Smart Fiber Research Articles

A review on recent trends in smart textiles

Recent advancements in both domestic and international research have considerably enhanced the development of smart fibers and smart textile, which are now being increasingly integrated into the textile industry. Advanced textiles encompass five primary functions; sensors, data processing, actuators, storage and communication. These technologies must be effectively integrated into clothing, ensuring they meet essential requirements like comfort, durability, and resilience to routine maintenance. Designers engaged with traditional textiles might address challenges by integrating smart materials and re-evaluating their design methodologies to leverage the distinctive properties of these advanced materials. This review examines recent developments in Smart Textiles, emphasizing the materials and their recent trends.

Photo-thermal effects initiate multi-level energy conversion in “solid-solid” phase-changing fibers

The current textiles primarily employ passive heat barriers to minimize heat loss and achieve effective thermal insulation for human beings. Accordingly, intelligent fibers with energy storage and temperature control capabilities have garnered significant attention due to their potential to revolutionize textile technology. The study integrates the photo-thermal effect and phase change energy storage materials onto a fiber, thereby fabricating a fully intelligent energy storage fiber. This innovation enables the multi-level conversion of sunlight: “Optical energy - Thermal energy - Phase transition energy - Thermal energy”. The intelligent fiber efficiently converts solar energy into heat energy through the photo-thermal coupling of CuNPs, subsequently inducing a spatial conformational change in the solid-solid phase change material within the fiber for effective heat storage. The hybrid fiber possesses enhanced mechanical properties but also exhibits a significantly high phase transition enthalpy value of 49.75 J g−1 and a phase transition temperature suitable for human body temperature (20.19–30.21 °C), especially the fiber is more durable. The photo-thermal conversion test vividly demonstrates the systematic transformation of four distinct forms of energy within the composite fiber. This approach holds significant potential for advancing the field of smart fiber technology.

Photo-induced time-dependent controllable wettability of dual-responsive multi-functional electrospun MXene/polymer fibers

Switchable wettability potential in smart fibers is of paramount importance in various applications. Light-induced controllable changes in surface wettability have a significant role in this area. Herein, smart waterborne homopolymer, functional copolymer with different polarity and flexibility, and multi-functional terpolymer particles containing a time-dependent dual-responsive acrylated spiropyran, as a polymerizable monomer, were successfully synthesized through eco-friendly single-step emulsifier-free emulsion polymerization. Presence of 10 wt% of butyl acrylate and dimethylaminoethyl methacrylate relative to methylmethacrylate as functional comonomers decreased the Tg of the samples almost 20 ℃ and increased their polarity. The optical properties of the particles were investigated, and the UV–vis and fluorescence spectroscopy results showed that not only polarity and flexibility of the polymer chains may have a positive effect on improving the optical properties, but also the simultaneous presence of functional groups has a synergistic effect. The smart polymer particles with flexibility and polarity features exhibited higher absorption and emission compared to other samples. Inspired by these findings, multi-functional smart polymer fibers were prepared using the electrospinning method. The smart multi-functional electrospun fibers containing few-layer Ti3C2 MXenes were synthesized to improve the fibers’ properties and change the surface wettability due to the hydrophilic functional groups of MXene. Field-emission scanning electron microscopy images displayed the successful preparation of few-layer MXenes. Smooth and bead-free fibers with bright red fluorescence emission under UV irradiation were shown using fluorescence microscopy. The study on the surface wettability of fibers revealed that UV and visible light irradiation induced reversible time-dependent changes in the wettability of the smart multi-functional MXene/polymer electrospun fibers from hydrophobic to hydrophilic, reaching a water contact angle of 10° from an initial water contact angle of 100° under UV light and also changing to superhydrophilic state with passing time. Upon visible light exposure, the fibers returned to their original state. Furthermore, the fibers demonstrated a high stability over five alternating cycles of UV and visible light irradiation. This study shows that the fabrication of time-dependent smart fibers, utilizing the flexibility and polarity in the presence of MXenes, significantly improves and controls surface wettability changes. The outstanding dynamically photo-switchable wettability of these fibers may offer exciting opportunities in various applications, especially in the separation of oil from water contaminants.

Enhanced multifunctional sensing in human motion with speed-controlled coaxial wet-spun hollow MWCNT-TPU/TPU smart fibers

In the field of personal health management and athletic performance optimization, the demand for multi-parameter human signal monitoring devices is rapidly increasing. Currently, flexible sensors produced through wet spinning techniques face challenges of simplistic structure and functionality, as well as difficulty in balancing strength and sensitivity. In-depth research is needed to develop high-performance wet spinning techniques, which will lay the foundation for commercial smart garments capable of unobtrusively monitoring human motion in the future. This study innovatively employs specialized slurry formulations and spinning speed controls to utilize the timing differences in fiber precipitation and the affinity among similar materials. Through the coaxial wet spinning process, it enables the continuous, large-scale manufacturing of hollow core–shell fibers, MT/T-S5, which feature a dense inner layer and a porous outer conductive layer. This special structure endows the fibers with high strength, high signal stability, and capabilities for both active and passive heating. These fibers achieve a maximum gauge factor (GF) 65.2 in stretch sensing applications and can detect pressures as low as 0.1 N. The MT/T-S5 smart fibers can sense human joint movements, and through connection with an Arduino microcontroller, they can control a robotic hand and perform independent and real-time motion detection of five fingers to distinguish gestures. This research not only provides a new type of fiber material for the development of future smart textiles but also reveals a formation mechanism for hollow core–shell fibers in the field of wet spinning. This discovery can offer valuable inspiration for fiber structural design in future research.

Smart fibers and products for aerospace applications

Smart fibers and products for aerospace applications

A Review of the Electrical Conductivity Test Methods for Conductive Fabrics

With the substantial growth of the smart textiles market, electrical properties are becoming a basic requirement for most of the advanced textiles used in the development of wearable solutions and other textile-based smart applications. Depending on the textile substrate, the test method to determine the electrical properties can be different. Unlike smart fibers and yarns, the characterization of the electrical properties of fabrics cannot be tested between two connection points because the result would not represent the behavior of the entire fabric, so the electrical properties must be related to an area. The parameters used to characterize the electrical properties of the fabrics include resistance, resistivity, and conductivity. Although all of them can be used to indicate electrical performance, there are significant differences between them and different methods available for their determination, whose suitability will depend on the function and the textile substrate. This paper revises the main parameters used to characterize the electrical properties of conductive fabrics and summarizes the most common methods used to test them. It also discusses the suitability of each method according to several intervening factors, such as the type of conductive fabric (intrinsically or extrinsically conductive), its conductivity range, other fabric parameters, or the final intended application. For intrinsically conductive woven fabrics, all the methods are suitable, but depending on the requirements of conductivity accuracy, the contact resistance from the measuring system should be determined. For intrinsically conductive knitted fabrics, two-point probe, Van der Pauw, and eddy current methods are the most suitable. And for intrinsically conductive nonwoven fabrics, two-point probe and four-point probe methods are the most appropriate. In the case of extrinsically conductive fabrics, the applied method should depend on the substrate and the properties of the conductive layer.

Modulating oxygen vacancies in MXene/MoO3-x smart fiber by defect engineering for ultrahigh volumetric energy density supercapacitors and wearable SERS sensors

MXene fibers are expected to accelerate the sustainable development of intelligent era as multi-functional smart fibers. However, MXene fibers have serious obstacles when used for multi-functional applications. Here, we fabricated a multi-functional MXene fiber by incorporating MoO3-x nanobelts with abundant oxygen vacancies via wet spinning and defect engineering methods. Benefiting from the presence of abundant oxygen vacancies, the produced MXene/MoO3-x fibers not only provide more active sites to interact with electrolyte ions, but also substantially augment the rate capacities of fibers due to the enlarged distances between MXene flakes. Thus, the assembled fiber-based supercapacitor (SCs) realized high capacitance of 869.1F cm−3 at 0.5 A cm−3, good volumetric energy density of 77.3 mWh cm−3 at a power density of 204.8 mW cm−3 and long-term cycling stability along with 86.4 % capacity retention after 5000 cycles. Moreover, due to the narrowed bandgap of MoO3-x produced by defect engineering enhanced the charge transfer between the fiber and molecules, MXene/MoO3-x fiber also demonstrated a low limit of detection and reliable biomarkers detection in artificial sweat. These findings provide the potential application of MXene-based fibers in multi-functional devices.

A hybrid cascade-parallel discriminative-generative model for pipeline integrity threat detection in a smart fiber optic surveillance system

A hybrid cascade-parallel discriminative-generative model for pipeline integrity threat detection in a smart fiber optic surveillance system

NP-Doped Fiber Smart Tendon: A Millimeter-Scale 3-D Shape Reconstruction With Embedded Distributed Optical Fiber Sensor System

NP-Doped Fiber Smart Tendon: A Millimeter-Scale 3-D Shape Reconstruction With Embedded Distributed Optical Fiber Sensor System

Large‐Area Knittable, Wash‐Durable, and Healable Smart Fibers for Dual‐Modal Sensing Applications

AbstractFiber‐based multimodal sensors with electrical/optical signals are highly desired for next‐generation wearable electronics. Despite the remarkable progress in this area, achieving large‐scale knittable, washable, and self‐healing performance in fiber‐based multimodal sensors simultaneously remains a great challenge. Here, a smart fiber capable of exhibiting piezoresistive/luminescent properties based on an H‐bonding connected multilayered core–shell nanostructure is developed. The core principle of this design involves constructing strong interfacial interactions between the fiber layers, which results in a sensor with high sensitivity (gauge factor = 12383500), exceptional water resistance, and robust self‐healing properties (tensile strength 30.9 MPa, healing efficiency 72.9%). Unlike traditional fiber‐based sensors where elaborate nanostructures are prone to shedding during knitting, this strategy enables the fiber sensors with excellent knittability to be patterned in the fabric, improving both optical and electrical sensitivities. This work is anticipated to make a significant contribution to the further development of wearable electronic products and visual human–computer interaction electronic devices.

Enhanced sensing performance of superelastic thermally drawn liquid metal fibers through helical architecture while eliminating directional signal errors

Due to their potential use in creating advanced electronic textiles for wearable technology, functional fibers have garnered enormous interests. The presence of stretchable smart fibers has significantly expanded the application scenarios of intelligent fibers. However, preparing fibers that possess both excellent electrical performance and high stretchability remains a formidable challenge. The fabrication of stretchable multifunctional fiber-based sensors employing a scalable method is reported here. Using a thermal drawing process, the collaborative interplay between the hollow confined channels of superelastic poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) thermally drawn fibers and the high fluidity of liquid metal (LM) ensures the exceptional electrical performance of the fibers. Simultaneously, the presence of a helical structure further enhances both the sensing and mechanical properties. The helical two LM channel fiber-based sensors are capable of displaying more than 1000 % strain, high stability over 1000 cycles, a quick pressure response and release time of 30.45 and 45.35 ms, and outstanding electrical conductivity of 8.075 × 105 S/m. In addition, the electrical conductivity of this fiber increases with strain level, reaching 3 × 106 S/m when the strain is 500 %. Furthermore, due to their superior tension and compression sensing capabilities, flexible helical sensors offer considerable potential for use in wearable electronics applications such as human motion detection, Morse code compilation, multichannel sensing, and more.

Silk-based intelligent fibers and textiles: structures, properties, and applications.

Multifunctional fibers represent a cornerstone of human civilization, playing a pivotal role in numerous aspects of societal development. Natural biomaterials, in contrast to synthetic alternatives, offer environmental sustainability, biocompatibility, and biodegradability. Among these biomaterials, natural silk is favored in biomedical applications and smart fiber technology due to its accessibility, superior mechanical properties, diverse functional groups, controllable structure, and exceptional biocompatibility. This review delves into the intricate structure and properties of natural silk fibers and their extensive applications in biomedicine and smart fiber technology. It highlights the critical significance of silk fibers in the development of multifunctional materials, emphasizing their mechanical strength, biocompatibility, and biodegradability. A detailed analysis of the hierarchical structure of silk fibers elucidates how these structural features contribute to their unique properties. The review also encompasses the biomedical applications of silk fibers, including surgical sutures, tissue engineering, and drug delivery systems, along with recent advancements in smart fiber applications such as sensing, optical technologies, and energy storage. The enhancement of functional properties of silk fibers through chemical or physical modifications is discussed, suggesting broader high-end applications. Additionally, the review addresses current challenges and future directions in the application of silk fibers in biomedicine and smart fiber technologies, underscoring silk's potential in driving contemporary technological innovations. The versatility and sustainability of silk fibers position them as pivotal elements in contemporary materials science and technology, fostering the development of next-generation smart materials.

NIR-induced photothermal-responsive shape memory polyurethane for versatile smart material applications.

Stimuli responsiveness has been an attractive feature of smart material design, allowing the chemical and physical properties of the materials to change in response to small environmental variations. The versatile shape memory polyurethane (SMPU) has been advanced into thermally-responsive SMPU, enabling its use in neurovascular stents, smart fibers for compression garments, and thermal-responsive components for aircraft and aerospace structures. While thermally-induced SMPU materials exhibit excellent shape recovery and fixity, they encounter limitations such as long response times, energy-intensive heating processes, and potential damage to heat-sensitive components, hindering their wide application. Thus, SMPU has further advanced into a photothermal-responsive material by incorporating photothermal agents into the polymer matrix, offering faster response times, compatibility with heat-sensitive materials, and enhanced mechanical properties, expanding the versatility and applicability of shape memory technology. This review focuses on the classes of NIR-induced photothermal agent used in SMPU systems, their synthesis methods, and photothermal-responsive mechanism under NIR-light, which offers a dual responsiveness to the host SMPU. The advantages and limitations of NIR-induced photothermal SMPU are reviewed, and challenges in their development are discussed.

Sodium alginate-based coaxial fibers synergistically integrate moisture actuation, length tracing, humidity sensing, and electric heating.

The development of wearable electronics has driven the need for smart fibers with advanced multifunctional synergy. In this paper, we present a design of a multifunctional coaxial fiber that is composed of a biopolymer-derived core and an MXene/silver nanowire (AgNW) sheath by wet spinning. The fiber synergistically integrates moisture actuation, length tracing, humidity sensing, and electric heating, making it highly promising for portable devices and protective systems. The biopolymer-derived core provides deformation for moisture-sensitive actuation, while the MXene/AgNW sheath with good conductivity enables the fiber to perform electric heating, humidity sensing, and self-sensing actuation. The coaxial fiber can be programmed to rapidly desorb water molecules to shrink to its original length by using the MXene/AgNW sheath as an electrical heater. We demonstrate proof-of-concept applications based on the multifunctional fibers for thermal physiotherapy and wound healing/monitoring. The sodium alginate@MXene-based coaxial fiber presents a promising solution for the next-generation of smart wearable electronics.

2D Materials Beyond Post-AI Era: Smart Fibers, Soft Robotics, and Single Atom Catalysts.

Recent consecutive discoveries of various 2D materials have triggered significant scientific and technological interests owing to their exceptional material properties, originally stemming from 2D confined geometry. Ever-expanding library of 2D materials can provide ideal solutions to critical challenges facing in current technological trend of the fourth industrial revolution. Moreover, chemical modification of 2D materials to customize their physical/chemical properties can satisfy the broad spectrum of different specific requirements across diverse application areas. This review focuses on three particular emerging application areas of 2D materials: smart fibers, soft robotics, and single atom catalysts (SACs),which hold immense potentials for academic and technological advancements in the post-artificial intelligence (AI) era. Smart fibers showcase unconventional functionalities including healthcare/environmental monitoring, energy storage/harvesting, and antipathogenic protection in the forms of wearable fibers and textiles. Soft robotics aligns with future trend to overcome longstanding limitations of hard-material based mechanics by introducing soft actuators and sensors. SACs are widely useful in energy storage/conversion and environmental management, principally contributing to low carbon footprint for sustainable post-AIera. Significance and unique values of 2D materials in these emerging applications are highlighted, where the research group has devoted research efforts for more than a decade.

Current Research Status and Development Trends of Cooling Suits in High-Temperature Mine Environments: A Review

To gain a deeper understanding of the current research status of cooling suits in high-temperature mines, this paper provides separate introductions to vest-type cooling suits and full-body cooling suits. It summarizes the categories of cooling suits based on different cooling media and systematically elucidates the advantages and disadvantages of each type. The paper also analyzes the current application status of cooling suits in mine environments. It suggests that the future research directions for cooling suits in mines include the miniaturization of components, intelligent temperature control, optimization of new phase-change materials, development of cooling fabrics, and research in smart fibers.

Emerging Smart Micro/Nanofiber‐Based Materials for Next‐Generation Wound Dressings

AbstractSmart wound dressings capable of detecting, monitoring, and regulating complicated dynamic healing processes hold tremendous potential in wound healing and tissue reconstruction. Micro/nanofiber‐based materials are regarded as one of the most promising candidates to develop smart wound dressings owing to their remarkable features including architectural mimicry of extracellular matrix, tunability in structural assembly, and diversity in functionality. Herein, the latest progress of smart micro/nanoscale fiber‐based materials in terms of composition engineering, structural design, and applications in wound management is comprehensively reviewed. This work begins with the advances in smart fibers including stimuli‐responsive fibers, shape memory fibers, and conductive fibers. Then, the structural design of fiber‐based materials from conventional 2D fibrous membrane to emerging 3D fibrous sponge/hydrogel is thoroughly discussed. Furthermore, the applications of smart micro/nanofibrous materials as wound dressings in stimuli‐responsive drug delivery, biomechanical stimulation, electrical stimulation, and wound monitoring are highlighted. Finally, the article offers perspectives on the existing challenges and future directions of smart fibrous materials for wound management.

Highly conductive and elastic multi-responsive phase change smart fiber and textile

Smart fiber, which can sense external environment changes intelligently and response quickly, has become an important building block to weave wearable system. Wet-spinning phase change materials (PCM) into smart fabrics offers great promise to regulate temperature and achieve personized thermal comfort in an intelligent way. However, the intrinsic low mechanical elasticity and stimuli responsiveness of PCM seriously blocking its application in wearable systems. In this work, we developed an ultra-stretchable PCM-based smart fiber for personal healthcare and thermal management, via wet-spinning PCM microcapsules embedded in elastic polyurethanes with dual responsive networks. Organic poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) “glued” inorganic carbon nanotubes/graphene skeleton into 3D hierarchically interconnected responsive and sensitive network along elastic fibers, which not only exhibits high sensitivity to multi stimuli (mechanical/electrical/thermal/light), but also facilitates efficient carrier transfer between PCM microcapsules for rapid response. Elastic PCM-based smart fiber with high mechanical stretchability (>200%) not only could adapt to the intense large movements seamlessly, but also convert these deformations into electrical signals for healthcare monitoring. Furthermore, the stretchable conductive PCM-based smart fiber(1.96×104 S/m) still remains robust stimuli-responsiveness with excellent Joule heating and photothermal effect even under large mechanical deformations, which could convert multi stimuli into latent thermal energy during response process and store it for self-powered personal thermal management. The robust PCM-based smart fiber with outstanding knotting capability can be woven into large-scale breathable textiles. The stretchable multi-responsive PCM-based fiber holds great potential in emerging wearable electronics and smart textiles.

Electricity trigger chameleon core-shell fiber via liquid metal drive thermochromic polyacrylonitrile

The discovery of color-controlled fiber holds profound importance for the development of flexible wearable devices and soft display equipment. In this study, a kind of electrically triggered chameleon fiber (ETF) was fabricated. Liquid metal was used as the conductive core structure, and red, blue and yellow thermochromic pigments were mixed into a polyacrylonitrile solution with dimethyl sulfoxide as solvent to form the thermochromic matrix shell structure. By coaxial wet spinning, reversible, ETF with a core-shell structure was prepared. We utilized joule heating to drive the thermochromic pigments change the conjugate plating by adjusting the color. ETF has therefore ideal electrochromism properties. This smart fiber appearing as a dark purple fiber at room temperature and can change color when the current is adjusted. The color expressive of ETFs changed from dark purple (0.2 A) to green (0.6 A), then to yellow (1 A), and finally to white (1.2 A). When the current was turned off, the fibers were able to return to their original color due to the conjugated structure transformation of the three thermochromic pigments. Moreover, ETFs demonstrated good thermal stability, tolerating temperatures of up to 200 ℃. This work offers a simple and cost-effective method for developing soft display equipment.

In-situ twisted spiral fiber with tree-ring like structure for joule heating, photothermal and humidity sensing

Smart fibers are increasingly becoming an optimal material for producing the next generation of flexible wearable electronics. However, balancing practical functionality and comfort remains a major challenge at this stage. Herein, we have prepared a bacterial cellulose (BC)/MXene-30% composite fiber using an in-situ twisting method, as this fiber possessed excellent conductivity (4050 S/m) and mechanical strength (108 Mpa). In addition, this BC/MXene spiral fiber has excellent joule heating and photothermal performance, which can be rapidly heated up to 70 °C within 25 s under a low voltage of only 9 V. They also have a stable and repeatable light-induced heating capability under 250 W infrared light. This new fiber material has a simple preparation process and versatile functional characteristics, which broadens its application in the fields of intelligent hyperthermia, respiratory monitoring, water level warnings and so on. The BC/MXene spiral fiber exhibited in this work is expected to provide a powerful database and theoretical reference for the next generation of flexible wearable electronic products.