Advanced Fiber Materials最新文献

Flexible wearable electronics have garnered substantial attention as promising alternatives to traditional rigid metallic conductors, particularly for personal health monitoring and bioinspired skin applications. However, these technologies face persistent challenges, including low sensitivity, limited mechanical strength, and difficulty in capturing weak signals. To address these issues, this study developed a hierarchical sandwich-structured piezoresistive foam sensor using phase inversion and NaCl sacrificial templating methods. The sensor exhibits an exceptional sensitivity of up to 83.4 kPa⁻¹ under an ultralow detection pressure of 2.43 Pa. By optimizing the foam porosity, its mechanical performance was significantly enhanced, reaching a tensile fracture elongation of 257.3% at 73.42% porosity. The hierarchical sandwich structure provided mechanical buffering and layer-enhancement functionalities for dynamic responses, whereas the nanostructure further refined signal acquisition and interference resistance. Signal analysis using discrete wavelet transform (DWT) and continuous wavelet transform (CWT) enables multiscale and multifrequency characterization of arterial resistance signals under varying applied pressures. These findings underscore the sensor’s ability to capture weak signals and analyze complex pulse dynamics. This advancement paves the way for the extensive application of multifunctional sensors in smart devices and health care. This method offers a robust scientific basis for further understanding and quantifying arterial pulse characteristics.

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Mechanical fiber sensors that can be seamlessly integrated into traditional fabrics have significant potential for imperceptible sleep monitoring. Wet-spinning techniques are an effective method for fabricating fiber sensors. However, the sensors produced by this process have a single, homogeneous linear structure, which limits their high sensitivity and linearity to low-pressure ranges and presents challenges for stability. To address this issue, we propose an improved wet-spinning process for the large-scale production of a capacitive sensor that features both multilevel structure of varying heights and a core-sheath configuration (with commercial conductive yarn as the core and TPU as the sheath).Thanks to its multilevel structure, a multilevel structure fabric pressure sensing belt (MSFPSB) woven from this fiber sensor exhibits excellent linearity (R² = 0.998) and sensitivity (0.077 kPa⁻¹) over a pressure range of 3.3–30 kPa. Furthermore, the commercial conductive core ensures the sensor's stability after 4000 compression cycles. Additionally, we have developed a battery-free, wireless, stick-on-and-use-immediately data acquisition tag based on near-field communication (NFC). The tag works with a reader placed 5 cm away to imperceptibly monitor breathing, ballistocardiogram (BCG), and body motion signals during both work and sleep. This approach enhances the comfort of sleep monitoring and helps detect potential sleep disorders.

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Filtration materials are designed with nanofibrous structures to address the trade-off effect between filtration efficiency and resistance. However, achieving a breakthrough in these performance metrics remains challenging. Inspired by the white stork wing, we present a novel rod‒ribbon interwoven nanofiber membrane with ultraefficient filtration efficiency for PM. The silica (SiO₂)/tin dioxide (SnO₂) hybrid membrane was fabricated using a one-step electrospinning approach, where its unique structure was formed under the influence of solvent nonequilibrium evaporation during the electrospinning process. The optimized interwoven structure enables the membranes to achieve an outstanding filtration efficiency of 99.96% for PM_0.3 at an airflow velocity of 5.33 cm/s while maintaining a minimal pressure drop of 62 Pa ((Q_{{text{f}}}) = 0.12 Pa⁻¹). The mechanisms underlying the material's formation and the enhancement of its filtration performance were systematically analyzed. Consequently, this study provides novel insights and methodologies for developing high-performance air filtration materials, thereby supporting the strategic objectives of low-carbon development.

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Aerogel fibers with high porosity, low thermal conductivity and flexibility have shown great potential for applications in personal thermal management. However, the porous structure of aerogel fibers significantly compromises their mechanical properties like tensile strength. Here, we propose a high-strength polyimide aerogel fiber with porous-cortex-dense-core structure prepared via a coaxial wet-spinning based on hierarchical phase separation. Porous-cortex is formed due to fast phase separation rate induced by weak electrostatic and hydrogen-bonding interactions between the fluorinated polyimide and the ethanol. In contrast, the poly(amic acid) with high polarity index in the core-layer exhibits a slow phase separation rate, allowing the fibers to produce a dense nanoporous structure. With the dense core undertaking stress and porous cortex hindering heat transfer, the obtained aerogel fiber exhibits a higher tensile strength of up to 55.2 MPa compared to most reported aerogel fibers (0.15 –30 MPa) and a low thermal conductivity of 37.2 mW m⁻¹ K⁻¹. This work offers a new way to prepare strong aerogel fibers and broadens their applications in thermal protection and infrared stealth.

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Fibres are being rapidly developed into intelligent devices and systems. Through the integration of microelectronic chips and controllers within individual fibres, these systems can now perform advanced functionalities including sensing, data storage, computational processing, and wireless communication—all integrated into a single fibre. Recently, Fink et al. demonstrated a textile-integrated fibre computer that achieves these multifunctional capabilities while weighing less than 5 g. This breakthrough work provides novel design paradigms for the integration of fibres and electronics, transcending the conventional functional limitations of individual fibres and establishing new research directions in computational textiles.

Stimuli-responsive polymers offer unprecedented control over drug release in implantable delivery systems. Shape memory polymer fibers (SMPFs), with their large specific surface area and programmable properties, present promising alternatives for triggerable drug delivery. However, the existing SMPFs face limitations in resolution, architecture, scalability, and functionality. We introduce thermal drawing as a materials and processing platform to fabricate microstructured, multimaterial SMPFs that are tens of meters long, with high resolution (10 μm) and extreme aspect ratios (> 10⁵). These novel fibers achieve highly controlled, sequential drug release over tailored time periods of 6 months. Post thermal drawing photothermal coatings enable accelerated, spatially precise drug release within 4 months and facilitate light-triggered, untethered shape recovery. The fibers’ fast self-tightening capability within 40 s shows their potential as smart sutures for minimally invasive procedures that deliver drugs simultaneously. In addition, the advanced multimaterial platform facilitates the integration of optical and metallic elements within SMP systems, allowing highly integrated fibers with shape memory attributes and unprecedented functionalities. This versatile technology opens new avenues for diverse biomedical applications, including implantable drug delivery systems, smart sutures, wound dressings, stents, and functional textiles. It represents a significant advancement in precise spatio-temporal control of drug delivery and adaptive medical devices.

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Achieving human skin-like sensitivity and wide-range pressure detection remains a significant challenge in the development of wearable pressure sensors. In this study, we engineered and fabricated a fibrous polyimide fiber (PIF)/carbon nanotube (CNT) composite aerogel with a gradient structure using a layer-by-layer freeze casting technique, aiming to overcome the limitations of traditional pressure sensors. Finite element analysis (FEA) reveals that this innovative gradient structure mimics the unique microstructure of human skin, enabling the sensor to detect a broad spectrum of pressure stimuli, ranging from subtle pressures as low as 10 Pa to intense pressures up to 1.58 MPa with exceptional sensitivity. Moreover, the sensor exhibits extraordinary pressure resolution across the entire pressure range, particularly at 1 MPa (0.001%). Additionally, the sensor demonstrates remarkable thermal stability, operating reliably across a wide temperature range from − 150 to 200 °C, making it suitable for extreme environments such as deep space exploration. When integrated with machine learning algorithms, the sensor shows great potential for real-time physiological monitoring, fitness tracking, and motion recognition. The proposed gradient fibrous pressure sensor, with its high sensitivity and resolution over a wide pressure range, paves the way for new opportunities in human–machine interaction.

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To enhance the bonding strength between the active material and the core yarn current collector through nano-entanglement, bacterial cellulose/carbon nanotube (BC/CNT) nanofiber yarns were developed using in situ cultivation and wet twisting. This method utilizes the large specific surface area and abundant active functional groups of BC-based nanofibers. Subsequently, V₂O₅/BC/CNT composite yarn electrodes were fabricated, exhibiting a core-sheath structure with excellent conformal characteristics. The influence of ultrasound duration on the conductivity and electrochromic performance of composite yarns was investigated. The initial discharge-specific capacity was recorded as 105.3 mAh/g, with a capacity retention rate of 60.2% after 100 cycles. The composite yarn exhibited 100 reversible transitions between yellow and blue, with reduction and oxidation response times of 2.35 s and 3.3 s, respectively. The modulation amplitude at 532 nm during the initial cycle was 20.31%, and after 100 cycles, the modulation amplitude retention rate remained at 68%.

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Mimicking human skin mechanoreceptors grouped by various thresholds creates an efficient system to detect interfacial stress between skin and environment, enabling precise human perception. Specifically, the detected signals are transmitted in the form of spikes in the neuronal network via synapses. However, current efforts replicating this mechanism for health-monitoring struggle with limitations in flexibility, durability, and performance, particularly in terms of low sensitivity and narrow detection range. This study develops novel soft mechanoreceptors with tunable pressure thresholds from 1.94 kPa to 15 MPa. The 0.455-mm-thin mechanoreceptor achieves an impressive on–off ratio of over eight orders of magnitude, up to 40,000 repeated compression cycles and after 20 wash cycles. In addition, the helical array reduces the complexity and port count, requiring only two output channels, and a differential simplification algorithm enables two-dimensional spatial mapping of pressure. This array shows stable performance across temperatures ranging from − 40 to 50 °C and underwater at depths of 1 m. This technology shows significant potential for wearable healthcare applications, including sensor stimulation for children and the elderly, and fall detection for Parkinson’s patients, thereby enhancing the functionality and reliability of wearable monitoring systems.

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Photo/electro-thermal evaporation is a promising tactic for alleviating the scarcity of fresh water, but its practical application still faces many challenges such as weak photoabsorption, high vaporization enthalpy and serious water-electrolysis during photo-thermal/electrothermal evaporation. To solve these problems, inspired by black rose petal and electric heater, we report a biomimetic design of fabric for achieving efficient photothermal/electrothermal desalination. The photo/electrothermal fabric is fabricated by decorating super-hydrophilic MnO₂ nanoplates as shell on hydrophobic carbon fiber (CF) as core via an electro-deposition method. MnO₂ nanoplate decoration as a stone confers three fascinating features (birds): (I) the hydrophilic nature of MnO₂ contributes to the fabric’s superhydrophilicity and decreased evaporation enthalpy (2032 kJ kg⁻¹) in comparison with that (2410 kJ kg⁻¹) of pure water; (II) nanoplate structure confers the light-trapping effect and thus the improved photoabsorption efficiency of 95.1%; (III) CF-core/MnO₂-shell structure can effectively suppress electrolysis of water and lead to good electrothermal conversion property. As a result, CF/MnO₂ fabric-based hanging evaporator shows the high photo-thermal evaporation rate of 2.3 kg m⁻² h⁻¹ at 1 sun (1 kW m⁻²) and electrothermal evaporation rate of 5.3 kg m⁻² h⁻¹ at 3 V. Importantly, by the combined effects of 1 sun and 3 V, CF/MnO₂ fabric achieves a striking synergetic evaporation rate of 8.5 kg m⁻² h⁻¹, exceeding the sum (7.5 kg m⁻² h⁻¹) of the individual photo-thermal and electro-thermal evaporation rates. The present high synergetic evaporation performance benefits from efficient photo/electrothermal conversion of the fabric and sufficient water-supplementation at the fiber-water interface resulting from thermosiphon effect. Thus, this study offers a novel possibility in the rational design of photo-electrothermal materials for efficient evaporation of seawater.

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