Wearable sensing systems have been designed to monitor health conditions in real-time by detecting analytes in human biofluids.Wound diagnosis remains challenging,necessitating suitable materials for high-performance ...Wearable sensing systems have been designed to monitor health conditions in real-time by detecting analytes in human biofluids.Wound diagnosis remains challenging,necessitating suitable materials for high-performance wearable sensors to offer prompt feedback.Existing devices have limitations in measuring pH and the concentration of pH-dependent electroactive species simultaneously,which is crucial for obtaining a comprehensive understanding of wound status and optimizing biosensors.Therefore,improving materials and analysis system accuracy is essential.This article introduces the first example of a flexible array capable of detecting pyocyanin,a bacterial virulence factor,while correcting dynamic pH fluctuations.We demonstrate that this combined sensor enhances accuracy by mitigating the impact of pH variability on pyocyanin sensor response.Customized screen-printable inks were developed to enhance analytical performance.The analytical performances of two sensitive sensor systems(i.e.,fully-printed porous graphene/multiwalled carbon nanotube(CNT)and polyaniline/CNT composites for pyocyanin and pH sensors)are evaluated.Partial least square regression is employed to analyze nonzero-order data arrays from square wave voltammetric and potentiometric measurements of pyocyanin and pH sensors to establish a predictive model for pyocyanin concentration in complex fluids.This sensitive and effective strategy shows potential for personalized applications due to its affordability,ease of use,and ability to adjust for dynamic pH changes.展开更多
Wearable wristband systems leverage deep learning to revolutionize hand gesture recognition in daily activities.Unlike existing approaches that often focus on static gestures and require extensive labeled data,the pro...Wearable wristband systems leverage deep learning to revolutionize hand gesture recognition in daily activities.Unlike existing approaches that often focus on static gestures and require extensive labeled data,the proposed wearable wristband with selfsupervised contrastive learning excels at dynamic motion tracking and adapts rapidly across multiple scenarios.It features a four-channel sensing array composed of an ionic hydrogel with hierarchical microcone structures and ultrathin flexible electrodes,resulting in high-sensitivity capacitance output.Through wireless transmission from a Wi-Fi module,the proposed algorithm learns latent features from the unlabeled signals of random wrist movements.Remarkably,only few-shot labeled data are sufficient for fine-tuning the model,enabling rapid adaptation to various tasks.The system achieves a high accuracy of 94.9%in different scenarios,including the prediction of eight-direction commands,and air-writing of all numbers and letters.The proposed method facilitates smooth transitions between multiple tasks without the need for modifying the structure or undergoing extensive task-specific training.Its utility has been further extended to enhance human–machine interaction over digital platforms,such as game controls,calculators,and three-language login systems,offering users a natural and intuitive way of communication.展开更多
The study projects a flexible and compact wearable pear-shaped Super High Frequency(SHF)antenna that can provide detailed location recognition and tracking applicable to defense beacon technology.This mini aperture wi...The study projects a flexible and compact wearable pear-shaped Super High Frequency(SHF)antenna that can provide detailed location recognition and tracking applicable to defense beacon technology.This mini aperture with electrical dimensions of 0.12λ_(0)×0.22λ_(0)×0.01λ_(0)attains a vast bandwidth over 3.1-34.5 GHz Super High Frequency(SHF)frequency band at S_(11)≤-10 dB,peak gain of 7.14 dBi and proportionately homogeneous radiation pattern.The fractional bandwidth(%BW)acquired is 168%that envelopes diversified frequency spectrum inclusive of X band specifically targeted to all kinds of defense and military operations.The proposed antenna can be worn on a soldier's uniform and hence the Specific Absorption Rate simulation is accomplished.The Peak SAR Value over 1 g of tissue is 1.48 W/kg and for 10 g of tissue is 0.27 W/kg well under the safety standards.The flexibility is proven by analyzing the full electromagnetic simulations for various bending conditions.Time response analysis is attained with its Fidelity Factor and Group Delay.Communication excellence is determined using Link Budget Analysis and it is seen that margin at 100 Mbps is 62 m and at 200 Mbps is 59 m.Prototype is fabricated along with experimental validation.All the results show harmony in shaping the antenna to provide critical situational awareness and data sharing capabilities required in defense beacon technology for location identification.展开更多
This review explores glucose monitoring and management strategies,emphasizing the need for reliable and userfriendly wearable sensors that are the next generation of sensors for continuous glucose detection.In additio...This review explores glucose monitoring and management strategies,emphasizing the need for reliable and userfriendly wearable sensors that are the next generation of sensors for continuous glucose detection.In addition,examines key strategies for designing glucose sensors that are multi-functional,reliable,and cost-effective in a variety of contexts.The unique features of effective diabetes management technology are highlighted,with a focus on using nano/biosensor devices that can quickly and accurately detect glucose levels in the blood,improving patient treatment and control of potential diabetes-related infections.The potential of next-generation wearable and touch-sensitive nano biomedical sensor engineering designs for providing full control in assessing implantable,continuous glucose monitoring is also explored.The challenges of standardizing drug or insulin delivery doses,low-cost,real-time detection of increased blood sugar levels in diabetics,and early digital health awareness controls for the adverse effects of injectable medication are identified as unmet needs.Also,the market for biosensors is expected to expand significantly due to the rising need for portable diagnostic equipment and an ever-increasing diabetic population.The paper concludes by emphasizing the need for further research and development of glucose biosensors to meet the stringent requirements for sensitivity and specificity imposed by clinical diagnostics while being cost-effective,stable,and durable.展开更多
Electronic textiles hold the merits of high conformability with the human body and natural surrounding,possessing large market demand and wide application foreground in smart wearable and portable devices.However,thei...Electronic textiles hold the merits of high conformability with the human body and natural surrounding,possessing large market demand and wide application foreground in smart wearable and portable devices.However,their further application is largely hindered by the shortage of flexible and stable power sources with multifunctional designability.Herein,a free-standing ZnHCF@CF electrode(ZnHCF grown on carbon nanotube fiber)with good mechanical deformability and high electrochemical performance for aqueous fiber-shaped calcium ion battery(FCIB)is reported.Benefiting from the unique Ca^(2+)/H^(+)co-insertion mechanism,the ZnHCF@CF cathode can exhibit great ion storage capability within a broadened voltage window.By pairing with a polyaniline(PANI)@CF anode,a ZnHCF@CF//PANI@CF FCIB is successfully fabricated,which exhibits a desirable volumetric energy density of 43.2mWh cm^(-3)and maintains superior electrochemical properties under different deformations.Moreover,the high-energy FCIB can be harmoniously integrated with a fiber-shaped strain sensor(FSS)to achieve real-time physiological monitoring on knees during long-running,exhibiting great promise for the practical application of electronic textiles.展开更多
Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional ...Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.展开更多
Thermal management is essential in our body as it affects various bodily functions,ranging from thermal discomfort to serious organ failures,as an example of the worst-case scenario.There have been extensive studies a...Thermal management is essential in our body as it affects various bodily functions,ranging from thermal discomfort to serious organ failures,as an example of the worst-case scenario.There have been extensive studies about wearable materials and devices that augment thermoregulatory functionalities in our body,employing diverse materials and systematic approaches to attaining thermal homeostasis.This paper reviews the recent progress of functional materials and devices that contribute to thermoregulatory wearables,particularly emphasizing the strategic methodology to regulate body temperature.There exist several methods to promote personal thermal management in a wearable form.For instance,we can impede heat transfer using a thermally insulating material with extremely low thermal conductivity or directly cool and heat the skin surface.Thus,we classify many studies into two branches,passive and active thermal management modes,which are further subdivided into specific strategies.Apart from discussing the strategies and their mechanisms,we also identify the weaknesses of each strategy and scrutinize its potential direction that studies should follow to make substantial contributions to future thermal regulatory wearable industries.展开更多
Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome gene...Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome general check-ups. The wearable technique provides a continuous measurement method for health monitoring by tracking a person's physiological data and analyzing it locally or remotely.During the health monitoring process,different kinds of sensors convert physiological signals into electrical or optical signals that can be recorded and transmitted, consequently playing a crucial role in wearable techniques. Wearable application scenarios usually require sensors to possess excellent flexibility and stretchability. Thus, designing flexible and stretchable sensors with reliable performance is the key to wearable technology. Smart composite hydrogels, which have tunable electrical properties, mechanical properties, biocompatibility, and multi-stimulus sensitivity, are one of the best sensitive materials for wearable health monitoring. This review summarizes the common synthetic and performance optimization strategies of smart composite hydrogels and focuses on the current application of smart composite hydrogels in the field of wearable health monitoring.展开更多
Continuous deforming always leads to the performance degradation of a flexible triboelectric nanogenerator due to the Young’s modulus mismatch of different functional layers.In this work,we fabricated a fiber-shaped ...Continuous deforming always leads to the performance degradation of a flexible triboelectric nanogenerator due to the Young’s modulus mismatch of different functional layers.In this work,we fabricated a fiber-shaped stretchable and tailorable triboelectric nanogenerator(FST-TENG)based on the geometric construction of a steel wire as electrode and ingenious selection of silicone rubber as triboelectric layer.Owing to the great robustness and continuous conductivity,the FST-TENGs demonstrate high stability,stretchability,and even tailorability.For a single device with ~6 cm in length and ~3 mm in diameter,the open-circuit voltage of ~59.7 V,transferred charge of ~23.7 nC,short-circuit current of ~2.67 μA and average power of ~2.13 μW can be obtained at 2.5 Hz.By knitting several FST-TENGs to be a fabric or a bracelet,it enables to harvest human motion energy and then to drive a wearable electronic device.Finally,it can also be woven on dorsum of glove to monitor the movements of gesture,which can recognize every single finger,different bending angle,and numbers of bent finger by analyzing voltage signals.展开更多
Wearable strain sensors are arousing increasing research interests in recent years on account of their potentials in motion detection,personal and public healthcare,future entertainment,man-machine interaction,artific...Wearable strain sensors are arousing increasing research interests in recent years on account of their potentials in motion detection,personal and public healthcare,future entertainment,man-machine interaction,artificial intelligence,and so forth.Much research has focused on fiber-based sensors due to the appealing performance of fibers,including processing flexibility,wearing comfortability,outstanding lifetime and serviceability,low-cost and large-scale capacity.Herein,we review the latest advances in functionalization and device fabrication of fiber materials toward applications in fiber-based wearable strain sensors.We describe the approaches for preparing conductive fibers such as spinning,surface modification,and structural transformation.We also introduce the fabrication and sensing mechanisms of state-of-the-art sensors and analyze their merits and demerits.The applications toward motion detection,healthcare,man-machine interaction,future entertainment,and multifunctional sensing are summarized with typical examples.We finally critically analyze tough challenges and future remarks of fiber-based strain sensors,aiming to implement them in real applications.展开更多
Phase change materials have a key role for wearable thermal management,but suffer from poor water vapor permeability,low enthalpy value and weak shape stability caused by liquid phase leakage and intrinsic rigidity of...Phase change materials have a key role for wearable thermal management,but suffer from poor water vapor permeability,low enthalpy value and weak shape stability caused by liquid phase leakage and intrinsic rigidity of solid–liquid phase change materials.Herein,we report for the first time a versatile strategy for designed assembly of high-enthalpy flexible phase change nonwovens(GB-PCN)by wet-spinning hybrid grapheneboron nitride(GB)fiber and subsequent impregnating paraffins(e.g.,eicosane,octadecane).As a result,our GB-PCN exhibited an unprecedented enthalpy value of 206.0 J g^(−1),excellent thermal reliability and anti-leakage capacity,superb thermal cycling ability of 97.6%after 1000 cycles,and ultrahigh water vapor permeability(close to the cotton),outperforming the reported PCM films and fibers to date.Notably,the wearable thermal management systems based on GB-PCN for both clothing and face mask were demonstrated,which can maintain the human body at a comfortable temperature range for a significantly long time.Therefore,our results demonstrate huge potential of GB-PCN for human-wearable passive thermal management in real scenarios.展开更多
Inspired by the sophisticated artificial leather garment industry and toward enhancing wearability of energy storage devices, we demonstrate a polyurethane artificial leather supercapacitor with large sheet electrodes...Inspired by the sophisticated artificial leather garment industry and toward enhancing wearability of energy storage devices, we demonstrate a polyurethane artificial leather supercapacitor with large sheet electrodes embedded in theleather layer simultaneously working as a polyelectrolyte. This design totally reserves textiles underneath and thus addresses the well-known challenge of wearing comfortability. It provides a revolutionary configuration of wearable supercapacitors: the artificial leather on garment is also a supercapacitor.Unlike the polyvinyl alcohol-based acidic electrolytes, which are widely used, sodium chloride is used to modify the intrinsically fluorescent polyurethane leather for ionic transportation, which has no harm to human. The fluorescent leather supercapacitor is easily transferrable from any arbitrary substrates to form various patterns, enabling multifunctionalities of practical wearability, fashion, and energy storage.展开更多
Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applicatio...Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications.Existing schemes are limited by flexibility,biosafety,and manufacturing costs,which create large barriers for wider applications.Here,we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface,robustness of microneedles to penetrate the skin without fracture,and a simplified process to allow mass production.The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording.The normalized electrode–skin contact impedance reaches 0.98 kΩcm^(2)at 1 kHz and 1.50 kΩcm^(2)at 10 Hz,a record low value compared to previous reports and approximately 1/250 of the standard electrodes.The morphology,biosafety,and electrical/mechanical properties are fully characterized,and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized.The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording(over 8 h per night),providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.展开更多
Wearable smart devices, such as smart watch, wristband are becoming increasingly popular recently. They generally integrate the MEMS-designed inertial sensors, including accelerometer, gyroscope and compass, which pro...Wearable smart devices, such as smart watch, wristband are becoming increasingly popular recently. They generally integrate the MEMS-designed inertial sensors, including accelerometer, gyroscope and compass, which provide a convenient and inexpensive way to collect motion data of users. Such rich, continuous motion data provide great potential for remote healthcare and decease diagnosis. Information processing algorithms play the critical role in these approaches, which is to extract the motion signatures and to access different kinds of judgements. This paper reviews key algorithms in these areas. In particular, we focus on three kinds of applications: 1) gait analysis; 2) fall detection and 3) sleep monitoring. They are the most popular healthcare applications based on the inertial data. By categorizing and introducing the key algorithms, this paper tries to build a clear map of how the inertial data are processed; how the inertial signatures are defined, extracted, and utilized in different kinds of applications. This will provide a valuable guidance for users to understand the methodologies and to select proper algorithm for specifi c application purpose.展开更多
Breathing is an inherent human activity;however,the composition of the air we inhale and gas exhale remains unknown to us.To address this,wearable vapor sensors can help people monitor air composition in real time to ...Breathing is an inherent human activity;however,the composition of the air we inhale and gas exhale remains unknown to us.To address this,wearable vapor sensors can help people monitor air composition in real time to avoid underlying risks,and for the early detection and treatment of diseases for home healthcare.Hydrogels with three-dimensional polymer networks and large amounts of water molecules are naturally flexible and stretchable.Functionalized hydrogels are intrinsically conductive,self-healing,self-adhesive,biocompatible,and room-temperature sensitive.Compared with traditional rigid vapor sensors,hydrogel-based gas and humidity sensors can directly fit human skin or clothing,and are more suitable for real-time monitoring of personal health and safety.In this review,current studies on hydrogel-based vapor sensors are investigated.The required properties and optimization methods of wearable hydrogel-based sensors are introduced.Subsequently,existing reports on the response mechanisms of hydrogel-based gas and humidity sensors are summarized.Related works on hydrogel-based vapor sensors for their application in personal health and safety monitoring are presented.Moreover,the potential of hydrogels in the field of vapor sensing is elucidated.Finally,the current research status,challenges,and future trends of hydrogel gas/humidity sensing are discussed.展开更多
With the rapid development of the Internet of Things and flexible electronic technologies,there is a growing demand for wireless,sustainable,multifunctional,and independently operating self-powered wearable devices.Ne...With the rapid development of the Internet of Things and flexible electronic technologies,there is a growing demand for wireless,sustainable,multifunctional,and independently operating self-powered wearable devices.Nevertheless,structural flexibility,long operating time,and wearing comfort have become key requirements for the widespread adoption of wearable electronics.Triboelectric nanogenerators as a distributed energy harvesting technology have great potential for application development in wearable sensing.Compared with rigid electronics,cellulosic self-powered wearable electronics have significant advantages in terms of flexibility,breathability,and functionality.In this paper,the research progress of advanced cellulosic triboelectric materials for self-powered wearable electronics is reviewed.The interfacial characteristics of cellulose are introduced from the top-down,bottom-up,and interfacial characteristics of the composite material preparation process.Meanwhile,the modulation strategies of triboelectric properties of cellulosic triboelectric materials are presented.Furthermore,the design strategies of triboelectric materials such as surface functionalization,interfacial structure design,and vacuum-assisted self-assembly are systematically discussed.In particular,cellulosic self-powered wearable electronics in the fields of human energy harvesting,tactile sensing,health monitoring,human–machine interaction,and intelligent fire warning are outlined in detail.Finally,the current challenges and future development directions of cellulosic triboelectric materials for self-powered wearable electronics are discussed.展开更多
Metal organic frameworks(MOFs) have been considered as compelling precursor for miscellaneous applications. However, their unsatisfied electrocatalytic performance limits their direct application as electrocatalyst. H...Metal organic frameworks(MOFs) have been considered as compelling precursor for miscellaneous applications. However, their unsatisfied electrocatalytic performance limits their direct application as electrocatalyst. Herein, by incorporating the cobalt-oxide bonds and polyaniline(PANI) with two-dimension zeolitic imidazolate frameworks(ZIFs), a novel bifunctional catalyst(Co-O-ZIF/PANI) for Zn-air battery was designed based on a facile and eco-friendly method. This Co-O-ZIF/PANI with optimized surface adsorption effect and suitable Co^(3+)/Co^(2+)ratio, exhibits eminent electrocatalytic activity toward both oxygen reduction and evolution reaction. The as-assembled liquid ZABs based on Co-O-ZIF/PANI achieves a remarkable maximum power density of 123.1 m W cm^(-2) and low discharge-charge voltage gap of 0.81 V at 5 m A cm^(-2) for over 300 cycles. Operando Raman spectroscopy reveals that the excellent performance origins from the optimized surface chemisorption property of O_(2) and H_(2)O brought by Co–O bonds and PANI. This work provides a novel prospect to develop efficient MOF derived bifunctional electrocatalysts by optimizing surface chemisorption properties.展开更多
Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a ...Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a delicate design of the highly wearable embroidered supercapacitors made from the conductive fibers composited.By rendering the conductive interdigitally patterned embroidery as both the current collector and skeleton for the SCs,the novel pseudocapacitive material cobalt phosphides were then successfully electrodeposited,forming the first flexible and wearable in-plane embroidery SCs.The electrochemical measurements manifested that the highest specific capacitance was nearly 156.6 mF cm?2(65.72 F g?1)at the current density of 0.6 mA cm?2(0.25 A g?1),with a high energy density of 0.013 mWh cm?2(5.55 Wh kg?1)at a power density of 0.24 mW cm?2(100 W kg?1).As a demonstration,a monogrammed pattern was ingeniously designed and embroidered on the laboratory gown as the wearable in-plane SCs,which showed both decent electrochemical performance and excellent flexibility.展开更多
Transition metal-nitrogen-carbon materials(M-N-Cs),particularly Fe-N-Cs,have been found to be electroactive for accelerating oxygen reduction reaction(ORR)kinetics.Although substantial efforts have been devoted to des...Transition metal-nitrogen-carbon materials(M-N-Cs),particularly Fe-N-Cs,have been found to be electroactive for accelerating oxygen reduction reaction(ORR)kinetics.Although substantial efforts have been devoted to design Fe-N-Cs with increased active species content,surface area,and electronic conductivity,their performance is still far from satisfactory.Hitherto,there is limited research about regulation on the electronic spin states of Fe centers for Fe-N-Cs electrocatalysts to improve their catalytic performance.Here,we introduce Ti_(3)C_(2) MXene with sulfur terminals to regulate the electronic configuration of FeN_(4) species and dramatically enhance catalytic activity toward ORR.The MXene with sulfur terminals induce the spin-state transition of FeN_(4) species and Fe 3d electron delocalization with d band center upshift,enabling the Fe(II)ions to bind oxygen in the end-on adsorption mode favorable to initiate the reduction of oxygen and boosting oxygen-containing groups adsorption on FeN_(4) species and ORR kinetics.The resulting FeN_(4)-Ti_(3)C_(2)Sx exhibits comparable catalytic performance to those of commercial Pt-C.The developed wearable ZABs using FeN_(4)-Ti_(3)C_(2)Sx also exhibit fast kinetics and excellent stability.This study confirms that regulation of the electronic structure of active species via coupling with their support can be a major contributor to enhance their catalytic activity.展开更多
Phase change materials(PCMs)are a highly promising candidate for thermal energy storage owing to their large latent heat and chemical stability.However,their intrinsic brittle induces poor flexibility and low mechanic...Phase change materials(PCMs)are a highly promising candidate for thermal energy storage owing to their large latent heat and chemical stability.However,their intrinsic brittle induces poor flexibility and low mechanical strength,which limits them use for wearable thermal management.And,the electrical insulation and weak solar absorption make them lack multi-responsive capability.Herein,we report a facile strategy to synthesize mechanically strong and flexible multi-responsive phase change films by stirring an aqueous dispersion of cellulose nanofibrils(CNFs),MXene(Ti_(2)C_(3))nanosheets,and polyethylene glycol(PEG),followed by air-drying self-assembly and coating with hydrophobic fluorocarbon.The hydrogen bonds and nacre-mimetic synergistic toughening networks formed by ternary CNFs,Ti_(2)C_(3)nanosheets,and PEG endow films with high mechanical strength(16.7 MPa)and strain(10.4%),which are 18.6 and 8.7 times higher than those of pure PEG film,respectively.The films exhibit outstanding flexibility and do not crack or fracture even when bent,twisted,and folded into a complex small boat.Meanwhile,the laminar structure formed by the self-assembly Ti_(3)C_(2)nanosheets enhances electrical conductivity(3.95 S/m)and solar absorption,affording excellent electro-thermal(68.3%–81.0%)and solarthermal(85.6%–90.6%)conversion efficiency,thus achieving multi-response to external stimuli(electron/solar radiation).In addition,the as-prepared films also deliver large latent heat(136.1 J/g),outstanding cyclic and shape stability,leak-free encapsulation even under compressed at above 5000 times its weight,excellent hydrophobicity(131.4°),and self-cleaning function.This work paves the way for developing flexible,mechanically strong,and self-cleaning phase change film with multi-responsive function for wearable thermal management devices under high humidity condition.展开更多
基金the Talent Management Project of Prince of Songkla University
文摘Wearable sensing systems have been designed to monitor health conditions in real-time by detecting analytes in human biofluids.Wound diagnosis remains challenging,necessitating suitable materials for high-performance wearable sensors to offer prompt feedback.Existing devices have limitations in measuring pH and the concentration of pH-dependent electroactive species simultaneously,which is crucial for obtaining a comprehensive understanding of wound status and optimizing biosensors.Therefore,improving materials and analysis system accuracy is essential.This article introduces the first example of a flexible array capable of detecting pyocyanin,a bacterial virulence factor,while correcting dynamic pH fluctuations.We demonstrate that this combined sensor enhances accuracy by mitigating the impact of pH variability on pyocyanin sensor response.Customized screen-printable inks were developed to enhance analytical performance.The analytical performances of two sensitive sensor systems(i.e.,fully-printed porous graphene/multiwalled carbon nanotube(CNT)and polyaniline/CNT composites for pyocyanin and pH sensors)are evaluated.Partial least square regression is employed to analyze nonzero-order data arrays from square wave voltammetric and potentiometric measurements of pyocyanin and pH sensors to establish a predictive model for pyocyanin concentration in complex fluids.This sensitive and effective strategy shows potential for personalized applications due to its affordability,ease of use,and ability to adjust for dynamic pH changes.
基金supported by the Research Grant Fund from Kwangwoon University in 2023,the National Natural Science Foundation of China under Grant(62311540155)the Taishan Scholars Project Special Funds(tsqn202312035)the open research foundation of State Key Laboratory of Integrated Chips and Systems.
文摘Wearable wristband systems leverage deep learning to revolutionize hand gesture recognition in daily activities.Unlike existing approaches that often focus on static gestures and require extensive labeled data,the proposed wearable wristband with selfsupervised contrastive learning excels at dynamic motion tracking and adapts rapidly across multiple scenarios.It features a four-channel sensing array composed of an ionic hydrogel with hierarchical microcone structures and ultrathin flexible electrodes,resulting in high-sensitivity capacitance output.Through wireless transmission from a Wi-Fi module,the proposed algorithm learns latent features from the unlabeled signals of random wrist movements.Remarkably,only few-shot labeled data are sufficient for fine-tuning the model,enabling rapid adaptation to various tasks.The system achieves a high accuracy of 94.9%in different scenarios,including the prediction of eight-direction commands,and air-writing of all numbers and letters.The proposed method facilitates smooth transitions between multiple tasks without the need for modifying the structure or undergoing extensive task-specific training.Its utility has been further extended to enhance human–machine interaction over digital platforms,such as game controls,calculators,and three-language login systems,offering users a natural and intuitive way of communication.
基金the Defense Institute of Advanced Technology,Pune(DIAT,Pune)IIT Delhi。
文摘The study projects a flexible and compact wearable pear-shaped Super High Frequency(SHF)antenna that can provide detailed location recognition and tracking applicable to defense beacon technology.This mini aperture with electrical dimensions of 0.12λ_(0)×0.22λ_(0)×0.01λ_(0)attains a vast bandwidth over 3.1-34.5 GHz Super High Frequency(SHF)frequency band at S_(11)≤-10 dB,peak gain of 7.14 dBi and proportionately homogeneous radiation pattern.The fractional bandwidth(%BW)acquired is 168%that envelopes diversified frequency spectrum inclusive of X band specifically targeted to all kinds of defense and military operations.The proposed antenna can be worn on a soldier's uniform and hence the Specific Absorption Rate simulation is accomplished.The Peak SAR Value over 1 g of tissue is 1.48 W/kg and for 10 g of tissue is 0.27 W/kg well under the safety standards.The flexibility is proven by analyzing the full electromagnetic simulations for various bending conditions.Time response analysis is attained with its Fidelity Factor and Group Delay.Communication excellence is determined using Link Budget Analysis and it is seen that margin at 100 Mbps is 62 m and at 200 Mbps is 59 m.Prototype is fabricated along with experimental validation.All the results show harmony in shaping the antenna to provide critical situational awareness and data sharing capabilities required in defense beacon technology for location identification.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (No.2022M3J7A1062940,2021R1A5A6002853,and 2021R1A2C3011585)supported by the Technology Innovation Program (20015577)funded by the Ministry of Trade,Industry&Energy (MOTIE,Korea)。
文摘This review explores glucose monitoring and management strategies,emphasizing the need for reliable and userfriendly wearable sensors that are the next generation of sensors for continuous glucose detection.In addition,examines key strategies for designing glucose sensors that are multi-functional,reliable,and cost-effective in a variety of contexts.The unique features of effective diabetes management technology are highlighted,with a focus on using nano/biosensor devices that can quickly and accurately detect glucose levels in the blood,improving patient treatment and control of potential diabetes-related infections.The potential of next-generation wearable and touch-sensitive nano biomedical sensor engineering designs for providing full control in assessing implantable,continuous glucose monitoring is also explored.The challenges of standardizing drug or insulin delivery doses,low-cost,real-time detection of increased blood sugar levels in diabetics,and early digital health awareness controls for the adverse effects of injectable medication are identified as unmet needs.Also,the market for biosensors is expected to expand significantly due to the rising need for portable diagnostic equipment and an ever-increasing diabetic population.The paper concludes by emphasizing the need for further research and development of glucose biosensors to meet the stringent requirements for sensitivity and specificity imposed by clinical diagnostics while being cost-effective,stable,and durable.
基金partially supported by the Natural Science Foundation of Liaoning Province(2023-MS-115)the Large Instrument and Equipment Open Foundation of Dalian University of Technology+1 种基金the National Natural Science Foundation of China(22308261)funding from the Fundamental Research Funds for the Central Universities,conducted at Tongji University。
文摘Electronic textiles hold the merits of high conformability with the human body and natural surrounding,possessing large market demand and wide application foreground in smart wearable and portable devices.However,their further application is largely hindered by the shortage of flexible and stable power sources with multifunctional designability.Herein,a free-standing ZnHCF@CF electrode(ZnHCF grown on carbon nanotube fiber)with good mechanical deformability and high electrochemical performance for aqueous fiber-shaped calcium ion battery(FCIB)is reported.Benefiting from the unique Ca^(2+)/H^(+)co-insertion mechanism,the ZnHCF@CF cathode can exhibit great ion storage capability within a broadened voltage window.By pairing with a polyaniline(PANI)@CF anode,a ZnHCF@CF//PANI@CF FCIB is successfully fabricated,which exhibits a desirable volumetric energy density of 43.2mWh cm^(-3)and maintains superior electrochemical properties under different deformations.Moreover,the high-energy FCIB can be harmoniously integrated with a fiber-shaped strain sensor(FSS)to achieve real-time physiological monitoring on knees during long-running,exhibiting great promise for the practical application of electronic textiles.
基金supported by the National Natural Science Foundation of China under(Grant No.52175531)in part by the Science and Technology Research Program of Chongqing Municipal Education Commission under Grant(Grant Nos.KJQN202000605 and KJZD-M202000602)。
文摘Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.
基金supported by the National Research Foundation of Korea(NRF)Grant funded through Basic Science Research Program(2021M3H4A1A02050237).
文摘Thermal management is essential in our body as it affects various bodily functions,ranging from thermal discomfort to serious organ failures,as an example of the worst-case scenario.There have been extensive studies about wearable materials and devices that augment thermoregulatory functionalities in our body,employing diverse materials and systematic approaches to attaining thermal homeostasis.This paper reviews the recent progress of functional materials and devices that contribute to thermoregulatory wearables,particularly emphasizing the strategic methodology to regulate body temperature.There exist several methods to promote personal thermal management in a wearable form.For instance,we can impede heat transfer using a thermally insulating material with extremely low thermal conductivity or directly cool and heat the skin surface.Thus,we classify many studies into two branches,passive and active thermal management modes,which are further subdivided into specific strategies.Apart from discussing the strategies and their mechanisms,we also identify the weaknesses of each strategy and scrutinize its potential direction that studies should follow to make substantial contributions to future thermal regulatory wearable industries.
基金financial support from the National Natural Science Foundation of China (No. 61801525)the Guangdong Basic and Applied Basic Research Foundation (Nos. 2020A1515010693, 2021A1515110269)+1 种基金the Fundamental Research Funds for the Central Universities, Sun Yatsen University (No. 22lgqb17)the Independent Fund of the State Key Laboratory of Optoelectronic Materials and Technologies (Sun Yat-sen University) under grant No. OEMT-2022-ZRC-05。
文摘Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome general check-ups. The wearable technique provides a continuous measurement method for health monitoring by tracking a person's physiological data and analyzing it locally or remotely.During the health monitoring process,different kinds of sensors convert physiological signals into electrical or optical signals that can be recorded and transmitted, consequently playing a crucial role in wearable techniques. Wearable application scenarios usually require sensors to possess excellent flexibility and stretchability. Thus, designing flexible and stretchable sensors with reliable performance is the key to wearable technology. Smart composite hydrogels, which have tunable electrical properties, mechanical properties, biocompatibility, and multi-stimulus sensitivity, are one of the best sensitive materials for wearable health monitoring. This review summarizes the common synthetic and performance optimization strategies of smart composite hydrogels and focuses on the current application of smart composite hydrogels in the field of wearable health monitoring.
基金supported by National Natural Science Foundation of China (NSFC) (No. 61804103)National Key R&D Program of China (No. 2017YFA0205002)+8 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Nos. 18KJA535001 and 14KJB 150020)Natural Science Foundation of Jiangsu Province of China (Nos. BK20170343 and BK20180242)China Postdoctoral Science Foundation (No. 2017M610346)State Key Laboratory of Silicon Materials, Zhejiang University (No. SKL2018-03)Nantong Municipal Science and Technology Program (No. GY12017001)Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University (KSL201803)supported by Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices
文摘Continuous deforming always leads to the performance degradation of a flexible triboelectric nanogenerator due to the Young’s modulus mismatch of different functional layers.In this work,we fabricated a fiber-shaped stretchable and tailorable triboelectric nanogenerator(FST-TENG)based on the geometric construction of a steel wire as electrode and ingenious selection of silicone rubber as triboelectric layer.Owing to the great robustness and continuous conductivity,the FST-TENGs demonstrate high stability,stretchability,and even tailorability.For a single device with ~6 cm in length and ~3 mm in diameter,the open-circuit voltage of ~59.7 V,transferred charge of ~23.7 nC,short-circuit current of ~2.67 μA and average power of ~2.13 μW can be obtained at 2.5 Hz.By knitting several FST-TENGs to be a fabric or a bracelet,it enables to harvest human motion energy and then to drive a wearable electronic device.Finally,it can also be woven on dorsum of glove to monitor the movements of gesture,which can recognize every single finger,different bending angle,and numbers of bent finger by analyzing voltage signals.
基金supported by the EU Horizon 2020 through project ETEXWELD-H2020-MSCA-RISE-2014(Grant No.644268)The University of Manchester through UMRI project“Graphene-Smart Textiles E-Healthcare Network”(AA14512)National Natural Science Foundation of China(No.22075046).
文摘Wearable strain sensors are arousing increasing research interests in recent years on account of their potentials in motion detection,personal and public healthcare,future entertainment,man-machine interaction,artificial intelligence,and so forth.Much research has focused on fiber-based sensors due to the appealing performance of fibers,including processing flexibility,wearing comfortability,outstanding lifetime and serviceability,low-cost and large-scale capacity.Herein,we review the latest advances in functionalization and device fabrication of fiber materials toward applications in fiber-based wearable strain sensors.We describe the approaches for preparing conductive fibers such as spinning,surface modification,and structural transformation.We also introduce the fabrication and sensing mechanisms of state-of-the-art sensors and analyze their merits and demerits.The applications toward motion detection,healthcare,man-machine interaction,future entertainment,and multifunctional sensing are summarized with typical examples.We finally critically analyze tough challenges and future remarks of fiber-based strain sensors,aiming to implement them in real applications.
基金supported by the National Natural Science Foundation of China(Nos.21903082,22003065,22125903,51872283,22075279,21805273,22273100)Dalian Innovation Support Plan for High Level Talents(2019RT09)+3 种基金Dalian National Laboratory For Clean Energy(DNL),CAS,DNL Cooperation Fund,CAS(DNL201912,DNL201915,DNL202016,DNL202019)DICP(DICP I2020032,DICP I202036,I202218)The Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(YLU-DNL Fund 2021002,YLU-DNL 2021007,YLU-DNL 2021009)Q.Shi would like to thank Dalian Outstanding Young Scientific Talent Program(Grant 2019RJ10).
文摘Phase change materials have a key role for wearable thermal management,but suffer from poor water vapor permeability,low enthalpy value and weak shape stability caused by liquid phase leakage and intrinsic rigidity of solid–liquid phase change materials.Herein,we report for the first time a versatile strategy for designed assembly of high-enthalpy flexible phase change nonwovens(GB-PCN)by wet-spinning hybrid grapheneboron nitride(GB)fiber and subsequent impregnating paraffins(e.g.,eicosane,octadecane).As a result,our GB-PCN exhibited an unprecedented enthalpy value of 206.0 J g^(−1),excellent thermal reliability and anti-leakage capacity,superb thermal cycling ability of 97.6%after 1000 cycles,and ultrahigh water vapor permeability(close to the cotton),outperforming the reported PCM films and fibers to date.Notably,the wearable thermal management systems based on GB-PCN for both clothing and face mask were demonstrated,which can maintain the human body at a comfortable temperature range for a significantly long time.Therefore,our results demonstrate huge potential of GB-PCN for human-wearable passive thermal management in real scenarios.
基金Funding of Harbin Institute of Technology (Shenzhen) (DD45001015)NSFC/RGC Joint Research Scheme (Project N_City U123/15)+2 种基金the Science Technology and Innovation Committee of Shenzhen Municipality (JCYJ20130401145617276 and R-IND4903)City University of Hong Kong (PJ7004645)the Hong Kong Polytechnic University (1-BBA3) supported this work
文摘Inspired by the sophisticated artificial leather garment industry and toward enhancing wearability of energy storage devices, we demonstrate a polyurethane artificial leather supercapacitor with large sheet electrodes embedded in theleather layer simultaneously working as a polyelectrolyte. This design totally reserves textiles underneath and thus addresses the well-known challenge of wearing comfortability. It provides a revolutionary configuration of wearable supercapacitors: the artificial leather on garment is also a supercapacitor.Unlike the polyvinyl alcohol-based acidic electrolytes, which are widely used, sodium chloride is used to modify the intrinsically fluorescent polyurethane leather for ionic transportation, which has no harm to human. The fluorescent leather supercapacitor is easily transferrable from any arbitrary substrates to form various patterns, enabling multifunctionalities of practical wearability, fashion, and energy storage.
基金supported by the China Capital Health Research and Development of Special (No. 2018-14111)the National Natural Science Foundation of China (grant No. 62004007 and No. 82027805)the China Postdoctoral Science Foundation Grant (No. 2021M700258)
文摘Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications.Existing schemes are limited by flexibility,biosafety,and manufacturing costs,which create large barriers for wider applications.Here,we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface,robustness of microneedles to penetrate the skin without fracture,and a simplified process to allow mass production.The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording.The normalized electrode–skin contact impedance reaches 0.98 kΩcm^(2)at 1 kHz and 1.50 kΩcm^(2)at 10 Hz,a record low value compared to previous reports and approximately 1/250 of the standard electrodes.The morphology,biosafety,and electrical/mechanical properties are fully characterized,and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized.The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording(over 8 h per night),providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.
基金supported in part by National Natural Science Foundation of China Grant 61202360, 61033001, 61361136003the National Basic Research Program of China Grant 2011CBA00300, 2011CBA00302
文摘Wearable smart devices, such as smart watch, wristband are becoming increasingly popular recently. They generally integrate the MEMS-designed inertial sensors, including accelerometer, gyroscope and compass, which provide a convenient and inexpensive way to collect motion data of users. Such rich, continuous motion data provide great potential for remote healthcare and decease diagnosis. Information processing algorithms play the critical role in these approaches, which is to extract the motion signatures and to access different kinds of judgements. This paper reviews key algorithms in these areas. In particular, we focus on three kinds of applications: 1) gait analysis; 2) fall detection and 3) sleep monitoring. They are the most popular healthcare applications based on the inertial data. By categorizing and introducing the key algorithms, this paper tries to build a clear map of how the inertial data are processed; how the inertial signatures are defined, extracted, and utilized in different kinds of applications. This will provide a valuable guidance for users to understand the methodologies and to select proper algorithm for specifi c application purpose.
基金Jin Wu acknowledges financial support from the National Natural Science Foundation of China(No.61801525)the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010693)+1 种基金the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.22lgqb17)the Independent Fund of the State Key Laboratory of Optoelectronic Materials and Technologies(Sun Yat-sen University)under grant No.OEMT-2022-ZRC-05.
文摘Breathing is an inherent human activity;however,the composition of the air we inhale and gas exhale remains unknown to us.To address this,wearable vapor sensors can help people monitor air composition in real time to avoid underlying risks,and for the early detection and treatment of diseases for home healthcare.Hydrogels with three-dimensional polymer networks and large amounts of water molecules are naturally flexible and stretchable.Functionalized hydrogels are intrinsically conductive,self-healing,self-adhesive,biocompatible,and room-temperature sensitive.Compared with traditional rigid vapor sensors,hydrogel-based gas and humidity sensors can directly fit human skin or clothing,and are more suitable for real-time monitoring of personal health and safety.In this review,current studies on hydrogel-based vapor sensors are investigated.The required properties and optimization methods of wearable hydrogel-based sensors are introduced.Subsequently,existing reports on the response mechanisms of hydrogel-based gas and humidity sensors are summarized.Related works on hydrogel-based vapor sensors for their application in personal health and safety monitoring are presented.Moreover,the potential of hydrogels in the field of vapor sensing is elucidated.Finally,the current research status,challenges,and future trends of hydrogel gas/humidity sensing are discussed.
基金supported by the National Natural Science Foundation of China(22278091).
文摘With the rapid development of the Internet of Things and flexible electronic technologies,there is a growing demand for wireless,sustainable,multifunctional,and independently operating self-powered wearable devices.Nevertheless,structural flexibility,long operating time,and wearing comfort have become key requirements for the widespread adoption of wearable electronics.Triboelectric nanogenerators as a distributed energy harvesting technology have great potential for application development in wearable sensing.Compared with rigid electronics,cellulosic self-powered wearable electronics have significant advantages in terms of flexibility,breathability,and functionality.In this paper,the research progress of advanced cellulosic triboelectric materials for self-powered wearable electronics is reviewed.The interfacial characteristics of cellulose are introduced from the top-down,bottom-up,and interfacial characteristics of the composite material preparation process.Meanwhile,the modulation strategies of triboelectric properties of cellulosic triboelectric materials are presented.Furthermore,the design strategies of triboelectric materials such as surface functionalization,interfacial structure design,and vacuum-assisted self-assembly are systematically discussed.In particular,cellulosic self-powered wearable electronics in the fields of human energy harvesting,tactile sensing,health monitoring,human–machine interaction,and intelligent fire warning are outlined in detail.Finally,the current challenges and future development directions of cellulosic triboelectric materials for self-powered wearable electronics are discussed.
基金financially supported by the National Natural Science Foundation of China (51772135 and 51872124)the Ministry of Education of China (6141A02022516)+6 种基金the Natural Science Foundation of Guangdong Province (2014A030306010)the Natural Science Foundation of Guangdong Province (2021A1515010504)the Natural Science Key Foundation of Guangdong Province (2019B1515120056)the Natural Science Foundation of Guangzhou (201904010049)the Jinan University (88016105)the Innovation Team Project of Foshan City (FS0AA-KJ919-4402-0086)the Fundamental Research Foundation for the Central Universities(21617326 and 11619103)。
文摘Metal organic frameworks(MOFs) have been considered as compelling precursor for miscellaneous applications. However, their unsatisfied electrocatalytic performance limits their direct application as electrocatalyst. Herein, by incorporating the cobalt-oxide bonds and polyaniline(PANI) with two-dimension zeolitic imidazolate frameworks(ZIFs), a novel bifunctional catalyst(Co-O-ZIF/PANI) for Zn-air battery was designed based on a facile and eco-friendly method. This Co-O-ZIF/PANI with optimized surface adsorption effect and suitable Co^(3+)/Co^(2+)ratio, exhibits eminent electrocatalytic activity toward both oxygen reduction and evolution reaction. The as-assembled liquid ZABs based on Co-O-ZIF/PANI achieves a remarkable maximum power density of 123.1 m W cm^(-2) and low discharge-charge voltage gap of 0.81 V at 5 m A cm^(-2) for over 300 cycles. Operando Raman spectroscopy reveals that the excellent performance origins from the optimized surface chemisorption property of O_(2) and H_(2)O brought by Co–O bonds and PANI. This work provides a novel prospect to develop efficient MOF derived bifunctional electrocatalysts by optimizing surface chemisorption properties.
基金The Hong Kong Polytechnic University for the funding support(Nos.1-YW1B,G-YBV2,and G-UACC).
文摘Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a delicate design of the highly wearable embroidered supercapacitors made from the conductive fibers composited.By rendering the conductive interdigitally patterned embroidery as both the current collector and skeleton for the SCs,the novel pseudocapacitive material cobalt phosphides were then successfully electrodeposited,forming the first flexible and wearable in-plane embroidery SCs.The electrochemical measurements manifested that the highest specific capacitance was nearly 156.6 mF cm?2(65.72 F g?1)at the current density of 0.6 mA cm?2(0.25 A g?1),with a high energy density of 0.013 mWh cm?2(5.55 Wh kg?1)at a power density of 0.24 mW cm?2(100 W kg?1).As a demonstration,a monogrammed pattern was ingeniously designed and embroidered on the laboratory gown as the wearable in-plane SCs,which showed both decent electrochemical performance and excellent flexibility.
基金supported by a Grant of the Innovation and Technology Commission of Hong Kong(Project number:ITS/461/18)City University of Hong Kong(Project number:9678179).
文摘Transition metal-nitrogen-carbon materials(M-N-Cs),particularly Fe-N-Cs,have been found to be electroactive for accelerating oxygen reduction reaction(ORR)kinetics.Although substantial efforts have been devoted to design Fe-N-Cs with increased active species content,surface area,and electronic conductivity,their performance is still far from satisfactory.Hitherto,there is limited research about regulation on the electronic spin states of Fe centers for Fe-N-Cs electrocatalysts to improve their catalytic performance.Here,we introduce Ti_(3)C_(2) MXene with sulfur terminals to regulate the electronic configuration of FeN_(4) species and dramatically enhance catalytic activity toward ORR.The MXene with sulfur terminals induce the spin-state transition of FeN_(4) species and Fe 3d electron delocalization with d band center upshift,enabling the Fe(II)ions to bind oxygen in the end-on adsorption mode favorable to initiate the reduction of oxygen and boosting oxygen-containing groups adsorption on FeN_(4) species and ORR kinetics.The resulting FeN_(4)-Ti_(3)C_(2)Sx exhibits comparable catalytic performance to those of commercial Pt-C.The developed wearable ZABs using FeN_(4)-Ti_(3)C_(2)Sx also exhibit fast kinetics and excellent stability.This study confirms that regulation of the electronic structure of active species via coupling with their support can be a major contributor to enhance their catalytic activity.
基金financial support by the Programme of Introducing Talents of Discipline to Universities(Project 111,B21022)the National Natural Science Foundation of China(22108014)the Beijing Nova Program(Z211100002121084)。
文摘Phase change materials(PCMs)are a highly promising candidate for thermal energy storage owing to their large latent heat and chemical stability.However,their intrinsic brittle induces poor flexibility and low mechanical strength,which limits them use for wearable thermal management.And,the electrical insulation and weak solar absorption make them lack multi-responsive capability.Herein,we report a facile strategy to synthesize mechanically strong and flexible multi-responsive phase change films by stirring an aqueous dispersion of cellulose nanofibrils(CNFs),MXene(Ti_(2)C_(3))nanosheets,and polyethylene glycol(PEG),followed by air-drying self-assembly and coating with hydrophobic fluorocarbon.The hydrogen bonds and nacre-mimetic synergistic toughening networks formed by ternary CNFs,Ti_(2)C_(3)nanosheets,and PEG endow films with high mechanical strength(16.7 MPa)and strain(10.4%),which are 18.6 and 8.7 times higher than those of pure PEG film,respectively.The films exhibit outstanding flexibility and do not crack or fracture even when bent,twisted,and folded into a complex small boat.Meanwhile,the laminar structure formed by the self-assembly Ti_(3)C_(2)nanosheets enhances electrical conductivity(3.95 S/m)and solar absorption,affording excellent electro-thermal(68.3%–81.0%)and solarthermal(85.6%–90.6%)conversion efficiency,thus achieving multi-response to external stimuli(electron/solar radiation).In addition,the as-prepared films also deliver large latent heat(136.1 J/g),outstanding cyclic and shape stability,leak-free encapsulation even under compressed at above 5000 times its weight,excellent hydrophobicity(131.4°),and self-cleaning function.This work paves the way for developing flexible,mechanically strong,and self-cleaning phase change film with multi-responsive function for wearable thermal management devices under high humidity condition.
