Ibrahim Abdalla

Continuous glucose monitoring is transforming analysis by using sweat, a less invasive and more accessible fluid, to provide more accurate readings during exercise. However, obtaining accurate results remains challenging due to its acidity, which can disrupt the alkaline conditions required for non-enzymatic sensing. Herein, we developed a high-surface-area carbon nanofiber (CNFs) composite functionalized with polypyrrole (PPy) and combined with a graphene oxide (GO) composite for non-enzymatic electrochemical glucose sensing in sweat. The composite was fabricated via a sequential drop-casting process using a metal-azolate framework (MAF) for its high electrochemical stability, thereby enabling OH-compensation and ensuring a continuous supply of hydroxyl (OH) groups from GO, compensating for any loss of OH caused by sweat acidity. The CNFs/PPy/GO/MAF composite works efficiently across pH levels 13, 12.5, and 12, with detection limits of 0.033, 0.043, and 0.0145 µM (S/N = 3), respectively. The composite shows high sensitivities of 663, 259.6, and 160.85 μA/(mM·cm2) within the linear ranges of 0.003 to 1.6, 0.003 to 1.4, and 0.003 to 0.7 mM at pH = 13, 12.5, and 12, respectively. Additionally, the composite exhibits high selectivity, stability under decreasing pH, and good repeatability and reproducibility. It yielded sweat analysis results from real samples that closely matched blood glucose levels measured by a glucometer at all tested pH values of 13, 12.5, and 12. This confirms that the composite offers accurate, reliable, real-time, non-invasive glucose detection under typical alkaline conditions.

Carbon nanofibers (CNFs) exhibit inherent dielectric properties that enhance electromagnetic (EM) wave absorption, yet challenges exist in expanding their effective absorption bandwidth (EAB) and improving flexibility. Many studies fail to adequately consider how structural factors influence performance when combining CNFs with magnetic materials. To address these issues, a 1D carbon nanocomposite is developed by embedding magnetic oxide nanoparticles within CNFs using a simple electrospinning technique. This approach improves membrane flexibility by disrupting rigid alignment and introducing dynamic magnetic interactions, while also creating defect‐rich interfaces that increase the amorphous content (61%) of the CNFsF composite, leading to improved EM wave absorption. The unique macro/mesoporous morphology provides internal interfaces and heterogeneous boundaries that effectively trap and dissipate EM waves. As a result, the flexible CNF composites demonstrate significant EM wave absorption performance, achieving a minimum reflection loss (RL_min) of −39.8 dB at 4.64 GHz and an abroad EAB of up to 7 GHz at only 2.5 mm thickness. Computer simulation technology (CST) simulations indicate a maximum radar cross‐section reduction of 21.1 dB m², highlighting the material's radar stealth capability. This research advances the development of high‐performance materials and offers new strategies for enhancing absorption properties through composite engineering.

For materials with coexisting phases, the transition from a random to an ordered distribution of materials often generates new mechanisms. Although the magnetic confinement effect has improved the electromagnetic (EM) performance, the transition from random to ordered magnetic confinement positions remains a synthetic challenge, and the underlying mechanisms are still unclear. Herein, precise control of magnetic nanoparticles is achieved through a spatial confinement growth strategy, preparing five different modalities of magnetic confined carbon fiber materials, effectively inhibiting magnetic agglomeration. Systematic studies have shown that the magnetic confinement network can refine CoNi NPs size and enhance strong magnetic coupling interactions. Compared to CoNi@HCNFs on the hollow carbon fibers (HCNFs) outer surface, HCNFs@CoNi constructed on the inner surface induce stronger spatial charge polarization relaxation at the interface and exhibit stronger magnetic coupling interactions at the inner surface due to the high‐density magnetic coupling units at the micro/nanoscale, thereby respectively enhancing dielectric and magnetic losses. Remarkably, they achieve a minimum reflection loss (RL_min) of −64.54 dB and an absorption bandwidth of 5.60 GHz at a thickness of 1.77 mm. This work reveals the microscale mechanism of magnetic confinement‐induced different polarization relaxation and magnetic response, providing a new strategy for designing magnetic materials.

The pursuit of eco‐friendly electromagnetic wave absorption (EMWA) materials with multifunctional capabilities has garnered significant attention in practical applications. However, achieving these desired qualities simultaneously poses a significant challenge. This study introduces a single‐step calcination and chemical polymerization process to obtain an environmentally friendly ant‐nest‐inspired hybrid composite by optimizing conductive polypyrrole nanotubes (PNTs) within a 3D carbonaceous structure. The biomimetic composite forms a highly efficient conductive network, providing a pathway for free electrons within the carbonaceous barriers and enhancing the conduction loss. Remarkably, the EMWA performance of the composite achieves ultrathin (1.6 mm), wide effective absorption band (5.4 GHz), and strong absorption intensity (−67.6 dB) features. Moreover, due to the complex and intertwined 3D continuous network, the obtained samples exhibit excellent thermal insulation and superhydrophobic behavior by inhibiting heat transfer and preventing localized areas from being prone to water absorption. These findings not only offer a sustainable and low‐cost production route for biomimetic carbonaceous composites but also demonstrate a high‐efficiency absorber with great multifunctionality as a green alternative to traditional EMWA materials.

There has been a recent transition from conventional textiles to smart and electronic textiles, mostly due to the rise of wearable technology. Functional yarns have been created to fulfil the varied application needs in various environments. Conductive yarns have attracted considerable interest because of their exceptional softness, comfort, and diverse capabilities, such as electromagnetic shielding and soft sensors. This paper presents a comprehensive examination of spinning techniques utilized for the production of conductive yarns, incorporating a range of conductive additives, conductive fabrics, and conventional electrical elements. The text emphasizes that the performance of conductive yarns is significantly affected by their structure, which is dictated by the geometrical configurations of their elements, and the spinning geometry, commonly known as the twisted triangle. The performance of conductive yarns is primarily determined by the concentration of conductive components in their structure. Moreover, this paper examines the possible uses of conductive fabrics in several technical domains. The mentioned applications encompass antistatic packaging, heating elements, wearable electronics, smart membrane technology, data storage and transmission, sensors, actuators, and protection against electromagnetic interference and electrostatic discharge. Conductive textiles possess a versatile character that presents a wide range of opportunities for progress in multiple industries. To summarize, this review thoroughly examines the spinning methods used to create conductive yarns, with a particular focus on the significance of yarn structure in influencing their performance. Furthermore, it emphasizes the wide range of technological applications in which conductive textiles can be utilized.