Search Results (4,572)

Continuous monitoring of vehicle engine vibration is a key enabler of real-time diagnostics, yet conventional accelerometers require an external power supply and fit poorly into the distributed sensor networks envisioned for next-generation vehicles. Triboelectric nanogenerators offer an attractive self-powered alternative, but their direct application to the vibration of a running passenger vehicle engine, and the explicit link between sensor design parameters and individual engine operating states, remains largely unexplored. Here, we address this gap by co-tuning the air gap and the substrate rigidity of a contact-separation triboelectric vibration sensor to the vibration spectrum of an automotive engine. A systematic 3 × 3 design sweep across three gap distances and three substrate types identifies a single configuration that simultaneously resolves the low-frequency idle band and the higher-frequency acceleration band of a four-cylinder gasoline engine. A frequency-amplitude response map confirms that the real engine operating points fall within the sensitive region of the optimized device, and an on-vehicle test demonstrates clean discrimination of all seven operating states, from ready to shut-down, without any external power. The results establish design guidelines for source-matched triboelectric vibration sensors and outline a practical path toward self-powered, wireless-ready engine health monitoring in future vehicles. Full article

Electrical stimulation enhances functionality and accelerates maturation in biofabricated tissues, which are particularly important for muscle tissue engineering applications. Accordingly, there is demand for 3D-printable electrically conductive cytocompatible scaffolds that enable patient-specific geometries and localized electrical stimulation, as well as incorporate further maturation-promoting geometrical cues. Filament-based scaffolds from fused filament fabrication could overcome current limitations in geometric freedom, size and partially cytotoxic additives. In this study, biodegradable polylactic acid (PLA)-based conductive filaments incorporating graphene nanoplatelets (GNPs) or carbon nanofibers (CNFs) were developed via melt-mixing extrusion to possibly enable the electrical functionalization of muscle scaffolds. A two-stage process combining twin-screw and single-screw extrusion was preferred to allow for higher filler incorporation. Filament morphology, printability, electrical conductivity, and cytocompatibility were systematically evaluated. Homogeneous filaments containing up to 16 wt.% GNPs or 3.6 wt.% CNFs were successfully produced and processed by fused filament fabrication into scaffold geometries supporting myoblast orientation. Electrical conductivity was measured above 16 wt.% GNPs, with up to 2.7 µS/m, with printed constructs capable of connecting a circuit. GNP-based filaments were cytocompatible, supporting myoblast attachment and elongated morphology. An adjustable electrical stimulation setup demonstrated improved muscle maturation and contractile responses of C2C12 myoblasts, highlighting biodegradable conductive filaments’ potential for electrically active muscle tissue scaffolds. Full article

Current approaches in neuro-technologies aim to design artificial devices capable of collecting information on in vitro and in vivo brain activities. In this view, a major challenge for new processing technologies is to integrate the peculiar properties of biomaterials and electrical circuits into engineered devices. Herein, the optimization of electroconductive polyvinyl alcohol (PVA) fibers loaded with polyanilines (PANIs) and produced via electrospinning is proposed. Two different polyaniline forms were selected, i.e., doped emeraldine base (dPANI-EB) and doped PANI nanofibers (dPANI-NFs) synthesized by a rapid mixing process. SEM morphological investigation indicated that conductive phases do not remarkably affect fiber morphology, slightly increasing the average diameter. Conversely, PANI fibers remarkably affect the PVA surface’s hydrophilicity, as confirmed by the increase in contact angle. The presence of conductive phases enhances the intrinsic ionic conductivity of PVA fibers, through protonic currents, which also increases the electronic conductivity from 10⁻¹⁰ to 10⁻⁷ S/cm. Preliminary in vitro studies performed on a human neuroblastoma cell line (SH-SY5Y) confirmed the biocompatibility of PVA/PANI nanofibers. These data demonstrate the potential of such nanofibers to be used as biotextiles, and specifically as electroactive interfaces capable of monitoring changes in the levels of biochemical signals (i.e., neurotransmitters) related to the brain’s microenvironment. Full article

Industrial dye wastewater poses serious environmental and health risks, demanding sustainable remediation strategies. Here, hierarchically porous hollow TiO₂ nanofibers (HNFTis) were fabricated and combined with blue, green, and orange graphene quantum dots (b-GQDs, g-GQDs, o-GQDs) to form heterojunction photocatalysts. Progressive fluorescence redshift of GQDs, induced by surface functionalization and S/B doping, narrows the bandgap and enhances visible-light absorption. Among the composites, 0.5 wt% o-GQDs/HNFTi exhibited the highest photocurrent and lowest charge-transfer resistance and degraded 99.5% of Methylene blue under visible light within 2 h, outperforming pristine HNFTi (77.7%). The synergistic effect of TiO₂ structural engineering and GQD fluorescence tuning demonstrates an effective strategy for designing high-performance photocatalysts for sustainable wastewater treatment. Full article

Voice disorders severely limit verbal communication, creating a need for intuitive assistive technologies. To meet this need, we present epidermal strain sensors that capture strain signals during silent speech and hand gesture. A thin electrospun nanofiber layer integrated onto commercial polyurethane films guides uniform, controlled microcrack formation in screen-printed carbon conductive paths, achieving a gauge factor up to 243 over 0–40% strain. Signals from the seven-channel strain sensor array are recognized by a hybrid neural network that combines convolutional and Transformer architectures, reaching over 98% accuracy. The recognized outputs are rendered in virtual reality (VR), enabling intuitive, real-time communication. Moreover, the approach simplifies fabrication by enabling crack-based strain sensing with only a thin electrospun surface layer on commercial polyurethane films, eliminating the need for thick freestanding electrospun substrates. This cost-effective approach addresses limitations of conventional electrospun substrates by minimizing the thickness of the electrospun layer, thereby shortening the electrospinning time. Overall, the work demonstrates a method for translating natural non-verbal expressions into speech and text in VR, with promising applications in healthcare and assistive communication. Full article

Sodium-ion batteries (SIBs) represent a compelling alternative to lithium-ion batteries for grid-scale energy storage, owing to the high natural abundance and low cost of sodium resources, as well as their strategic alignment with national energy security priorities. Nevertheless, the sluggish Na⁺ diffusion kinetics and limited specific capacity of anode materials continue to impede practical deployment. Herein, nitrogen-doped carbon-coated TiO₂ nanofibers (TiO₂/C-N) were rationally engineered through a facile electrospinning route integrated with synergistic defect and coating engineering. The in situ-formed N-doped carbon shell establishes a continuous, high-conductivity electron-transport network while simultaneously buffering volumetric strain during repeated (de)sodiation, thereby preserving long-term structural integrity. Electrochemical assessments demonstrate that the TiO₂/C-N electrode delivers a reversible specific capacity of 233.64 mAh g⁻¹ at 0.1 A g⁻¹ (initial Coulombic efficiency 54.13%). Quantitative kinetic analysis reveals a pronounced pseudocapacitive contribution of 41.4% at 1.2 mV s⁻¹, confirming a surface-controlled Na⁺ storage pathway that markedly enhances rate capability. Moreover, the electrode retains 245.5 mAh g⁻¹ after 150 cycles at 1 A g⁻¹, underscoring exceptional cycling stability. This work elucidates the synergistic regulation of N-doped carbon coating and pseudocapacitive kinetics in TiO₂-based anodes, offering a robust design strategy for high-rate, long-cycle-life SIB anodes. Full article

The need for reliable preventive medicine tools is growing, especially for diseases with long diagnostic delays, such as endometriosis, which can take several years to diagnose. In this context, cellulose acetate nanofibrous membranes were prepared via electrospinning, to create the absorbent core of a smart wearable in the form of a sanitary pad, intended to support electronic diagnostic devices. A multi-layered structure was opted for, with each layer acting in a specific way according to its position within the pad, regarding mainly absorbency and porosity. The membranes were ultralight and highly absorbent, with single membranes showing an absorbency of 20–70 times their initial weight, and multi-layered membranes 15–30 times. Morphological evaluation of the pad was used as the basis for the optimization of the fabrication parameters, while liquid absorption capacity confirmed the pad’s high absorbency. Additionally, chemical and toxicological assessments indicated in vitro biocompatibility of the pad. The potential of the electrospinning process in the fabrication of menstrual hygiene pads is shown by these results. Future studies should focus on the integration of smart devices within the pad, as well as their functionality and effectiveness. Full article

Conductive hydrogels are attractive for flexible electronics, but their practical use is often limited by resistance drift during repeated deformation and performance degradation at low temperatures. Here, core–shell polyaniline-coated polyacrylonitrile (PANi@PAN) electrospun nanofibers were incorporated into a polyacrylamide/hydroxypropyl cellulose (PAM/HPC) hydrogel matrix to construct a hybrid conductive network. The PANi shell serves as an electronic pathway alongside ionic conduction in the hydrated polymer network, leading to markedly improved electromechanical stability. The resistance drift is about 11% after 2000 stretching–relaxation cycles at 0–100% strain, about 12 times lower than that of the nanofiber-free hydrogel. Stable electrical responses are maintained under large deformation, with a resistance drift as low as 3.3% over a strain range of 0–400%. The hydrogels show a conductivity of 0.32 S m⁻¹ while retaining high stretchability (>600%). An ethylene glycol/water binary solvent is used to suppress ice formation and improve moisture retention, allowing stable electromechanical performance at −15 °C over 500 cycles. The hydrogel also adheres reliably to human skin (about 10.25 kPa) and functions as a conformal strain sensor without extra fixation. Full article

This study introduces advanced epoxy formulations incorporating carbon-based nanofillers, carbon nanotubes, nanofibers, and functionalized graphene. The epoxy matrix was optimized to lower moisture absorption and enhance multifunctional properties. A non-stoichiometric epoxy/hardener ratio reduced equilibrium water concentration (C_eq) by up to 30% compared to unmodified epoxy, achieved by minimizing polar groups responsible for water bonding. These improvements benefit the aerospace, marine, and wind energy sectors. All nanofillers form a secondary phase with reduced glass transition temperature (T_g), but functionalized graphene performs best. Its self-assembled sheet architectures trap resin, limit water interaction, and create conductive pathways, improving strength, reducing moisture uptake, and achieving a low electrical percolation threshold (EPT). Full article

Polycystic ovarian syndrome (PCOS) is a complex endocrine and metabolic disorder that affects reproductive health, metabolic function, and long-term cardiovascular health in women of reproductive age. The syndrome is characterized by hyperandrogenism, chronic anovulation, insulin resistance, oxidative stress, and ovarian microenvironment remodeling. While current treatments focus on symptom relief through hormone regulation, insulin sensitizers, or ovulation induction, there is a need to target the underlying molecular and cellular processes that drive disease progression and infertility. Breakthroughs in reproductive and metabolic medicine have led to the development of next-generation therapeutics for PCOS that aim to restore ovarian function at the molecular level. Nanoparticle- and nanofiber-based drug delivery systems offer targeted delivery to the ovaries, improved bioavailability, and controlled release of insulin sensitizers, antioxidants, and anti-androgens. Metabolic reprogramming strategies that target insulin resistance, mitochondrial dysfunction, and autophagy have emerged as potential disease-modifying interventions. In addition, AI-enabled precision medicine approaches are reshaping PCOS management through phenotype-based classification, predictive modeling, and personalized fertility optimization. In this review, we highlight recent advancements in understanding the molecular pathophysiology of PCOS and introduce novel therapeutics that harness intelligent drug delivery, ovarian microenvironment restoration, and AI-based interventions. We discuss the potential of these innovative strategies to update PCOS management options for long-term ovarian restoration and fertility. Full article

Mineral powder–based bone grafts exhibit excellent osteoconductivity; however, their clinical efficacy is often compromised by insufficient early-stage tissue ingrowth, leading to particle aggregation and pocket formation within the defect site during the initial healing phase. Here, we report a cotton-type nanofiber-guided mineral graft designed to overcome this early integration failure by creating fibrous pathways for tissue ingress. Cotton-type polycaprolactone (PCL) nanofibers were fabricated via electrospinning using a pin-based collector engineered to induce strong inter-fiber repulsion, resulting in a highly expanded, three-dimensional cottony architecture. Tetracalcium phosphate (TTCP) and α-tricalcium phosphate (α-TCP) mineral particles were subsequently deposited onto the surface of the cottony nanofibers, forming a fibrous–mineral hybrid graft (c-NF@T/α-TCP) in which the nanofibers act as a transient, functionally defined tissue-guiding framework during the early healing phase. The cottony nanofiber network effectively prevented mineral particle aggregation and generated continuous pathways within the graft, facilitating early tissue infiltration and vascular ingress during the first week after implantation. In vivo evaluation in a bone defect model demonstrated that c-NF@T/α-TCP significantly reduced tissue pocket formation at early time points and promoted subsequent bone regeneration compared to mineral powder-only grafts. This study highlights the critical importance of early-stage structural guidance in mineral-based bone grafts and introduces cotton-type nanofiber–guided pathway engineering as a simple yet effective strategy to unlock the regenerative potential of conventional inorganic bone substitutes. Full article

Flexible and wearable electronics require soft sensing materials that balance mechanical compliance, stable signal transduction, and durability for human–machine interfaces (HMIs). To address the limitations of single-filler systems, we propose a poly(vinyl alcohol) (PVA)/aramid nanofiber (ANF)/MXene organogel (PAM) as a multifunctional soft platform. This design integrates a PVA physically crosslinked network with ANF for mechanical reinforcement and MXene for electrical functionality. The optimized PAM composite exhibits outstanding mechanical properties, including a fracture stress of 2931 kPa, a fracture strain of 676%, and a fracture toughness of 9.04 MJ m⁻³. Importantly, PAM serves as a single material platform configurable into three sensing modalities. The resistive strain sensor achieves a gauge factor of 3.1 over 10–100% strain and enables the reliable recognition of human joint movements and gestures. The capacitive pressure sensor delivers a sensitivity of 0.298 kPa⁻¹, rapid response/recovery times of 30/10 ms, and is integrated with a wireless module to control a smart car. Furthermore, the PAM-based triboelectric nanogenerator (TENG) delivers excellent electrical outputs (V_oc = 123 V, I_sc = 0.52 μA, Q_sc = 58 nC) and functions as a self-powered smart handwriting pad, achieving a machine-learning-based recognition accuracy of 97.6%. This work demonstrates the immense potential of the PAM organogel for advanced, self-powered HMIs. Full article

A nanostructured sensing platform based on electrospun functionalized multi-walled carbon nanotubes/poly(3-aminobenzylamine) (FMWCNTs/P3ABA) was developed for the electrochemical detection of dopamine (DA) on fluorine-doped tin oxide (FTO) glass substrate. The electrochemical characteristics of the electrodes were investigated by chronocoulometry (CC) and cyclic voltammetry (CV) in phosphate-buffered saline solution containing K₃[Fe(CN)₆] as a redox mediator. The zeta potential analysis confirmed the presence of a stable surface charge that favors electrostatic interaction with DA molecules. The DA detection was performed in human urine by differential pulse voltammetry (DPV) over a potential of −0.2 to 0.8 V and at scan rate of 5 mV s⁻¹, where the FMWCNTs/P3ABA nanofiber electrode exhibited a high sensitivity of 1.502 µA cm⁻² nM⁻¹, a linear detection range of 10–500 nM (R² = 0.992), and a limit of detection of 1.753 nM. The sensor exhibited stable and reproducible responses, and the fibrous composite effectively discriminated DA from common electroactive interferents, including ascorbic acid, uric acid, creatinine, and glucose. Furthermore, reliable dopamine quantification in human urine samples demonstrates the strong potential of the electrospun FMWCNTs/P3ABA composite nanofiber platform for practical bioanalytical and non-invasive sensing applications in the future. Full article

Background and Objectives: Postoperative pain and intra-abdominal adhesions are common complications following surgery. Pain delays early mobilization, whereas adhesions can lead to bowel obstruction, chronic pain, or infertility. Current treatments, including systemic analgesics and physical barrier methods, are only partially effective. We hypothesized that combining these modalities would yield superior outcomes. Accordingly, we investigated whether a lidocaine-loaded alginate–carboxymethyl cellulose–polyethylene oxide (ACPE) electrospun film could more effectively reduce both postoperative pain and adhesion formation than either component alone. Materials and Methods: An electrospun nanofiber film composed of ACPE containing lidocaine was prepared. Its effects were evaluated in rats using an incisional pain and a peritoneal adhesion model. Four groups were compared: saline control, free lidocaine, drug-free ACPE film, and lidocaine-loaded ACPE film. Fifteen rats were allocated to each group. The primary outcome was the mechanical withdrawal threshold (MWT) after plantar incision, while secondary outcomes included histological changes and adhesion scores assessed by the Moreno system. Results: The lidocaine–ACPE film significantly increased MWT compared with all other groups, demonstrating a stronger and longer-lasting analgesic effect than free lidocaine. Adhesion scores were also lowest in the film group. Histological analysis confirmed a reduction in inflammatory cell infiltration and collagen deposition. Conclusions: A lidocaine-loaded ACPE nanofiber film effectively reduced both postoperative pain and adhesion formation in a rodent model. The combination of sustained local drug release and physical barrier function provides a promising strategy to address two major postoperative complications. Further preclinical studies are warranted before clinical application. Full article