Silver nanowire films are promising alternatives to tin-doped indium oxide(ITO)films as transparent conductive electrodes.In this paper,we report the use of vacuum filtration and a polydimethylsiloxane(PDMS)-assisted ...Silver nanowire films are promising alternatives to tin-doped indium oxide(ITO)films as transparent conductive electrodes.In this paper,we report the use of vacuum filtration and a polydimethylsiloxane(PDMS)-assisted transfer printing technique to fabricate silver nanowire films on both rigid and flexible substrates,bringing advantages such as the capability of patterned transfer,the best performance among various ITO alternatives(10Ω/sq at 85%transparency),and good adhesion to the underlying substrate,thus eliminating the previously reported adhesion problem.In addition,our method also allows the preparation of high quality patterned films of silver nanowires with different line widths and shapes in a matter of few minutes,making it a scalable process.Furthermore,use of an anodized aluminum oxide(AAO)membrane in the transfer process allows annealing of nanowire films at moderately high temperature to obtain films with extremely high conductivity and good transparency.Using this transfer technique,we obtained silver nanowire films on a flexible polyethylene terephthalate(PET)substrate with a transparency of 85%,a sheet resistance of 10Ω/sq,with good mechanical flexibility.Detailed analysis revealed that the Ag nanowire network exhibits two-dimensional percolation behavior with good agreement between experimentally observed and theoretically predicted values of critical volume。展开更多
Full-Bridge Modular Multilevel Converter(FBMMC) has strong ability to ride through serious DC faults,thus it is very suitable for multi-terminal flexible HVDC applications.However,no references have reported the locat...Full-Bridge Modular Multilevel Converter(FBMMC) has strong ability to ride through serious DC faults,thus it is very suitable for multi-terminal flexible HVDC applications.However,no references have reported the locating and isolating of DC faults and corresponding DC faults ride-through capability evaluation index.This paper introduces the topology mechanism of FBMMC and its loss reduction operation mode,theoretically certifies that the universal decoupled control strategy of Voltage Source Converter(VSC) and the similar modulation strategies of Half-Bridge MMC(HBMMC) can be applied to FBMMC for constructing complete closed-loop control system.On the basis of the existing DC faults locating and isolating schemes of 2-level VSC based Multi-Terminal HVDC(VSC-MTDC) system and the particularity of FBMMC,this paper proposes the DC faults wire selection "handshaking" method of the FBMMC-MTDC system,and proposes the DC Fault Ride-Through Capability Index(DFRTI) for evaluating the DC faults suppressing capability of the VSC-MTDC systems,including FBMMC-MTDC.Simulations of FBMMC-MTDC in PSCAD/EMTDC validate the correctness and effectiveness of the proposed control strategy and evaluation index.展开更多
Flexible job shop scheduling problems(FJSP)have received much attention from academia and industry for many years.Due to their exponential complexity,swarm intelligence(SI)and evolutionary algorithms(EA)are developed,...Flexible job shop scheduling problems(FJSP)have received much attention from academia and industry for many years.Due to their exponential complexity,swarm intelligence(SI)and evolutionary algorithms(EA)are developed,employed and improved for solving them.More than 60%of the publications are related to SI and EA.This paper intents to give a comprehensive literature review of SI and EA for solving FJSP.First,the mathematical model of FJSP is presented and the constraints in applications are summarized.Then,the encoding and decoding strategies for connecting the problem and algorithms are reviewed.The strategies for initializing algorithms?population and local search operators for improving convergence performance are summarized.Next,one classical hybrid genetic algorithm(GA)and one newest imperialist competitive algorithm(ICA)with variables neighborhood search(VNS)for solving FJSP are presented.Finally,we summarize,discus and analyze the status of SI and EA for solving FJSP and give insight into future research directions.展开更多
The hydrodynamics of turbulent flow through submerged flexible vegetation is investigated in a flume using acoustic Doppler velocimetery(ADV)measurements.The flow characteristics such as the energetics and momentum tr...The hydrodynamics of turbulent flow through submerged flexible vegetation is investigated in a flume using acoustic Doppler velocimetery(ADV)measurements.The flow characteristics such as the energetics and momentum transfer derived from convcntional spectral and quadrant analyses are considered as the flow encounters a finite vegetation patch.Consistent with numerous canopy flow experiments,a shear layer and coherent vortex structures near the canopy top emerge caused by Kelvin-Helmholtz instabilities after the flow equilibrates with the vegetated layer.These in stabilities are commonly attributed to velocity differences between non-vegetated and vegetated canopy layers in agreement with numerous experiments and simulations conducted on dense rigid canopies.The power-spectral density function for vertical velocity turbulent fluctuations at different downstream positions starting from the edge of the vegetation layer are also computed.For a preset water depth,the dominant dimensionless frequency is found to be surprisingly invariant around 0.027 despite large differences in vegetation densities.The ejection and sweep events significantly contribute to the Reynolds stresses near the top of the vegetation.The momentum flux carried by ejections is larger than its counterpart carried by the sweeps above the canopy top.However,the momentum flux carried by sweeps is larger below the top of the canopy.展开更多
A series of inkjet printing processes have been studied using graphene-based inks. Under optimized conditions, using water-soluble single-layered graphene oxide （GO） and few-layered graphene oxide （FGO）, various h...A series of inkjet printing processes have been studied using graphene-based inks. Under optimized conditions, using water-soluble single-layered graphene oxide （GO） and few-layered graphene oxide （FGO）, various high image quality patterns could be printed on diverse flexible substrates, including paper, poly（ethylene terephthalate） （PET） and polyimide （PI）, with a simple and low-cost inkjet printing technique. The graphene-based patterns printed on plastic substrates demonstrated a high electrical conductivity after thermal reduction, and more importantly, they retained the same conductivity over severe bending cycles. Accordingly, flexible electric circuits and a hydrogen peroxide chemical sensor were fabricated and showed excellent performances, demonstrating the applications of this simple and practical inkjet printing technique using graphene inks. The results show that graphene materials--which can be easily produced on a large scale and possess outstanding electronic properties--have great potential for the convenient fabrication of flexible and low-cost graphene- based electronic devices, by using a simple inkjet printing technique.展开更多
Smart energy storage has revolutionized portable electronics and electrical vehicles.The current smart energy storage devices have penetrated into flexible electronic markets at an unprecedented rate.Flexible batterie...Smart energy storage has revolutionized portable electronics and electrical vehicles.The current smart energy storage devices have penetrated into flexible electronic markets at an unprecedented rate.Flexible batteries are key power sources to enable vast flexible devices,which put forward additional requirements,such as bendable,twistable,stretchable,and ultrathin,to adapt mechanical deformation under the working conditions.This review summarizes the recent advances in construction and configuration of flexible batteries and discusses the general metrics to benchmark various flexible batteries with different materials and chemistries.Moreover,we present advanced prototype flexible batteries developed by some companies to afford general envision of the technological status.Lastly,the critical points are summarized in the development of flexible batteries and remaining challenges are also presented for the future design of flexible batteries in practical perspectives.展开更多
Urban water-related problems associated with rapid urbanization, including waterlogging, water pollution, the ecological degradation of water, and water shortages, have caused global concerns in recent years. In 2013,...Urban water-related problems associated with rapid urbanization, including waterlogging, water pollution, the ecological degradation of water, and water shortages, have caused global concerns in recent years. In 2013, in order to mitigate increasingly severe urban water-related problems, China set forth a new strategy for integrated urban water management(IUWM) called the "Sponge City". This is the first holistic IUWM strategy implemented in a developing country that is still undergoing rapid urbanization, and holds promise for application in other developing countries. This paper aims to comprehensively summarize the sponge city. First, this paper reviews prior studies and policies on urban water management in China as important background for the sponge city proposal. Then, the connotations, goals, and features of the sponge city are summarized and discussed.Finally, the challenges, research needs, and development directions pertinent to the sponge city are discussed based on investigations and studies conducted by the authors. The sponge city in China has a short history—given this, there are many issues that should be examined with regard to the stepwise implementation of the Sponge City Programme(SCP). Accordingly, the authors perceive this study as only the beginning of abundant studies on the sponge city.展开更多
With the development of power electronics technology,the flexible DC grid will play a significant role in promoting the transformation and reformation of the power grid.It is immune to commutation failure and has high...With the development of power electronics technology,the flexible DC grid will play a significant role in promoting the transformation and reformation of the power grid.It is immune to commutation failure and has high flexibility in power control and renewable energy grid integration.However,the protection and fault handling technology for a flexible DC grid is a big challenge because of the limited overcurrent capability of the converters.This paper summarizes the development of the flexible DC grid,and analyzes the fault characteristics in detail.Next,the applicability,advantages and disadvantages of the existing protection principle,fault isolation and recovery schemes are reviewed.Finally,the key problems and development trend of the future flexible DC grid are pointed out and forecasted respectively.展开更多
The development of pressure sensors with highly sensitivity, fast response and facile fabrication technique is desirable for wearable electronics. Here, we successfully fabricated a flexible transparent capacitive pre...The development of pressure sensors with highly sensitivity, fast response and facile fabrication technique is desirable for wearable electronics. Here, we successfully fabricated a flexible transparent capacitive pressure sensor based on patterned microstructured silver nanowires(AgNWs)/polydimethylsiloxane(PDMS) composite dielectrics. Compared with the pure PDMS dielectric layer with planar structures, the patterned microstructured sensor exhibits a higher sensitivity(0.831 kPa^-1, <0.5 kPa), a lower detection limit,good stability and durability. The enhanced sensing mechanism about the conductive filler content and the patterned microstructures has also been discussed. A 5×5 sensor array was then fabricated to be used as flexible and transparent wearable touch keyboards systems. The fabricated pressure sensor has great potential in the future electronic skin area.展开更多
Li-ion batteries(LIBs)with excellent cycling stability and high-energy densities have already occupied the commercial rechargeable battery market.Unfortunately,the high cost and intrinsic insecurity induced by organic...Li-ion batteries(LIBs)with excellent cycling stability and high-energy densities have already occupied the commercial rechargeable battery market.Unfortunately,the high cost and intrinsic insecurity induced by organic electrolyte severely hinder their applications in large-scale energy storage.In contrast,aqueous Zn-ion batteries(ZIBs)are being developed as an ideal candidate because of their cheapness and high security.Benefiting from high operating voltage and acceptable specific capacity,recently,manganese-based oxides with different various crystal structures have been extensively studied as cathode materials for aqueous ZIBs.This review presents research progress of manganese-based cathodes in aqueous ZIBs,including various manganese-based oxides and their zinc storage mechanisms.In addition,we also discuss some optimization strategies that aim at improving the electrochemical performance of manganese-based cathodes,and the design of flexible aqueous ZIBs based on manganese-based cathodes(MZIBs).Finally,this review summarizes some valuable research directions,which will promote the further development of aqueous MZIBs.展开更多
Rechargeable lithium-sulfur(Li-S)batteries have attracted significant research attention due to their high capacity and energy density.However,their commercial applications are still hindered by challenges such as the...Rechargeable lithium-sulfur(Li-S)batteries have attracted significant research attention due to their high capacity and energy density.However,their commercial applications are still hindered by challenges such as the shuttle effect of soluble lithium sulfide species,the insulating nature of sulfur,and the fast capacity decay of the electrodes.Various efforts are devoted to address these problems through questing more conductive hosts with abundant polysulfide chemisorption sites,as well as modifying the separators to physically/chemically retard the polysulfides migration.Two dimensional transition metal carbides,carbonitrides and nitrides,so-called MXenes,are ideal for confining the polysulfides shuttling effects due to their high conductivity,layered structure as well as rich surface terminations.As such,MXenes have thus been widely studied in Li-S batteries,focusing on the conductive sulfur hosts,polysulfides interfaces,and separators.Therefore,in this review,we summarize the significant progresses regarding the design of multifunctional MXene-based Li-S batteries and discuss the solutions for improving electrochemical performances in detail.In addition,challenges and perspectives of MXenes for Li-S batteries are also outlined.展开更多
Electronic skin(e-skin) and flexible wearable devices are currently being developed with broad application prospects. Transforming electronic skin(e-skin) into true ¨skin¨is the ultimate goal. Tactile sensin...Electronic skin(e-skin) and flexible wearable devices are currently being developed with broad application prospects. Transforming electronic skin(e-skin) into true ¨skin¨is the ultimate goal. Tactile sensing is a fundamental function of skin and the development of high-performance flexible pressure sensors is necessary to realize thus. Many reports on flexible pressure sensors have been published in recent years,including numerous studies on improving sensor performance, and in particular, sensitivity. In addition,a number of studies have investigated self-healing materials, multifunctional sensing, and so on. Here,we review recent developments in flexible pressure sensors. First, working principles of flexible pressure sensors, including piezoresistivity, capacitance, and piezoelectricity, are introduced, as well as working mechanisms such as triboelectricity. Then studies on improving the performance of piezoresistive and capacitive flexible pressure sensors are discussed, in addition to other important aspects of this intriguing research field. Finally, we summarize future challenges in developing novel flexible pressure sensors.展开更多
基金funded by the U.S.Department of Energy,Office of Science and Office of Basic Energy Sciences under Award No.DE-SC0001013.
文摘Silver nanowire films are promising alternatives to tin-doped indium oxide(ITO)films as transparent conductive electrodes.In this paper,we report the use of vacuum filtration and a polydimethylsiloxane(PDMS)-assisted transfer printing technique to fabricate silver nanowire films on both rigid and flexible substrates,bringing advantages such as the capability of patterned transfer,the best performance among various ITO alternatives(10Ω/sq at 85%transparency),and good adhesion to the underlying substrate,thus eliminating the previously reported adhesion problem.In addition,our method also allows the preparation of high quality patterned films of silver nanowires with different line widths and shapes in a matter of few minutes,making it a scalable process.Furthermore,use of an anodized aluminum oxide(AAO)membrane in the transfer process allows annealing of nanowire films at moderately high temperature to obtain films with extremely high conductivity and good transparency.Using this transfer technique,we obtained silver nanowire films on a flexible polyethylene terephthalate(PET)substrate with a transparency of 85%,a sheet resistance of 10Ω/sq,with good mechanical flexibility.Detailed analysis revealed that the Ag nanowire network exhibits two-dimensional percolation behavior with good agreement between experimentally observed and theoretically predicted values of critical volume。
基金supported by the National Natural Science Foundation of China (Grant No. 51177042)the Key Project of the National Twelfth FiveYear Research Program of China (Grant No. 2010BAA01B01)
文摘Full-Bridge Modular Multilevel Converter(FBMMC) has strong ability to ride through serious DC faults,thus it is very suitable for multi-terminal flexible HVDC applications.However,no references have reported the locating and isolating of DC faults and corresponding DC faults ride-through capability evaluation index.This paper introduces the topology mechanism of FBMMC and its loss reduction operation mode,theoretically certifies that the universal decoupled control strategy of Voltage Source Converter(VSC) and the similar modulation strategies of Half-Bridge MMC(HBMMC) can be applied to FBMMC for constructing complete closed-loop control system.On the basis of the existing DC faults locating and isolating schemes of 2-level VSC based Multi-Terminal HVDC(VSC-MTDC) system and the particularity of FBMMC,this paper proposes the DC faults wire selection "handshaking" method of the FBMMC-MTDC system,and proposes the DC Fault Ride-Through Capability Index(DFRTI) for evaluating the DC faults suppressing capability of the VSC-MTDC systems,including FBMMC-MTDC.Simulations of FBMMC-MTDC in PSCAD/EMTDC validate the correctness and effectiveness of the proposed control strategy and evaluation index.
基金supported in part by the National Natural Science Foundation of China(61603169,61773192,61803192)in part by the funding from Shandong Provincial Key Laboratory for Novel Distributed Computer Software Technologyin part by Singapore National Research Foundation(NRF-RSS2016-004)
文摘Flexible job shop scheduling problems(FJSP)have received much attention from academia and industry for many years.Due to their exponential complexity,swarm intelligence(SI)and evolutionary algorithms(EA)are developed,employed and improved for solving them.More than 60%of the publications are related to SI and EA.This paper intents to give a comprehensive literature review of SI and EA for solving FJSP.First,the mathematical model of FJSP is presented and the constraints in applications are summarized.Then,the encoding and decoding strategies for connecting the problem and algorithms are reviewed.The strategies for initializing algorithms?population and local search operators for improving convergence performance are summarized.Next,one classical hybrid genetic algorithm(GA)and one newest imperialist competitive algorithm(ICA)with variables neighborhood search(VNS)for solving FJSP are presented.Finally,we summarize,discus and analyze the status of SI and EA for solving FJSP and give insight into future research directions.
基金the National Natural Science Foundation of China(Grant Nos.51439007,11672213,11872285 and 51809286).
文摘The hydrodynamics of turbulent flow through submerged flexible vegetation is investigated in a flume using acoustic Doppler velocimetery(ADV)measurements.The flow characteristics such as the energetics and momentum transfer derived from convcntional spectral and quadrant analyses are considered as the flow encounters a finite vegetation patch.Consistent with numerous canopy flow experiments,a shear layer and coherent vortex structures near the canopy top emerge caused by Kelvin-Helmholtz instabilities after the flow equilibrates with the vegetated layer.These in stabilities are commonly attributed to velocity differences between non-vegetated and vegetated canopy layers in agreement with numerous experiments and simulations conducted on dense rigid canopies.The power-spectral density function for vertical velocity turbulent fluctuations at different downstream positions starting from the edge of the vegetation layer are also computed.For a preset water depth,the dominant dimensionless frequency is found to be surprisingly invariant around 0.027 despite large differences in vegetation densities.The ejection and sweep events significantly contribute to the Reynolds stresses near the top of the vegetation.The momentum flux carried by ejections is larger than its counterpart carried by the sweeps above the canopy top.However,the momentum flux carried by sweeps is larger below the top of the canopy.
基金Acknowledgements The authors gratefully acknowledge financial support from the the National Natural Science Foundation of China （Grants No. 50933003, 50902073, 50903044, and 20774047）, Ministry of Science and Technology of China （Grant No. 2009AA032304, 2011CB932602）, Natural Science Foundation of Tianjin City （Grant No. 08JCZDJC25300）.
文摘A series of inkjet printing processes have been studied using graphene-based inks. Under optimized conditions, using water-soluble single-layered graphene oxide （GO） and few-layered graphene oxide （FGO）, various high image quality patterns could be printed on diverse flexible substrates, including paper, poly（ethylene terephthalate） （PET） and polyimide （PI）, with a simple and low-cost inkjet printing technique. The graphene-based patterns printed on plastic substrates demonstrated a high electrical conductivity after thermal reduction, and more importantly, they retained the same conductivity over severe bending cycles. Accordingly, flexible electric circuits and a hydrogen peroxide chemical sensor were fabricated and showed excellent performances, demonstrating the applications of this simple and practical inkjet printing technique using graphene inks. The results show that graphene materials--which can be easily produced on a large scale and possess outstanding electronic properties--have great potential for the convenient fabrication of flexible and low-cost graphene- based electronic devices, by using a simple inkjet printing technique.
基金National Natural Science Foundation of China,Grant/Award Numbers:21805162,21825501,and U1801257。
文摘Smart energy storage has revolutionized portable electronics and electrical vehicles.The current smart energy storage devices have penetrated into flexible electronic markets at an unprecedented rate.Flexible batteries are key power sources to enable vast flexible devices,which put forward additional requirements,such as bendable,twistable,stretchable,and ultrathin,to adapt mechanical deformation under the working conditions.This review summarizes the recent advances in construction and configuration of flexible batteries and discusses the general metrics to benchmark various flexible batteries with different materials and chemistries.Moreover,we present advanced prototype flexible batteries developed by some companies to afford general envision of the technological status.Lastly,the critical points are summarized in the development of flexible batteries and remaining challenges are also presented for the future design of flexible batteries in practical perspectives.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFC0401401)the National Natural Science Foundation of China(Grant Nos.51522907&51739011)supported by the Research Fund of the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research(Grant No.2017ZY02)
文摘Urban water-related problems associated with rapid urbanization, including waterlogging, water pollution, the ecological degradation of water, and water shortages, have caused global concerns in recent years. In 2013, in order to mitigate increasingly severe urban water-related problems, China set forth a new strategy for integrated urban water management(IUWM) called the "Sponge City". This is the first holistic IUWM strategy implemented in a developing country that is still undergoing rapid urbanization, and holds promise for application in other developing countries. This paper aims to comprehensively summarize the sponge city. First, this paper reviews prior studies and policies on urban water management in China as important background for the sponge city proposal. Then, the connotations, goals, and features of the sponge city are summarized and discussed.Finally, the challenges, research needs, and development directions pertinent to the sponge city are discussed based on investigations and studies conducted by the authors. The sponge city in China has a short history—given this, there are many issues that should be examined with regard to the stepwise implementation of the Sponge City Programme(SCP). Accordingly, the authors perceive this study as only the beginning of abundant studies on the sponge city.
基金funded by the Fundamental Research Funds for the Central Universities(No.2019YJS179).
文摘With the development of power electronics technology,the flexible DC grid will play a significant role in promoting the transformation and reformation of the power grid.It is immune to commutation failure and has high flexibility in power control and renewable energy grid integration.However,the protection and fault handling technology for a flexible DC grid is a big challenge because of the limited overcurrent capability of the converters.This paper summarizes the development of the flexible DC grid,and analyzes the fault characteristics in detail.Next,the applicability,advantages and disadvantages of the existing protection principle,fault isolation and recovery schemes are reviewed.Finally,the key problems and development trend of the future flexible DC grid are pointed out and forecasted respectively.
基金supported by the National Natural Science Foundation for Distinguished Young Scholars of China(NSFC,61625404)the Key Research Program of Frontier Sciences,CAS(QYZDY-SSW-JWC004)the NSFC(61504136)
文摘The development of pressure sensors with highly sensitivity, fast response and facile fabrication technique is desirable for wearable electronics. Here, we successfully fabricated a flexible transparent capacitive pressure sensor based on patterned microstructured silver nanowires(AgNWs)/polydimethylsiloxane(PDMS) composite dielectrics. Compared with the pure PDMS dielectric layer with planar structures, the patterned microstructured sensor exhibits a higher sensitivity(0.831 kPa^-1, <0.5 kPa), a lower detection limit,good stability and durability. The enhanced sensing mechanism about the conductive filler content and the patterned microstructures has also been discussed. A 5×5 sensor array was then fabricated to be used as flexible and transparent wearable touch keyboards systems. The fabricated pressure sensor has great potential in the future electronic skin area.
基金This work was financially supported by This work was financially supported by the National Natural Science Foundation of China(21725103 and 51631004)National Key R&D Program of China(2016YFB0100103,2017YFA0206704)+2 种基金People's Government of Jilin Province Science and Technology Development Plan Funding Project(20180101203JC)Changchun Science and Technology Development Plan Funding Project(18DY012,19SS010)the Program for the JLU Science and Technology Innovative Research Team(2017TD-09).
文摘Li-ion batteries(LIBs)with excellent cycling stability and high-energy densities have already occupied the commercial rechargeable battery market.Unfortunately,the high cost and intrinsic insecurity induced by organic electrolyte severely hinder their applications in large-scale energy storage.In contrast,aqueous Zn-ion batteries(ZIBs)are being developed as an ideal candidate because of their cheapness and high security.Benefiting from high operating voltage and acceptable specific capacity,recently,manganese-based oxides with different various crystal structures have been extensively studied as cathode materials for aqueous ZIBs.This review presents research progress of manganese-based cathodes in aqueous ZIBs,including various manganese-based oxides and their zinc storage mechanisms.In addition,we also discuss some optimization strategies that aim at improving the electrochemical performance of manganese-based cathodes,and the design of flexible aqueous ZIBs based on manganese-based cathodes(MZIBs).Finally,this review summarizes some valuable research directions,which will promote the further development of aqueous MZIBs.
基金the support from an Empa interal research grant.
文摘Rechargeable lithium-sulfur(Li-S)batteries have attracted significant research attention due to their high capacity and energy density.However,their commercial applications are still hindered by challenges such as the shuttle effect of soluble lithium sulfide species,the insulating nature of sulfur,and the fast capacity decay of the electrodes.Various efforts are devoted to address these problems through questing more conductive hosts with abundant polysulfide chemisorption sites,as well as modifying the separators to physically/chemically retard the polysulfides migration.Two dimensional transition metal carbides,carbonitrides and nitrides,so-called MXenes,are ideal for confining the polysulfides shuttling effects due to their high conductivity,layered structure as well as rich surface terminations.As such,MXenes have thus been widely studied in Li-S batteries,focusing on the conductive sulfur hosts,polysulfides interfaces,and separators.Therefore,in this review,we summarize the significant progresses regarding the design of multifunctional MXene-based Li-S batteries and discuss the solutions for improving electrochemical performances in detail.In addition,challenges and perspectives of MXenes for Li-S batteries are also outlined.
基金supported by the National Natural Science Foundation of China(Nos.61775032,61475134 and 11604042)the Fundamental Research Funds for the Central Universities(N170405007,N180406002,N180408018 and N160404009)the 111 Project(B16009)。
文摘Electronic skin(e-skin) and flexible wearable devices are currently being developed with broad application prospects. Transforming electronic skin(e-skin) into true ¨skin¨is the ultimate goal. Tactile sensing is a fundamental function of skin and the development of high-performance flexible pressure sensors is necessary to realize thus. Many reports on flexible pressure sensors have been published in recent years,including numerous studies on improving sensor performance, and in particular, sensitivity. In addition,a number of studies have investigated self-healing materials, multifunctional sensing, and so on. Here,we review recent developments in flexible pressure sensors. First, working principles of flexible pressure sensors, including piezoresistivity, capacitance, and piezoelectricity, are introduced, as well as working mechanisms such as triboelectricity. Then studies on improving the performance of piezoresistive and capacitive flexible pressure sensors are discussed, in addition to other important aspects of this intriguing research field. Finally, we summarize future challenges in developing novel flexible pressure sensors.
