Advanced Fiber Materials最新文献

Biodegradable and biocompatible organic polymers play a pivotal role in designing the next generation of wearable smart electronics, reducing electronic waste and carbon emissions while promoting a toxin-free environment. Herein, an electrospun fibrous polyhydroxybutyrate (PHB) organic mat-based, energy-autonomous, skin-adaptable temperature sensor is developed, eliminating the need for additional storage or circuit components. The electrospun PHB mat exhibits an enhanced β-crystalline phase with a β/α phase ratio of 3.96 using 1,1,1,3,3,3-hexafluoro-2-propanol as a solvent. Solvent and film processing techniques were tailored to obtain high-quality PHB films with the desired thickness, flexibility, and phase conversion. The PHB mat-based temperature sensor (PHB–TS) exhibits a negative temperature coefficient of resistance, with a sensitivity of − 2.94%/°C and a thermistor constant of 4676 K, outperforming pure metals and carbon-based sensors. A triboelectric nanogenerator (TENG) based on the enhanced β-phase PHB mat was fabricated, delivering an output of 156 V, 0.43 µA, and a power density of 1.71 mW/m². The energy-autonomous PHB–TS was attached to the index finger to monitor temperature changes upon contact with hot and cold surfaces, demonstrating good reliability and endurance.

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As an emerging nanomaterial, nanofibrous aerogel possesses advantages such as low density, large specific surface area, low thermal conductivity, and high mechanical stability. Preparing nanofiber aerogels through electrospinning is an emerging research topic. This review focuses on the key fabrication techniques for electrospun nanofibrous aerogels, including freeze-drying, direct electrospinning, layer-by-layer stacking, and thermally induced self-agglomeration. In addition, by combining nanofibers’ distinctive properties and aerogels’ physical characteristics, nanofibrous aerogels demonstrate various potential academic and industrial applications, including thermal insulation, sound absorption, solar desalination, air filtration, oil–water separation, and biomedical engineering. This paper provides an overview of the fundamentals and recent advancements in electrospinning, summarizes the fabrication methods and applications of the most representative nanofibrous aerogels in recent years, and offers insights into nanofibrous aerogels’ challenges and prospects.

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Peripheral nerve injury presents a significant clinical challenge due to the limited regenerative capacity of the injured nerves, often resulting in permanent functional deficits. A key obstacle to effective nerve regeneration is the inability to modulate the inflammatory response, guide axonal elongation, and promote myelination. To address these challenges, we developed a multi-channel nerve guidance conduit (NGC) that integrated immune-modulating drug with gradient cues to enhance peripheral nerve regeneration. The inner tubes of the conduit were composed of degradable electrospun gelatin methacryloyl/collagen (GelMA/COL) fibers loaded with 1400W, an inducible nitric oxide synthase (iNOS) inhibitor. The outer tube consisted of electrospun polycaprolactone (PCL) fibers decorated with a density gradient of collagen particles encapsulating acidic fibroblast growth factor (aFGF). The release of 1400W enhanced macrophage activity and promoted their polarization from the pro-inflammatory M1 phenotype to the reparative M2 phenotype, thereby creating a pro-regenerative microenvironment conducive to nerve repair. The incorporation of gradient cues guided and promoted Schwann cell migration and neurite extension in vitro. In a rat sciatic nerve injury model, the conduit significantly improved nerve regeneration by sequentially modulating the inflammatory response and guiding axonal elongation, providing both spatial support and biological activity. Furthermore, the conduit promoted organized nerve fiber alignment, enhanced myelination, and achieved functional recovery outcomes that closely resembled those of the autograft. These findings suggest that the integration of immune-regulatory drug release, gradient cues, and a multi-channel structure presents a promising strategy for enhancing peripheral nerve repair.

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Flexible photodetectors are ideal for short-range communication in lightweight microintegrated systems. However, low-bonding interface and high-power cost of photosensitive components greatly limit their application in flexible communication systems. To address this, herein, piezophototronic effect-enhanced sensing components are proposed for flexible photodetectors. This approach leverages the piezophototronic effect to modulate nanoscale charge transport and the precision of electrohydrodynamic direct-writing to achieve controlled nanofiber assembly, thereby enhancing interfacial bonding and overall device performance. By employing electrohydrodynamic direct-writing, a copper-ammonia complex ((Cu(NH₃))(CN)) nanofiber is self-stacked on a zinc oxide (ZnO) nanofiber to construct a zinc oxide and copper ammine complex (ZnO@(Cu(NH₃))(CN)) photodetector with low static power consumption and high responsiveness through the combined effects of piezoelectricity and fiber self-stacking. The dark current is reduced to 1.12 × 10⁻⁷ A, and the static power consumption of the photodetector is also decreased. The responsiveness is up to 13.3 A/W, with response and recovery times of 11 and 9 ms under ultraviolet (UV) light illumination, respectively, fulfilling the requirements for highly sensitive photodetection owing to the high interface bonding. The detector's threshold voltage is tunable, ranging from 6 V for 5 stacking layers to 20 V for 25 stacking layers, thereby allowing the device's performance to be precisely tailored to specific application requirements. Leveraging the exceptional optoelectronic performance of the ZnO@(Cu(NH₃))(CN) photodetector, this study expands the application scenarios of flexible photodetectors and demonstrates their potential in the fields of 6G technology and battlefield communication.

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Electrocaloric (EC) polymers have garnered significant attention in recent years due to their zero direct greenhouse gas emissions during cooling processes. However, only a few polymers exhibit sufficient refrigeration capacity at low fields, which limits the application of the EC cooling technology. In this work, we show that electrospinning, a mature polymer processing technology, can introduce a complex fibrous matrix that leads to nano-, meso-, and micro-scale structures, and hence a series of hierarchical polar interfaces. The following thermal treatment was applied to enhance breakdown fields and reduce dielectric losses. A series of polyvinylidene fluoride (PVDF)-based fluoropolymers containing cellulose acetate (CA) were prepared. By introducing 10 wt% of CA, the electrospinning process significantly improves the polar entropy of the fluoropolymer system and significantly improves the polymer’s breakdown strength, polarization, and electrocaloric performances, compared to their solution cast counterparts. The polar entropy variations among various polymeric composites were elucidated using data acquired from multiple structural characterization tools. By linking the optimized hierarchical interface structures and the overall EC performances, this study provides new routes for designing high-performance EC nanocomposites that can be facilely tailored by the matured processes of fibrous, polymeric composites.

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Piezoelectric filler-based composite fiber sensors have emerged as promising candidates for wearable textiles due to their self-powered capability and excellent sensing performance. However, current spinning fabrication methods face significant challenges in achieving uniform distribution and optimal orientation of piezoelectric fillers within polymer matrices, which limits their sensing performance. To address these issues, an innovative electric-assisted coaxial wet spinning method is developed to fabricate piezoelectric composite fiber (denoted as P-B fiber), which was composed of boron nitride nanosheets (BNNSs) as piezoelectric fillers and polyvinylidene fluoride (PVDF) as a piezoelectric polymer matrix. The radial electric field applied during spinning promotes the radial orientation of BNNSs, leading to enhanced stress transfer efficiency and, as a result, improved piezoelectricity. Moreover, the radial electric field enables the simultaneous in-situ polarization of BNNSs and PVDF during spinning process, further improving the piezoelectric performance. As a result, the P-B fiber exhibits an exceptional piezoelectric sensitivity of (186.4 ± 1.1) mV/N, approximately sixfold higher than that of fibers produced without electric field assistance. Accordingly, the P-B fiber demonstrates remarkable capability in detecting tiny mechanical loads, such as pulse waves and respiration, making it particularly suitable for wearable physiological monitoring textiles, providing a promising strategy for developing high-performance piezoelectric fiber sensors.

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Flexible mechanical sensors offer extensive application prospects in the field of smart wearables. However, developing highly sensitive, flexible mechanical sensors that can simultaneously detect strain and pressure remains a significant challenge. Herein, we present a flexible mechanical sensor based on AgNPs/MWCNTsCOOH/PDA/PU/PVB nanofiber-covered yarn (AMPPPNY) featuring a DNA-like double-helix wrinkled structure. The sensor is fabricated by electrospraying polyvinyl butyral (PVB) onto a pre-stretched double-helix elastic yarn, followed by electrospinning a polyurethane (PU) nanofiber membrane and inducing the self-polymerization of dopamine (DA) to create an adhesive layer. Then, one-dimensional carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) and zero-dimensional silver nanoparticles (AgNPs) are dispersed onto the structure, synergistically forming a stable conductive network for efficient signal transmission. The integration of conductive fillers with different dimensionalities and DNA-like double-helix wrinkled structure endows the sensor with high strain sensitivity (gauge factor of 11,977) in the strain range of 0–310% and high pressure sensitivity (0.475 kPa⁻¹) in the pressure range of 0–2 kPa. Moreover, the fabricated sensor exhibits rapid response and recovery times (130 ms/135 ms) and outstanding cyclic stability (over 10,000 cycles of both strain and pressure). Next, the fibrous sensor is weaved into a large-area fabric, and the developed smart textiles demonstrate impressive performance in detecting both subtle and large human movements. The proposed sensor is a promising candidate for flexible wearable applications.

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Developing methods to non-destructively deposit conductive materials onto existing objects can enhance their functionalities on-demand. However, designing and creating such structures to accommodate diverse shapes and surface textures of pre-fabricated objects remains challenging. We report an on-demand printing strategy for creating substrate-less, conducting microfiber patterns that can be adaptively deposited onto a wide range of objects, including daily-use stationery, tools, smartwatches, and unconventional materials like porous graphene aerogels. Solution-drawn microfibers are directly deposited onto the object in a semi-wet state upon synthesis, enabling seamless fiber-object integration in a single step. The design and format of the microfiber patterns can be tuned on-demand to adapt to the shapes and surface textures of target objects, ensuring compatibility with user-specific applications. These air-permissive, highly transparent layers minimally obstruct the original appearance and functions of the objects while equipping them with additional sensing, energy conversion, and electronic connectivity capabilities.

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Modulating trained immunity while simultaneously initiating regenerative cues presents a significant challenge in large bone defect therapy. This study introduces a cell-free approach utilizing a 3D microenvironment-responsive scaffold to orchestrate immune reprogramming. To mitigate maladaptive trained immunity and activate regenerative signaling, a composite fibrous scaffold is functionalized with immune-engineered exosomes derived from inflammation-primed mesenchymal stem cells (PSS-iEXO) in a reactive oxygen species (ROS)-responsive manner. The PSS-iEXO scaffolds incorporate boronic ester linkages as ROS-sensitive moieties, enabling rapid, dynamic, and “on-demand” exosome release in response to elevated ROS levels characteristic of the early inflammatory phase post-injury, thereby initiating regeneration. In vitro and in vivo analyses reveal that these scaffolds precisely target and modulate maladaptive trained immunity, reprogramming immune responses by shifting macrophage polarization from a hyperactivated type I phenotype to a balanced state while promoting CD4⁺ regulatory T cell activation—both critical for coupling angiogenesis and osteogenesis. Mechanistic insights highlight the role of engineered exosomes in enhancing mitochondrial function and oxidative phosphorylation in macrophages, establishing a cell-free immune-regenerative niche for large bone defect therapy.

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Schematic diagram of the fabrication, function, and mechanism of ROS-responsive 3D electrospun nanofiber scaffolds loaded with immunoengineered exosomes (PSS-iEXO) for promoting large bone repair.

With the increasing global energy consumption and cooling demands, traditional active cooling technologies face inefficiency and environmental challenges. Recently published in Science, a team led by Prof. Hai-bo Zhao has proposed and developed a biomass-based photoluminescent aerogel made from DNA and gelatin to address these challenges. This material achieves a solar-weighted reflectance of over 100% (0.4–0.8 μm) and provides a cooling effect of 16.0 °C under sunlight. This sustainable material is repairable, recyclable, and biodegradable, offering significant potential for energy-efficient buildings and wearable cooling devices.