Najib Alam

This study explores the energy-harvesting performance of aluminum (Al)- and iron (Fe)-filled styrene–butadiene rubber (SBR) composites, with a focus on their mechanical durability and triboelectric properties. Comprehensive mechanical characterization—including tensile strength, elongation at break, fracture toughness, and elasticity—reveals that Fe-filled composites exhibit significantly enhanced reinforcement compared to Al-filled systems at equivalent filler loadings. Raman spectroscopy indicates that Fe atoms can coordinate with the benzene rings of SBR chains through stronger physicochemical bonding, a feature less present in Al-based composites. In addition to improved mechanical properties, Fe-filled composites demonstrate higher electrical conductivity and superior triboelectric energy-harvesting performance. Notably, the composite containing 15 vol% Fe under 1% cyclic compressive strain achieves a peak current density of 127.05 µA/m², a total generated charge of 5.01 nC, and a peak power density of 48.22 µW/m². These values represent substantial enhancements of 246%, 236%, and 2398%, respectively, compared to Al-filled counterparts. Cyclic energy-harvesting tests confirm stable performance with negligible degradation in output or mechanical integrity over repeated cycles. Rubber composite shows good humidity resistance in current and voltage outputs. Furthermore, a layer-by-layer triboelectric nanogenerator (TENG) based on the Fe-filled composite produces output signals of approximately ±1.0 µA and ±5 V under biomechanical hand patting. The superior performance of Fe-based composites is attributed to stronger filler–rubber interactions, likely facilitated by electrostatic interactions, which enhances interfacial charge transfer during mechanical deformation. Overall, Fe-filled SBR composites demonstrate strong potential for cost-effective, environmentally friendly, and durable self-powered energy-harvesting applications.

Rubber and elastomer matrices are widely used in advanced engineering and technological applications due to their robust mechanical flexibility and favorable electrical properties

Fluorescent nanoprobes operating in the NIR-II window have gained considerable attention for biomedical imaging because of their deep-tissue penetration, reduced scattering, and high spatial resolution. Their tunable optical behavior, flexible surface chemistry, and capacity for multifunctional design enable sensitive detection and targeted visualization of biological structures in vivo. This review highlights recent advances in the design and optical engineering of four widely studied NIR-II nanoprobe families: quantum dots, carbon dots, upconversion nanoparticles, and dye-doped silica nanoparticles. These materials were selected because they offer well-defined architectures, controllable emission properties, and substantial mechanistic insight supporting discussions of imaging performance and translational potential. Particular focus is placed on emerging strategies for activatable, targeted, and ratiometric probe construction. Recent efforts addressing biosafety, large-scale synthesis, optical stability, and early preclinical validation are also summarized to clarify the current progress and remaining challenges that influence clinical readiness. By outlining these developments, this review provides an updated and focused perspective on how engineered NIR-II nanoprobes are advancing toward practical use in biomedical imaging and precision diagnostics.

The integration of smart nanomaterials into pharmaceutics has transformed approaches to disease diagnosis, targeted therapy, and tissue regeneration. These nanoscale materials exhibit unique features such as controlled responsiveness, biocompatibility, and precise site-specific action, offering new possibilities for personalized healthcare. This review provides a comprehensive overview of recent advances in the design and application of functional nanomaterials, including nanoparticle-based drug carriers, responsive hydrogels, and nanostructured scaffolds. Special focus is placed on stimuli-triggered systems that achieve controlled drug release and localized therapeutic effects. In addition, the review explores how these materials enhance diagnostic imaging and support tissue regeneration through adaptive and multifunctional designs. Importantly, this work uniquely integrates stimuli-responsive nanomaterials across therapeutic, imaging, and regenerative domains, providing a unified view of their biomedical potential. The challenges of clinical translation, large-scale synthesis, and regulatory approval are critically analyzed to outline future directions for research and real-world implementation. Overall, this review highlights the pivotal role of smart nanomaterials in advancing modern pharmaceutics toward more effective and patient-centered therapies.

At present, the utilization of electronic devices is rapidly increasing due to the growing demand for a more sophisticated and convenient lifestyle

Polymer composite materials have emerged as a key class of advanced materials with robust properties

Recently, rubber and elastomer materials have expanded their applications from traditional mechanical uses to advanced mechanical, electrical, and sensor applications