Organic electrochemical transistor(OECT)devices demonstrate great promising potential for reservoir computing(RC)systems,but their lack of tunable dynamic characteristics limits their application in multi-temporal sca...Organic electrochemical transistor(OECT)devices demonstrate great promising potential for reservoir computing(RC)systems,but their lack of tunable dynamic characteristics limits their application in multi-temporal scale tasks.In this study,we report an OECT-based neuromorphic device with tunable relaxation time(τ)by introducing an additional vertical back-gate electrode into a planar structure.The dual-gate design enablesτreconfiguration from 93 to 541 ms.The tunable relaxation behaviors can be attributed to the combined effects of planar-gate induced electrochemical doping and back-gateinduced electrostatic coupling,as verified by electrochemical impedance spectroscopy analysis.Furthermore,we used theτ-tunable OECT devices as physical reservoirs in the RC system for intelligent driving trajectory prediction,achieving a significant improvement in prediction accuracy from below 69%to 99%.The results demonstrate that theτ-tunable OECT shows a promising candidate for multi-temporal scale neuromorphic computing applications.展开更多
Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen ba...Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen batteries(LOBs)due to their poor OER performance,resulting from poor electrical conductivity and overly strong intermediate adsorption.In this work,fancy double heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)(1T/2H-MCS)were constructed derived from the charge donation from Co to Mo ions,thus inducing the phase transformation of Mo S_(2)from 2H to 1T.The unique features of these double heterojunctions endow the1T/2H-MCS with complementary catalysis during charging and discharging processes.It is worth noting that 1T-Mo S2@Co3S4could provide fast Co-S-Mo electron transport channels to promote ORR/OER kinetics,and 2H-MoS_(2)@Co_(3)S_(4)contributed to enabling moderate egorbital occupancy when adsorbed with oxygen-containing intermediates.On the basis,the Li_(2)O_(2)nucleation route was changed to solution and surface dual pathways,improving reversible deposition and decomposition kinetics.As a result,1T/2H-MCS cathodes exhibit an improved electrocatalytic performance compared with those of Co_(3)S_(4)and Mo S2cathodes.This innovative heterostructure design provides a reliable strategy to construct efficient transition metal sulfide catalysts by improving electrical conductivity and modulating adsorption toward oxygenated intermediates for LOBs.展开更多
Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectr...Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectronic integration,but still faces serious challenges.Herein,we propose a facile method to synthesize cesium lead halide(CsPbX3)microstructures with well-defined morphologies,sizes,and constituent element gradient.The scheme is conducted using a chemical vapor deposition(CVD),which is subsequently associated with annealing-assisted solid-solid anion exchange.For the plate-shaped structures,the controllability on the cross-sectional dimension enables to precisely modulate the lasing modes,thus achieving single-mode operation;while tuning the stoichiometric of the halogen anion components in the plate-shaped CsPbI_(x)Br_(3−x) alloy samples,the lasing wavelengths are straightforwardly varied to span the entire visible spectrum.By comparison,the experimental scheme on synthesizing alloyed CsPbI_(x)Br_(3−x) perovskites is conducted using an in-situ approach,thereby achieving precise modulation of bandgap-controlled microlasers by controlling the reaction time.Such laser properties like controllable microcavity modes and broad stoichiometry-dependent tunability of light-emitting/lasing colors,associated with the facile synthesizing method of monocrystalline CsPbI_(x)Br_(3−x) structures,make lead halide perovskites ideal materials for the development of wavelength-controlled microlasers toward practical photonic integration.展开更多
Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz ba...Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.展开更多
Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated thr...Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated through depositing ZnO on patterned silicon on an insulator(SOI)substrate.The cavity structure,morphology,and photoluminescence(PL)properties are studied systematically.The cavity shows a well-defined circular structure with oxygen vacancies.Under the synergistic action of surface tension and stress,the ZnO microdisk shows a unique toroid structure with a high sidewall surface finish.The ZnO microcavity(8μm in diameter)shows optically pumped whispering gallery modes(WGMs)lasing in the ultraviolet region with a Q factor exceeding 1300.More interestingly,the quality of the toroid ZnO microdisk cavity is high enough to support the bandgap renormalization(BGR)phenomenon.With the increasing pumping power,the lasing spectra will be modulated.The lasing spectrum undergoes a Burstein-Moss(BM)effect-induced blueshift and an electron-hole plasma(EHP)effect-induced redshift.展开更多
Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating...Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.展开更多
We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with du...We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.展开更多
Fiber-based strain sensors have emerged as revolutionary components in flexible electronics owing to their intrinsic compliance and textile compatibility,particularly in human-centric applications ranging from health ...Fiber-based strain sensors have emerged as revolutionary components in flexible electronics owing to their intrinsic compliance and textile compatibility,particularly in human-centric applications ranging from health diagnostics to motion tracking.While substantial progress has been achieved,a critical challenge persists in reconciling the contradictory demands of ultrahigh sensitivity and stable signal transmission through rational structural design.Herein,we develop dual-structure silver(Ag)/polyurethane(PU)fiber-based strain sensors(Ag@PU_(x))via an integrated wet spinning and interfacial metal ion deposition(IMID)strategy.Notably,we propose a mechanical pre-stretching strategy that enables precise regulation of strain sensitivity and sensing range through controlled substrate deformation.Systematic characterization reveals that pre-stretched PU fibers form ordered microscale conductive networks,exhibiting exceptional electrical stability(conductivity(σ)=1.9×105 S·m^(-1);the change in resistance value under external tensile force(ΔR)/the initial resistance of the sensor(R_(0))<0.03 under 360°torsional deformation)with a high quality factor(Q)of 10.1 at 50%strain.In contrast,non-prestretched counterparts develop microcrack-dominated architectures,achieving a high sensitivity(gauge factor(GF)=7.7)through strain-induced crack propagation and a fracture strain exceeding 660%.A systematic investigation elucidates the underlying mechanisms behind these distinct sensing performances.The Ag@PU_(x)fiber-based electronics are capable of adapting to various tasks including human motion monitoring,voice recognition,and gesture recognition.Importantly,we developed the Ag@PU_(x)fiber-based electronics to monitor motion states while stably transmitting electrical signals.Ultimately,the Ag@PU_(x)show great promise in applications such as motion monitoring,waist rehabilitation,thermal management,electromagnetic shielding,and antibacterial deodorization.展开更多
Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex...Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.展开更多
Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on ...Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on the fact that a variational reversible locally resonant elastic metamaterial(LREM) with four configurations is proposed. Through a combination of theoretical analysis and numerical simulations, this newly designed metamaterial is proven to exhibit different bandgap ranges and vibration attenuation properties in each configuration. Especially, there is tunable anisotropy shown in these configurations, which enables the bandgaps in two directions to be separated or overlapped. A model with a bandgap shifting ratio(BSR) of 100% and an overlap ratio of 25% is set to validate the multistable strategy feasibility. The proposed design strategy demonstrates significant potentials for applications in versatile scenarios.展开更多
In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature o...In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature of VO_(2),the design can realize active tuning of the plasmon induced transparency(PIT)effect at terahertz frequency,thereby converting from a single PIT to a double-PIT.When VO_(2) is in the insulating state,the structure is symmetric to obtain a single-band PIT effect.When VO_(2) is in the metallic state,the structure turns asymmetric to realize a dual-band PIT effect.This design provides a reference direction for the design of actively tunable metamaterials.Additionally,it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship.In addition,the structure achieves superior refractive index sensitivity in the terahertz band,surpassing 1 THz/RIU.Consequently,the design exhibits encouraging potential for application in refractive index sensors and optical switches.展开更多
As a semiconductor material with inorganic functional properties,titanium dioxide(TiO_(2))demonstrates exceptional optical,electrical,and catalytic characteristics.The catalytic performance of TiO_(2)is notably affect...As a semiconductor material with inorganic functional properties,titanium dioxide(TiO_(2))demonstrates exceptional optical,electrical,and catalytic characteristics.The catalytic performance of TiO_(2)is notably affected by the proportion of anatase to rutile within its mixed phase,which plays a crucial role in modulating its performance.The phase transition in TiO_(2)enhances the effective separation of photogenerated charge carriers,thereby improving their utilization.In this study,we present an efficient and proportionally adjustable TiO_(2)phase transition strategy induced by near-infrared light(NIR light)utilizing TiO_(2)and titanium carbide(Ti C)composites.Notably,the transition ratio of anatase to rutile phases can be adjusted by controlling the NIR light irradiation time in 1s intervals(within 6 s),resulting in conversion rates of 5.88%,13.29%,20.42%,26.02%,32.8%and 40.12%,respectively.This capability for tunable ratios is attributed to the photothermal effect of Ti C,which converts to anatase at higher temperatures while simultaneously promoting the layer-by-layer aggregation of adjacent anatase grains,thereby facilitating the phase transition.In addition,we assessed the photocatalytic efficiency of tetracycline hydrochloride(TC-HCl,an antibiotic)and methylene blue(MB,a dye)when exposed to visible light using different ratios of obtained phase junctions.The findings revealed that after a brief 3 s exposure to laser sintering,the weight fractions of rutile and anatase TiO_(2)were approximately 0.2 and 0.8,respectively.This specific ratio of phase transition exhibits superior photocatalytic performance compared to alternative phase transition ratios.The creation of heterojunctions in anatase/rutile TiO_(2)facilitated greater oxygen adsorption and heightened the density of localized states,thus effectively boosting the production of superoxide radicals(·O_(2)^(-))and hole(h^(+))species.The phase junction of TiO_(2)shows significant potential for application in wastewater treating,resulting in improved photocatalytic degradation of pollutants and highlighting its efficacy in environmental pollution control.展开更多
Tamm plasmon polaritons(TPPs)are localized photonic states at the interface between a metal layer and one-dimensional(1D)photonic crystal substrate.Unlike surface plasmon polaritons(SPPs),TPPs can be excited by both t...Tamm plasmon polaritons(TPPs)are localized photonic states at the interface between a metal layer and one-dimensional(1D)photonic crystal substrate.Unlike surface plasmon polaritons(SPPs),TPPs can be excited by both transverse magnetic and electric waves without requiring additional coupling optics.TPPs offer robust color filtering,making them ideal for applications such as complementary metal oxide semiconductor(CMOS)image detectors.However,obtaining a large-area,reversible,and reconfigurable filter remains challenging.This study demonstrates a dynamically reconfigurable reflective color filter by integrating an ultrathin antimony trisulfide(Sb_(2)S_(3))layer with Tamm plasmonic photonic crystals.Reconfigurable tuning was achieved by inducing Sb_(2)S_(3) crystallization and reamorphization via thermal and optical activation,respectively.The material exhibited good stability after multiple switching cycles.The reflectance spectrum can be tuned across the visible range,with a shift of approximately 50 nm by switching Sb_(2)S_(3) between its amorphous and crystalline phases.This phase transition is nonvolatile and substantially minimizes the energy consumption,enhancing efficiency for practical applications.Tamm plasmonic photonic crystals are low-cost and large-scale production,offering a platform for compact color display systems and customizable photonic crystal filters for realistic system integration.展开更多
Color as an indispensable element in our life brings vitality to us and enriches our lifestyles through decorations,indicators,and information carriers.Structural color offers an intriguing strategy to achieve novel f...Color as an indispensable element in our life brings vitality to us and enriches our lifestyles through decorations,indicators,and information carriers.Structural color offers an intriguing strategy to achieve novel functions and endows color with additional levels of significance in anti-counterfeiting,display,sensor,and printing.Furthermore,structural colors possess excellent properties,such as resistance to extreme external conditions,high brightness,saturation,and purity.Devices and platforms based on structural color have significantly changed our life and are becoming increasingly important.Here,we reviewed four typical applications of structural color and analyzed their advantages and shortcomings.First,a series of mechanisms and fabrication methods are briefly summarized and compared.Subsequently,recent progress of structural color and its applications were discussed in detail.For each application field,we classified them into several types in terms of their functions and properties.Finally,we analyzed recent emerging technologies and their potential for integration into structural color devices,as well as the corresponding challenges.展开更多
The development of stretchable conductors with high deformation,conductivity,and thermal conductivity using liquid metal(LM)has sparked widespread interest in the fields of flexible electronics,electromagnetic interfe...The development of stretchable conductors with high deformation,conductivity,and thermal conductivity using liquid metal(LM)has sparked widespread interest in the fields of flexible electronics,electromagnetic interference(EMI),and multifunctional materi-als.However,fabricating desirable shielding materials by directly coating LMs on soft polymer substrates remains a challenge because of the huge surface tension and weak wettability of LMs.In this study,Ga-based composite paste is prepared from a mixture of Ga and dia-mond nonmetallic particles through ultrasonic fragmentation.At various temperatures,the resulting LM composite putty(LMP)exhibits soft and hard properties and can thus be molded into specific shapes according to application needs.In addition,the composite can be eas-ily coated onto polymer substrates,such as thermoplastic polyurethane(TPU)elastomer.The fabricated LMP–TPU exhibits an impress-ive shape deformation capacity of 1100%,demonstrating exceptional tensile properties and achieving electromagnetic interference–shielding effectiveness of up to 52 dB.Furthermore,it retains an ultrahigh conductivity of 20000 S/m,even under a strain of 600%.This feature further makes it a highly competitive multifunctional material.展开更多
Terahertz(THz)switches are essential components of THz communication systems.THz switches based on conventional waveguides and photonic crystal structures are sensitive to manufacturing defects and sharp bending,resul...Terahertz(THz)switches are essential components of THz communication systems.THz switches based on conventional waveguides and photonic crystal structures are sensitive to manufacturing defects and sharp bending,resulting in high scattering losses.In addition,THz switches with tunable working bandwidths have not yet been demonstrated.Here,we design THz switches based on a topological valley photonic crystal(VPC)structure using magnetic materials,which can achieve high forward transmittance based on the unique spin–valley locking effect.The broad working bandwidth allows selective turning on and off at a designed wavelength region by controlling the applied magnetic field.The designed THz switch can achieve an extinction ratio of up to 31.66 dB with an insertion loss of less than 0.13 dB.The 3-dB bandwidth is up to 49 GHz.This tunable THz switch can be experimentally fabricated by current fabrication techniques and thus can find broad applications in THz communication systems.展开更多
The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface...The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface with various physical systems.Equipped with gate electrodes,it has been demonstrated that these exceptional device properties can be electrically manipulated,leading to a variety of nanomechanical/acoustic applications.Here,we review the recent progress of graphene nanomechanical resonators with a focus on their electrical tunability.First,we provide an overview of diferent graphene nanomechanical resonators,including their device structures,fabrication methods,and measurement setups.Then,the key mechanical properties of these devices,for example,resonant frequencies,nonlinearities,dissipations,and mode coupling mechanisms,are discussed,with their behaviors upon electrical gating being highlighted.After that,various potential classical/quantum applications based on these graphene nanomechanical resonators are reviewed.Finally,we briefy discuss challenges and opportunities in this feld to ofer future prospects for the ongoing studies on graphene nanomechanical resonators.展开更多
The unique arrangement of panels and folds in origami structures provides distinct mechanical properties,such as the ability to achieve multiple stable states,reconfigure shapes,and adjust performance.However,combinin...The unique arrangement of panels and folds in origami structures provides distinct mechanical properties,such as the ability to achieve multiple stable states,reconfigure shapes,and adjust performance.However,combining movement and control functions into a simple yet efficient origami-based system remains a challenge.This study introduces a practical and efficient bistable origami mechanism,realized through lightweight and tailored designs in two bio-inspired applications.The mechanism is constructed from two thin materials:a PET sheet with precisely cut flexible hinges and a pre-tensioned elastic band.Its mechanical behavior is studied using nonlinear spring models.These components can be rearranged to create new bistable structures,enabling the integration of movement and partial control features.Inspired by natural systems,the mechanism is applied to two examples:a passive origami gripper that can quickly and precisely grasp moving objects in less than 100 ms,and an active magnetic-driven fish tail capable of high-speed swimming in multiple modes,reaching a maximum straight-line speed of 3.35 body lengths per second and a turning speed of 2.3 radians per second.This bistable origami mechanism highlights its potential for flexible design and high performance,offering useful insights for developing origami-based robotic systems.展开更多
In this paper,a tunable metamaterial absorber based on a Dirac semimetal is proposed.It consists of three different structures,from top to bottom,namely a double semicircular Dirac semimetal resonator,a silicon dioxid...In this paper,a tunable metamaterial absorber based on a Dirac semimetal is proposed.It consists of three different structures,from top to bottom,namely a double semicircular Dirac semimetal resonator,a silicon dioxide substrate and a continuous vanadium dioxide(VO_(2))reflector layer.When the Fermi energy level of the Dirac semimetal is 10 meV,the absorber absorbs more than 90%in the 39.06-84.76 THz range.Firstly,taking advantage of the tunability of the conductivity of the Dirac semimetal,dynamic tuning of the absorption frequency can be achieved by changing the Fermi energy level of the Dirac semimetal without the need to optimise the geometry and remanufacture the structure.Secondly,the structure has been improved by the addition of the phase change material VO_(2),resulting in a much higher absorption performance of the absorber.Since VO_(2)is a temperature-sensitive metal oxide with an insulating phase below the phase transition temperature(about 68℃)and a metallic phase above the phase transition temperature,this paper also analyses the effect of VO_(2)on the absorptive performance at different temperatures,with the aim of further improving absorber performance.展开更多
Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microl...Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microlasers remains challenging.In this work,we address this challenge by demonstrating a tunable vertical cavity surface emitting laser(VCSEL)employing a tunable gain medium of halide phase-change perovskites-specifically MAPbI_(3) perovskite,sandwiched between two highly reflective mirrors composed of bottom-distributed Bragg reflectors(DBRs).This VCSEL possesses single-mode lasing emission with a low threshold of 23.5μJ cm^(−2) under 160 K,attributed to strong optical confinement in the high-quality(Q)cavity.Upon the phase change of MAPbI_(3) perovskite,both its gain and dielectric constant changes dramatically,enabling a wide(Δλ>9 nm)and temperature-sensitive(0.30 nm K^(−1) rate)spectral tunability of lasing mode in the near-infrared(N-IR)region.The laser displays excellent stability,demonstrating an 80%lifetime of>2.4×107 pulses excitation.Our findings may provide a versatile platform for the next generation of tunable coherent light sources.展开更多
基金supported by the National Key Research and Development Program of China under Grant 2022YFB3608300in part by the National Nature Science Foundation of China(NSFC)under Grants 62404050,U2341218,62574056,62204052。
文摘Organic electrochemical transistor(OECT)devices demonstrate great promising potential for reservoir computing(RC)systems,but their lack of tunable dynamic characteristics limits their application in multi-temporal scale tasks.In this study,we report an OECT-based neuromorphic device with tunable relaxation time(τ)by introducing an additional vertical back-gate electrode into a planar structure.The dual-gate design enablesτreconfiguration from 93 to 541 ms.The tunable relaxation behaviors can be attributed to the combined effects of planar-gate induced electrochemical doping and back-gateinduced electrostatic coupling,as verified by electrochemical impedance spectroscopy analysis.Furthermore,we used theτ-tunable OECT devices as physical reservoirs in the RC system for intelligent driving trajectory prediction,achieving a significant improvement in prediction accuracy from below 69%to 99%.The results demonstrate that theτ-tunable OECT shows a promising candidate for multi-temporal scale neuromorphic computing applications.
基金financially supported by the National Natural Science Foundation of China(U21A20311,U24A2040,52171141,52272117)the Natural Science Foundation of Shandong Province(ZR2022JQ19)+3 种基金the Key Technology Research Project of Shandong Province(2023CXGC010202)the Taishan Industrial Experts Program(TSCX202306142)the Core Facility Sharing Platform of Shandong Universitythe Foundation of Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University。
文摘Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen batteries(LOBs)due to their poor OER performance,resulting from poor electrical conductivity and overly strong intermediate adsorption.In this work,fancy double heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)(1T/2H-MCS)were constructed derived from the charge donation from Co to Mo ions,thus inducing the phase transformation of Mo S_(2)from 2H to 1T.The unique features of these double heterojunctions endow the1T/2H-MCS with complementary catalysis during charging and discharging processes.It is worth noting that 1T-Mo S2@Co3S4could provide fast Co-S-Mo electron transport channels to promote ORR/OER kinetics,and 2H-MoS_(2)@Co_(3)S_(4)contributed to enabling moderate egorbital occupancy when adsorbed with oxygen-containing intermediates.On the basis,the Li_(2)O_(2)nucleation route was changed to solution and surface dual pathways,improving reversible deposition and decomposition kinetics.As a result,1T/2H-MCS cathodes exhibit an improved electrocatalytic performance compared with those of Co_(3)S_(4)and Mo S2cathodes.This innovative heterostructure design provides a reliable strategy to construct efficient transition metal sulfide catalysts by improving electrical conductivity and modulating adsorption toward oxygenated intermediates for LOBs.
基金supported by the National Natural Science Foundation of China(No.12374257)。
文摘Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectronic integration,but still faces serious challenges.Herein,we propose a facile method to synthesize cesium lead halide(CsPbX3)microstructures with well-defined morphologies,sizes,and constituent element gradient.The scheme is conducted using a chemical vapor deposition(CVD),which is subsequently associated with annealing-assisted solid-solid anion exchange.For the plate-shaped structures,the controllability on the cross-sectional dimension enables to precisely modulate the lasing modes,thus achieving single-mode operation;while tuning the stoichiometric of the halogen anion components in the plate-shaped CsPbI_(x)Br_(3−x) alloy samples,the lasing wavelengths are straightforwardly varied to span the entire visible spectrum.By comparison,the experimental scheme on synthesizing alloyed CsPbI_(x)Br_(3−x) perovskites is conducted using an in-situ approach,thereby achieving precise modulation of bandgap-controlled microlasers by controlling the reaction time.Such laser properties like controllable microcavity modes and broad stoichiometry-dependent tunability of light-emitting/lasing colors,associated with the facile synthesizing method of monocrystalline CsPbI_(x)Br_(3−x) structures,make lead halide perovskites ideal materials for the development of wavelength-controlled microlasers toward practical photonic integration.
文摘Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.
文摘Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated through depositing ZnO on patterned silicon on an insulator(SOI)substrate.The cavity structure,morphology,and photoluminescence(PL)properties are studied systematically.The cavity shows a well-defined circular structure with oxygen vacancies.Under the synergistic action of surface tension and stress,the ZnO microdisk shows a unique toroid structure with a high sidewall surface finish.The ZnO microcavity(8μm in diameter)shows optically pumped whispering gallery modes(WGMs)lasing in the ultraviolet region with a Q factor exceeding 1300.More interestingly,the quality of the toroid ZnO microdisk cavity is high enough to support the bandgap renormalization(BGR)phenomenon.With the increasing pumping power,the lasing spectra will be modulated.The lasing spectrum undergoes a Burstein-Moss(BM)effect-induced blueshift and an electron-hole plasma(EHP)effect-induced redshift.
基金supported by the National Key Research and Development Program of China(No.2022YFC2805200)the National Natural Science Foundation of China(No.52373094)+4 种基金Zhejiang Provincial Natural Science Foundation(No.LR25E030004)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2023313)Sino-German Mobility Program(No.M-0424),Ningbo Major Research and Development Plan Project(No.20241ZDYF020148)Ningbo International Cooperation(No.2023H019)Ningbo Science&Technology Bureau(No.2024QL003)。
文摘Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,12404378,92480001,12134001,12174113,12174107,12474325,12404379,and 12474378)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)+1 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Fundamental Research Funds for the Central Universities,the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005).
文摘We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.
基金supported by the National Key Research and Development Program(2022YFB3805802)the Key Research and Development Program of Shandong Province(2024CXGC010411)+11 种基金the National Natural Science Foundation of China(52473307,22208178,and 62301290)the Taishan Scholar Program of Shandong Province in China(tsqn202211116)the Shandong Provincial Universities Youth Innovation Technology Plan Team(2023KJ223)the Natural Science Foundation of Shandong Province of China(ZR2023YQ037,ZR2023QE043,ZR2022QE174,and ZR2024ME012)the Shandong Province Science and Technology Small and Medium sized Enterprise Innovation Ability Enhancement Project(2023TSGC0344 and 2023TSGC1006)the Natural Science Foundation of Qingdao(23-2-1-249-zyyd-jch and 24-4-4-zrjj-56-jch)the China Postdoctoral Science Foundation(2024M761560)the Anhui Province Postdoctoral Researcher Research Activity Funding Project(2023B706)the Qingdao Key Technology Research and Industrialization Demonstration Projects(23-1-7-zdfn-2-hz)the Qingdao Postdoctoral Funding Project(QDBSH20240201011)the Suqian Key Research and Development Plan(H202310)the Systems Science Plus Joint Research Program of Qingdao University(XT2024202).
文摘Fiber-based strain sensors have emerged as revolutionary components in flexible electronics owing to their intrinsic compliance and textile compatibility,particularly in human-centric applications ranging from health diagnostics to motion tracking.While substantial progress has been achieved,a critical challenge persists in reconciling the contradictory demands of ultrahigh sensitivity and stable signal transmission through rational structural design.Herein,we develop dual-structure silver(Ag)/polyurethane(PU)fiber-based strain sensors(Ag@PU_(x))via an integrated wet spinning and interfacial metal ion deposition(IMID)strategy.Notably,we propose a mechanical pre-stretching strategy that enables precise regulation of strain sensitivity and sensing range through controlled substrate deformation.Systematic characterization reveals that pre-stretched PU fibers form ordered microscale conductive networks,exhibiting exceptional electrical stability(conductivity(σ)=1.9×105 S·m^(-1);the change in resistance value under external tensile force(ΔR)/the initial resistance of the sensor(R_(0))<0.03 under 360°torsional deformation)with a high quality factor(Q)of 10.1 at 50%strain.In contrast,non-prestretched counterparts develop microcrack-dominated architectures,achieving a high sensitivity(gauge factor(GF)=7.7)through strain-induced crack propagation and a fracture strain exceeding 660%.A systematic investigation elucidates the underlying mechanisms behind these distinct sensing performances.The Ag@PU_(x)fiber-based electronics are capable of adapting to various tasks including human motion monitoring,voice recognition,and gesture recognition.Importantly,we developed the Ag@PU_(x)fiber-based electronics to monitor motion states while stably transmitting electrical signals.Ultimately,the Ag@PU_(x)show great promise in applications such as motion monitoring,waist rehabilitation,thermal management,electromagnetic shielding,and antibacterial deodorization.
基金supported by Jiangsu Special Project for Frontier Leading Base Technology(Grant Nos.BK20192004)Fundamental Research Funds for Central Universities(Grant Nos.B240201190)+3 种基金Changzhou Social Development Science and Technology Support Project(Grant Nos.CE20225037)Changzhou Science and Technology Project(Grant Nos.CM20223014)Suzhou Key Industrial Technology Innovation Forward-Looking Application Research Project(Grant Nos.SYG202143)Changzhou Science and Technology Project(Grant Nos.CJ20241061).
文摘Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.
基金supported by the National Natural Science Foundation of China(No.52192633)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2025JC-YBMS-050)。
文摘Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on the fact that a variational reversible locally resonant elastic metamaterial(LREM) with four configurations is proposed. Through a combination of theoretical analysis and numerical simulations, this newly designed metamaterial is proven to exhibit different bandgap ranges and vibration attenuation properties in each configuration. Especially, there is tunable anisotropy shown in these configurations, which enables the bandgaps in two directions to be separated or overlapped. A model with a bandgap shifting ratio(BSR) of 100% and an overlap ratio of 25% is set to validate the multistable strategy feasibility. The proposed design strategy demonstrates significant potentials for applications in versatile scenarios.
基金supported by the Natural Science Foundation of Chongqing of China(No.CSTB2024NSCQ-MSX0746)the Young Scientists Fund of the National Natural Science Foundation of China(No.11704053)+1 种基金the National Natural Science Foundation of China(No.52175531)the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN 201800629,KJZD-M202000602 and 62375031)。
文摘In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature of VO_(2),the design can realize active tuning of the plasmon induced transparency(PIT)effect at terahertz frequency,thereby converting from a single PIT to a double-PIT.When VO_(2) is in the insulating state,the structure is symmetric to obtain a single-band PIT effect.When VO_(2) is in the metallic state,the structure turns asymmetric to realize a dual-band PIT effect.This design provides a reference direction for the design of actively tunable metamaterials.Additionally,it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship.In addition,the structure achieves superior refractive index sensitivity in the terahertz band,surpassing 1 THz/RIU.Consequently,the design exhibits encouraging potential for application in refractive index sensors and optical switches.
基金supported by Zhejiang Provincial Natural Science Foundation of China(No.LTGC23C160002)Zhejiang Provincial Academy Cooperation Forestry Science and Technology Project(No.2023SY14)+7 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LR20A050001)Scientific Research Project of Education Department of Hunan Province(No.22A0560)General Project of Zhejiang Provincial Department of Education(No.Y202147215)the National Natural Science Foundation of China(Nos.12275240,12075210)Zhejiang Provincial Public Welfare Technology and Application Research Project(No.GN21B020001)the Scientific Research and Developed Fund of Zhejiang A&F University(Nos.2021FR0009,2022LFR042)Scientific Research Foundation of Zhejiang A&F University(No.2023CFR136)the 2024 Open Fund for Henan Key Laboratory of Water Pollution Control and Rehabilitation Technology(No.CJSZ2024012)。
文摘As a semiconductor material with inorganic functional properties,titanium dioxide(TiO_(2))demonstrates exceptional optical,electrical,and catalytic characteristics.The catalytic performance of TiO_(2)is notably affected by the proportion of anatase to rutile within its mixed phase,which plays a crucial role in modulating its performance.The phase transition in TiO_(2)enhances the effective separation of photogenerated charge carriers,thereby improving their utilization.In this study,we present an efficient and proportionally adjustable TiO_(2)phase transition strategy induced by near-infrared light(NIR light)utilizing TiO_(2)and titanium carbide(Ti C)composites.Notably,the transition ratio of anatase to rutile phases can be adjusted by controlling the NIR light irradiation time in 1s intervals(within 6 s),resulting in conversion rates of 5.88%,13.29%,20.42%,26.02%,32.8%and 40.12%,respectively.This capability for tunable ratios is attributed to the photothermal effect of Ti C,which converts to anatase at higher temperatures while simultaneously promoting the layer-by-layer aggregation of adjacent anatase grains,thereby facilitating the phase transition.In addition,we assessed the photocatalytic efficiency of tetracycline hydrochloride(TC-HCl,an antibiotic)and methylene blue(MB,a dye)when exposed to visible light using different ratios of obtained phase junctions.The findings revealed that after a brief 3 s exposure to laser sintering,the weight fractions of rutile and anatase TiO_(2)were approximately 0.2 and 0.8,respectively.This specific ratio of phase transition exhibits superior photocatalytic performance compared to alternative phase transition ratios.The creation of heterojunctions in anatase/rutile TiO_(2)facilitated greater oxygen adsorption and heightened the density of localized states,thus effectively boosting the production of superoxide radicals(·O_(2)^(-))and hole(h^(+))species.The phase junction of TiO_(2)shows significant potential for application in wastewater treating,resulting in improved photocatalytic degradation of pollutants and highlighting its efficacy in environmental pollution control.
文摘Tamm plasmon polaritons(TPPs)are localized photonic states at the interface between a metal layer and one-dimensional(1D)photonic crystal substrate.Unlike surface plasmon polaritons(SPPs),TPPs can be excited by both transverse magnetic and electric waves without requiring additional coupling optics.TPPs offer robust color filtering,making them ideal for applications such as complementary metal oxide semiconductor(CMOS)image detectors.However,obtaining a large-area,reversible,and reconfigurable filter remains challenging.This study demonstrates a dynamically reconfigurable reflective color filter by integrating an ultrathin antimony trisulfide(Sb_(2)S_(3))layer with Tamm plasmonic photonic crystals.Reconfigurable tuning was achieved by inducing Sb_(2)S_(3) crystallization and reamorphization via thermal and optical activation,respectively.The material exhibited good stability after multiple switching cycles.The reflectance spectrum can be tuned across the visible range,with a shift of approximately 50 nm by switching Sb_(2)S_(3) between its amorphous and crystalline phases.This phase transition is nonvolatile and substantially minimizes the energy consumption,enhancing efficiency for practical applications.Tamm plasmonic photonic crystals are low-cost and large-scale production,offering a platform for compact color display systems and customizable photonic crystal filters for realistic system integration.
基金financially supported by the Natural Science Foundation of Shaanxi Province(Grant No.2024JC-YBMS-291)Special Support Program for High-level Talents of Shaanxi Province(No.2020-44)。
文摘Color as an indispensable element in our life brings vitality to us and enriches our lifestyles through decorations,indicators,and information carriers.Structural color offers an intriguing strategy to achieve novel functions and endows color with additional levels of significance in anti-counterfeiting,display,sensor,and printing.Furthermore,structural colors possess excellent properties,such as resistance to extreme external conditions,high brightness,saturation,and purity.Devices and platforms based on structural color have significantly changed our life and are becoming increasingly important.Here,we reviewed four typical applications of structural color and analyzed their advantages and shortcomings.First,a series of mechanisms and fabrication methods are briefly summarized and compared.Subsequently,recent progress of structural color and its applications were discussed in detail.For each application field,we classified them into several types in terms of their functions and properties.Finally,we analyzed recent emerging technologies and their potential for integration into structural color devices,as well as the corresponding challenges.
基金supported by the National Natural Science Foundation of China(Nos.52271167 and U21A2064)the Key Program of Natural Science Foundation of Henan Province,China(No.242300421188)+1 种基金ZUA Innovation Fund for Graduate Education,China(No.2024CX134)Henan Key Laboratory of Aeronautical Material and Technology Open Foundation,China(No.ZHKF-240103).
文摘The development of stretchable conductors with high deformation,conductivity,and thermal conductivity using liquid metal(LM)has sparked widespread interest in the fields of flexible electronics,electromagnetic interference(EMI),and multifunctional materi-als.However,fabricating desirable shielding materials by directly coating LMs on soft polymer substrates remains a challenge because of the huge surface tension and weak wettability of LMs.In this study,Ga-based composite paste is prepared from a mixture of Ga and dia-mond nonmetallic particles through ultrasonic fragmentation.At various temperatures,the resulting LM composite putty(LMP)exhibits soft and hard properties and can thus be molded into specific shapes according to application needs.In addition,the composite can be eas-ily coated onto polymer substrates,such as thermoplastic polyurethane(TPU)elastomer.The fabricated LMP–TPU exhibits an impress-ive shape deformation capacity of 1100%,demonstrating exceptional tensile properties and achieving electromagnetic interference–shielding effectiveness of up to 52 dB.Furthermore,it retains an ultrahigh conductivity of 20000 S/m,even under a strain of 600%.This feature further makes it a highly competitive multifunctional material.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1404201)Australia Research Council(Grant Nos.DP220100603 and FT220100559)+7 种基金the National Natural Science Foundation of China(Grant No.U23A20375)the Natural Science Foundation of Shanxi Province(Grant No.202403021211011)Research Project Supported by Shanxi Scholarship Council of China(Grant No.2024-032)Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant No.20240006)the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices(Grant No.KF202402)Basic Scientific Research Conditions and Major Scientific Instrument and Equipment Development of Anhui Science and Technology Department(Grant No.2023YFF0715700)Key Research Project of Shanxi Province(Grant No.202302150101001)Linkage Project Scheme(Grant Nos.LP210200345 and LP210100467).
文摘Terahertz(THz)switches are essential components of THz communication systems.THz switches based on conventional waveguides and photonic crystal structures are sensitive to manufacturing defects and sharp bending,resulting in high scattering losses.In addition,THz switches with tunable working bandwidths have not yet been demonstrated.Here,we design THz switches based on a topological valley photonic crystal(VPC)structure using magnetic materials,which can achieve high forward transmittance based on the unique spin–valley locking effect.The broad working bandwidth allows selective turning on and off at a designed wavelength region by controlling the applied magnetic field.The designed THz switch can achieve an extinction ratio of up to 31.66 dB with an insertion loss of less than 0.13 dB.The 3-dB bandwidth is up to 49 GHz.This tunable THz switch can be experimentally fabricated by current fabrication techniques and thus can find broad applications in THz communication systems.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20240123)the National Key Research and Development Program of China(Grant No.2022YFA1405900)the National Natural Science Foundation of China(Grant Nos.12274397,12274401,and 12034018)。
文摘The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface with various physical systems.Equipped with gate electrodes,it has been demonstrated that these exceptional device properties can be electrically manipulated,leading to a variety of nanomechanical/acoustic applications.Here,we review the recent progress of graphene nanomechanical resonators with a focus on their electrical tunability.First,we provide an overview of diferent graphene nanomechanical resonators,including their device structures,fabrication methods,and measurement setups.Then,the key mechanical properties of these devices,for example,resonant frequencies,nonlinearities,dissipations,and mode coupling mechanisms,are discussed,with their behaviors upon electrical gating being highlighted.After that,various potential classical/quantum applications based on these graphene nanomechanical resonators are reviewed.Finally,we briefy discuss challenges and opportunities in this feld to ofer future prospects for the ongoing studies on graphene nanomechanical resonators.
基金supported in part by the Fundamental Research Funds for the Central Universities under Grant CSA-TS202404in part by the National Natural Science Foundation of China under Grant 12172226.
文摘The unique arrangement of panels and folds in origami structures provides distinct mechanical properties,such as the ability to achieve multiple stable states,reconfigure shapes,and adjust performance.However,combining movement and control functions into a simple yet efficient origami-based system remains a challenge.This study introduces a practical and efficient bistable origami mechanism,realized through lightweight and tailored designs in two bio-inspired applications.The mechanism is constructed from two thin materials:a PET sheet with precisely cut flexible hinges and a pre-tensioned elastic band.Its mechanical behavior is studied using nonlinear spring models.These components can be rearranged to create new bistable structures,enabling the integration of movement and partial control features.Inspired by natural systems,the mechanism is applied to two examples:a passive origami gripper that can quickly and precisely grasp moving objects in less than 100 ms,and an active magnetic-driven fish tail capable of high-speed swimming in multiple modes,reaching a maximum straight-line speed of 3.35 body lengths per second and a turning speed of 2.3 radians per second.This bistable origami mechanism highlights its potential for flexible design and high performance,offering useful insights for developing origami-based robotic systems.
文摘In this paper,a tunable metamaterial absorber based on a Dirac semimetal is proposed.It consists of three different structures,from top to bottom,namely a double semicircular Dirac semimetal resonator,a silicon dioxide substrate and a continuous vanadium dioxide(VO_(2))reflector layer.When the Fermi energy level of the Dirac semimetal is 10 meV,the absorber absorbs more than 90%in the 39.06-84.76 THz range.Firstly,taking advantage of the tunability of the conductivity of the Dirac semimetal,dynamic tuning of the absorption frequency can be achieved by changing the Fermi energy level of the Dirac semimetal without the need to optimise the geometry and remanufacture the structure.Secondly,the structure has been improved by the addition of the phase change material VO_(2),resulting in a much higher absorption performance of the absorber.Since VO_(2)is a temperature-sensitive metal oxide with an insulating phase below the phase transition temperature(about 68℃)and a metallic phase above the phase transition temperature,this paper also analyses the effect of VO_(2)on the absorptive performance at different temperatures,with the aim of further improving absorber performance.
基金supported by the National Key Research and Development Program of China(2020YFA0714504,2019YFA0709100 to T.C.)the program of the National Natural Science Foundation of China(No.62105054 to T.C.)+1 种基金the New Cornerstone Science Foundation(AoE/P502/20 to S.Z.)the Research Grants Council of Hong Kong(17315522 to S.Z.).
文摘Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microlasers remains challenging.In this work,we address this challenge by demonstrating a tunable vertical cavity surface emitting laser(VCSEL)employing a tunable gain medium of halide phase-change perovskites-specifically MAPbI_(3) perovskite,sandwiched between two highly reflective mirrors composed of bottom-distributed Bragg reflectors(DBRs).This VCSEL possesses single-mode lasing emission with a low threshold of 23.5μJ cm^(−2) under 160 K,attributed to strong optical confinement in the high-quality(Q)cavity.Upon the phase change of MAPbI_(3) perovskite,both its gain and dielectric constant changes dramatically,enabling a wide(Δλ>9 nm)and temperature-sensitive(0.30 nm K^(−1) rate)spectral tunability of lasing mode in the near-infrared(N-IR)region.The laser displays excellent stability,demonstrating an 80%lifetime of>2.4×107 pulses excitation.Our findings may provide a versatile platform for the next generation of tunable coherent light sources.
