On Mechanism of The Effect of Rare Earth on Wearability of Nickel Base Self-Fluxing Alloy Spray-Welding Layers

The mechansim of the effect of rare earth(RE)on wearability of spray-welding layers has been investi- gated by adding RE in ppm into Nickel base self-fluxing alloy powder.The test results show that the microalloy- ing effect of RE can refine the structure of spray-welding layers,and change the amount,size,shape and distri- bution of hard phase in spray-welding layers.The wearability of spray-welding layers is increased consequently.

Mechanism of Improving the Wearability of WC78-TiC14-Co8 Cemented Carbide with Yttrium Addition

The influence of yttrium addition on microstructure and wearability of WC78 TiC14 Co8 cemented carbide has been studied It is shown that the wearability of the carbide tool is significantly improved by adding trace amount of yttrium and the optimal adding amount is about 0 27%(wt)(in binder) Experimental results indicate that owing to adding yttrium, in as sintered cemented carbides the sizes of carbide grains and Co rich binder regions are reduced and their size homogeneity is improved, while in the binder, both dissolved contents of tungsten and titanium and volume proportion of the ductile α Co phase with f c c lattice are increased Therefore, the strength toughness of the binder and the cemented carbide which consists of the carbides and the binder are apparently enhanced Besides, it is found that many Y 2WO 6 particles appear along the WC/WC or WC/Co rich phase interfaces in as sintered carbide alloy with yttrium addition until 4 5%(wt), showing that during liquid phase sintering process of the alloys the segregation of yttrium atoms and Y 2WO 6 forming reaction might take place on the carbide particles/liquid binder interfaces, reducing the oxide films on the surface of WC particles and strengthening the cohesion of WC particles with Co rich binder

SURFACING ELECTRODE WITH CRACKING RESISTANCE AND WEARABILITY

A new surfacing electrode is developed with cracking resistance andwearability based on high microhardness of TiC and VC, carbides of Ti and V are formed in depositedmetal by means of high temperature arc metallurgic reaction. The results show the hardness ofsurfacing metal increases with the increase of ferrotitanium (Fe-Ti), ferrovanadium (Fe-V) andgraphite in the coat. However, when graphite reaches the volume fraction of 11 percent, the hardnessreaches its peak value, and when beyond 11 percent, the hardness falls off. As Fe-Ti, Fe-V andgraphite increase, the cracking resistance of deposited metal and usability of electrode declines.Carbides are dispersedly distributed in the matrix structure. The matrix micro structure ofdeposited metal is lath martensite. Carbides present irregular block. When using the researchedsurfacing electrode to continue weld with non-preheated, no seeable crack or only a few micro-crackscan be observed in the surface of deposited metal. The hardness is above 60 HRC. The wearresistance is better than that of EDZCr-C-15.

Classification of Preparation Methods and Wearability of Smart Textiles

In recent years,smart textiles have attracted the attention of scholars from all walks of life,but there is an imbalance between functionality and usability,which affects their marketization process.Firstly,five representative smart textiles are introduced and their respective wearability is described around preparation methods.Secondly,it is concluded that the preparation methods of smart textiles can be divided into two categories:fiber methods and finishing methods.The fiber methods refer to making smart fibers into smart textiles.Textiles made by fiber methods are breathable and feel good in the hand,but the mechanical properties are influenced by the production equipment,and the process cost is high.The finishing methods refer to the functional finishing of ordinary textiles.Although the finishing method is simple and convenient,it may reduce the comfort of the textile.Finally,applications and new research in various fields of smart textiles are presented with promising prospects.It is anticipated that this review will serve as a theoretical basis for future research and development of smart textiles.Researchers are expected to create new technologies to overcome the tension between functionality and usability,as well as to increase user comfort and convenience.

Toward Enhancing Wearability and Fashion of Wearable Supercapacitor with Modified Polyurethane Artificial Leather Electrolyte

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.

多功能热电织物用于可穿戴无线传感系统

Flexible thermoelectric materials play an important role in smart wearables,such as wearable power generation,self-powered sensing,and personal thermal management.However,with the rapid development of Internet of Things(IoT)and artificial intelligence(AI),higher standards for comfort,multifunctionality,and sustainable operation of wearable electronics have been proposed,and it remains challenging to meet all the requirements of currently reported thermoelectric devices.Herein,we present a multifunctional,wearable,and wireless sensing system based on a thermoelectric knitted fabric with over 600 mm·s^(-1)air permeability and a stretchability of 120%.The device coupled with a wireless transmission system realizes self-powered monitoring of human respiration through an mobile phone application(APP).Furthermore,an integrated thermoelectric system was designed to combine photothermal conversion and passive radiative cooling,enabling the characteristics of being powered by solar-driven in-plane temperature differences and monitoring outdoor sunlight intensity through the APP.Additionally,we decoupled the complex signals of resistance and thermal voltage during deformation under solar irradiation based on the anisotropy of the knitted fabrics to enable the device to monitor and optimize the outdoor physical activity of the athlete via the APP.This novel thermoelectric fabricbased wearable and wireless sensing platform has promising applications in next-generation smart textiles.

Soft,body conformable electronics for thermoregulation enabled by kirigami

The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.

Artificial Intelligence Meets Flexible Sensors:Emerging Smart Flexible Sensing Systems Driven by Machine Learning and Artificial Synapses

The recent wave of the artificial intelligence(AI)revolution has aroused unprecedented interest in the intelligentialize of human society.As an essential component that bridges the physical world and digital signals,flexible sensors are evolving from a single sensing element to a smarter system,which is capable of highly efficient acquisition,analysis,and even perception of vast,multifaceted data.While challenging from a manual perspective,the development of intelligent flexible sensing has been remarkably facilitated owing to the rapid advances of brain-inspired AI innovations from both the algorithm(machine learning)and the framework(artificial synapses)level.This review presents the recent progress of the emerging AI-driven,intelligent flexible sensing systems.The basic concept of machine learning and artificial synapses are introduced.The new enabling features induced by the fusion of AI and flexible sensing are comprehensively reviewed,which significantly advances the applications such as flexible sensory systems,soft/humanoid robotics,and human activity monitoring.As two of the most profound innovations in the twenty-first century,the deep incorporation of flexible sensing and AI technology holds tremendous potential for creating a smarter world for human beings.

Recent developments in selective laser processes for wearable devices

Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods.Lasers have long been used to develop original solutions to such challenging technological problems due to their remote,sterile,rapid,and site-selective processing of materials.In this review,recent developments in relevant laser processes are summarized under two separate categories.First,transformative approaches,such as for laser-induced graphene,are introduced.In addition to design optimization and the alteration of a native substrate,the latest advances under a transformative approach now enable more complex material compositions and multilayer device configurations through the simultaneous transformation of heterogeneous precursors,or the sequential addition of functional layers coupled with other electronic elements.In addition,the more conventional laser techniques,such as ablation,sintering,and synthesis,can still be used to enhance the functionality of an entire system through the expansion of applicable materials and the adoption of new mechanisms.Later,various wearable device components developed through the corresponding laser processes are discussed,with an emphasis on chemical/physical sensors and energy devices.In addition,special attention is given to applications that use multiple laser sources or processes,which lay the foundation for the all-laser fabrication of wearable devices.

MXene-Based Elastomer Mimetic StretchableSensors: Design, Properties, and Applications

Flexible sensors based on MXene-polymer composites are highly prospective for next-generation wearable electronics used in human-machine interfaces.One of the motivating factors behind the progress of flexible sensors is the steady arrival of new conductive materials.MXenes,a new family of 2D nanomaterials,have been draw-ing attention since the last decade due to their high electronic conduc-tivity,processability,mechanical robustness and chemical tunability.In this review,we encompass the fabrication of MXene-based polymeric nanocomposites,their structure-property relationship,and applications in the flexible sensor domain.Moreover,our discussion is not only lim-ited to sensor design,their mechanism,and various modes of sensing platform,but also their future perspective and market throughout the world.With our article,we intend to fortify the bond between flexible matrices and MXenes thus promoting the swift advancement of flexible MXene-sensors for wearable technologies.

Recent advances and innovations in the design and fabrication of wearable flexible biosensors and human health monitoring systems based on conjugated polymers

Wearable biosensors have received great interest as patient-friendly diagnostic technologies because of their high flexibility and conformability.The growing research and utilization of novel materials in designing wearable biosensors have accelerated the development of point-of-care sensing platforms and implantable biomedical devices in human health care.Among numerous potential materials,conjugated polymers(CPs)are emerging as ideal choices for constructing high-performance wearable biosensors because of their outstanding conductive and mechanical properties.Recently,CPs have been extensively incorporated into various wearable biosensors to monitor a range of target biomolecules.However,fabricating highly reliable CP-based wearable biosensors for practical applications remains a significant challenge,necessitating novel developmental strategies for enhancing the viability of such biosensors.Accordingly,this review aims to provide consolidated scientific evidence by summarizing and evaluating recent studies focused on designing and fabricating CP-based wearable biosensors,thereby facilitating future research.Emphasizing the superior properties and benefits of CPs,this review aims to clarify their potential applicability within this field.Furthermore,the fundamentals and main components of CP-based wearable biosensors and their sensing mechanisms are discussed in detail.The recent advancements in CP nanostructures and hybridizations for improved sensing performance,along with recent innovations in next-generation wearable biosensors are highlighted.CPbased wearable biosensors have been—and will continue to be—an ideal platform for developing effective and user-friendly diagnostic technologies for human health monitoring.

A mixed-coordination electron trapping-enabled high-precision touch-sensitive screen for wearable devices

Touch-sensitive screens are crucial components of wearable devices.Materials such as reduced graphene oxide(rGO),carbon nanotubes(CNTs),and graphene offer promising solutions for flexible touch-sensitive screens.However,when stacked with flexible substrates to form multilayered capacitive touching sensors,these materials often suffer from substrate delamination in response to deformation;this is due to the materials having different Young’s modulus values.Delamination results in failure to offer accurate touch screen recognition.In this work,we demonstrate an induced charge-based mutual capacitive touching sensor capable of high-precision touch sensing.This is enabled by electron trapping and polarization effects related to mixed-coordinated bonding between copper nanoparticles and vertically grown graphene nanosheets.Here,we used an electron cyclotron resonance system to directly fabricate graphene-metal nanofilms(GMNFs)using carbon and copper,which are firmly adhered to flexible substrates.After being subjected to 3000 bending actions,we observed almost no change in touch sensitivity.The screen interaction system,which has a signal-to-noise ratio of 41.16 dB and resolution of 650 dpi,was tested using a handwritten Chinese character recognition trial and achieved an accuracy of 94.82%.Taken together,these results show the promise of touch-sensitive screens that use directly fabricated GMNFs for wearable devices.

Flexible Graphene Field‑Effect Transistors and Their Application in Flexible Biomedical Sensing

Flexible electronics are transforming our lives by making daily activities more convenient.Central to this innovation are field-effect transistors(FETs),valued for their efficient signal processing,nanoscale fabrication,low-power consumption,fast response times,and versatility.Graphene,known for its exceptional mechanical properties,high electron mobility,and biocompatibility,is an ideal material for FET channels and sensors.The combination of graphene and FETs has given rise to flexible graphene field-effect transistors(FGFETs),driving significant advances in flexible electronics and sparked a strong interest in flexible biomedical sensors.Here,we first provide a brief overview of the basic structure,operating mechanism,and evaluation parameters of FGFETs,and delve into their material selection and patterning techniques.The ability of FGFETs to sense strains and biomolecular charges opens up diverse application possibilities.We specifically analyze the latest strategies for integrating FGFETs into wearable and implantable flexible biomedical sensors,focusing on the key aspects of constructing high-quality flexible biomedical sensors.Finally,we discuss the current challenges and prospects of FGFETs and their applications in biomedical sensors.This review will provide valuable insights and inspiration for ongoing research to improve the quality of FGFETs and broaden their application prospects in flexible biomedical sensing.

IWTW:A Framework for IoWT Cyber Threat Analysis

The Internet of Wearable Things(IoWT)or Wearable Internet of Things(WIoT)is a new paradigm that combines IoT and wearable technology.Advances in IoT technology have enabled the miniaturization of sensors embedded in wearable devices and the ability to communicate data and access real-time information over low-power mobile networks.IoWT devices are highly interdependent with mobile devices.However,due to their limited processing power and bandwidth,IoWT devices are vulnerable to cyberattacks due to their low level of security.Threat modeling and frameworks for analyzing cyber threats against existing IoT or low-power protocols have been actively researched.The threat analysis framework used in existing studies was limited to specific protocols and did not target IoWT devices.In addition,In the literature surveyed to date,no cyber threat analysis framework is targeting IoWT.Therefore,the threat model presented in the existing research on cyber threat analysis and modeling for IoWT is specialized for specific devices.In addition,because it does not present standardized attack tactics and techniques,there is a limitation in that it is difficult to identify attacks quickly.In this paper,we propose an Internet of Wearable Things threat analysis frameWork(IWTW)framework that can derive security threats through systematic analysis of IoWT attack cases and possible security threats and perform cyber threat analysis based on them.The methodology for developing the IWTW framework consists of three steps:Analysis,Standardization,and Compilation.IoWT attack cases and potential security threats are analyzed in the analysis stage.In the standardization stage,attack tactics and techniques derived from the analysis of attack cases and potential security threats are standardized,resulting in 3 attack categories,18 attack tactics,and 68 attack techniques.In the compilation stage,standardized security threats are combined to develop the IWTW framework ultimately.We present four case studies targeting MiBand 2,Fitbit Charge HR/Surge,Samsung Gear 3,Xiaomi Amazifit,Honor Band 5,Honor Watch ES,and Senbono CF-58 devices to validate the proposed IWTW framework.We analyzed the attack process through a case study and applied the IWTW framework to derive standardized attack categories,tactics,and techniques effectively.By applying the IWTW framework to cyber threat analysis targeting IoWT,security threats can be standardized,and the attack process can be quickly derived,enabling effective attack analysis on IoWT.

Device-measured physical activity and sedentary time in the Nordic countries:A scoping review of population-based studies

Purpose:The purpose of this scoping review was to summarize and describe the methodology and results from population-based studies of physical activity and sedentary time measured with devices in the Nordic countries(Denmark,Finland,Iceland,Norway,and Sweden)and published in 2000 or later.Methods:A systematic search was carried out in PubMed and Web of Science in June 2023 using predefined search terms.Results:Fourteen unique research projects or surveillance studies were identified.Additionally,2 surveillance studies published by national agencies were included,resulting in a total of 16 studies for inclusion.National surveillance systems exist in Finland and Norway,with regular survey waves in school-aged children/adolescents and adults.In Denmark,recent nationally representative data have been collected in school children only.So far,Sweden has no regular national surveillance system using device-based data collection.No studies were found from Iceland.The first study was conducted in 2001 and the most recent in 2022,with most data collected from 2016 to date.Five studies included children/adole scents 6-18 years,no study included preschoolers.In total 11 studies included adults,of which 8 also covered older adults.No study focused specifically on older adults.The analytical sample size ranged from 205 to 27,890.Detailed methodology is presented,such as information on sampling strategy,device type and placement,wear protocols,and physical activity classification schemes.Levels of physical activity and sedentary time in children/adolescents,adults,and older adults across the Nordic countries are presented.Conclusion:A growing implementation of device-based population surveillance of physical activity and sedentary behavior in the Nordic countries has been identified.The variety of devices,placement,and data procedures both within and between the Nordic countries highlights the challenges when it comes to comparing study outcomes as well as the need for more standardized data collection.

A randomized controlled trial of Promoting Physical Activity in Regional and Remote Cancer Survivors(PPARCS)

Background:Physical activity(PA)is important for cancer survivors.Trials of remotely delivered interventions are needed to assist in reaching under-served non-metropolitan cancer survivors.The objective of this study was to ascertain whether wearable technology,coupled with health coaching was effective in increasing PA in breast and colorectal cancer survivors living in regional and remote areas in Australia.Methods:Cancer survivors from 5 states were randomized to intervention and control arms.Intervention participants were given a Fitbit Charge 2TMand received up to 6 telephone health coaching sessions.Control participants received PA print materials.Accelerometer assessments at baseline and 12 weeks measured moderate-to-vigorous PA(MVPA),light PA,and sedentary behavior.Results:Eighty-seven participants were recruited(age=63±11 years;74(85%)female).There was a significant net improvement in MVPA of 49.8 min/week,favoring the intervention group(95%confidence interval(95%CI):13.6-86.1,p=0.007).There was also a net increase in MVPA bouts of 39.5 min/week(95%CI:11.9-67.1,p=0.005),favoring the intervention group.Both groups improved light PA and sedentary behavior,but there were no between-group differences.Conclusion:This’s the first study to demonstrate that,when compared to standard practice(i.e.,PA education),a wearable technology intervention coupled with distance-based health coaching,improves MVPA in non-metropolitan cancer survivors.The results display promise for the use of scalable interventions using smart wearable technology in conjunction with phone-based health coaching to foster increased PA in geographically disadvantaged cancer survivors.

A Rapid Adaptation Approach for Dynamic Air‑Writing Recognition Using Wearable Wristbands with Self‑Supervised Contrastive Learning

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.

A tensile wearable SHF antenna with efficient communication in defense beacon technology

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.

Nanomaterial-assisted wearable glucose biosensors for noninvasive real-time monitoring:Pioneering point-of-care and beyond

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.

Efficient Real-Time Devices Based on Accelerometer Using Machine Learning for HAR on Low-Performance Microcontrollers

Analyzing physical activities through wearable devices is a promising research area for improving health assessment.This research focuses on the development of an affordable and real-time Human Activity Recognition(HAR)system designed to operate on low-performance microcontrollers.The system utilizes data from a bodyworn accelerometer to recognize and classify human activities,providing a cost-effective,easy-to-use,and highly accurate solution.A key challenge addressed in this study is the execution of efficient motion recognition within a resource-constrained environment.The system employs a Random Forest(RF)classifier,which outperforms Gradient Boosting Decision Trees(GBDT),Support Vector Machines(SVM),and K-Nearest Neighbors(KNN)in terms of accuracy and computational efficiency.The proposed features Average absolute deviation(AAD),Standard deviation(STD),Interquartile range(IQR),Range,and Root mean square(RMS).The research has conducted numerous experiments and comparisons to establish optimal parameters for ensuring system effectiveness,including setting a sampling frequency of 50 Hz and selecting an 8-s window size with a 40%overlap between windows.Validation was conducted on both the WISDM public dataset and a self-collected dataset,focusing on five fundamental daily activities:Standing,Sitting,Jogging,Walking,and Walking the stairs.The results demonstrated high recognition accuracy,with the system achieving 96.7%on the WISDM dataset and 97.13%on the collected dataset.This research confirms the feasibility of deploying HAR systems on low-performance microcontrollers and highlights the system’s potential applications in patient support,rehabilitation,and elderly care.