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.

Waste Cotton-Derived Fiber-Based Thermoelectric Aerogel for Wearable and Self-Powered Temperature-Compression Strain Dual-Parameter Sensing

The rapid development of the global economy and population growth are accompanied by the production of numerous waste textiles.This leads to a waste of limited resources and serious environmental pollution problems caused by improper disposal.The rational recycling of wasted textiles and their transformation into high-value-added emerging products,such as smart wearable devices,is fascinating.Here,we propose a novel roadmap for turning waste cotton fabrics into three-dimensional elastic fiber-based thermoelectric aerogels by a one-step lyophilization process with decoupled self-powered temperature-compression strain dual-parameter sensing properties.The thermoelectric aerogel exhibits a fast compression response time of 0.2 s,a relatively high Seebeck coefficient of 43μV·K^(-1),and an ultralow thermal conductivity of less than 0.04 W·m^(-1)·K^(-1).The cross-linking of trimethoxy(methyl)silane(MTMS)and cellulose endowed the aerogel with excellent elasticity,allowing it to be used as a compressive strain sensor for guessing games and facial expression recognition.In addition,based on the thermoelectric effect,the aerogel can perform temperature detection and differentiation in self-powered mode with the output thermal voltage as the stimulus signal.Furthermore,the wearable system,prepared by connecting the aerogel-prepared array device with a wireless transmission module,allows for temperature alerts in a mobile phone application without signal interference due to the compressive strains generated during gripping.Hence,our strategy is significant for reducing global environmental pollution and provides a revelatory path for transforming waste textiles into high-value-added smart wearable devices.

Highly stretchable,durable,and breathable thermoelectric fabrics for human body energy harvesting and sensing

Stretchable thermoelectrics have recently attracted widespread attention in the field of self-powered wearable electronics due to their unique capability of harvesting body heat.However,it remains challenging to develop thermoelectric materials with excellent stretchability,durable thermoelectric properties,wearable comfort,and multifunctional sensing properties simultaneously.Herein,an advanced preparation strategy combining electrospinning and spraying technology is proposed to prepare carbon nanotube(CNT)/polyvinyl pyrrolidone(PVP)/polyurethane(PU)composite thermoelectric fabrics that have high air permeability and stretchability(~250%)close to those of pure PU nanofiber fabrics.Furthermore,PVP can not only improve the dispersion of CNTs but also act as interfacial binders between the CNT and the elastic PU skeleton.Consequently,both the electrical conductivity and the Seebeck coefficient remain unchanged even after bending 1000 times.In addition,self-powered sensors for the mutual conversion of finger temperature and language and detection of the movement of joints to optimize an athlete's movement state were successfully fabricated.This study paves the way for stretchable thermoelectric fabrics with fascinating applications in smart wearable fields such as power generation,health monitoring,and human–computer interaction.

A Rapid-Ab/Desorption and Portable Photothermal MIL- 101(Cr) Nanofibrous Composite Membrane Fabricated by Spray-Electrospinning for Atmosphere Water Harvesting

MIL-101(Cr)is a promising moisture absorbent for solar-driven water harvesting from moisture to tackle the worldwide water shortage issue.However,the MIL-101(Cr)powder suffers from a long ab/desorption cycle due to the crystal aggregation caused by its inherent powder properties.Here,we demonstrate a MIL-101(Cr)nanofibrous composite membrane with a nanofibrous matrix where MIL-101(Cr)is monodisperse in the 3D porous nanofibrous matrix through a simple spray-electrospinning strategy.The continuous porous nanofibrous matrix not only offers sufficient sites for MIL-101(Cr)loading but also provides rapid moisture transport channels,resulting in a super-rapid ab/desorption duration of 50 min(including an absorption process for 40 min and a desorption process for 10 min)and multicycle daily water production of 15.9 L kg^(−1) d^(−1).Besides,the MIL-101(Cr)nanofibrous composite membrane establishes a high solar absorption of 92.8%,and excellent photothermal conversion with the surface temperature of 70.7°C under one-sun irradiation.In addition,the MIL-101(Cr)nanofibrous composite membrane shows excellent potential for practical application due to its flexibility,portability,and use stability.This work provides a new perspective of shortening MOF ab/desorption duration by introducing a porous nanofibrous matrix to improve the specific water production for the solar-driven ab/desorption water harvesting technique.

A General Strategy to Electrospin Nanofibers with Ultrahigh Molecular Chain Orientation

The degree of polymer chain orientation is a key structural parameter that determines the mechanical and physical properties of fibers.However,understanding and significantly tuning the orientation of fiber macromolecular chains remain elusive.Herein,we propose a novel electrospinning technique that can efficiently modulate molecular chain orientation by controlling the electric field.In contrast to the typical electrospinning method,this technique can piecewise control the electric field by applying high voltage to the metal ring instead of the needle.Benefiting from this change,a new electric field distribution can be realized,leading to a non-monotonic change in the drafting force.As a result,the macromolecular chain orientation of polyethylene oxide(PEO)nanofibers was significantly improved with a recordhigh infrared dichroic ratio.This was further confirmed by the sharp decrease in the PEO jet fineness of approximately 80%and the nanofiber diameter from 298 to 114 nm.Interestingly,the crystallinity can also be adjusted,with an obvious drop from 74.9%to 31.7%,which is different from the high crystallinity caused by oriented chains in common materials.This work guides a new perspective for the preparation of advanced electrospun nanofibers with optimal orientation–crystallinity properties,a merited feature for various applications.

Shape‑Controllable Nanofiber Core‑Spun Yarn for Multifunctional Applications

Nanofiber core-spun yarn(NCSY)combines the advantages of traditional fibers and nanofibers to be widely used in smart wearable textiles,biomedical textiles,and functional textiles.Here,for the first time,the forming process of NCSY and its shape regulation mechanism were explored via finite element analysis and response surface analysis method to obtain mathematical model for predicting the various forms of yarn.As proof-of-concept applications,shape-controllable nanofiber core-spun yarns were prepared for thermal–moisture management and solar steam generation,respectively.The as-obtained shape-controllable PAN nanofiber/cotton composite yarns could achieve an interval control of average water transfer velocity in the horizontal(0.17–0.24 cm min^(-1))and vertical(0.24–0.33 cm min^(-1))directions within 30 min due to the arrangement of PAN nanofibers causes microchannels and hydrophilicity,matching the sweat secretion of human bodies under dynamic or static conditions and realizing the purpose of thermal and moisture comfort.Furthermore,PAN nanofiber wrapped CNTs/cotton composite yarn-based(PAN@CNTs-NCSY)evaporator was designed,which shows a fast water evaporation rate of 1.40 kg m^(-2)h^(-1),exceeding in most fabric-based evaporators reported to date.These findings have guiding significance for preparing rich style NCSY according to demand and designing functional and intelligent textiles via adjusting the type of core and shell fibers.

Structural insight into substrate specificity of human intestinal maltase-glucoamylase

Human maltase-glucoamylase(MGAM)hydrolyzes linear alpha-1,4-linked oligosaccharide substrates,playing a crucial role in the production of glucose in the human lumen and acting as an efficient drug target for type 2 diabetes and obesity.The amino-and carboxyl-terminal portions of MGAM(MGAM-N and MGAM-C)carry out the same catalytic reaction but have different substrate specificities.In this study,we report crystal structures of MGAM-C alone at a resolution of 3.1Å,and in complex with its inhibitor acarbose at a resolution of 2.9Å.Structural studies,combined with biochemical analysis,revealed that a segment of 21 amino acids in the active site of MGAM-C forms additional sugar subsites(+2 and+3 subsites),accounting for the preference for longer substrates of MAGM-C compared with that of MGAM-N.Moreover,we discovered that a single mutation of Trp1251 to tyrosine in MGAM-C imparts a novel catalytic ability to digest branched alpha-1,6-linked oligosaccharides.These results provide important information for understanding the substrate specificity of alphaglucosidases during the process of terminal starch digestion,and for designing more efficient drugs to control type 2 diabetes or obesity.

3D printing of silk fibroin-based hybrid scaffold treated with platelet rich plasma for bone tissue engineering

3D printing/bioprinting are promising techniques to fabricate scaffolds with well controlled and patient-specific structures and architectures for bone tissue engineering.In this study,we developed a composite bioink consisting of silk fibroin(SF),gelatin(GEL),hyaluronic acid(HA),and tricalcium phosphate(TCP)and 3D bioprinted the silk fibroin-based hybrid scaffolds.The 3D bioprinted scaffolds with dual crosslinking were further treated with human platelet-rich plasma(PRP)to generate PRP coated scaffolds.Live/Dead and MTT assays demonstrated that PRP treatment could obviously promote the cell growth and proliferation of human adipose derived mesenchymal stem cells(HADMSC).In addition,the treatment of PRP did not significantly affect alkaline phosphatase(ALP)activity and expression,but significantly upregulated the gene expression levels of late osteogenic markers.This study demonstrated that the 3D printing of silk fibroin-based hybrid scaffolds,in combination with PRP post-treatment,might be a more efficient strategy to promote osteogenic differentiation of adult stem cells and has significant potential to be used for bone tissue engineering.

Reconfiguration and self-healing integrated Janus electrospinning nanofiber membranes for durable seawater desalination

Janus electrospinning nanofiber membranes have attracted extensive attention in the fields such as solar-driven interfacial desalination,liquid filtration,and waterproof and breathable fabrics.However,the Janus structures suffer from weak interfacial bonding and vulnerability to damage,making the durability and sustainability are highly sought after in real-word applications.Herein,we fabricate the simply reconfigurable and entirely self-healing Janus evaporator by electrospinning polypropylene glycol based polyurethane(PPG@PU)and polydimethylsiloxane based polyurethane-CNTs(PDMS@PU-CNTs)with different wettability,which are both designed based on dynamic Diels–Alder(DA)bond.The interface of the Janus membrane is stitched by the covalent bonds to directly improve the interface adhesion to 22 N·m−1,constructing an integrated evaporator,and thereby achieving a stable desalination rate of 1.34 kg·m−2·h−1 under one sun.Reversible dissociation of DA networks allows the evaporators for self-healing and reconfiguration abilities,after which the photothermal performance is maintained.This is the first work for the crosslinked self-healing polymer to be directly electrospun,achieving the improved interfacial bond and reconfiguration of entire evaporators,which presented promising new design principles and materials for interfacial solar seawater desalination.

Emerging design principles,materials,and applications for moisture-enabled electric generation

Smart generators that collect energy from the ambient environment are a new approach for meeting growing global energy needs.Moisture is one of the most abundant resources in the ambient environment,and using it to generate electricity has aroused great interest in recent years.In this review,we first summarize the emerging design principles of moisture power generation,including ion diffusion,streaming potential,and charged surface potential.Then,based on these fundamental principles,we systematically summarize the materials thus far known to be suitable for moisture power generation.Finally,we highlight the application of moisture energy generators in various fields,such as thermoelectricity,solar thermal evaporation,capacitors,strain sensors,and information storage,and discuss current challenges and future prospects for the development of moisture energy generators.

A waterproof,environment-friendly,multifunctional,and stretchable thermoelectric fabric for continuous self-powered personal health signal collection at high humidity

Thermoelectric sensors have attracted increasing attention in smart wearables due to the recognition of multiple signals in self-powered mode.However,present thermoelectric devices show disadvantages of low durability,weak wearability,and complex preparation processes and are susceptible to moisture in the microenvironment of the human body,which hinders their further application in wearable electronics.Herein,we prepared a new thermoelectric fabric with thermoplastic polyurethane/carbon nanotubes(TPU/CNTs)by combining vacuum filtration and electrospraying techniques.Electrospraying TPU microsphere coating with good biocompatibility and environmental friendliness made the fabric worn directly and exhibits preferred water resistance,mechanical durability,and stability even after being bent 4000 times,stretched 1000 times,and washed 1000 times.Moreover,this fabric showed a Seebeck coefficient of 49μVK−1 and strain range of 250%and could collect signals well and avoided interference from moisture.Based on the biocompatibility and safety of the fabric,it can be fabricated into devices and mounted on the human face and elbow for long-term and continuous collection of data on the body’s motion and breathing simultaneously to provide collaborative support information.This thermoelectric fabric-based sensor will show great potential in advanced smart wearables for health monitoring,motion detection,and human–computer interaction.

Diameter Refnement of Electrospun Nanofbers:From Mechanism,Strategies to Applications

Electrospinning has drawn wide attention for its powerful capacity to produce ultrafne nanofbers(UNFs)from various materials.These UNFs demonstrated signifcantly enhanced performance,such as ultra-high surface area,more porosity and stronger mechanical properties.Here,we comprehensively review their basic principles,state-of-the-art methods and preponderant applications.We begin with a brief introduction to the refnement theory of polymer jets,followed by discussion of factors afecting fber refnement.We then discuss the refning strategies from the aspects of solution properties,spinning parameters,auxiliary force and post-treatment.Afterward,we highlight the most relevant and recent applications associated with the remarkable features of UNFs,including fltration materials,supercapacitors,biomedical materials and other applications.At the end,we ofer perspectives on the challenges,opportunities,and new directions for future development of electrospun UNFs.