In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy...In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.展开更多
Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power sta...Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power stations).To solve the problem,we propose an energy harvesting based task scheduling and resource management framework to provide robust and low-cost edge computing services for smart grid.First,we formulate an energy consumption minimization problem with regard to task offloading,time switching,and resource allocation for mobile devices,which can be decoupled and transformed into a typical knapsack problem.Then,solutions are derived by two different algorithms.Furthermore,we deploy renewable energy and energy storage units at edge servers to tackle intermittency and instability problems.Finally,we design an energy management algorithm based on sampling average approximation for edge computing servers to derive the optimal charging/discharging strategies,number of energy storage units,and renewable energy utilization.The simulation results show the efficiency and superiority of our proposed framework.展开更多
Climate variability significantly impacts agricultural water resources,particularly in regions like Vietnam's Plain of Reeds that heavily utilize rain-fed conditions.This study employs the FAO-AquaCrop model to es...Climate variability significantly impacts agricultural water resources,particularly in regions like Vietnam's Plain of Reeds that heavily utilize rain-fed conditions.This study employs the FAO-AquaCrop model to estimate current and future irrigation water needs for rice cultivation in this critical subregion,aiming to identify optimal sowing schedules(OSS)that enhance rainwater utilization and reduce irrigation dependency.The model was driven by current climate data and future projections(2041-2070 and 2071-2099)derived from downscaled Global Circulation Models under RCP4.5 and RCP8.5 scenarios.The AquaCrop model demonstrated robust performance during validation and calibration,with d-values(0.82-0.93)and R²values(0.85-0.92)indicating strong predictive accuracy for rice yield.Simulation results for efficient irrigation water potential(IWP)under RCP4.5 revealed that strategic shifts in sowing dates can substantially alter water requirements;for instance,advancing the winter-spring sowing to December 5th decreased IWP by 15.6%in the 2041-2070 period,while delaying summer-autumn crop sowing to April 20th increased IWP by 48.6%due to greater reliance on irrigation as rainfall patterns shift.Similar dynamic responses were observed for the 2071-2099 period and for autumn-winter crops.These findings underscore that AquaCrop modeling can effectively predict future irrigation needs and that adjusting cultivation calendars presents a viable,low-cost adaptation strategy.This approach allows farmers in the Plain of Reeds to optimize rainwater use,thereby reducing dependency on supplementary irrigation and mitigating the adverse impacts of climate variability,contributing to more sustainable agricultural water management.展开更多
Nowadays, we are witnessing an era marked by the autonomy of wireless devices and sensor networks without the aid of batteries. RF energy harvesting therefore becomes a promising alternative for battery dependence. Th...Nowadays, we are witnessing an era marked by the autonomy of wireless devices and sensor networks without the aid of batteries. RF energy harvesting therefore becomes a promising alternative for battery dependence. This work presents the design of an RF energy harvesting system consisting mainly of a rectenna (antenna and rectification circuit) and an adaptation circuit. First of all, we designed two dipole type antennas. One operates in the GSM 900 MHz band and the other in the GSM 1800 MHz band. The performances of the proposed antennas are provided by the ANSYS HFSS software. Secondly, we proposed two rectification circuits in order to obtain conversion efficiencies at 0 dBm of 64% for the system operating at the frequency of 900 MHz and 37% for the system at the frequency of 1800 MHz RF-DC. The rectifiers used are based on Schottky diodes. For maximum transfer of power between the antenna and the rectification circuit, L-type matching circuits have been proposed. This rectifier offers DC voltage values of 806 mV for the circuit at the frequency of 900 MHz and 616 mV for the circuit at the frequency of 1800 MHz. The adaptation circuits are obtained by carrying out simulations on the ADS (Advanced Design System) software.展开更多
Capturing of ambient energy is emerging as a transformative area in energy technology,potentially replacing batteries or significantly extending their lifespan.Harnessing of energy from ambient sources presents a sign...Capturing of ambient energy is emerging as a transformative area in energy technology,potentially replacing batteries or significantly extending their lifespan.Harnessing of energy from ambient sources presents a significant opportunity to support sustainable development while mitigating environmental issues.Repurposing energy that would otherwise be wasted from highconsumption systems such as engines and industrial furnaces is essential for reducing ecological footprints and moving toward carbon-neutral goals.Furthermore,compact energy harvesting technologies will play a pivotal role in powering the rapidly expanding Internet of Things,enabling innovative advancements in smart homes,cities,industries,and health care that elevate our living standards.To achieve significant advancements in energy harvesting technologies,the development of innovative materials is crucial for converting ambient energy into electricity.In this regard,two-dimensional(2D)materials,a rising star in the material world,are profoundly and technologically intriguing for energy harvesting.The exceptional atomic thickness,high surface-tovolume ratio,flexibility,and tunable band gap effectively enhance their electronic,optical,and chemical properties,making them a potential candidate for use in flexible electronics and wearable energy harvesting technologies.Consequently,these unique properties of 2D materials remarkably enhance their energy harvesting capabilities,including photovoltaic,triboelectric,thermoelectric,and piezoelectric energy harvesting.Here,we present a tutorial-style review of 2D materials for harvesting energy from different ambient sources(aimed particularly at guiding and educating researchers,especially those new to the field),which starts with a brief overview of the promising properties of 2D materials for energy harvesting,then looks deeply into its advantages as compared to traditional materials along with their 3D counterparts,followed by providing insight into the mechanisms and performance of 2D material-based energy harvesters in portable/wearable electronics,and finally,based on current progress,an overview of the challenges along with corresponding strategies are identified and discussed.展开更多
This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of ...This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of previous systems.Notably,the traditional single-buoyed system,which is characterized by a long beam extending to the sea floor,proves impractical in deep-sea environments,especially in distant offshore regions.The proposed double-buoyed model replaces the long beam with a second buoy to increase energy harvesting efficiency.A parametric analysis that included the density and height of the first buoy and wave period was conducted to enhance the proposed model further.Results indicated that with the selection of optimal parameters,the power output of the double-buoyed system increased by approximately 13-fold,thereby enhancing the viability and efficiency of wave energy harvesting.展开更多
Unmanned Aerial Vehicles(UAVs)have been considered to have great potential in supporting reliable and timely data harvesting for Sensor Nodes(SNs)from an Internet of Things(IoT)perspective.However,due to physical limi...Unmanned Aerial Vehicles(UAVs)have been considered to have great potential in supporting reliable and timely data harvesting for Sensor Nodes(SNs)from an Internet of Things(IoT)perspective.However,due to physical limitations,UAVs are unable to further process the harvested data and have to rely on terrestrial servers,thus extra spectrum resource is needed to convey the harvested data.To avoid the cost of extra servers and spectrum resources,in this paper,we consider a UAV-based data harvesting network supported by a Cell-Free massive Multiple-Input-Multiple-Output(CF-mMIMO)system,where a UAV is used to collect and transmit data from SNs to the central processing unit of CF-mMIMO system for processing.In order to avoid using additional spectrum resources,the entire bandwidth is shared among radio access networks and wireless fronthaul links.Moreover,considering the limited capacity of the fronthaul links,the compress-and-forward scheme is adopted.In this work,in order to maximize the ergodically achievable sum rate of SNs,the power allocation of ground access points,the compression of fronthaul links,and also the bandwidth fraction between radio access networks and wireless fronthaul links are jointly optimized.To avoid the high overhead introduced by computing ergodically achievable rates,we introduce an approximate problem,using the large-dimensional random matrix theory,which relies only on statistical channel state information.We solve the nontrivial problem in three steps and propose an algorithm based on weighted minimum mean square error and Dinkelbach’s methods to find solutions.Finally,simulation results show that the proposed algorithm converges quickly and outperforms the baseline algorithms.展开更多
The evolution of enabling technologies in wireless communications has paved the way for supporting novel applications with more demanding QoS requirements,but at the cost of increasing the complexity of optimizing the...The evolution of enabling technologies in wireless communications has paved the way for supporting novel applications with more demanding QoS requirements,but at the cost of increasing the complexity of optimizing the digital communication chain.In particular,Millimeter Wave(mmWave)communications provide an abundance of bandwidth,and energy harvesting supplies the network with a continual source of energy to facilitate self-sustainability;however,harnessing these technologies is challenging due to the stochastic dynamics of the mmWave channel as well as the random sporadic nature of the harvested energy.In this paper,we aim at the dynamic optimization of update transmissions in mmWave energy harvesting systems in terms of Age of Information(AoI).AoI has recently been introduced to quantify information freshness and is a more stringent QoS metric compared to conventional delay and throughput.However,most prior art has only addressed averagebased AoI metrics,which can be insufficient to capture the occurrence of rare but high-impact freshness violation events in time-critical scenarios.We formulate a control problem that aims to minimize the long-term entropic risk measure of AoI samples by configuring the“sense&transmit”of updates.Due to the high complexity of the exponential cost function,we reformulate the problem with an approximated mean-variance risk measure as the new objective.Under unknown system statistics,we propose a two-timescale model-free risk-sensitive reinforcement learning algorithm to compute a control policy that adapts to the trio of channel,energy,and AoI states.We evaluate the efficiency of the proposed scheme through extensive simulations.展开更多
The shortage of freshwater has become a global challenge,exacerbated by global warming and the rapid growth of the world’s population.Researchers across various fields have made numerous attempts to efficiently colle...The shortage of freshwater has become a global challenge,exacerbated by global warming and the rapid growth of the world’s population.Researchers across various fields have made numerous attempts to efficiently collect freshwater for human use.These efforts include seawater desalination through reverse osmosis or distillation,sewage treatment technologies,and atmospheric water harvesting.However,after thoroughly exploring traditional freshwater harvesting methods,it has become clear that bio-inspired fog harvesting technology offers new prospects due to its unique advantages of efficiency and sustainability.This paper systematically introduces the current principles of fog harvesting and wettability mechanism found in nature.It reviews the research status of combining bionic fog harvesting materials with textile science from two distinct dimensions.Additionally,it describes the practical applications of fog harvesting materials in agriculture,industry,and domestic water use,analyzes their prospects and feasibility in engineering projects,discusses potential challenges in practical applications,and envisions future trends and directions for the development of these materials.展开更多
Yongtao Yu,Yuelin Yu et al.Solvent-Resistant Wearable Triboelectric Nanogenerator for Energy-Harvesting and Self-Powered Sensors.Energy Environ.Mater.2024,7,e12700.On page 4 of this article,the first paragraph of 2.4,...Yongtao Yu,Yuelin Yu et al.Solvent-Resistant Wearable Triboelectric Nanogenerator for Energy-Harvesting and Self-Powered Sensors.Energy Environ.Mater.2024,7,e12700.On page 4 of this article,the first paragraph of 2.4,line 14(PDF version,same below),there is a spelling mistake of“sui,”.It should be changed to“suitable”.The denominator“dt”in the Equation(3)should be changed to“dt”.展开更多
Water-induced electric generators(WEGs)exhibit tremendous promise as sustainable energy sources harvesting electricity through the interaction between materials and water utilizing the hydrovoltaic effect,an innovativ...Water-induced electric generators(WEGs)exhibit tremendous promise as sustainable energy sources harvesting electricity through the interaction between materials and water utilizing the hydrovoltaic effect,an innovative green energy harvesting method.However,existing water-induced electric generator devices predominantly rely on inorganic materials with limited research on naturally available,bio-based materials for hydrovoltaic energy harvesting.This study introduces a novel nutshell-based hydrovoltaic water-induced electric generator for the first time.This low-cost,organic,and efficient renewable energy source can generate a voltage above 600 mV with a power density exceeding 5.96μW cm^(–2)utilizing streaming and evaporation potential methodologies,which can be sustained for more than a week.Notably,after further chemical treatments and combining the physical and chemical phenomena,output voltage and maximum current density reach a record high of 1.21 V and 347.2μA cm^(–2)respectively,which outperforms most inorganic and organic materials-based water-induced electric generators.By connecting two units in series and parallel,this eco-friendly water-induced electric generator can power an LCD calculator without the assistance of any rectifier.We believe that this novel nutshell-based water-induced electric generator provides a significant advancement in water-induced electric generator technology by offering a sustainable solution for powering electronic devices utilizing agricultural waste.展开更多
The global healthcare landscape is increasingly challenged by the rising prevalence of chronic diseases and the demographic shift towards an aging population,necessitating the development of innovative and sustainable...The global healthcare landscape is increasingly challenged by the rising prevalence of chronic diseases and the demographic shift towards an aging population,necessitating the development of innovative and sustainable healthcare solutions.In this context,the emergence of triboelectric energy harvesters as a key technological breakthrough offers a viable pathway towards self-powered,efficient,and sustainable personal health management.This review critically examines the transformative potential of triboelectric nanogenerators(TENGs)in addressing the pressing challenges of modern healthcare,underscoring their unique benefits such as being battery-free,easy to fabricate,and cost-efficient.We begin by reviewing the fundamental mechanisms of triboelectrification at the atomic scale and presenting the contact electrification among various materials,such as metals,polymers,and semiconductors.The discussion subsequently extends to the commonly used materials for TENGs and explores advancements in their design and functionality,with an emphasis on structural and chemical innovations.Furthermore,the application spectrum of TENGs in personal health management is extensively reviewed,covering aspects including health monitoring,therapeutic intervention,health protection,and device powering,while highlighting their capacity for self-sustainability.The review concludes by addressing existing challenges while mapping out the latest significant contributions and prospective directions in TENG-based healthcare innovations.By facilitating a paradigm shift towards a more autonomous,cost-effective,and personalized healthcare model,independent of external power sources,TENGs are poised to markedly enhance the quality of care and overall well-being,marking the dawn of a new era in integrated personal health management.展开更多
Solar-driven interfacial evaporation is one of the most attractive approaches to addressing the global freshwater shortage.However,achieving an integrated high evaporation rate,salt harvesting,and multifunctionality i...Solar-driven interfacial evaporation is one of the most attractive approaches to addressing the global freshwater shortage.However,achieving an integrated high evaporation rate,salt harvesting,and multifunctionality in evaporator is still a crucial challenge.Here,a novel composite membrane with biomimetic micronanostructured superhydrophobic surface is designed via ultrafast laser etching technology.Attractively,the double-transition-metal(V_(1/2)Mo_(1/2))_(2)CT_(x)MXene nanomaterials as a photothermal layer,exhibiting the enhanced photothermal conversion performance due to elevated joint densities of states,which enables high populations of photoexcited carrier relaxation and heat release,provides a new insight into the photothermal conversion mechanism for multiple principal element MXene.Hence,the(V_(1/2)Mo_(1/2))_(2)CT_(x)MXene-200 composite membrane can achieve a high evaporation rate of 2.23 kg m^(−2)h^(−1)under one sun,owing to the enhanced“light trap”effect,photothermal conversion,and high-throughput water transfer.Synergetically,the membrane can induce the directed precipitation of salt at the membrane edge,thus enabling salt harvesting for recycling and zero-emission of brine water.Moreover,the composite membrane is endowed with excellent multifunctionality of anti-/de-icing,anti-fouling,and antibacterial,overcoming the disadvantage that versatility is difficult to be compatible.Therefore,the evaporator and the promising strategy hold great potential for the practical application of solar evaporation.展开更多
In recent years,polymer-based triboelectric nanogenerators(TENGs)have been increasingly applied in the field of flexible wearable electronics.However,the lack of flame retardancy of existing TENGs greatly lim-its thei...In recent years,polymer-based triboelectric nanogenerators(TENGs)have been increasingly applied in the field of flexible wearable electronics.However,the lack of flame retardancy of existing TENGs greatly lim-its their applications in extreme circumstances.Herein,an ultra-thin and highly flexible aramid nanofiber(ANF)/MXene(Ti_(3)C_(2)T_(x))/Ni nanochain composite paper was prepared through vacuum-assisted filtration and freeze-drying technology.Owing to the synergistic effect between ANF and MXene,the composite paper not only possessed excellent mechanical properties,which were able to withstand over 10,000 times its own weight,but also exhibited outstanding flame-retardant and controllable Joule heating ca-pabilities.Moreover,the mechanical energy capture characteristics of the composite paper-based TENG were evaluated,resulting in the open-circuit voltage(55.6 V),short-circuit current(0.62μA),and trans-ferred charge quantity(25μC).It also could enable self-powering as a wearable electronic device with an instantaneous power of 15.6μW at the optimal external resistance of 10 MΩ.This work is intended to set TENG as safe energy harvesting devices for reducing fire hazards,and will provide a new strategy to broaden the application ranges of TENG.展开更多
In this paper,we study the power allocation problem in energy harvesting internet of things(IoT)communication system,with the aim to maximize the total throughput while avoiding data buffer overflow or energy exhausti...In this paper,we study the power allocation problem in energy harvesting internet of things(IoT)communication system,with the aim to maximize the total throughput while avoiding data buffer overflow or energy exhausting.The IoT node has a finite battery to store the harvested energy and a limited buffer for the storage of the unsent data.The energy/-data arrives following a Markov process.Assuming the node has no prior knowledge of the energy/data process and only knows the values of the current time slot,the optimal power allocation problem is modeled as a reinforcement learning task.The state consists of the data in the buffer,the energy stored in the battery,the new coming data amount,the energy harvesting amount and the channel coefficient at time slot t.Then the action is defined as the selected transmitting power.With the growth of the state or action space,it is challenging to visit every state-action pair sufficiently and store all the state-action values,so a deep Q-learning based algorithm is proposed to solve this problem.Simulation results show the advantages of our proposed algorithms,and we also analyze the effect of different system setting parameters.展开更多
The ocean,as one of Earth’s largest natural resources,covers over 70% of the planet’s surface and holds vast water energy potential.Building on this context,this study designs a hybrid generator(WWR-TENG)that integr...The ocean,as one of Earth’s largest natural resources,covers over 70% of the planet’s surface and holds vast water energy potential.Building on this context,this study designs a hybrid generator(WWR-TENG)that integrates a triboelectric nanogenerator(TENG)and an electromagnetic generator(EMG).TENG is a new technology that can capture mechanical energy from the environment and convert it into electrical energy,and is particularly suitable for common natural or man-made power sources such as human movement,wind power,and water flow.EMG is a device that converts mechanical energy into electrical energy through the principle of electromagnetic induction and can usually provide stable power output.The composite design leverages the complementary advantages of both technologies to efficiently capture and convert marine wave energy.By combining the TENG’s high energy conversion efficiency,lowcost,lightweight structure,and simple designwith the EMG’s capabilities,the systemprovides a sustainable solution for marine energy development.Experimental results demonstrate that at a rotational speed of 3.0 r/s,the TENG component of the WWR-TENG achieves an open-circuit voltage of approximately 280 V and a shortcircuit current of 20μA.At the same time,the EMG unit exhibits an open-circuit voltage of 14 V and a short-circuit current of 14 mA.Furthermore,when integrated with a power management circuit,the WWR-TENG charges a 680μF capacitor to 3 V within 10 s at a rotational speed of 3.0 r/s.A simulated wave environment platform was established,enabling the WWR-TENG to maintain the thermo-hygrometer in normal operation under simulated wave conditions.These findings validate the hybrid system’s effectiveness in harnessing and storingwave energy,highlighting its potential for practical marine energy applications.展开更多
This paper provides an overview of the recent advancements in magnetic structured triboelectric nanogenerators(MSTENGs)and their potential for energy harvesting and sensing in coastal bridge infrastructure.This paper ...This paper provides an overview of the recent advancements in magnetic structured triboelectric nanogenerators(MSTENGs)and their potential for energy harvesting and sensing in coastal bridge infrastructure.This paper begins with a brief discussion on the fundamental physics modes of triboelectric nanogenerators(TENGs),triboelectric series,and factors affecting TENG power generation and transmission,providing a foundation for the subsequent sections.The review focuses on the different types of MSTENGs and their applications in coastal infrastructure.Specifically,it covers magnetic spherical TENG networks,magnet-assisted TENGs,MSTENGs for bridges,and magnetic multilayer structures based on TENGs.The advantages and limitations of each type of MSTENG are discussed in detail,highlighting their respective suitability for different coastal bridge infrastructure applications.In addition,the paper addresses the challenges and provides insights into the future of MSTENGs.These include the need for improved durability and sustainability of MSTENGs in harsh coastal environments,increasing their power-output levels to fulfll high energy needs,and the requirement for collaborative efforts between academia,industry,and government institutions to optimize MSTENG performance.展开更多
A new piezoelectric energy harvester is proposed which employs the coupling effect between a piezoelectric beam and an elastic-supported sphere to capture wind energy from multiple directions.As wind flows across the ...A new piezoelectric energy harvester is proposed which employs the coupling effect between a piezoelectric beam and an elastic-supported sphere to capture wind energy from multiple directions.As wind flows across the sphere,it induces vortical vibrations that transfer to the piezoelectric beam,converting wind energy into electricity.A nonlinear coupled dynamic theoretical model based on the Euler-Lagrange equation is developed to study the interactions between the sphere and beam vibrations.The vortex-induced force acting on the sphere is determined,and the dynamic model of the coupled system is validated through experiments.The results show that in order to reach convergence,at least four modes are required in the Galerkin discretization.Moreover,the output performance of the energy harvester strongly depends on the frequency ratio between the sphere and the piezoelectric beam.We find that at a frequency ratio of approximately 1.34,the harvester achieves a maximum average power of 190μW at a wind speed of 3.90 m/s,with the lock-in region between 2.63 and 5.30 m/s.Subsequently,the impact of wind flow direction on the electrical performance of the energy harvester is investigated in a wind tunnel,by adjusting the angle between the harvester and incoming flows ranging from 0°to 360°.The findings indicate that the harvester maintains strong and consistent performance across variable wind flow directions and speeds.Particularly within the lock-in region,the output voltage fluctuations are below 5.5%,showcasing the robustness of the design.This result points to the potential utility of this novel harvester in complex environments.Our study also provides a theoretical basis for the development of small-scale offshore wind energy harvesting technologies.展开更多
This paper studies the use of unmannedaerial vehicles (UAV) equipped with radio frequency(RF) energy harvesting (EH) technology to quickly establishtemporary communication networks in disasterareas to provide artifici...This paper studies the use of unmannedaerial vehicles (UAV) equipped with radio frequency(RF) energy harvesting (EH) technology to quickly establishtemporary communication networks in disasterareas to provide artificial intelligence (AI) basedservices to users with limited resources. In particular,to ensure the quality of AI-based services and improvethe lifetime of emergency communication networks,we study how to reduce the service latency andenergy consumption when fine-tuning models of AIbasedservices in the resource-constrained emergencysystem. A joint optimization problem of model trainingand RF EH for UAV-based emergency communicationnetwork is formulated. Due to the nonlinear RFEH circuit characteristics, the optimization problemis non-convex. We transform the non-convex probleminto solvable subproblems and propose an energyefficientand low-latency federated learning algorithm(EL-FL) to solve these subproblems. Theoretical analysisof the convergence and computational complexityof EL-FL is provided. Simulation results show thatthe proposed scheme significantly outperforms otherbaseline methods in various network environments.展开更多
This paper proposes a novel three-directional functionally graded(3D FG)vibration energy harvesting model based on a bimorph pipe structure.A rectangular pipe has material properties that vary continuously along the a...This paper proposes a novel three-directional functionally graded(3D FG)vibration energy harvesting model based on a bimorph pipe structure.A rectangular pipe has material properties that vary continuously along the axial,width,and height directions,and a steady fluid flows inside the pipe.Two piezoelectric layers are attached to the upper and lower surfaces of the pipe,and are connected in series with a load resistance.The output electricity is predicted theoretically and validated by finite element(FE) simulation.The complex mechanisms regulating the energy harvesting performance are investigated,focusing particularly on the effects of 3D FG material(FGM) parameters,load resistance,fluid-structure interaction(FSI),and geometry.Numerical results indicate that among several material gradient parameters,the axial gradient index has the most significant impact.Increasing the axial and height gradient indices can markedly enhance the energy harvesting performance.The optimal resistances differ between the first two modes.Overall,the maximum power is generated at lower resistances.The FSI effect can also improve the energy harvesting performance;however,higher flow velocities may destabilize the system,causing failure of harvesting energy.This research is capable of providing new insights into the design of a pipe energy harvester in engineering applications.展开更多
基金Supported by the National Natural Science Foundation of China(12261018)Universities Key Laboratory of Mathematical Modeling and Data Mining in Guizhou Province(2023013)。
文摘In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.
基金supported in part by the National Natural Science Foundation of China under Grant No.61473066in part by the Natural Science Foundation of Hebei Province under Grant No.F2021501020+2 种基金in part by the S&T Program of Qinhuangdao under Grant No.202401A195in part by the Science Research Project of Hebei Education Department under Grant No.QN2025008in part by the Innovation Capability Improvement Plan Project of Hebei Province under Grant No.22567637H
文摘Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power stations).To solve the problem,we propose an energy harvesting based task scheduling and resource management framework to provide robust and low-cost edge computing services for smart grid.First,we formulate an energy consumption minimization problem with regard to task offloading,time switching,and resource allocation for mobile devices,which can be decoupled and transformed into a typical knapsack problem.Then,solutions are derived by two different algorithms.Furthermore,we deploy renewable energy and energy storage units at edge servers to tackle intermittency and instability problems.Finally,we design an energy management algorithm based on sampling average approximation for edge computing servers to derive the optimal charging/discharging strategies,number of energy storage units,and renewable energy utilization.The simulation results show the efficiency and superiority of our proposed framework.
文摘Climate variability significantly impacts agricultural water resources,particularly in regions like Vietnam's Plain of Reeds that heavily utilize rain-fed conditions.This study employs the FAO-AquaCrop model to estimate current and future irrigation water needs for rice cultivation in this critical subregion,aiming to identify optimal sowing schedules(OSS)that enhance rainwater utilization and reduce irrigation dependency.The model was driven by current climate data and future projections(2041-2070 and 2071-2099)derived from downscaled Global Circulation Models under RCP4.5 and RCP8.5 scenarios.The AquaCrop model demonstrated robust performance during validation and calibration,with d-values(0.82-0.93)and R²values(0.85-0.92)indicating strong predictive accuracy for rice yield.Simulation results for efficient irrigation water potential(IWP)under RCP4.5 revealed that strategic shifts in sowing dates can substantially alter water requirements;for instance,advancing the winter-spring sowing to December 5th decreased IWP by 15.6%in the 2041-2070 period,while delaying summer-autumn crop sowing to April 20th increased IWP by 48.6%due to greater reliance on irrigation as rainfall patterns shift.Similar dynamic responses were observed for the 2071-2099 period and for autumn-winter crops.These findings underscore that AquaCrop modeling can effectively predict future irrigation needs and that adjusting cultivation calendars presents a viable,low-cost adaptation strategy.This approach allows farmers in the Plain of Reeds to optimize rainwater use,thereby reducing dependency on supplementary irrigation and mitigating the adverse impacts of climate variability,contributing to more sustainable agricultural water management.
文摘Nowadays, we are witnessing an era marked by the autonomy of wireless devices and sensor networks without the aid of batteries. RF energy harvesting therefore becomes a promising alternative for battery dependence. This work presents the design of an RF energy harvesting system consisting mainly of a rectenna (antenna and rectification circuit) and an adaptation circuit. First of all, we designed two dipole type antennas. One operates in the GSM 900 MHz band and the other in the GSM 1800 MHz band. The performances of the proposed antennas are provided by the ANSYS HFSS software. Secondly, we proposed two rectification circuits in order to obtain conversion efficiencies at 0 dBm of 64% for the system operating at the frequency of 900 MHz and 37% for the system at the frequency of 1800 MHz RF-DC. The rectifiers used are based on Schottky diodes. For maximum transfer of power between the antenna and the rectification circuit, L-type matching circuits have been proposed. This rectifier offers DC voltage values of 806 mV for the circuit at the frequency of 900 MHz and 616 mV for the circuit at the frequency of 1800 MHz. The adaptation circuits are obtained by carrying out simulations on the ADS (Advanced Design System) software.
基金supported by the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(MSIT),Project No.RS-2025-24533268.
文摘Capturing of ambient energy is emerging as a transformative area in energy technology,potentially replacing batteries or significantly extending their lifespan.Harnessing of energy from ambient sources presents a significant opportunity to support sustainable development while mitigating environmental issues.Repurposing energy that would otherwise be wasted from highconsumption systems such as engines and industrial furnaces is essential for reducing ecological footprints and moving toward carbon-neutral goals.Furthermore,compact energy harvesting technologies will play a pivotal role in powering the rapidly expanding Internet of Things,enabling innovative advancements in smart homes,cities,industries,and health care that elevate our living standards.To achieve significant advancements in energy harvesting technologies,the development of innovative materials is crucial for converting ambient energy into electricity.In this regard,two-dimensional(2D)materials,a rising star in the material world,are profoundly and technologically intriguing for energy harvesting.The exceptional atomic thickness,high surface-tovolume ratio,flexibility,and tunable band gap effectively enhance their electronic,optical,and chemical properties,making them a potential candidate for use in flexible electronics and wearable energy harvesting technologies.Consequently,these unique properties of 2D materials remarkably enhance their energy harvesting capabilities,including photovoltaic,triboelectric,thermoelectric,and piezoelectric energy harvesting.Here,we present a tutorial-style review of 2D materials for harvesting energy from different ambient sources(aimed particularly at guiding and educating researchers,especially those new to the field),which starts with a brief overview of the promising properties of 2D materials for energy harvesting,then looks deeply into its advantages as compared to traditional materials along with their 3D counterparts,followed by providing insight into the mechanisms and performance of 2D material-based energy harvesters in portable/wearable electronics,and finally,based on current progress,an overview of the challenges along with corresponding strategies are identified and discussed.
文摘This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of previous systems.Notably,the traditional single-buoyed system,which is characterized by a long beam extending to the sea floor,proves impractical in deep-sea environments,especially in distant offshore regions.The proposed double-buoyed model replaces the long beam with a second buoy to increase energy harvesting efficiency.A parametric analysis that included the density and height of the first buoy and wave period was conducted to enhance the proposed model further.Results indicated that with the selection of optimal parameters,the power output of the double-buoyed system increased by approximately 13-fold,thereby enhancing the viability and efficiency of wave energy harvesting.
基金supported in part by the Jiangsu Provincial Key Research and Development Program(No.BE2022068-2)in part by the National Natural Science Foundation of China under Grant 62201285+1 种基金in part by Young Elite Scientists Sponsorship Program by CAST under Grant 2022QNRC001in part by the Postgraduate Research&Practice Innovation Program of Jiangsu Province under Grant KYCX23_1012.
文摘Unmanned Aerial Vehicles(UAVs)have been considered to have great potential in supporting reliable and timely data harvesting for Sensor Nodes(SNs)from an Internet of Things(IoT)perspective.However,due to physical limitations,UAVs are unable to further process the harvested data and have to rely on terrestrial servers,thus extra spectrum resource is needed to convey the harvested data.To avoid the cost of extra servers and spectrum resources,in this paper,we consider a UAV-based data harvesting network supported by a Cell-Free massive Multiple-Input-Multiple-Output(CF-mMIMO)system,where a UAV is used to collect and transmit data from SNs to the central processing unit of CF-mMIMO system for processing.In order to avoid using additional spectrum resources,the entire bandwidth is shared among radio access networks and wireless fronthaul links.Moreover,considering the limited capacity of the fronthaul links,the compress-and-forward scheme is adopted.In this work,in order to maximize the ergodically achievable sum rate of SNs,the power allocation of ground access points,the compression of fronthaul links,and also the bandwidth fraction between radio access networks and wireless fronthaul links are jointly optimized.To avoid the high overhead introduced by computing ergodically achievable rates,we introduce an approximate problem,using the large-dimensional random matrix theory,which relies only on statistical channel state information.We solve the nontrivial problem in three steps and propose an algorithm based on weighted minimum mean square error and Dinkelbach’s methods to find solutions.Finally,simulation results show that the proposed algorithm converges quickly and outperforms the baseline algorithms.
文摘The evolution of enabling technologies in wireless communications has paved the way for supporting novel applications with more demanding QoS requirements,but at the cost of increasing the complexity of optimizing the digital communication chain.In particular,Millimeter Wave(mmWave)communications provide an abundance of bandwidth,and energy harvesting supplies the network with a continual source of energy to facilitate self-sustainability;however,harnessing these technologies is challenging due to the stochastic dynamics of the mmWave channel as well as the random sporadic nature of the harvested energy.In this paper,we aim at the dynamic optimization of update transmissions in mmWave energy harvesting systems in terms of Age of Information(AoI).AoI has recently been introduced to quantify information freshness and is a more stringent QoS metric compared to conventional delay and throughput.However,most prior art has only addressed averagebased AoI metrics,which can be insufficient to capture the occurrence of rare but high-impact freshness violation events in time-critical scenarios.We formulate a control problem that aims to minimize the long-term entropic risk measure of AoI samples by configuring the“sense&transmit”of updates.Due to the high complexity of the exponential cost function,we reformulate the problem with an approximated mean-variance risk measure as the new objective.Under unknown system statistics,we propose a two-timescale model-free risk-sensitive reinforcement learning algorithm to compute a control policy that adapts to the trio of channel,energy,and AoI states.We evaluate the efficiency of the proposed scheme through extensive simulations.
基金Shandong Provincial Key Research and Development Program(Major Scientific and Technological Innovation Project)(2021CXGC011001)Huafon Microfibre(Jiangsu)Co.Ltd.(2021120011000234)+1 种基金Textile Vision Basic Research Program(J202306)China Postdoctoral Science Foundation(No.2023M732103).
文摘The shortage of freshwater has become a global challenge,exacerbated by global warming and the rapid growth of the world’s population.Researchers across various fields have made numerous attempts to efficiently collect freshwater for human use.These efforts include seawater desalination through reverse osmosis or distillation,sewage treatment technologies,and atmospheric water harvesting.However,after thoroughly exploring traditional freshwater harvesting methods,it has become clear that bio-inspired fog harvesting technology offers new prospects due to its unique advantages of efficiency and sustainability.This paper systematically introduces the current principles of fog harvesting and wettability mechanism found in nature.It reviews the research status of combining bionic fog harvesting materials with textile science from two distinct dimensions.Additionally,it describes the practical applications of fog harvesting materials in agriculture,industry,and domestic water use,analyzes their prospects and feasibility in engineering projects,discusses potential challenges in practical applications,and envisions future trends and directions for the development of these materials.
文摘Yongtao Yu,Yuelin Yu et al.Solvent-Resistant Wearable Triboelectric Nanogenerator for Energy-Harvesting and Self-Powered Sensors.Energy Environ.Mater.2024,7,e12700.On page 4 of this article,the first paragraph of 2.4,line 14(PDF version,same below),there is a spelling mistake of“sui,”.It should be changed to“suitable”.The denominator“dt”in the Equation(3)should be changed to“dt”.
文摘Water-induced electric generators(WEGs)exhibit tremendous promise as sustainable energy sources harvesting electricity through the interaction between materials and water utilizing the hydrovoltaic effect,an innovative green energy harvesting method.However,existing water-induced electric generator devices predominantly rely on inorganic materials with limited research on naturally available,bio-based materials for hydrovoltaic energy harvesting.This study introduces a novel nutshell-based hydrovoltaic water-induced electric generator for the first time.This low-cost,organic,and efficient renewable energy source can generate a voltage above 600 mV with a power density exceeding 5.96μW cm^(–2)utilizing streaming and evaporation potential methodologies,which can be sustained for more than a week.Notably,after further chemical treatments and combining the physical and chemical phenomena,output voltage and maximum current density reach a record high of 1.21 V and 347.2μA cm^(–2)respectively,which outperforms most inorganic and organic materials-based water-induced electric generators.By connecting two units in series and parallel,this eco-friendly water-induced electric generator can power an LCD calculator without the assistance of any rectifier.We believe that this novel nutshell-based water-induced electric generator provides a significant advancement in water-induced electric generator technology by offering a sustainable solution for powering electronic devices utilizing agricultural waste.
基金supported by the National Research Foundation of Korea(NRF)Grant funded by the Korea government(MSIT)(Nos.2020R1A5A1019131 and 2022M3D1A2054488)。
文摘The global healthcare landscape is increasingly challenged by the rising prevalence of chronic diseases and the demographic shift towards an aging population,necessitating the development of innovative and sustainable healthcare solutions.In this context,the emergence of triboelectric energy harvesters as a key technological breakthrough offers a viable pathway towards self-powered,efficient,and sustainable personal health management.This review critically examines the transformative potential of triboelectric nanogenerators(TENGs)in addressing the pressing challenges of modern healthcare,underscoring their unique benefits such as being battery-free,easy to fabricate,and cost-efficient.We begin by reviewing the fundamental mechanisms of triboelectrification at the atomic scale and presenting the contact electrification among various materials,such as metals,polymers,and semiconductors.The discussion subsequently extends to the commonly used materials for TENGs and explores advancements in their design and functionality,with an emphasis on structural and chemical innovations.Furthermore,the application spectrum of TENGs in personal health management is extensively reviewed,covering aspects including health monitoring,therapeutic intervention,health protection,and device powering,while highlighting their capacity for self-sustainability.The review concludes by addressing existing challenges while mapping out the latest significant contributions and prospective directions in TENG-based healthcare innovations.By facilitating a paradigm shift towards a more autonomous,cost-effective,and personalized healthcare model,independent of external power sources,TENGs are poised to markedly enhance the quality of care and overall well-being,marking the dawn of a new era in integrated personal health management.
基金supported by the National Natural Science Foundation of China(No.U2106216,52331004)the Natural Science Foundation of Shandong Province(No.ZR2022ZD12)+5 种基金the Key R&D Program of Shandong Province,China(2023ZLGX05,2023CXGC010406)the Taishan Scholarship of Climbing Plan(No.tspd20230603)the Fundamental Research Funds for the Central Universities(202461105)the China Postdoctoral Science Foundation(2023M732677)Shandong Province Postdoctoral Innovation Project(SDCX-ZG-202303086)Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education(LOEC-202309).
文摘Solar-driven interfacial evaporation is one of the most attractive approaches to addressing the global freshwater shortage.However,achieving an integrated high evaporation rate,salt harvesting,and multifunctionality in evaporator is still a crucial challenge.Here,a novel composite membrane with biomimetic micronanostructured superhydrophobic surface is designed via ultrafast laser etching technology.Attractively,the double-transition-metal(V_(1/2)Mo_(1/2))_(2)CT_(x)MXene nanomaterials as a photothermal layer,exhibiting the enhanced photothermal conversion performance due to elevated joint densities of states,which enables high populations of photoexcited carrier relaxation and heat release,provides a new insight into the photothermal conversion mechanism for multiple principal element MXene.Hence,the(V_(1/2)Mo_(1/2))_(2)CT_(x)MXene-200 composite membrane can achieve a high evaporation rate of 2.23 kg m^(−2)h^(−1)under one sun,owing to the enhanced“light trap”effect,photothermal conversion,and high-throughput water transfer.Synergetically,the membrane can induce the directed precipitation of salt at the membrane edge,thus enabling salt harvesting for recycling and zero-emission of brine water.Moreover,the composite membrane is endowed with excellent multifunctionality of anti-/de-icing,anti-fouling,and antibacterial,overcoming the disadvantage that versatility is difficult to be compatible.Therefore,the evaporator and the promising strategy hold great potential for the practical application of solar evaporation.
基金financially supported by the Zhejiang Provin-cial Natural Science Foundation of China(No.LQ22E030016)the National Natural Science Foundation of China(Nos.52275137,51705467),the China Postdoctoral Science Foundation(No.2022M722831)+2 种基金the Postdoctoral Research Selected Funding Project of Zhejiang Province(No.ZJ2022063)the Self-Topic Fund of Zhe-jiang Normal University(No.2020ZS04)the National Key Re-search and Development Program of China(No.2018YFE0199100).
文摘In recent years,polymer-based triboelectric nanogenerators(TENGs)have been increasingly applied in the field of flexible wearable electronics.However,the lack of flame retardancy of existing TENGs greatly lim-its their applications in extreme circumstances.Herein,an ultra-thin and highly flexible aramid nanofiber(ANF)/MXene(Ti_(3)C_(2)T_(x))/Ni nanochain composite paper was prepared through vacuum-assisted filtration and freeze-drying technology.Owing to the synergistic effect between ANF and MXene,the composite paper not only possessed excellent mechanical properties,which were able to withstand over 10,000 times its own weight,but also exhibited outstanding flame-retardant and controllable Joule heating ca-pabilities.Moreover,the mechanical energy capture characteristics of the composite paper-based TENG were evaluated,resulting in the open-circuit voltage(55.6 V),short-circuit current(0.62μA),and trans-ferred charge quantity(25μC).It also could enable self-powering as a wearable electronic device with an instantaneous power of 15.6μW at the optimal external resistance of 10 MΩ.This work is intended to set TENG as safe energy harvesting devices for reducing fire hazards,and will provide a new strategy to broaden the application ranges of TENG.
文摘In this paper,we study the power allocation problem in energy harvesting internet of things(IoT)communication system,with the aim to maximize the total throughput while avoiding data buffer overflow or energy exhausting.The IoT node has a finite battery to store the harvested energy and a limited buffer for the storage of the unsent data.The energy/-data arrives following a Markov process.Assuming the node has no prior knowledge of the energy/data process and only knows the values of the current time slot,the optimal power allocation problem is modeled as a reinforcement learning task.The state consists of the data in the buffer,the energy stored in the battery,the new coming data amount,the energy harvesting amount and the channel coefficient at time slot t.Then the action is defined as the selected transmitting power.With the growth of the state or action space,it is challenging to visit every state-action pair sufficiently and store all the state-action values,so a deep Q-learning based algorithm is proposed to solve this problem.Simulation results show the advantages of our proposed algorithms,and we also analyze the effect of different system setting parameters.
文摘The ocean,as one of Earth’s largest natural resources,covers over 70% of the planet’s surface and holds vast water energy potential.Building on this context,this study designs a hybrid generator(WWR-TENG)that integrates a triboelectric nanogenerator(TENG)and an electromagnetic generator(EMG).TENG is a new technology that can capture mechanical energy from the environment and convert it into electrical energy,and is particularly suitable for common natural or man-made power sources such as human movement,wind power,and water flow.EMG is a device that converts mechanical energy into electrical energy through the principle of electromagnetic induction and can usually provide stable power output.The composite design leverages the complementary advantages of both technologies to efficiently capture and convert marine wave energy.By combining the TENG’s high energy conversion efficiency,lowcost,lightweight structure,and simple designwith the EMG’s capabilities,the systemprovides a sustainable solution for marine energy development.Experimental results demonstrate that at a rotational speed of 3.0 r/s,the TENG component of the WWR-TENG achieves an open-circuit voltage of approximately 280 V and a shortcircuit current of 20μA.At the same time,the EMG unit exhibits an open-circuit voltage of 14 V and a short-circuit current of 14 mA.Furthermore,when integrated with a power management circuit,the WWR-TENG charges a 680μF capacitor to 3 V within 10 s at a rotational speed of 3.0 r/s.A simulated wave environment platform was established,enabling the WWR-TENG to maintain the thermo-hygrometer in normal operation under simulated wave conditions.These findings validate the hybrid system’s effectiveness in harnessing and storingwave energy,highlighting its potential for practical marine energy applications.
文摘This paper provides an overview of the recent advancements in magnetic structured triboelectric nanogenerators(MSTENGs)and their potential for energy harvesting and sensing in coastal bridge infrastructure.This paper begins with a brief discussion on the fundamental physics modes of triboelectric nanogenerators(TENGs),triboelectric series,and factors affecting TENG power generation and transmission,providing a foundation for the subsequent sections.The review focuses on the different types of MSTENGs and their applications in coastal infrastructure.Specifically,it covers magnetic spherical TENG networks,magnet-assisted TENGs,MSTENGs for bridges,and magnetic multilayer structures based on TENGs.The advantages and limitations of each type of MSTENG are discussed in detail,highlighting their respective suitability for different coastal bridge infrastructure applications.In addition,the paper addresses the challenges and provides insights into the future of MSTENGs.These include the need for improved durability and sustainability of MSTENGs in harsh coastal environments,increasing their power-output levels to fulfll high energy needs,and the requirement for collaborative efforts between academia,industry,and government institutions to optimize MSTENG performance.
基金supported by the National Key R&D Program of China(No.2021YFF0501001)the National Natural Science Foundation of China(Nos.52308315,51922046,and 52192661)+4 种基金the Research Funds of Huazhong University of Science and Technology(No.2023JCYJ014)the China Postdoctoral Science Foundation(No.2023M731206)the Research Funds of China Railway Siyuan Survey and Design Group Co.,Ltd.(Nos.KY2023014S,KY2023126S,2021K085,2020K006,and 2020K172)the Research Fund of China Construction Science and Industry(No.CSCEC-PT-004-2022-KT-3.3)the Autonomous Innovation Fund of Hubei Province(No.5003242027),China.
文摘A new piezoelectric energy harvester is proposed which employs the coupling effect between a piezoelectric beam and an elastic-supported sphere to capture wind energy from multiple directions.As wind flows across the sphere,it induces vortical vibrations that transfer to the piezoelectric beam,converting wind energy into electricity.A nonlinear coupled dynamic theoretical model based on the Euler-Lagrange equation is developed to study the interactions between the sphere and beam vibrations.The vortex-induced force acting on the sphere is determined,and the dynamic model of the coupled system is validated through experiments.The results show that in order to reach convergence,at least four modes are required in the Galerkin discretization.Moreover,the output performance of the energy harvester strongly depends on the frequency ratio between the sphere and the piezoelectric beam.We find that at a frequency ratio of approximately 1.34,the harvester achieves a maximum average power of 190μW at a wind speed of 3.90 m/s,with the lock-in region between 2.63 and 5.30 m/s.Subsequently,the impact of wind flow direction on the electrical performance of the energy harvester is investigated in a wind tunnel,by adjusting the angle between the harvester and incoming flows ranging from 0°to 360°.The findings indicate that the harvester maintains strong and consistent performance across variable wind flow directions and speeds.Particularly within the lock-in region,the output voltage fluctuations are below 5.5%,showcasing the robustness of the design.This result points to the potential utility of this novel harvester in complex environments.Our study also provides a theoretical basis for the development of small-scale offshore wind energy harvesting technologies.
基金supported in part by the Key Program of the National Natural Science Foundation of China under Grant 62436004in part by the National Key Research and Development Program of China under Grant 2022YFB3104903.
文摘This paper studies the use of unmannedaerial vehicles (UAV) equipped with radio frequency(RF) energy harvesting (EH) technology to quickly establishtemporary communication networks in disasterareas to provide artificial intelligence (AI) basedservices to users with limited resources. In particular,to ensure the quality of AI-based services and improvethe lifetime of emergency communication networks,we study how to reduce the service latency andenergy consumption when fine-tuning models of AIbasedservices in the resource-constrained emergencysystem. A joint optimization problem of model trainingand RF EH for UAV-based emergency communicationnetwork is formulated. Due to the nonlinear RFEH circuit characteristics, the optimization problemis non-convex. We transform the non-convex probleminto solvable subproblems and propose an energyefficientand low-latency federated learning algorithm(EL-FL) to solve these subproblems. Theoretical analysisof the convergence and computational complexityof EL-FL is provided. Simulation results show thatthe proposed scheme significantly outperforms otherbaseline methods in various network environments.
基金Project supported by the National Natural Science Foundation of China (Nos. 12372025 and 12072311)。
文摘This paper proposes a novel three-directional functionally graded(3D FG)vibration energy harvesting model based on a bimorph pipe structure.A rectangular pipe has material properties that vary continuously along the axial,width,and height directions,and a steady fluid flows inside the pipe.Two piezoelectric layers are attached to the upper and lower surfaces of the pipe,and are connected in series with a load resistance.The output electricity is predicted theoretically and validated by finite element(FE) simulation.The complex mechanisms regulating the energy harvesting performance are investigated,focusing particularly on the effects of 3D FG material(FGM) parameters,load resistance,fluid-structure interaction(FSI),and geometry.Numerical results indicate that among several material gradient parameters,the axial gradient index has the most significant impact.Increasing the axial and height gradient indices can markedly enhance the energy harvesting performance.The optimal resistances differ between the first two modes.Overall,the maximum power is generated at lower resistances.The FSI effect can also improve the energy harvesting performance;however,higher flow velocities may destabilize the system,causing failure of harvesting energy.This research is capable of providing new insights into the design of a pipe energy harvester in engineering applications.
