ray photoelectron spectroscopy(XPS),Fourier-transform infrared spectroscopy(FTIR),and scanning electron microscopy(SEM))confirmed the effective removal of magnesium and waxy functional groups,along with enhanced fiber crosslinking.Cytotoxicity tests further validated the biocompatibility of the SCSP-WA-treated membranes.This environmentally sustainable approach expands the potential of reed membranes in flexible bioelectronics and bio-integrated acoustic systems.展开更多
With the rapid development of intelligent electronic and military equipment,multifunctional flexible materials that integrat electromagnetic interference(EMI)shielding,temperature sensing,and information encryption ar...With the rapid development of intelligent electronic and military equipment,multifunctional flexible materials that integrat electromagnetic interference(EMI)shielding,temperature sensing,and information encryption are urgently required.This study presents a bio-inspired hierarchical composite foam fabricated using supercritical nitrogen foaming technology.This material exhibits a honeycomb structure,with pore cell sizes controllable within a range of 30–92μm by regulating the filler.The carbon fiber felt(CFf)provides efficient reflection of electromagnetic waves,while the chloroprene rubber/carbon fiber/carbon black foam facilitates both wave absorption and temperature monitoring through its optimized conductive network.This synergistic mechanism results in an EMI shielding effectiveness(SE)of 60.06 d B with excellent temperature sensing performance(The temperature coefficient of resistance(TCR)is-2.642%/℃)in the 24–70℃ range.Notably,the material has a thermal conductivity of up to 0.159 W/(m·K),and the bio-inspired layered design enables information encryption,demonstrating the material's potential for secure communication applications.The foam also has tensile properties of up to 5.13 MPa and a tear strength of 33.02 N/mm.This biomimetic design overcomes the traditional limitations of flexible materials and provides a transformative solution for next-generation applications such as flexible electronics,aerospace systems and military equipment,which urgently need integrated electromagnetic protection,thermal management and information security.展开更多
Flexible pressure sensors(FPSs)offer unique benefits for fall detection and rehabilitation training,but conventional FPSs made from synthetic materials have drawbacks,including resource-heavy manufacturing,high costs,...Flexible pressure sensors(FPSs)offer unique benefits for fall detection and rehabilitation training,but conventional FPSs made from synthetic materials have drawbacks,including resource-heavy manufacturing,high costs,and environmental pollution.To address these limitations,this study proposes an innovative fabrication strategy for FPS based on natural materials.The upper and lower electrodes were made by treating a natural wood strip with a flame retardant,converting it into high-quality graphene via a costeffective infrared laser,and transferring it onto starch-based substrates.The dielectric layer was created by electrospinning a composite nanofiber membrane with cyclodextrin and carbon nanotubes.The resulting capacitive FPS shows high sensitivity(2.15 kPa^(-1) within 0-10 kPa),a low detection limit(~6.5 Pa),fast response and recovery times(29 and 39 ms),and excellent long-term stability(over 5000 cycles).It also demonstrates excellent biocompatibility(cell viability>98%)and fully degrades within 6 h.By integrating this sensor with wireless technology,a fall detection and rehabilitation monitoring system was developed.Data processing was handled by a Tiny Machine Learning module on a mobile platform,which transmitted relevant data to a cloud-based platform.The system accurately identified five common fall postures and assisted clinicians in guiding rehabilitation exercises,achieving recognition accuracies of 99%and 100%,respectively,offering a sustainable healthcare solution for the elderly.展开更多
The advancement of flexible memristors has significantly promoted the development of wearable electronic for emerging neuromorphic computing applications.Inspired by in-memory computing architecture of human brain,fle...The advancement of flexible memristors has significantly promoted the development of wearable electronic for emerging neuromorphic computing applications.Inspired by in-memory computing architecture of human brain,flexible memristors exhibit great application potential in emulating artificial synapses for highefficiency and low power consumption neuromorphic computing.This paper provides comprehensive overview of flexible memristors from perspectives of development history,material system,device structure,mechanical deformation method,device performance analysis,stress simulation during deformation,and neuromorphic computing applications.The recent advances in flexible electronics are summarized,including single device,device array and integration.The challenges and future perspectives of flexible memristor for neuromorphic computing are discussed deeply,paving the way for constructing wearable smart electronics and applications in large-scale neuromorphic computing and high-order intelligent robotics.展开更多
Zinc-air batteries(ZABs)are promising candidates for flexible electronics due to their high energy density and low cost.However,their development is hindered by the sluggish kinetics of the oxygen evolution reaction(O...Zinc-air batteries(ZABs)are promising candidates for flexible electronics due to their high energy density and low cost.However,their development is hindered by the sluggish kinetics of the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Herein,we present a novel heterostructured electrocatalyst composed of vertically aligned N-doped graphene(NVG)arrays anchored on Ru-doped ceria(RCO)nanofibers,synthesized via a one-step plasma-enhanced chemical vapor deposition process.Notably,during the plasma-enhanced driven NVG growth,Ru nanoparticles are spontaneously in-situ exsolved from the RCO lattice,forming a unique Ru@RCO-NVG heterostructure.Density functional theory calculations reveal that the Ru@RCO-NVG heterojunction induces interfacial electronic redistribution,thereby significantly lowering the energy barriers for both OER and ORR.Benefiting from the synergistic effects,the Ru@RCO-NVG catalyst exhibits exceptional intrinsic activity towards OER/ORR(an overpotential of 370 mV for OER at 10 mA cm^(−2)and a half-wave potential of 0.86 V for ORR),and higher all-solid-state flexible ZAB performance(peak power density of 286.1 mW cm^(−2)),surpassing commercial Pt/C-IrO_(2)catalysts.This work not only advances the integration of synergistic graphene/ceria composites but also offers a promising strategy for designing efficient electrocatalysts for next-generation energy conversion technologies.展开更多
Photo-assisted flexible energy storage devices,combining photoelectric conversion and electrochemical energy storage,emerge as an innovative solution for sustainable energy systems.This review comprehensively summariz...Photo-assisted flexible energy storage devices,combining photoelectric conversion and electrochemical energy storage,emerge as an innovative solution for sustainable energy systems.This review comprehensively summarizes recent advances in photo-assisted flexible energy storage technology,covering material design,working mechanisms,and practical applications.We systematically examine diverse electrode materials,such as metal oxides,metal sulfides,organic photosensitive materials,and composites,emphasizing their roles in boosting device performance.Special focus is placed on emerging technologies—including heterostructure engineering,surface modification,and intelligent control systems—that have notably enhanced energy conversion efficiency and storage capacity.The review also discusses current challenges,such as material stability,conversion efficiency,and standardization,and proposes strategic directions for future development.Recent breakthroughs in photo-assisted supercapacitors,lithium-based batteries,zinc-based batteries,and other innovative storage systems are critically assessed,offering key insights into their practical application potential in wearable electronics,self-powered sensors,and beyond.This comprehensive analysis establishes a framework for understanding the current status of photo-assisted flexible energy storage technology and guides future research toward high-performance,sustainable energy storage solutions.展开更多
Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short...Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short time remains a major challenge.In this study,a multifunctional mussel-inspired hydrogel was synthesized in only 5 min,with polydopamine(PDA)-polypyrrole(Ppy)-polyaniline(PANi)and poly(vinyl alcohol)(PVA)nanoparticles incorporated into the polyacrylamide(PAM)network.The resulting hydrogel exhibited high transparency(about 90% light transmission in the range of 400-800 nm),high conductivity((95.4±0.4)×10^(-4)S/cm),tensile strength(32.60±1.03 k Pa),strain at break(904.46%±11.50%),and adhesive strength(30-60 k Pa).It also demonstrated rapid self-healing properties(about 48% strength recovery within 1h at 50℃)and water-dependent shape memory behavior.As a wearable strain sensor,the hydrogel successfully detected finger flexion,wrist movements,facial expression changes,and breathing with high sensitivity and stability.The calculated gauge factor(GF)was 7.44±0.31,which is higher than that of many previously reported hydrogels.Compared with previous oyster-inspired or Ppy-based hydrogels,our system showed a much shorter synthesis time,higher transparency,and enhanced multifunctionality.These findings highlight the potential of the proposed hydrogel for next-generation flexible electronics,e-skin,and biomedical monitoring devices.展开更多
The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem...The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem,we design a flexible support structure including connectors,a support plate,and flexible structures,and construct an equivalent mirror by installing connectors and a support plate on the back of the mirror.While ensuring that the neutral surface of the equivalent mirror is moved away from the mirror surface,we optimize the support structure so that the rotary center of the flexible structure is located on the neutral surface of the equivalent mirror,avoiding the tilting moment.Following design and modeling of the structure,we analyze the static and dynamic characteristics using a finite element simulation,finding a root-mean-square(RMS)value for the surface shape error of 9.28 nm under the coupled effects of 1g gravity load,4℃ temperature rise,and 0.005 mm unevenness assembly error,with a fundamental frequency of 170.75 Hz,which all meet the design requirements.Finally,we carry out a surface shape error test of the mirror assembly,confirming it to meet the design index requirement of the mirror assembly.Simulation and test results verify the reliability and effectiveness of our proposed support structure.展开更多
With the widespread application of lithium batteries in electric vehicles and energy storage systems,battery-related safety and reliability issues have become increasingly prominent.Conventional monitoring methods oft...With the widespread application of lithium batteries in electric vehicles and energy storage systems,battery-related safety and reliability issues have become increasingly prominent.Conventional monitoring methods often struggle to address dynamic changes under complex operando.In recent years,flexible sensing technology has emerged as a promising solution for battery health monitoring due to its high adaptability and conformability to complex structures.Meanwhile,empowered by artificial intelligence(AI)for data analysis,the collected data enables efficient and accurate state assessment,offering robust support for accident prevention.Against this background,this paper first explores the integrated applications of flexible sensors in battery health monitoring and their unique advantages in addressing complex battery operating conditions,while analyzing the potential of AI in battery state analysis.Subsequently,it systematically reviews mainstream flexible sensing technologies(e.g.,film sensors,thermocouples,and optical fiber sensors),elucidating their mechanisms for revealing intricate internal battery processes during operation.Finally,the paper discusses AI’s role in enhancing monitoring efficiency and accuracy,and envisions future research directions and application prospects.This work aims to provide technical references for the battery health monitoring field as well as promote the application of flexible sensing technologies in improving battery system safety and reliability.展开更多
In bio-inspired flapping-wing flight,lift generation and flexible deformation are intrinsically coupled.Thus,an experimental study is conducted to reveal the fluid-structure interaction mechanism for a flexible plate ...In bio-inspired flapping-wing flight,lift generation and flexible deformation are intrinsically coupled.Thus,an experimental study is conducted to reveal the fluid-structure interaction mechanism for a flexible plate undergoing pitching and plunging motion,and theoretical models are proposed to predict either lift or deformation based on a series of simplifying assumptions.It is indicated that flexible plates can effectively reduce the amplitude of lift and pitching moment coefficients during dynamic stall,with increased flexibility leading to higher load reduction.To investigate the effect of plate flexibility on lift,a definition of effective angle of attack is proposed,incorporating the pitching and plunging motion and chordwise deformation of the flexible plate,which can reduce the hysteresis effect of the lift coefficient during dynamic stall.As a consequence,a theoretical model is developed to predict lift based on observed motion and deformation.On the other hand,another theoretical model is developed to predict flexible-plate deformation utilizing aerodynamic forces,revealing the effect of leading-edge vortex evolution on passive deformation.The influence of kinematic parameters,including the maximum effective angle of attack,reduced frequency,and Strouhal number,on the aerodynamic forces is further studied.Compared with the rigid plate,flexible plates exhibit lower sensitivity of aerodynamic forces to changes in kinematic parameters due to their inherent compliance and resulting deformation.The proposed theoretical models can serve as a reference for aerodynamic and deformation prediction in bio-inspired flexible structures.展开更多
The development of high-performance bifunctional electrocatalysts is crucial for advancing zinc-air batteries.However,the fundamentally distinct mechanisms of the oxygen reduction and evolution reactions(ORR/OER)hinde...The development of high-performance bifunctional electrocatalysts is crucial for advancing zinc-air batteries.However,the fundamentally distinct mechanisms of the oxygen reduction and evolution reactions(ORR/OER)hinder the simultaneous realization of high activity within a single catalyst.Herein,we propose a spatial decoupling strategy to overcome this limitation by engineering isolated Fe singleatoms and Fe-Ir dual-atom pairs on a nitrogen-doped carbon matrix(Fe/FeIr-NC).In this architecture,Fe single atoms serve as ORR centers,while Fe-Ir pairs with tunable spacing are tailored for OER,enabling complete functional separation and independent optimization of the reactions.As a result,the catalyst delivers an ORR half-wave potential of 0.91 V and an OER overpotential of 250 mV at 10 mA cm^(-2),yielding a record-low bifunctional gap(ΔE=0.57 V)that outperforms all reported single-and dual-atom catalysts.A flexible fiber zincair battery was developed based on this catalyst,delivering a peak power density of 3920 W kg^(-1),along with a 1.4-fold increase in energy efficiency and a 2.6-fold extension in cycle life compared to the commercial Pt/C+IrO_(2)benchmark.This work not only breaks the traditional activity trade-off in bifunctional catalysis but also offers a promising route toward high-performance power sources for wearable electronics.展开更多
基金the National Natural Science Foundation of China(Grant No.51305350,Grant No.11802235)National Key Basic Research Program of China(Grant No.613268)Aeronautics Power Foundation Program of China(Grant No.6141B090320).
文摘In this paper,the nonlinear parametric vibration of fluid-conveying pipes flexibly restrained at both ends and subjected to the pulsation flow excitation is investigated.The nonlinear equation of motion is derived using Hamilton^principle by considering the Kevin-Voigt viscoelastic damping,the geometric nonlinearity and the translational and rotational springs supported at the ends.The mode functions and eigen-frequencies are determined by the assumed mode method according to the elastic boundary conditions.The Galerkin method is implemented to obtain the natural frequencies and mode shapes of the pipe conveying fluid with different flow velocities.The effects of flexibly restrained conditions on stability of the pipe are analyzed.The nonlinear responses of the pipe under pulsating flow excitation are solved by the direct numerical method.The vibration behaviors are discussed in details,such as time history,frequency spectrum,phase-plane portrait,Poincare map and motion trajectory.The results show that the responses of sub-harmonic resonance and combination resonance can also be reflected in the rigidly supported pipes.The 1/5,1/8 and 1/13 sub-harmonic resonances can occur at certain excitation frequencies of the nonlinear parametric vibration system.The steady-state response amplitudes increase by a large margin and significantly affect the stability of the pipe.The effects of different spring stiffness coefficients on the parametric resonance responses are presented.For larger translational springs and rotational stiffness coefficients,the resonance frequencies shift to higher regions and the resonance amplitudes may reduce by a certain extent in accordance with the rigid-body motion.This study can provide helpful guidance on the analysis and design of piping systems subject to vibrations.
基金supported by the National Natural Science Foundation of China(Nos.22205105,61874053,22075136)National Key Basic Research Program of China(No.2020YFA0709900)Jiangsu Provincial Postgraduate Scientific Research Innovation Program(No.KYCX24_1649).
文摘Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior and mechanical property of molecular crystals simultaneously via supramolecular salt strategy is rarely reported,which is very important to improve their photophysical behavior and softness for the fabrication of flexible light-emitting device.Herein,supramolecular salt approach has been successfully applied to synthesize two elastic organic fluorescent crystals(CMOH-Py-Cl and CMOH-Py-Br)derived from non-emissive and brittle pyridine-substituted coumarin derivative(CMOH-Py).Their elastic properties can be attributed to the prevalent presence of numerous weak interactions introduced by halogen atoms,which are beneficial to the absorption and release of mechanical energy.Furthermore,density functional theory(DFT)calculations demonstrated a narrowing of the HOMO-LUMO energy gaps from CMOH-Py to CMOH-Py-Cl/CMOH-Py-Br via supramolecular salt approach.Finally,the application of flexible crystal materials in the field of optical waveguides has been investigated.The transformation of crystals in terms of photophysical and mechanical properties,achieved by the supramolecular salt approach,offers novel insights into the design and construction of flexible crystalline materials,providing a new path for the development of next-generation smart materials.
基金supported by the Key Project of the National Key R&D Program of China (Grant No.2022YFA1404500)the National Natural Science Foundation of China (Grant Nos.12434017,62005183)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2025A1515010329)。
文摘Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limitations due to size constraints and mechanical inflexibility. To address these challenges, this study develops a hybrid composite structure— polycrystalline powder(PCP) matrix(PCPM)—by strategically homogenizing 20 μm PCPs within a poly(methyl methacrylate) matrix. Such a configuration enables the formation of densely packed PCP microstructures while maintaining electric conductivity and mechanical flexibility. In the single-photon regime, responsivity(R) and external quantum efficiency(EQE) decline by 50%, with concurrent 3–4-fold enhancements in the On/Off ratio and 12–16-fold improvements in specific detectivity(D), compared with those of SC counterparts. Notably, in the two-photon regime, R and EQE exhibit a 2–3-fold increase, and the On/Off ratio and D exhibit 12–16-fold improvements. The PCPM configuration enables the high-repetitionrate wafer-scale fabrication of active layers for imaging PDs and provides exceptional mechanical flexibility and self-recovery. These findings establish PCPMs as a scalable platform for next-generation perovskite wearable electronics.
基金supported by the National Natural Science Foundation of China(No.52403035)the Shanghai Sailing Program(23YF1400300)+1 种基金the Fundamental Research Funds for the Central Universities(2232023D-05)the Weiqiao Teaching and Research Innovation Program.
文摘The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.
基金the financial support of the National Natural Science Foundation of China(NO.52173028)。
文摘Since the first design of tactile sensors was proposed by Harmon in 1982,tactile sensors have evolved through four key phases:industrial applications(1980s,basic pressure detection),miniaturization via MEMS(1990s),flexible electronics(2010s,stretchable materials),and intelligent systems(2020s-present,AI-driven multimodal sensing).With the innovation of material,processing techniques,and multimodal fusion of stimuli,the application of tactile sensors has been continuously expanding to a diversity of areas,including but not limited to medical care,aerospace,sports and intelligent robots.Currently,researchers are dedicated to develop tactile sensors with emerging mechanisms and structures,pursuing high-sensitivity,high-resolution,and multimodal characteristics and further constructing tactile systems which imitate and approach the performance of human organs.However,challenges in the combination between the theoretical research and the practical applications are still significant.There is a lack of comprehensive understanding in the state of the art of such knowledge transferring from academic work to technical products.Scaled-up production of laboratory materials faces fatal challenges like high costs,small scale,and inconsistent quality.Ambient factors,such as temperature,humidity,and electromagnetic interference,also impair signal reliability.Moreover,tactile sensors must operate across a wide pressure range(0.1 k Pa to several or even dozens of MPa)to meet diverse application needs.Meanwhile,the existing algorithms,data models and sensing systems commonly reveal insufficient precision as well as undesired robustness in data processing,and there is a realistic gap between the designed and the demanded system response speed.In this review,oriented by the design requirements of intelligent tactile sensing systems,we summarize the common sensing mechanisms,inspired structures,key performance,and optimizing strategies,followed by a brief overview of the recent advances in the perspectives of system integration and algorithm implementation,and the possible roadmap of future development of tactile sensors,providing a forward-looking as well as critical discussions in the future industrial applications of flexible tactile sensors.
基金The authors extend their appreciation to King Saud University,Saudi Arabia for funding this work through the Ongoing Research Funding Program(ORF-2025-704),King Saud University,Riyadh,Saudi Arabia.
文摘A novel siphon-based divide-and-conquer(SbDaC)policy is presented in this paper for the synthesis of Petri net(PN)based liveness-enforcing supervisors(LES)for flexible manufacturing systems(FMS)prone to deadlocks or livelocks.The proposed method takes an uncontrolled and bounded PN model(UPNM)of the FMS.Firstly,the reduced PNM(RPNM)is obtained from the UPNM by using PN reduction rules to reduce the computation burden.Then,the set of strict minimal siphons(SMSs)of the RPNM is computed.Next,the complementary set of SMSs is computed from the set of SMSs.By the union of these two sets,the superset of SMSs is computed.Finally,the set of subnets of the RPNM is obtained by applying the PN reduction rules to the superset of SMSs.All these subnets suffer from deadlocks.These subnets are then ordered from the smallest one to the largest one based on a criterion.To enforce liveness on these subnets,a set of control places(CPs)is computed starting from the smallest subnet to the largest one.Once all subnets are live,this process provides the LES,consisting of a set of CPs to be used for the UPNM.The live controlled PN model(CPNM)is constructed by merging the LES with the UPNM.The SbDaC policy is applicable to all classes of PNs related to FMS prone to deadlocks or livelocks.Several FMS examples are considered from the literature to highlight the applicability of the SbDaC policy.In particular,three examples are utilized to emphasize the importance,applicability and effectiveness of the SbDaC policy to realistic FMS with very large state spaces.
基金supported by the National Natural Science Foundation of China(52422205,52403154)the National Key Research and Development Program of China(2023YFB3811303)+2 种基金the Natural Science Foundation of Sichuan Province(2026NSFSCZY0103,2026NSFSC1406)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZC20230383)the China Postdoctoral Science Foundation(2025M770159)。
文摘Flexible energy storage and harvesting devices,as core components of the flexible electronic system,have driven the transformation of electronic system from“external power supply”to“self-powering”and from“fixed forms”to“adaptive configurations”,thus playing an important role in the advancement of wearable technology,the internet of things,and other related fields.MXenes,a class of two-dimensional transition metal carbides,nitrides,and carbonitrides,emerge as promising candidates for flexible energy storage and harvesting devices,attributed to their excellent conductivity,mechanical flexibility,and tunable interfacial characteristics.Specifically,the interfacial characteristics of MXenes,including surface energy,surface terminations,and interlayer spacing,have a decisive influence on the performance of MXene-based energy devices.This review summarizes the influence of microcosmic interfacial characteristics on macroscopic properties,the interfacial regulation strategies,and applications in flexible energy storage and harvesting of MXenes,concluding with current challenges and perspectives to guide the design of high-performance MXene-based energy devices.
文摘The new RE 6 EL from KARL MAYER brings a breath of fresh air to raschel fabric production.Nowadays textile companies increasingly need to produce small production runs and respond to market changes with instantaneous pattern changes in order to operate profitably–meaning they require machines that offer maximum flexibility,reliability and cost efficiency.KARL MAYER understands the challenges of the market and is launching its new RE 6 EL.The Raschel machine offers the core strengths of the classic RSE 6 EL and essentially the same performance parameters,but has been further cost-optimised largely due to local production advantages.This makes the newcomer an efficiency champion in production,especially when it comes to frequent pattern changes.
基金financially supported by the National Key R&D Program of China(No.2023YFB3812400)the National Natural Science Foundation of China(No.51890871)the GJYC Program of Guangzhou(No.2024D02J0004)。
文摘The development of high-performance transparent substrates is critical for next-generation flexible electronic devices.Herein,we designed two novel meta-substituted diamines incorporating trifluoromethyl(―CF_(3))and methyl(―CH_(3))groups to synthesize colorless copolyimide(CPI)films via copolymerization with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)/3,3′,4,4′-biphenyltetracarboxylic dianhydride(BPDA).The combination of meta-substituted architecture and substituents enables the simultaneous attainment of an ultralow dielectric constant(D_k)and high transparency.The meta-substitution geometry and electronic effects of―CF_(3)/―CH_(3) effectively suppressed charge-transfer complex(CTC)formation,expanded fractional free volume(FFV),and restricted π-electron conjugation,as validated by DFT calculations and wide-angle X-ray diffraction(WAXD)analysis.The optimized CPI film(PIA_(1)-6FDA/BPDA(10/0))achieved outstanding transmittance(T_(450)=88.15%),ultralow dielectric constant(D_(k)=2.08 at 1 k Hz),and minimal dielectric loss(D_(f)=0.0012),while maintaining robust thermal stability(T_(d5%)>523℃)and mechanical strength(σ=87.5 MPa).This work establishes a molecular engineering strategy to concurrently enhance the optical and dielectric properties,positioning meta-substituted CPIs as promising candidates for transparent flexible devices.
基金supported by the Shenzhen Scientific and Technological Foundation(RCYX20231211090332037 and JCYJ20240813160211015)the National Natural Science Foundation of China(62474008 and 62204007)+2 种基金the Guangdong Provincial Natural Science Foundation(2024A1515030044)the Guangdong Provincial Key Laboratory of In-Memory Computing Chips(2024B1212020002)the Shenzhen Science and Technology Program(KJZD20230923115005009)。
文摘Reed membrane,a natural cellulosic material traditionally used in musical instruments,holds promise in flexible electronics due to its abundance,low cost,and excellent biocompatibility.However,its native form contains water-soluble ions and lipid-soluble waxes that hinder performance in acoustic and electronics by compromising electrical insulation and mechanical stability.Here,supercritical fluid superposition purification(SCSP-WA)is introduced,which utilizes supercritical CO_(2)with water and acetone as bipolar co-solvents to selectively remove these impurities.Post-SCSP-WA treatment,the reed membrane exhibits significant enhancements in mechanical strength and electrical insulation,achieving a 4-fold increase in elongation at break,improved tensile strength and Young’s modulus,and a 98.5%reduction in leakage current,all while maintaining low and stable capacitance.These improvements stem from the restructuring of the fibrous network into a porous,interconnected microstructure.Material characterization(X-ray photoelectron spectroscopy(XPS),Fourier-transform infrared spectroscopy(FTIR),and scanning electron microscopy(SEM))confirmed the effective removal of magnesium and waxy functional groups,along with enhanced fiber crosslinking.Cytotoxicity tests further validated the biocompatibility of the SCSP-WA-treated membranes.This environmentally sustainable approach expands the potential of reed membranes in flexible bioelectronics and bio-integrated acoustic systems.
基金financially supported by the Natural Science Foundation of Shandong Province(No.ZR2024QE446)。
文摘With the rapid development of intelligent electronic and military equipment,multifunctional flexible materials that integrat electromagnetic interference(EMI)shielding,temperature sensing,and information encryption are urgently required.This study presents a bio-inspired hierarchical composite foam fabricated using supercritical nitrogen foaming technology.This material exhibits a honeycomb structure,with pore cell sizes controllable within a range of 30–92μm by regulating the filler.The carbon fiber felt(CFf)provides efficient reflection of electromagnetic waves,while the chloroprene rubber/carbon fiber/carbon black foam facilitates both wave absorption and temperature monitoring through its optimized conductive network.This synergistic mechanism results in an EMI shielding effectiveness(SE)of 60.06 d B with excellent temperature sensing performance(The temperature coefficient of resistance(TCR)is-2.642%/℃)in the 24–70℃ range.Notably,the material has a thermal conductivity of up to 0.159 W/(m·K),and the bio-inspired layered design enables information encryption,demonstrating the material's potential for secure communication applications.The foam also has tensile properties of up to 5.13 MPa and a tear strength of 33.02 N/mm.This biomimetic design overcomes the traditional limitations of flexible materials and provides a transformative solution for next-generation applications such as flexible electronics,aerospace systems and military equipment,which urgently need integrated electromagnetic protection,thermal management and information security.
基金supported by the National Natural Science Foundation of China(62301291,61904092,and 62181240278)Natural Science Foundation of Shandong Province(ZR2025MS1072)+1 种基金Youth Innovation Team Project of Shandong Provincial Education Department(2022KJ141)Taishan Scholars Project Special Funds(tsqn202312035)。
文摘Flexible pressure sensors(FPSs)offer unique benefits for fall detection and rehabilitation training,but conventional FPSs made from synthetic materials have drawbacks,including resource-heavy manufacturing,high costs,and environmental pollution.To address these limitations,this study proposes an innovative fabrication strategy for FPS based on natural materials.The upper and lower electrodes were made by treating a natural wood strip with a flame retardant,converting it into high-quality graphene via a costeffective infrared laser,and transferring it onto starch-based substrates.The dielectric layer was created by electrospinning a composite nanofiber membrane with cyclodextrin and carbon nanotubes.The resulting capacitive FPS shows high sensitivity(2.15 kPa^(-1) within 0-10 kPa),a low detection limit(~6.5 Pa),fast response and recovery times(29 and 39 ms),and excellent long-term stability(over 5000 cycles).It also demonstrates excellent biocompatibility(cell viability>98%)and fully degrades within 6 h.By integrating this sensor with wireless technology,a fall detection and rehabilitation monitoring system was developed.Data processing was handled by a Tiny Machine Learning module on a mobile platform,which transmitted relevant data to a cloud-based platform.The system accurately identified five common fall postures and assisted clinicians in guiding rehabilitation exercises,achieving recognition accuracies of 99%and 100%,respectively,offering a sustainable healthcare solution for the elderly.
基金supported by the NSFC(12474071)Natural Science Foundation of Shandong Province(ZR2024YQ051)+5 种基金Open Research Fund of State Key Laboratory of Materials for Integrated Circuits(SKLJC-K2024-12)the Shanghai Sailing Program(23YF1402200,23YF1402400)Natural Science Foundation of Jiangsu Province(BK20240424)Taishan Scholar Foundation of Shandong Province(tsqn202408006)Young Talent of Lifting engineering for Science and Technology in Shandong,China(SDAST2024QTB002)the Qilu Young Scholar Program of Shandong University.
文摘The advancement of flexible memristors has significantly promoted the development of wearable electronic for emerging neuromorphic computing applications.Inspired by in-memory computing architecture of human brain,flexible memristors exhibit great application potential in emulating artificial synapses for highefficiency and low power consumption neuromorphic computing.This paper provides comprehensive overview of flexible memristors from perspectives of development history,material system,device structure,mechanical deformation method,device performance analysis,stress simulation during deformation,and neuromorphic computing applications.The recent advances in flexible electronics are summarized,including single device,device array and integration.The challenges and future perspectives of flexible memristor for neuromorphic computing are discussed deeply,paving the way for constructing wearable smart electronics and applications in large-scale neuromorphic computing and high-order intelligent robotics.
基金supported by the National Natural Science Foundation of China(Grant No.22479133,and No.22469008)the Natural Science Foundation of Guangdong Province(Grant No.2024A1515012235).
文摘Zinc-air batteries(ZABs)are promising candidates for flexible electronics due to their high energy density and low cost.However,their development is hindered by the sluggish kinetics of the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Herein,we present a novel heterostructured electrocatalyst composed of vertically aligned N-doped graphene(NVG)arrays anchored on Ru-doped ceria(RCO)nanofibers,synthesized via a one-step plasma-enhanced chemical vapor deposition process.Notably,during the plasma-enhanced driven NVG growth,Ru nanoparticles are spontaneously in-situ exsolved from the RCO lattice,forming a unique Ru@RCO-NVG heterostructure.Density functional theory calculations reveal that the Ru@RCO-NVG heterojunction induces interfacial electronic redistribution,thereby significantly lowering the energy barriers for both OER and ORR.Benefiting from the synergistic effects,the Ru@RCO-NVG catalyst exhibits exceptional intrinsic activity towards OER/ORR(an overpotential of 370 mV for OER at 10 mA cm^(−2)and a half-wave potential of 0.86 V for ORR),and higher all-solid-state flexible ZAB performance(peak power density of 286.1 mW cm^(−2)),surpassing commercial Pt/C-IrO_(2)catalysts.This work not only advances the integration of synergistic graphene/ceria composites but also offers a promising strategy for designing efficient electrocatalysts for next-generation energy conversion technologies.
基金funded by the National Key Research and Development Program of China(2022YFB3807105)National Natural Science Foundation of China(52090033)+3 种基金State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(KF222318)Jiangsu Province Industry-University-Research Cooperation Project(BY2022799)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX243534KYCX243521)。
文摘Photo-assisted flexible energy storage devices,combining photoelectric conversion and electrochemical energy storage,emerge as an innovative solution for sustainable energy systems.This review comprehensively summarizes recent advances in photo-assisted flexible energy storage technology,covering material design,working mechanisms,and practical applications.We systematically examine diverse electrode materials,such as metal oxides,metal sulfides,organic photosensitive materials,and composites,emphasizing their roles in boosting device performance.Special focus is placed on emerging technologies—including heterostructure engineering,surface modification,and intelligent control systems—that have notably enhanced energy conversion efficiency and storage capacity.The review also discusses current challenges,such as material stability,conversion efficiency,and standardization,and proposes strategic directions for future development.Recent breakthroughs in photo-assisted supercapacitors,lithium-based batteries,zinc-based batteries,and other innovative storage systems are critically assessed,offering key insights into their practical application potential in wearable electronics,self-powered sensors,and beyond.This comprehensive analysis establishes a framework for understanding the current status of photo-assisted flexible energy storage technology and guides future research toward high-performance,sustainable energy storage solutions.
文摘Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short time remains a major challenge.In this study,a multifunctional mussel-inspired hydrogel was synthesized in only 5 min,with polydopamine(PDA)-polypyrrole(Ppy)-polyaniline(PANi)and poly(vinyl alcohol)(PVA)nanoparticles incorporated into the polyacrylamide(PAM)network.The resulting hydrogel exhibited high transparency(about 90% light transmission in the range of 400-800 nm),high conductivity((95.4±0.4)×10^(-4)S/cm),tensile strength(32.60±1.03 k Pa),strain at break(904.46%±11.50%),and adhesive strength(30-60 k Pa).It also demonstrated rapid self-healing properties(about 48% strength recovery within 1h at 50℃)and water-dependent shape memory behavior.As a wearable strain sensor,the hydrogel successfully detected finger flexion,wrist movements,facial expression changes,and breathing with high sensitivity and stability.The calculated gauge factor(GF)was 7.44±0.31,which is higher than that of many previously reported hydrogels.Compared with previous oyster-inspired or Ppy-based hydrogels,our system showed a much shorter synthesis time,higher transparency,and enhanced multifunctionality.These findings highlight the potential of the proposed hydrogel for next-generation flexible electronics,e-skin,and biomedical monitoring devices.
基金supported by the National Natural Science Foundation of China(12473085).
文摘The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem,we design a flexible support structure including connectors,a support plate,and flexible structures,and construct an equivalent mirror by installing connectors and a support plate on the back of the mirror.While ensuring that the neutral surface of the equivalent mirror is moved away from the mirror surface,we optimize the support structure so that the rotary center of the flexible structure is located on the neutral surface of the equivalent mirror,avoiding the tilting moment.Following design and modeling of the structure,we analyze the static and dynamic characteristics using a finite element simulation,finding a root-mean-square(RMS)value for the surface shape error of 9.28 nm under the coupled effects of 1g gravity load,4℃ temperature rise,and 0.005 mm unevenness assembly error,with a fundamental frequency of 170.75 Hz,which all meet the design requirements.Finally,we carry out a surface shape error test of the mirror assembly,confirming it to meet the design index requirement of the mirror assembly.Simulation and test results verify the reliability and effectiveness of our proposed support structure.
基金supported by the grant of State Key Laboratory of Space Environment Interaction with Matters,the Science and Technology on Vacuum Technology and Physics Laboratory Fund(HTKJ2023KL510008)Key Program of the National Natural Science Foundation of China(No.62433017)+6 种基金the National Natural Science Foundation of China(No.62274140)the Fundamental Research Funds for the Central Universities(20720230030)the Xiaomi Young Talents Program/Xiaomi Foundation,Shenzhen Science and Technology Program(JCYJ20230807091401003)the Young Elite Scientist Sponsorship Program by Cast(No.YESS20230523)the State Key Laboratory of Space Environment Interaction with Matters(WDZC-HGD-2022-08)the Gansu Provincial Science and Technology Major Project(2244ZZDD1133GGAA000077)the China Aerospace Science and Technology Group Corporation Young Top Talents.
文摘With the widespread application of lithium batteries in electric vehicles and energy storage systems,battery-related safety and reliability issues have become increasingly prominent.Conventional monitoring methods often struggle to address dynamic changes under complex operando.In recent years,flexible sensing technology has emerged as a promising solution for battery health monitoring due to its high adaptability and conformability to complex structures.Meanwhile,empowered by artificial intelligence(AI)for data analysis,the collected data enables efficient and accurate state assessment,offering robust support for accident prevention.Against this background,this paper first explores the integrated applications of flexible sensors in battery health monitoring and their unique advantages in addressing complex battery operating conditions,while analyzing the potential of AI in battery state analysis.Subsequently,it systematically reviews mainstream flexible sensing technologies(e.g.,film sensors,thermocouples,and optical fiber sensors),elucidating their mechanisms for revealing intricate internal battery processes during operation.Finally,the paper discusses AI’s role in enhancing monitoring efficiency and accuracy,and envisions future research directions and application prospects.This work aims to provide technical references for the battery health monitoring field as well as promote the application of flexible sensing technologies in improving battery system safety and reliability.
基金supported by the National Natural Science Foundation of China(Grant No.12472279)。
文摘In bio-inspired flapping-wing flight,lift generation and flexible deformation are intrinsically coupled.Thus,an experimental study is conducted to reveal the fluid-structure interaction mechanism for a flexible plate undergoing pitching and plunging motion,and theoretical models are proposed to predict either lift or deformation based on a series of simplifying assumptions.It is indicated that flexible plates can effectively reduce the amplitude of lift and pitching moment coefficients during dynamic stall,with increased flexibility leading to higher load reduction.To investigate the effect of plate flexibility on lift,a definition of effective angle of attack is proposed,incorporating the pitching and plunging motion and chordwise deformation of the flexible plate,which can reduce the hysteresis effect of the lift coefficient during dynamic stall.As a consequence,a theoretical model is developed to predict lift based on observed motion and deformation.On the other hand,another theoretical model is developed to predict flexible-plate deformation utilizing aerodynamic forces,revealing the effect of leading-edge vortex evolution on passive deformation.The influence of kinematic parameters,including the maximum effective angle of attack,reduced frequency,and Strouhal number,on the aerodynamic forces is further studied.Compared with the rigid plate,flexible plates exhibit lower sensitivity of aerodynamic forces to changes in kinematic parameters due to their inherent compliance and resulting deformation.The proposed theoretical models can serve as a reference for aerodynamic and deformation prediction in bio-inspired flexible structures.
基金financially supported by the Zhejiang Provincial Natural Science Foundation of China(LMS25E030001)the Fundamental Research Funds of Zhejiang Sci-Tech University(25212142-Y and 23212200-Y)。
文摘The development of high-performance bifunctional electrocatalysts is crucial for advancing zinc-air batteries.However,the fundamentally distinct mechanisms of the oxygen reduction and evolution reactions(ORR/OER)hinder the simultaneous realization of high activity within a single catalyst.Herein,we propose a spatial decoupling strategy to overcome this limitation by engineering isolated Fe singleatoms and Fe-Ir dual-atom pairs on a nitrogen-doped carbon matrix(Fe/FeIr-NC).In this architecture,Fe single atoms serve as ORR centers,while Fe-Ir pairs with tunable spacing are tailored for OER,enabling complete functional separation and independent optimization of the reactions.As a result,the catalyst delivers an ORR half-wave potential of 0.91 V and an OER overpotential of 250 mV at 10 mA cm^(-2),yielding a record-low bifunctional gap(ΔE=0.57 V)that outperforms all reported single-and dual-atom catalysts.A flexible fiber zincair battery was developed based on this catalyst,delivering a peak power density of 3920 W kg^(-1),along with a 1.4-fold increase in energy efficiency and a 2.6-fold extension in cycle life compared to the commercial Pt/C+IrO_(2)benchmark.This work not only breaks the traditional activity trade-off in bifunctional catalysis but also offers a promising route toward high-performance power sources for wearable electronics.
