Search Results (736)

Controlling low-frequency noise and achieving multi-band sound insulation remain significant challenges and have long been hot topics in industrial research. This study introduces a novel multifunctional device based on the principles of acoustic metamaterials, which not only offers high-performance sound insulation but also converts low-frequency acoustic energy into electrical energy. Through an innovative design featuring multiple local resonance design, the proposed device effectively mitigates the impact of pre-tension on the membrane, while enabling efficient multi-band sound insulation that can be finely tuned by adjusting structural parameters. Experimental results demonstrate that the device achieves a maximum sound insulation of 40 dB and an average sound insulation exceeding 25 dB within the 1000 Hz frequency range. Moreover, by utilizing its local resonance property, a triboelectric nanogenerator (TENG) is specifically designed for low-frequency acoustic–electric conversion, maintaining high performance low-frequency sound insulation while simultaneously powering small scale electronic devices. This work provides a promising approach for multi-band sound insulation and low-frequency acoustic–electric conversion, offering broad potential for industrial applications. Full article

The development of bioactive dental materials with antimicrobial and biocompatible properties is important for improving clinical outcomes and reducing complications associated with intraoral devices. This study presents a novel approach that combines a 3D-printed shape-memory resin (TC-85DAC) with green-synthesized zinc oxide nanoparticles (ZnO NPs) to enhance biological performance. ZnO NPs were synthesized using Dysphania ambrosioides extract, producing quasi-spherical particles with a crystalline hexagonal structure and sizes between 15 and 40 nm. Resin discs were coated with ZnO NPs at 10%, 20%, and 30%, then assessed for biocompatibility with human gingival fibroblasts and antibacterial activity against Porphyromonas gingivalis and Streptococcus mutans. Surface roughness was also considered with and without ZnO NPs. Biocompatibility assays revealed a concentration- and time-dependent increase in cell viability, with the highest values at 30% ZnO NPs after 72 h of exposure to the NPs. Antibacterial testing confirmed the inhibition of both species, with Porphyromonas gingivalis showing greater sensitivity. Surface roughness increased with higher ZnO NPs concentrations, significantly influencing biological interactions. The integration of green-synthesized ZnO NPs with shape-memory resin produced a multifunctional dental material with improved bioactivity. This sustainable strategy enables bioactive coatings on 3D-printed resins, with potential applications in the next generation of smart dental devices. Full article

Multifunctional metasurfaces, capable of flexible electromagnetic wave manipulation, have become a focus of research for their high integration and utility. In particular, those operating simultaneously in transmission and reflection modes have attracted growing interest, as they integrate multiple functions within a single aperture, save physical space, and further expand wave control capabilities across full space. In this work, an inspiring strategy of transmission-reflection-integrated bifunctional metasurface by hybridizing geometric phase and propagation phase is proposed. The transmission and reflection modes can be independently and flexibly controlled in full space: the co-polarized reflection under left-handed circular polarization (LCP) incidence is governed by rotation-induced geometric phase modulation, while the co-polarized transmission under right-handed circular polarization (RCP) incidence is modulated through scaling-induced propagation phase modulation. Moreover, arbitrary amplitude modulation of the co-polarized transmission under RCP incidence can be realized by incorporating lumped resistors. As a proof of concept, a bifunctional meta-device is constructed, which can generate vortex beam carrying arbitrary topological charge for LCP reflected wave and achieve high-quality holographic imaging for RCP transmitted wave. Both the simulated and experimental results validate the feasibility of the proposed strategy, which significantly enhances the integration density of multifunctional metasurfaces while reducing inter-functional crosstalk, expanding its potential applications in electronic engineering. Moreover, it can also serve as a fundamental machine learning platform, facilitating multimodal fusion and cross-modal learning in radar signals and visual imaging. Full article

This study proposes an innovative silver-nanoparticle-assisted electrochemical etching method for the fabrication of porous silicon Bragg reflectors with multi-wavelength reflection characteristics. By introducing silver nanoparticles at varying concentrations (0.1–10 mg/mL) into the conventional HF–ethanol electrolyte and applying periodically modulated current densities (40/100 mA/cm²), the transition from single-peak to multi-peak reflection spectra was successfully achieved. The results demonstrate that at a concentration of 10 mg/mL silver nanoparticles, up to four distinct reflection bands can be obtained. A systematic investigation was conducted on the influence of etching cycles (4–20 cycles) and silver nanoparticle concentration on the optical performance and microstructure. SEM analysis revealed well-defined periodic multilayer structures, while XPS analysis confirmed the presence of metallic silver on the porous silicon surface. This work provides a simple, controllable, and cost-effective approach to the development of multifunctional photonic devices, with promising applications in laser optics, solar cells, chemical sensing, and surface-enhanced Raman scattering. Full article

Polymer materials have become promising candidates for next-generation energy storage, with structural tunability, multifunctionality, and compatibility with a variety of device platforms. They have a molecular design capable of customizing ion and electron transport routes, integrating redox-active species, and enhancing interfacial stability, surpassing the drawbacks of traditional inorganic systems. New developments have been made in multifunctional polymers that have the ability to combine conductivity, mechanical properties, thermal stability, and self-healing into a single scaffold system, which is useful in battery, supercapacitor, and solid-state applications. By incorporating polymers with carbon nanostructures, ceramics, or two-dimensional materials, hybrid polymer nanocomposites improve electrochemical performance, durability, and mechanical compliance, and the solid polymer electrolytes, as well as artificial solid electrolyte interphases, resolve dendrite growth and safety issues. The multifunctionality also extends to flexibility, stretchability, and miniaturization, which implies that polymers are suitable for use in wearable devices and biomedical devices. At the same time, sustainable polymer innovation focuses on bio-based feedstocks, which can be recycled, and green synthesis pathways. Polymer discovery using artificial intelligence and machine learning is faster than standard methods, predicts structure–property–performance relationships, and can be rationally engineered. Although there are difficulties in stability during long periods, scalability, and trade-offs between indeedness and mechanical endurance, polymers are a promising avenue with regard to dependable, safe, and sustainable power storage. This review presents the molecular strategies, multifunctional uses, and prospects, where polymers are at the center of the next-generation energy technologies. Full article

Fiber-optic sensing (FOS) technology has emerged as a cutting-edge research focus in the sensor field due to its miniaturized structure, high sensitivity, and remarkable electromagnetic interference immunity. Compared with conventional sensing technologies, FOS demonstrates superior capabilities in distributed detection and multi-parameter multiplexing, thereby accelerating its applications across biomedical, industrial, and aerospace fields. This paper conducts a systematic analysis of the sensing mechanisms in fiber-optic pressure sensors, with a particular focus on the performance optimization effects of fiber structures and materials, while elucidating their application characteristics in different sensing scenarios. This review further examines current manufacturing technologies for fiber-optic pressure sensors, covering key processes including fiber processing and packaging. Regarding practical applications, the multifunctional characteristics of fiber-optic pressure sensors are thoroughly investigated in various fields, including biomedical monitoring, industrial and energy monitoring, and wearable devices, as well as aerospace monitoring. Furthermore, current challenges are discussed regarding performance degradation in extreme environments and multi-parameter cross-sensitivity issues, while future research directions are proposed, encompassing the integration and exploration of novel structures and materials. By synthesizing recent advancements and development trends, this review serves as a critical reference bridging the gap between research and practical applications, accelerating the advancement of fiber-optic pressure sensors. Full article

This work presents a comprehensive first-principles investigation of the structural, electronic, magnetic, optical, and thermodynamic properties of Ti-based full-Heusler compounds TiMCu₂ (M = Al, Ga, In). Using density functional theory within the GGA+U framework, the compounds were optimized and analyzed to evaluate their stability and potential for functional applications. The results confirm robust structural and dynamic stability, as verified by elastic constants and phonon dispersion curves. All studied systems exhibit metallic character with pronounced spin polarization, while TiGaCu₂ shows the strongest total magnetization, highlighting its suitability for spintronic devices. Optical analyses reveal strong absorption across the visible and near-UV regions, low reflectivity, and favorable dielectric behavior, indicating promise for photovoltaic and optoelectronic applications. Thermodynamic modeling further confirms stability under high temperature and pressure, reinforcing their practical viability. Overall, the TiMCu₂ family demonstrates multifunctional characteristics, positioning them as eco-friendly and cost-effective candidates for next-generation renewable energy, spintronic, and optoelectronic technologies. Full article

Multifunctional coatings integrating high transparency, thermal insulation, and self-cleaning properties are critically needed for optical devices and energy-saving applications, yet simultaneously optimizing these functions remains challenging due to material and structural limitations. This study designed a superhydrophobic transparent thermal insulation coating via synergistic co-construction of micro–nano structures using antimony-doped tin oxide (ATO) and SiO₂ nanoparticles dispersed in an epoxy resin matrix, with surface modification by perfluorodecyltriethoxysilane (PFDTES) and γ-glycidyl ether oxypropyltrimethoxysilane (KH560). The optimal superhydrophobic transparent thermal insulating (SHTTI) coating, prepared with 0.6 g SiO₂ and 0.8 g ATO (SHTTI-0.6-0.8), achieved a water contact angle (WCA) of 162.4°, sliding angle (SA) of 3°, and visible light transmittance of 72% at 520 nm. Under simulated solar irradiation, it reduced interior temperature by 7.3 °C compared to blank glass. The SHTTI-0.6-0.8 coating demonstrated robust mechanical durability by maintaining superhydrophobicity through 40 abrasion cycles, 30 tape-peel tests, and sand impacts, combined with chemical stability, effective self-cleaning capability, and exceptional anti-icing performance that prolonged freezing time to 562 s versus 87 s for blank glass. This work provides a viable strategy for high-performance multifunctional coatings through rational component ratio optimization. Full article

Wood is a renewable, carbon-sequestering, and structurally versatile material that has supported human civilization for millennia and continues to play a central role in advancing sustainable development. Although its low density, high specific strength, and esthetic appeal make it highly attractive, its intrinsic flammability presents significant challenges for safety-critical uses. This review offers a comprehensive analysis that uniquely integrates three key domains, covering advanced processing technologies, flame-retardant functionalization strategies, and multifunctional applications. Clear connections are drawn between processing approaches such as delignification, densification, and nanocellulose extraction and their substantial influence on improving flame-retardant performance. The review systematically explores how these engineered wood substrates enable more effective fire-resistant systems, including eco-friendly impregnation methods, surface engineering techniques, and bio-based hybrid systems. It further illustrates how combining processing and functionalization strategies allows for multifunctional applications in architecture, transportation, electronics, and energy devices where safety, durability, and sustainability are essential. Future research directions are identified with a focus on creating scalable, cost-effective, and environmentally compatible wood-based materials, positioning engineered wood as a next-generation high-performance material that successfully balances structural functionality, fire safety, and multifunctionality. Full article

The rapid development of nanotechnology has significantly transformed the design and performance of glucose biosensors, leading to enhanced sensitivity, selectivity, and real-time monitoring capabilities. This review highlights recent advances in glucose-sensing platforms facilitated by nanomaterials, including metal and metal oxide nanoparticles, carbon-based nanostructures, two-dimensional materials, and metal–organic frameworks (MOFs). The integration of these nanoscale materials into electrochemical, optical, and wearable biosensors has addressed longstanding challenges associated with enzyme stability, detection limits, and invasiveness. Special emphasis is placed on non-enzymatic glucose sensors, flexible and wearable devices, and hybrid nanocomposite systems. The multifunctional properties of nanomaterials, such as large surface area, excellent conductivity, and biocompatibility, have enabled the development of next-generation sensors for clinical, point-of-care, and personal healthcare applications. The review also discusses emerging trends such as biodegradable nanosensors, AI-integrated platforms, and smart textiles, which are poised to drive the future of glucose monitoring toward more sustainable and personalized healthcare solutions. Full article

True wireless stereo (TWS) earbuds are evolving into multifunctional wearable devices, offering opportunities not only for audio streaming but also for health-related applications. A fundamental requirement for such devices is the ability to accurately detect whether they are being worn, yet conventional proximity sensors remain limited in both reliability and functionality. This work explores the use of photoplethysmography (PPG) sensors, which are widely applied in heart rate and blood oxygen monitoring, as an alternative solution for wearing detection. A PPG sensor was embedded into a TWS prototype to capture blood flow changes, and the wearing status was classified in real time using a lightweight k-nearest neighbor (k-NN) algorithm on an edge AI processor. Experimental evaluation showed that incorporating a validity check enhanced classification performance, achieving F1 scores above 0.95 across all wearing conditions. These results indicate that PPG-based sensing can serve as a robust alternative to proximity sensors and expand the capabilities of TWS devices. Full article

Cobalt-doped iron disulfide (FeS₂) thin films were synthesized via chemical bath deposition (CBD) followed by annealing at 450 °C, yielding phase-pure pyrite structures with multifunctional properties. A deposition temperature of 95 °C is critical for promoting Co incorporation, suppressing sulphur vacancies, and achieving structural stabilization of the film. After annealing, the dendritic morphologies transformed into compact quasi-spherical nanoparticles (~100 nm), which enhanced the crystallinity and optoelectronic performance of the films. The films exhibited strong absorption (>50%) in the visible and near-infrared regions and tunable direct bandgaps (1.14 to 0.96 eV, within the optimal range for single-junction solar cells. Electrical characterization revealed a fourth-order increase in conductivity after annealing (up to 4.78 Ω⁻¹ cm⁻¹) and confirmed stable p-type behavior associated with Co²⁺-induced acceptor states and defect passivation. These results demonstrate that CBD enabled the fabrication of Co-doped FeS₂ thin films with synergistic structural, electrical, and optical properties. The integration of earth-abundant elements and tunable electronic properties makes these films promising absorber materials for the next-generation photovoltaic devices. Full article

The development of a multifunctional invention requires several refinements for optimizing each function. This study presents a Theory of Inventive Problem Solving (TRIZ)-based conceptual framework for enhancing an innovative multifunctional assistive technology device that integrates the functionalities of a rollator walker, wheelchair, Pilates chair, and stepladder. The limitations of the multifunctional rollator walker were identified from the user feedback of a foundational work and were then addressed by identifying the engineering and physical contradictions and problem modeling using Su-field analysis. Through TRIZ Inventive Principles, the proposed design eliminates common trade-offs between portability, stability, and usability. The conceptual enhancement incorporates features such as deployable steps, the utilization of high strength–to–weight ratio material, foldability, a passive mechanical brake-locking system, retractable armrests, the incorporation of spring-assist hinges, and the use of large tires with vibration-dampening hubs. This study contributes a novel, user-focused, and space-saving mobility solution that aligns with the evolving demands of assistive technology, laying the groundwork for future iterations involving smart control, power assist, and modular enhancements. Full article

Neuromorphic computing, inspired by the human brain’s architecture, offers a transformative approach to overcoming the limitations of traditional von Neumann systems by enabling highly parallel, energy-efficient information processing. Among emerging materials, MXenes—a class of two-dimensional transition metal carbides and nitrides—have garnered significant attention due to their exceptional electrical conductivity, tunable surface chemistry, and mechanical flexibility. This review comprehensively examines recent advancements in MXene-based optoelectronic synapses and neurons, focusing on their structural properties, device architectures, and operational mechanisms. We emphasize synergistic electrical–optical modulation in memristive and transistor-based synaptic devices, enabling improved energy efficiency, multilevel plasticity, and fast response times. In parallel, MXene-enabled optoelectronic neurons demonstrate integrate-and-fire dynamics and spatiotemporal information integration crucial for biologically inspired neural computations. Furthermore, this review explores innovative neuromorphic hardware platforms that leverage multifunctional MXene devices to achieve programmable synaptic–neuronal switching, enhancing computational flexibility and scalability. Despite these promising developments, challenges remain in device stability, reproducibility, and large-scale integration. Addressing these gaps through advanced synthesis, defect engineering, and architectural innovation will be pivotal for realizing practical, low-power optoelectronic neuromorphic systems. This review thus provides a critical roadmap for advancing MXene-based materials and devices toward next-generation intelligent computing and adaptive sensory applications. Full article

This study presents a novel strategy for designing photocurable resins tailored for the additive manufacturing of smart thermoset materials. A quaternary formulation was developed by integrating bis(2-methacryloyl)oxyethyl disulfide (DADS) with an epoxy/thiol-ene system (ETES) composed of diglycidyl ether of bisphenol A (EP), pentaerythritol tetrakis(3-mercaptopropionate) (PTMP), and 4,4′-methylenebis(N,N-diallylaniline) (ACA4). This unique combination enables the simultaneous activation of four polymerization mechanisms: radical photopolymerization, thiol-ene coupling, thiol-Michael addition, and anionic ring-opening, within a single resin matrix. A key innovation lies in the exothermic nature of DADS photopolymerization, which initiates and sustains ETES curing at room temperature, enabling 3D printing without thermal assistance. This represents a significant advancement over conventional systems that require elevated temperatures or post-curing steps. The resulting hybrid poly(acrylate–co-ether–co-thioether) network exhibits enhanced mechanical integrity, shape memory behavior, and intrinsic self-healing capabilities. Dynamic Mechanical Analysis revealed a shape fixity and recovery of 93%, while self-healing tests demonstrated a 94% recovery of viscoelastic properties, as evidenced by near-overlapping storage modulus curves compared to a reference sample. This integrated approach broadens the design space for multifunctional photopolymers and establishes a versatile platform for advanced applications in soft robotics, biomedical devices, and sustainable manufacturing. Full article