Advanced Fiber Materials最新文献

Conventional wound dressings only protect passively against bacterial infection. Emerging mechanically active adhesive dressings (AADs) are inspired by the active closure of embryonic wounds. It can promote wound healing by actively contracting the wound bed. AADs meet the requirements of high toughness, stimulus–response, and dynamic adhesion properties, which are challenging. Hence, we construct a water-responsive shape memory polyurea fibrous membrane (PU-fm) featuring favorable toughness, wet-adhesion, breathability, absorbency of four times its weight, and antibacterial. First, the water-toughened electrospun PU-fm is fabricated using a homemade polyurea (PU) elastomer with multistage hydrogen bond networks as a spinning solution. Furthermore, a Janus-structured polyurea-polydopamine-silver fibrous membrane (PU@PDA@Ag-fm) is engineered, integrating antibacterial properties without compromising mechanical robustness. It demonstrates strong adhesion to the skin, actively promotes wound contraction, and enables adaptive wrapping of tissues of varying sizes by the water-driven shape memory effect. Antibacterial tests and wound healing experiments indicate that the PU@PDA@Ag-fm has favorable antibacterial properties against Escherichia coli (E.coli) and accelerates the wound healing rate by 20%. For the first time, water-responsive shape memory PU-fm as the AADs is constructed, providing a new strategy for wound management. This can be extended to applications in other smart devices for biomedicine such as tendon repair, and bioelectronic interfaces.

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Currently, the development of clean and green energy-harvesting solutions is becoming increasingly critical. Batteries have long been considered as the most traditional and efficient technology for powering electronic devices. However, they have a limited lifetime and require constant observation and replacement. To address this issue, triboelectric nanogenerator (TENG) has garnered considerable attention as a prospective sustainable power source for smart devices. Further, several approaches for improving their output performance have been investigated. Herein, we created a unique TENG based on densely packed molybdenum disulfide (MoS₂) petals grown on electrospun polyacrylonitrile (PAN) fibers (MPF) using a hydrothermal technique. Designed MPF-TENG is used for mechanical energy-harvesting and smart study room touch sensor applications. The effects of pure MoS₂ powder, PAN fibers, and MoS₂ grown on the PAN fibers were investigated. MoS₂ addition enhanced the surface charge, surface roughness, and electrical performance. The MPF-TENG had a maximum triboelectric output voltage, current, charge, and average power density of 245.3 V, 5.12 µA, 60.2 nC, and 1.75 W/m², respectively. The MPF-TENG remained stable for more than 10,000 cycles. The MPF-TENG successfully illuminated blue LEDs, turned on a timer clock, and could be used in smart study rooms to generate energy. This study provides an effective method for improving the performance of TENG by growing MoS₂ petals on PAN fibers, with promising applications in power supplies for portable electronic devices. Furthermore, the fabricated MPF-TENG was demonstrated to be a potential touch sensor for smart study rooms to save electricity.

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A bimodal coupled multifunctional tactile perceptron for contactless gesture recognition and material identification is proposed to address the challenges posed by limited functionality, signal interference from multimodal collaborative work, and the high power consumption of traditional tactile sensors. This perceptron integrates a capacitive sensor and a triboelectric sensor symmetrically, employing an energy complementarity strategy to reduce power consumption and implementing symmetrical distribution of two sensors for physical isolation to prevent signal interference. The capacitive sensor detects external pressure, providing information on material properties such as hardness, softness, and deformation, with a wide linear response range of 0–745.3 kPa. The triboelectric sensor captures the electron affinity of measured object. Further, by utilising machine learning algorithms, a system for contactless gesture recognition and material identification is engineered. This system demonstrates a remarkable accuracy rate of 98.5% when recognising 5 gestures, and achieves a perfect identification (100%) of 10 different materials aided by incorporating capacitive and triboelectric response. These results greatly advance the progress of tactile perceptrons with high integration, low power consumption, and multifunctionality, enhancing their effectiveness and reliability in smart device applications.

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Wearable sensors have been rapidly developed for application in various human monitoring systems. However, the wearing comfort and thermal properties of these devices have been largely ignored, and these characteristics urgently need to be studied. Herein, we develop a wearable and breathable nanofiber-based sensor with excellent thermal management functionality based on passive heat preservation and active Joule heating effects. The multifunctional device consists of a micropatterned carbon nanotube (CNT)/thermoplastic polyurethane (TPU) nanofiber electrode, a microporous ionic aerogel electrolyte and a microstructured Ag/TPU nanofiber electrode. Due to the presence of a supercapacitive sensing mechanism and the application of microstructuration, the sensor shows excellent sensing performance, with a sensitivity of 24.62 kPa⁻¹. Moreover, due to the overall porous structure and hydrophobicity of TPU, the sensor shows good breathability (62 mm/s) and water repellency, with a water contact angle of 151.2°. In addition, effective passive heat preservation is achieved by combining CNTs with high solar absorption rates (85%) as the top layer facing the outside, aerogel with a low thermal conductivity (0.063 W m⁻¹ k⁻¹) as the middle layer for thermal insulation, and Ag with a high infrared reflectance rate as the bottom layer facing the skin. During warming, this material yields a higher temperature than cotton. Furthermore, the active Joule heating effect is realized by applying current through the bottom resistive electrode, which can quickly increase the temperature to supply controlled warming on demand. The proposed wearable and breathable sensor with tunable thermal properties is promising for monitoring and heat therapy applications in cold environments.

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We reported a wearable and breathable nanofiber-based sensor with excellent thermal management functionality based on passive heat preservation and active Joule heating effects.

Spiral fibers with high energy storage and high output efficiency are highly desirable for soft robots and actuators. However, it is still a great challenge to achieve spiral fibers with excellent water actuation performance, structural stability, and high scalability in a low-cost strategy. A coaxial spiral structure is reported for the fabrication of high-performance fiber actuators. The developed shell–core helical fiber actuators were based on alginate/poly(ethylene glycol) acrylate shell and alginate/GO core with green and excellent spinnability. Owing to the high water-absorbing-swelling capacity and energy storage of the shell, the prepared spiral fibers are characterized by fast response, high energy output, and good repeatability of cycling. On the other hand, the core endows the spiral fibers with the additional features of strong force retention and photothermal response. The shell–core spiral structure promotes the output efficiency of the twisted fiber actuator with a large rotation (2500°/cm), untwisting speed (2250 rpm), and recovery speed (2700 rpm). In addition, the tertiary spiral structure based on TAPG fibers exhibits excellent humidity and photothermal response efficiency. The application of fibers to smart textiles enables efficient human epidermal thermal management.

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Developing an advanced individual protection cloth is a pivotal factor in combating global pathogen epidemics. However, formidable challenges are posed by the triangularity imbalance effect, necessitating the simultaneous fulfillment of requirements for high comfort, high safety, and mass production. In this study, a mass-producible hybrid polytetrafluoroethylene nanofiber mat (HPNFM) was developed by integrating technologies of organic–inorganic hybridization and membrane asynchronous stretching. Exceptional comfort was attained by conferring waterproofing and breathability attributes, achieved through the radial island-chain architecture exhibiting hydrophobicity and nanoporosity. Furthermore, through the incorporation of high-efficiency anti-pathogen nanoparticles, the HPNFM ensures high safety, demonstrating active antibacterial and antiviral effects. This is achieved through the synergistic effects of electrostatic induction and reactive oxygen species-based pathogen inactivation. More significantly, an HPNFM-based individual protective suit is designed and manufactured, which successfully encapsulates the advantages of high comfort, safety, and mass production, displaying competitiveness as a commercial product. Positioned as a viable strategy, this work holds substantial potential for practical applications in responding to future epidemics.

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Graphene composite yarns have demonstrated significant potential in the development of multifunctional wearable electronics, showcasing exceptional conductivity, mechanical properties, flexibility, and lightweight design. However, their performance is limited by the weak interfacial interaction between the fibers and graphene. Herein, a polydopamine–reduced graphene oxide (PDA–RGO) interfacial modulation strategy is proposed to prepare graphene-coated cotton yarns with high electrical conductivity and strength. PDA–RGO serves as an interfacial bonding molecule that interacts with the cotton yarn (CY) substrate to establish a hydrogen interface, while interconnecting with highly conductive graphene through π–π interactions. The developed interface-designed graphene-coated yarn demonstrates an impressive average electrical conductivity of (856.27 ± 7.02) S/m (i.e., average resistance of (57.57 ± 5.35) Ω). Simultaneously, the obtained conductive yarn demonstrates an exceptional average tensile strength of (172.03 ± 8.03) MPa, surpassing that of primitive CY by approximately 1.59 times. The conductive yarns can be further used as low-voltage flexible wearable heaters and high-sensitivity pressure sensors, thus showcasing their remarkable potential for high-performance and multifunctional wearable devices in real-world applications.

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Cellulose has sparked considerable interest in the advancement of biodegradable functional materials owing to its abundant natural sources and exceptional biocompatibility. This review offers a comprehensive review of the latest research and development concerning cellulose-based films, with a specific emphasis on their classification, properties, and applications. Specifically, this review classifies cellulose according to the various morphologies of cellulose (e.g., nanocrystals, nanospheres, and hollow ring cellulose) and cellulose derivatives (e.g., methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and cellulose acetate). The subsequent section presents an analysis of cellulose-based films with improved mechanical properties, antibacterial characteristics, gas regulation, and hydrophobicity. A detailed discussion of the mechanisms that underlie these properties is provided. Additionally, representative applications of cellulosic composites, such as food packaging, medical supplies, and electronic devices, are summarized. Finally, the challenges faced by cellulosic materials are outlined, and a novel and feasible prospect is proposed to accelerate the future development of this material.

Absorption-dominated electromagnetic interference (EMI) shielding fabrics are urgently needed to address the increasingly severe electromagnetic radiation pollution, especially the secondary radiation problem. In this study, we design novel core-sheath CNT@MXene fibers with a gradient conductive structure and corresponding fabrics to realize absorption-dominated EMI shielding performances. This coaxial structure utilizes carbon nanotubes (CNTs) as the sheath and MXene as the core and is constructed through a wet spinning technique. By virtue of the core-sheath structure, the conductive gradient structure in the fibers is easily optimized by adjusting the core MXene and sheath CNT content. This gradient conductive network of fiber effectively facilitates the incidence of electromagnetic waves and strong interactions between electromagnetic waves and the composites, resulting in excellent EMI absorption ability. Within the X-band frequency range, the fabric exhibits an electromagnetic interference shielding effectiveness of 23.40 dB and an absorption coefficient of 0.63. Due to the protection of polymer, the fiber’s electrical conductivity remains stable under conditions such as multi-cycle bending, stretching, and ultrasonic treatment, and in high relative humidity environments. Additionally, the fabric also demonstrates EMI shielding stability in indoor environments. This work indicates the great potential of the gradient structured fibers to achieve an absorption-dominated mechanism for next-generation eco-friendly EMI shielding fabrics.

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Fiber-based material systems are emerging as key elements for next-generation wearable devices due to their remarkable advantages, including large mechanical deformability, breathability, and high durability. Recently, greatly improved mechanical stability has been established in functional fiber systems by introducing atomic-thick two-dimensional (2D) materials. Further development of intelligent fibers that can respond to various external stimuli is strongly needed for versatile applications. In this work, helical-shaped semiconductive fibers capable of multifunctional sensing are obtained by wet-spinning MoS₂ liquid crystal (LC) dispersions. The mechanical properties of the MoS₂ fibers were improved by exploiting high-purity LC dispersions consisting of uniformly-sized MoS₂ nanoflakes. Notably, three-dimensional (3D) helical fibers with structural chirality were successfully constructed by controlling the wet-spinning process parameters. The helical fibers exhibited multifunctional sensing characteristics, including (1) photodetection, (2) pH monitoring, (3) gas detection, and (4) 3D strain sensing. 2D materials with semiconducting properties as well as abundant surface reactive sites enable smart multifunctionalities in one-dimensional (1D) and helical fiber geometry, which is potentially useful for diverse applications such as wearable internet of things (IoT) devices and soft robotics.

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