Extremely Robust and Multifunctional Nanocomposite Fibers for Strain-Unperturbed Textile Electronics

Gas-liquid two-phase bubble flow spinning for hydrovoltaic flexible electronics

Hydrovoltaic technologies that generate electricity by absorbing or transferring free water without chemical reactions have been explored as potential candidates for renewable energy. Self-powered flexible sensors, including hydrovoltaic fibers, are becoming an important research direction in the field of renewable energy. However, integrating sensing and power generation in functional fibers remains challenging due to the need to regulate water movement to achieve performance differences. Here, we present a gas-liquid two-phase flow spinning method, inspired by spider multimodal spinning, that uses bubble-triggered spinning-liquid deformation to fabricate hollow, solid spindle, and ratchet tooth-shaped fibers. These structures alter water adsorption and transfer behaviors, making them suitable for targeted applications in hydrovoltaic devices for energy and sensing fields. Shaped fibers prepared from alginate-bridged MoS₂ enable a wide range of hydrovoltaic applications. The obtained fiber has a power density of 2.18 mW/cm3, stable operation at 2.1 V for 43 hours, and sensitivity of 9.36 mV/RH%/s, leading to the development of smart masks for nasal cycle monitoring, diagnosis, and therapy as potential applications. Spinning materials were extended to materials such as carboxymethyl cellulose, polyvinyl alcohol, etc., inspiring the design of structure-responsive hydroelectric materials and advancing textile electronics.

Biomimetic Interfacial Manipulation in Ti3C2Tx Fibers Toward Strengthened Interlayer Cross-linking, Regulated Ion Diffusion and Suppressed Self-Discharge

Simultaneous improvements in mechanical and electrochemical properties of MXene (Ti3C2Tx) fibers, especially tensile strength, output capacitance, and self-discharge suppression remain challenging, yet are critical important for promoting the practical applications of fiber supercapacitors (FSCs) as advanced power supplier in future wearable electronics. Inspired by a tree trunk that not only provides enough structure stability against external attacks but also plays a vital role in nutrient transportation through luxuriant micro-conduits, the strategy of interfacial engineering is proposed for designing Ti3C2Tx fibers. 3-aminopropyltriethoxysilane (APTES) is employed as a reinforcer and spacer that is anchored on Ti3C2Tx surfaces via covalent bonds for modulating stress transfer and increasing accessible active sites, while tannic acid (TA) with abundant phenolic hydroxyl groups is introduced to construct a biomimetic interface for tuning ion diffusion kinetics and further improving tensile strength. The optimized fiber exhibits a high specific capacitance of 1573 F cm-3 at 1 A cm-3 with 83.8% retained at 15 A cm-3 (1318 F cm-3), an improved tensile strength of 152 MPa, and more sustainable self-discharge time twice as long as that of bare MXene fiber. The assembled symmetric FSCs deliver a volumetric energy density of 26.8 mWh cm-3 at a power density of 418.7 mW cm-3.

Thermally Conductive Ti3C2Tx Fibers with Superior Electrical Conductivity

High-performance Ti3C2Tx fibers have garnered significant potential for smart fibers enabled fabrics. Nonetheless, a major challenge hindering their widespread use is the lack of strong interlayer interactions between Ti3C2Tx nanosheets within fibers, which restricts their properties. Herein, a versatile strategy is proposed to construct wet-spun Ti3C2Tx fibers, in which trace amounts of borate form strong interlayer crosslinking between Ti3C2Tx nanosheets to significantly enhance interactions as supported by density functional theory calculations, thereby reducing interlayer spacing, diminishing microscopic voids and promoting orientation of the nanosheets. The resultant Ti3C2Tx fibers exhibit exceptional electrical conductivity of 7781 S cm-1 and mechanical properties, including tensile strength of 188.72 MPa and Young's modulus of 52.42 GPa. Notably, employing equilibrium molecular dynamics simulations, finite element analysis, and cross-wire geometry method, it is revealed that such crosslinking also effectively lowers interfacial thermal resistance and ultimately elevates thermal conductivity of Ti3C2Tx fibers to 13 W m-1 K-1, marking the first systematic study on thermal conductivity of Ti3C2Tx fibers. The simple and efficient interlayer crosslinking enhancement strategy not only enables the construction of thermal conductivity Ti3C2Tx fibers with high electrical conductivity for smart textiles, but also offers a scalable approach for assembling other nanomaterials into multifunctional fibers.

Visualizing the Sliding Motion of Dynamic Rotaxanes by Surface Wrinkles

Visualizing the sliding dynamics of a topological network can provide critical insight into determining the design and properties of mechanically interlocked materials. Although several auxiliary techniques have been proposed to infer the microscopic motion of rotaxanes, employing intuitive and convenient methods to explore the microscopic dynamics of a mechanically interlocked polymer remains a significant challenge. Herein, this work introduces a mechanically interlocked network (MIN) into the patterned surfaces for visualizing and regulating the sliding process of [2]rotaxane units through the evolution of surface wrinkles. Upon the photodimerization of the anthracene-functionalized polymer chain, the surface wrinkle can be formed after thermal treatment and subsequent cooling to room temperature. Specifically, the cross-linked films exhibit visible changes in wrinkle topography through the disruption of host-guest recognition by alkaline stimuli. Moreover, by leveraging the unique mechanical properties of surface wrinkles, we prolonged and amplified the originally extremely transient and difficult-to-detect sliding motion of rotaxane units in terms of time scale. Through statistical analysis of the changes in wrinkle morphology, we were able to correspondingly deconstruct the three processes of the rotaxane sliding motion: (I) unrestricted rapid sliding following host-guest dissociation; (II) restricted sliding; and (III) termination of sliding. The novel approach we propose opens a new avenue for studying the microscopic molecular motion of mechanically interlocked materials, facilitating the advancement and application of mechanically interlocked structures. In addition to using macroscopic surface patterns to visualize and explore microscopic molecular motion, the motion of microscopic molecules can also be used to regulate macroscopic surface patterns.

Hot-Air Spinning Technology Enables the High-Efficiency Production of Nanofiber

Water is the most environmentally friendly solvent; however, conventional solution spinning using water as a solvent is challenging due to its low evaporation rate. We developed a double-pronged solution blow spinning (DP-SBS) system. This spinning technique significantly enhances solvent evaporation, and the designed structure (double-pronged) avoids the common problem of needle clogging caused by heating. DP-SBS enables high-yield production of water-soluble polymer nanofibers, with a production rate of up to 5.94 g/h, which far exceeds what can be achieved with traditional electrospinning or solution blow spinning. This method is also highly efficient for producing non-water-soluble polymer nanofibers, achieving a production rate of up to 7.91 g/h, the highest reported value to date. Additionally, this approach can be used to produce not only common two-dimensional fiber membranes but also fiber sponges in a single step using the double-pronged airflow system. For the first time, chitosan nanofiber sponges were successfully produced and demonstrated to have excellent hemostatic properties in medical hemostasis. This method can also be extended to the production of other 3D nanomaterials, such as mullite nanofiber sponges, which exhibit outstanding thermal insulation performance at high temperatures.

Confined Hydrothermal Assembly of Hierarchical Porous MXene/RGO Composite Fibers with Enhanced Oxidation Resistance for High-Performance Wearable Supercapacitors

MXene fibers have emerged as a promising material for energy storage applications due to their exceptional electrical conductivity and surface chemistry. However, the inherent challenges of oxidation instability and severe restacking of MXene nanosheets significantly limit their practical applications in flexible energy storage devices. Here, an innovative confined hydrothermal strategy combined with chemical crosslinking to construct 3D hierarchical porous MXene/reduced graphene oxide (RGO) composite fibers is reported. This rationally designed architecture effectively prevents MXene stacking while creating efficient ion transport channels. Notably, thiourea serves dual roles as both a chemical cross-linker and selective reducing agent, while RGO nanosheets act as physical barriers, synergistically enhancing the composite's oxidation resistance. The optimized composite fiber exhibits outstanding electrical conductivity (862.2 S cm-1), mechanical strength (93.1 MPa), and remarkable oxidation resistance (90.5% conductivity retention after 60 days). The assembled solid-state supercapacitor achieves excellent mechanical flexibility, superior cycling stability, and impressive energy density (13.5 mWh cm-3) and power density (1.9 W cm-3). This work provides a novel and effective strategy for developing high-performance flexible wearable energy storage devices.

Stretchable [2]rotaxane-bridged MXene films applicable for electroluminescent devices

Titanium carbide (Ti3C2TX) MXene has prominent mechanical properties and electrical conductivity. However, fabricating high-performance macroscopic films is challenging, as weak interlayer interactions limit their mechanical performance. Here, we introduce [2]rotaxane, a mechanically interlocked molecule, to enhance MXene films. Compared to pure MXene (fracture strain: 4.6%, toughness: 0.6 MJ/m3), [2]rotaxane-bridged MXene (RBM) films achieve record-high strain (20.0%) and toughness (11.9 MJ/m3) with only 3.6% [2]rotaxane by weight. Additionally, RBM films endure 500 stretch cycles (0 to 15% strain) with stable and reversible resistance alterations, making them ideal for stretchable electrodes. Notably, RBM films enable stretchable electroluminescent devices with reliable operation under 20% elongation and customizable luminescent patterns. This innovative use of mechanically interlocked molecules to cross-link MXene platelets advances MXene films and other two-dimensional materials in stretchable electronics.

Interfacial Confinement Derived High-Strength MXene@Graphene Oxide Core-Shell Fibers for Electromagnetic Wave Regulation, Thermochromic Alerts, and Visible Camouflage

Although electrically conductive Ti₃C₂Tx MXene fibers are promising for wearable electronics, the poor inter-sheet interactions and the random stacking structure of MXene sheets seriously hinder electron transport and load transfer of the fibers. Herein, mechanically strong and electrically conductive MXene@graphene oxide (GO) core-shell fibers are fabricated with a coaxial wet-spinning methodology for electromagnetic wave regulation, thermochromic alerts, and visible camouflage. During the coaxial wet-spinning, the trace-carboxylated GO sheets in the shell align readily because of the spatial confinement of the coaxial needle, while the MXene sheets in the core are progressively oriented and flattened because of the spatial confinement of the GO shell. The positively charged chitosan in the coagulating solution enhances the interfacial interactions between the GO and MXene sheets and facilitates the sheet's orientation inside the fibers. Consequently, the highly aligned core-shell fibers exhibit an ultrahigh tensile strength of 613.7 MPa and an outstanding conductivity of ≈7766 S cm-1. Furthermore, fiber-woven textiles not only offer excellent electromagnetic interference shielding performance but also achieve quantitative regulation of electromagnetic wave transmission by adjusting the angle of the double-layered textiles. The textiles can combine with thermochromic coatings for thermotherapy alerts, visual thermochromic warnings, and visible camouflage.

Multifunctional Fiber Robotics with Low Mechanical Hysteresis for Magnetic Navigation and Inhaled Gas Sensing

Recently, increasing research attention has been directed toward detecting the distribution of hazardous gases in the respiratory system for potential diagnosis and treatment of lung injury. Among various technologies, magnetic fiber robots exhibit great potential for minimally invasive surgery and in situ disease diagnosis. However, integrating magnetic fibers with functionalized sensitive materials remains challenging while preserving the miniaturized fibers' mechanical properties. Herein, we report Ti3C2Tx/TPU/NdFeB fibers prepared by facile wet spinning, spray coating, and magnetization, obtaining fibers with decent strength (4.34 MPa) and low hysteresis while maintaining mechanical robustness and magnetoelectric properties. Such fiber robotics could be magnetically actuated for complex movement, while the surface-coated MXene endowed them with the specific response of 5.2% to 40 ppm of triethylamine gas. Fiber robotics realized magnetically driven omnidirectional steering and navigation for propulsion in tubular environments by combination with nitinol guide wires. Consequently, based on magnetic navigation and the chemiresistive gas response, the proposed fiber robotics could locate the position with the highest level of the triethylamine gas inside a bronchial model and provide information on its distribution. This provides a proof-of-concept demonstration for inhaled hazardous gas detection and minimally invasive robotic surgery by multifunctional fiber robotics.

Multi-Level High Entropy-Dissipative Structure Enables Efficient Self-Decoupling of Triple Signals

The theory of high entropy-dissipative structure is confined to high-entropy alloys and their oxide materials under harsh conditions, but it is very difficult to obtain high entropy-dissipative structure for smart sensors based on polymers and metal oxides under mild conditions. Moreover, multiple signal coupling effect heavily hinder the sensor applications, and current multimodal integrated devices can solve two signal-decoupling, but need very complicated process way. In this work, new synthesis concept is the first time to fabricate high entropy-dissipative conductive layer of smart sensors with triple-signal response and self-decoupling ability within poly-pyrrole/zinc oxide (PPy/ZnO) system. The sensor (SPZ20) amplifies pressure (17.54%/kPa) and gas (0.37%/ppm), reduces humidity (0.41%/% RH) and temperature (0.12%/°C) signals, simultaneously achieving the triple self-decoupling effect of pressure and gas in the complex temperature-humidity field because of the enlarged pressure-contact area, enhanced gas-responsive sites, altered vapor path and its own heat insulation function. Additionally, it inherits the strong robustness (500 rubbing, washing, and heating or freezing cycles) and endurance (10 000 photo-purification cycles) of traditional high-entropy materials for information transmission and smart alarms in emergencies or harsh environments. This work gives a new insight into the multiple-signal response and smart flexible electronic design from natural fibers.

MXene-based fibers: Preparation, applications, and prospects

With the vigorous development and huge demand for portable wearable devices, wearable electronics based on functional fibers continue to emerge in a wide range of energy storage, motion monitoring, disease prevention, electromagnetic interference (EMI) shielding, etc. MXene, as an emerging two-dimensional inorganic compound, has shown great potential in functional fiber manufacturing and has attracted much research attention due to its own good mechanical properties, high electrical conductivity, excellent electrochemical properties and favorable processability. Herein, this paper reviews recent advances of MXene-based fibers. Speaking to MXene dispersions, the properties of MXene dispersions including dispersion stability, rheological properties and liquid crystalline properties are highlighted. The preparation techniques used to produce MXene-based fibers and application progress regarding MXene-based fibers into supercapacitors, sensors, EMI shielding and Joule heaters are summarized. Challenges and prospects surrounding the development of MXene-based fibers are proposed in future. This review aims to provide processing guidelines for MXene-based fiber manufacturing, thereby achieving more possibilities of MXene-based fibers in advanced applications with a view to injecting more vitality into the field of smart wearables.

Nature's Load-Bearing Design Principles and Their Application in Engineering: A Review

Biological structures optimized through natural selection provide valuable insights for engineering load-bearing components. This paper reviews six key strategies evolved in nature for efficient mechanical load handling: hierarchically structured composites, cellular structures, functional gradients, hard shell-soft core architectures, form follows function, and robust geometric shapes. The paper also discusses recent research that applies these strategies to engineering design, demonstrating their effectiveness in advancing technical solutions. The challenges of translating nature's designs into engineering applications are addressed, with a focus on how advancements in computational methods, particularly artificial intelligence, are accelerating this process. The need for further development in innovative material characterization techniques, efficient modeling approaches for heterogeneous media, multi-criteria structural optimization methods, and advanced manufacturing techniques capable of achieving enhanced control across multiple scales is underscored. By highlighting nature's holistic approach to designing functional components, this paper advocates for adopting a similarly comprehensive methodology in engineering practices to shape the next generation of load-bearing technical components.

Cyclodextrins-Based Polyrotaxanes: From Functional Polymers to Applications in Electronics and Energy Storage Materials

The concept of polyrotaxane comes from the rotaxane structure in the supramolecular field. It is a mechanically interlocked supramolecular assembly composed of linear polymer chains and cyclic molecules. Over recent decades, the synthesis and application of polyrotaxanes have seen remarkable growth. Particularly, cyclodextrin-based polyrotaxanes have been extensively reported due to the low-price raw materials, good biocompatibility, and ease of modification. Hence, it is also one of the most promising mechanically interlocking supramolecules for wide industrialization in the future. Polyrotaxanes are widely introduced into materials such as elastomers, hydrogels, and engineering polymers to improve their mechanical properties or impart functionality to the materials. In these materials, polyrotaxane acts as a slidable cross-linker to dissipate energy through sliding or assist in dispersing stress concentration in the cross-linked network, thereby enhancing the toughness of the materials. Further, the unique sliding-ring effect of cyclodextrin-based polyrotaxanes has pioneered advancements in stretchable electronics and energy storage materials. This includes their innovative use in stretchable conductive composite and binders for anodes, addressing critical challenges in these fields. In this mini-review, our focus is to highlight the current progress and potential wider applications in the future, underlining their transformative impact across various domains of material science.

Mechanical Stretch α-Cyclodextrin Pseudopolyrotaxane Elastomer with Reversible Phosphorescence Behavior

Polyethylene glycol chains in two terminals of the naphthalene functional group are threaded into α-cyclodextrin cavities to form the pseudopolyrotaxane (NPR), which not only effectively induces the phosphorescence of the naphthalene functional group by the cyclodextrin macrocycle confinement, but also provides interfacial hydrogen bonding assembly function between polyhydroxy groups of cyclodextrin and waterborne polyurethane (WPU) chains to construct elastomers. The introduction of NPR endows the elastomer with enhanced mechanical properties and excellent room temperature phosphorescent (RTP) emission (phosphorescence remains in water, acid, alkali, and organic solvents, even at 160 °C high temperatures). Especially, the reversible mechanically responsive room temperature phosphorescence behavior (phosphorescence intensity increased three times under 200% strain) can be observed in the mechanical stretch and recover process, owing to strain-induced microstructural changes further inhibiting the non-radiative transition and the vibration of NPR. Therefore, changing the phosphorescence behavior of supramolecular elastomers through mechanical stretching provides a new approach for supramolecular luminescent materials.

Highly Elastic, Robust, and Efficient Hydrogel Solar Absorber against Harsh Environmental Impacts

Solar distillation is a promising approach for addressing water scarcity, but relentless stress/strain perturbations induced by wind and waves would inevitably cause structural damage to solar absorbers. Despite notable advances in efficient solar absorbers, there have been no reports of compliant and robust solar absorbers withstanding practical mechanical impacts. Herein, an elastic and robust hydrogel absorber that exhibited a high level of evaporation performance was fabricated by introducing ion-coordinated MXene nanosheets as photothermal conversion units and mechanically enhanced fillers. The ion-coordinated MXene nanosheets acting as strong cross-linking points provided excellent elasticity and robustness to the hydrogel absorber. As a result, the evaporation rate of hydrogel absorber, with a high initial value of 2.61 kg m-2 h-1 under one sun irradiation, remained at 2.15 kg m-2 h-1 under a 100% tensile strain state and 2.40 kg m-2 h-1 after 10 000 stretching-releasing cycles. This continuous and stable water desalination approach provides a promising device for actual seawater distillation.

Aesthetic Cellulose Filaments with Water-Triggered Switchable Internal Stress and Customizable Polarized Iridescence Toward Green Fashion Innovation

Healthy, convenient, and aesthetic hair dyeing and styling are essential to fashion trends and personal-social interactions. Herein, we fabricate green, scalable, and aesthetic regenerated cellulose filaments (ACFs) with customizable iridescent colors, outstanding mechanical properties, and water-triggered moldability for convenient and fashionable artificial hairdressing. The fabrication of ACFs involves cellulose dissolution, cross-linking, wet-spinning, and nanostructured orientation. Notably, the cross-linking strategy endows the ACFs with significantly weakened internal stress, confirmed by monitoring the offset of the C-O-C group in the cellulose molecular chain with Raman imaging, which ensures a tailorable orientation of the nanostructure during wet stretching and tunable iridescent polarization colors. Interestingly, ACFs can be tailored for three-dimensional shaping through a facile water-triggered adjustable internal stress: temporary shaping with low-level internal stress in the wet state and permanent shaping with high-level internal stress in the dry state. The health, convenience, and green aesthetic filaments show great potential in personal wearables.

Elastic properties and tensile strength of 2D Ti3C2Tx MXene monolayers

Two-dimensional (2D) transition metal nitrides and carbides (MXenes), represented by Ti3C2Tx, have broad applications in flexible electronics, electromechanical devices, and structural membranes due to their unique physical and chemical properties. Despite the Young's modulus of 2D Ti3C2Tx has been theoretically predicted to be 0.502 TPa, which has not been experimentally confirmed so far due to the measurement is extremely restricted. Here, by optimizing the sample preparation, cutting, and transfer protocols, we perform the direct in-situ tensile tests on monolayer Ti3C2Tx nanosheets using nanomechanical push-to-pull equipment under a scanning electron microscope. The effective Young's modulus is 0.484 ± 0.013 TPa, which is much closer to the theoretical value of 0.502 TPa than the previously reported 0.33 TPa by the disputed nanoindentation method, and the measured elastic stiffness is ~948 N/m. Moreover, during the process of tensile loading, the monolayer Ti3C2Tx shows an average elastic strain of ~3.2% and a tensile strength as large as ~15.4 GPa. This work corrects the previous reports by nanoindentation method and demonstrates that the Ti3C2Tx indeed keeps immense potential for broad range of applications.

Bioinspired Organic Porous Coupling Agent for Enhancement of Nanoparticle Dispersion and Interfacial Strength

Composite materials have significantly advanced with the integration of inorganic nanoparticles as fillers in polymers. Achieving fine dispersion of these nanoparticles within the composites, however, remains a challenge. This study presents a novel solution inspired by the natural structure of Xanthium. We have developed a polymer of intrinsic microporosity (PIM)-based porous coupling agent, named PCA. PCA's rigid backbone structure enhances interfacial interactions through a unique intermolecular interlocking mechanism. This approach notably improves the dispersion of SiO2 nanoparticles in various organic solvents and low-polarity polymers. Significantly, PCA-modified SiO2 nanoparticles embedded in polyisoprene rubber showed enhanced mechanical properties. The Young's modulus increases to 30.7 MPa, compared to 5.4 MPa in hexadecyltrimethoxysilane-modified nanoparticles. Further analysis shows that PCA-modified composites not only become stiffer but also gain strength and ductility. This research demonstrates a novel biomimetic strategy for enhancing interfacial interactions in composites, potentially leading to stronger, more versatile composite materials.

High-strength nacre-like composite films based on pre-polymerised polydopamine and polyethyleneimine cross-linked MXene layers via multi-bonding interactions

Demands for high-strength flexible electrodes have significantly increased across various fields, especially in wearable electronics. Inspired by the strong integrated layered structure of the natural nacre via multi-bonding interactions, we report the fabrication of the strong integrated nacre-like composite films based on pre-polymerised polydopamine and polyethyleneimine cross-linked MXene layers (p-DEM), achieving the synergic effect of hydrogen bonding, covalent bonding and electrostatic interactions. As a result, a high-level tensile strength of ∼302 MPa, 10.8 times higher than that of the plain MXene film, is obtained for the prepared p-DE0.5M composite film. Meanwhile, the composite film also delivers superior energy storage (∼1218F cm-3 at 5 mV s-1) and rate performances (capacitance retention of 81.3% at 1000 mV s-1). To demonstrate the practical application of the composite films, a symmetrical supercapacitor based on p-DE0.5M electrodes is assembled, which shows stable energy storage performances under different deformation states such as bending angles at 0, 60, 90 and 180°, or withstand repeated bending times (1000 cycles). This type of multi-bonding interactions induced strong integrated MXene assembly may promote the wide applications of MXene-based films in flexible electronics, artificial intelligence, and tissue engineering, to name a few.

Liquid Metal-Based Stable and Stretchable Zn-Ion Battery for Electronic Textiles

Electronic textiles harmoniously interact with the human body and the surrounding environment, offering tremendous interest in smart wearable electronics. However, their wide application faces challenges due to the lack of stable and stretchable power electrodes/devices with multifunctional design. Herein, an intrinsically stretchable liquid metal-based fibrous anode for a stable Zn-ion battery (ZIB) is reported. Benefiting from the liquid feature and superior deformability of the liquid metal, optimized Zn ion concentration distribution and Zn (002) deposition behavior are observed, which result in dendrite-free performance even under stretching. With a strain of 50%, the ZIB maintains a high capacity of 139.8 mAh cm-3 (corresponding to 83.0% of the initial value) after 300 cycles, outperforming bare Zn fiber-based ZIB. The fibrous ZIB seamlessly integrates with the sensor, Joule heater, and wirelessly charging device, which provides a stable power supply for human signal monitoring and personal thermal management, holding promise for the application of wearable multifunctional electronic textiles.

Interlocking-Governed Ultra-Strong and Highly Conductive MXene Fibers Through Fluidics-Assisted Thermal Drawing

High-performance MXene fibers are always of significant interest for flexible textile-based devices. However, achieving high mechanical property and electrical conductivity remains challenging due to the uncontrolled loose microstructures of MXene (Ti3 C2 Tx and Ti3 CNTx ) nanosheets. Herein, high-performance MXene fibers directly obtained through fluidics-assisted thermal drawing are demonstrated. Tablet interlocks are formed at the interface layer between the outer cyclic olefin copolymer and inner MXene nanosheets due to the thermal drawing induced stresses, resulting in thousands of meters long macroscopic compact MXene fibers with ultra-high tensile strength, toughness, and outstanding electrical conductivity. Further, large-scale woven textiles constructed by these fibers offer exceptional electromagnetic interference shielding performance with excellent durability and stability. Such an effective and sustainable approach can be applied to produce functional fibers for applications in both daily life and aerospace.

Rheology Engineering for Dry-Spinning Robust N-Doped MXene Sediment Fibers toward Efficient Charge Storage

MXene nanosheets are believed to be an ideal candidate for fabricating fiber supercapacitors (FSCs) due to their metallic conductivity and superior volumetric capacitance, while challenges remain in continuously collecting bare MXene fibers (MFs) via the commonly used wet-spinning technique due to the intercalation of water molecules and a weak interaction between Ti3 C2 TX nanosheets in aqueous coagulation bath that ultimately leads to a loosely packed structure. To address this issue, for the first time, a dry-spinning strategy is proposed by engineering the rheological behavior of Ti3 C2 TX sediment and extruding the highly viscose stock directly through a spinneret followed by a solvent evaperation induced solidification. The dry-spun Ti3 C2 TX fibers show an optimal conductivity of 2295 S cm-1 , a tensile strength of 64 MPa and a specific capacitance of 948 F cm-3 . Nitrogen (N) doping further improves the capacitance of MFs to 1302 F cm-3 without compromising their mechanical and electrical properties. Moreover, the FSC based on N-doped MFs exhibits a high volumetric capacitance of 293 F cm-3 , good stability over 10 000 cycles, excellent flexibility upon bending-unbending, superior energy/power densities and anti-self-discharging property. The excellent electrochemical and mechanical properties endow the dry-spun MFs great potential for future applications in wearable electronics.

Recent Advances in MXene-Based Fibers: Fabrication, Performance, and Application

Two-dimensional transition metal carbide/nitrides (MXenes) have recently received extensive attention due to their diverse material types and versatile structures, large-scale production, and excellent properties. MXene sheets possess abundant hydrophilic functional groups on their surface, which enable them to be assembled into macroscopic fibers or compounded with other functional materials to produce composite fibers. This review aims to provide a comprehensive analysis of MXene fibers in terms of their fabrication, structure, properties, and recent applications as flexible and wearable electronics. The review will discuss the principles of different methods used to synthesize MXene fibers and analyze the characteristics of the as-synthesized fibers, with a particular focus on the wet spinning method. The fundamental relationships between the microstructure of MXene fibers and their resulting mechanical and electrical properties will be explored. Furthermore, the review will elaborate on the progress made in MXene-based fibers in the rapidly growing field of wearable electronics applications, provide insights into future development of MXene fiber materials and propose solutions to the challenges facing practical applications.

MXene Fibers for Flexible and Wearable Electronics: Recent Progress and Future Perspectives

With the impetus of flexible electronics and micro-nano fabrication technology, the human demand for flexible intelligent wearable devices is on an upsurge. In recent years, new functional fibers have undergone rapid development and emerged as an indispensable carrier of flexible wearable e-textiles. However, to achieve their functional applications and durability, new functional fibers must possess good electrical and mechanical properties. As an emerging two-dimensional material, MXenes have attracted immense attention for their high electrical conductivity, mechanical strength, specific surface area, adjustable surface properties, and exceptional processability. As such, MXenes have become an ideal candidate for the primary functional component of functional fibers. This paper presents a comprehensive review of research progress on MXene-based fibers in the construction of flexible wearable electronic textiles. Firstly, we briefly outline the preparation methods of MXenes materials. Next, we summarize the processing types of MXene-based fibers and highlight their performance parameters. Lastly, we summarize the primary application scenarios of MXene-based fibers and anticipate the future development of flexible wearable e-textiles.