Search Results (34)

Functionalized hydrogels represent an emerging class of smart materials being explored for advancing next-generation wearable technologies, owing to their flexibility, biocompatibility, stimuli-responsiveness, and tunable properties. This review provides an overview of recent developments in hydrogel-based wearables, highlighting their potential to enhance adaptive, multifunctional, and environmentally sustainable devices and textiles. It begins by examining progress in wearable sensors, energy storage and harvesting, biosignal monitoring, and smart textiles, as well as the associated challenges, including limited battery life, inadequate skin adhesion, user discomfort, and constrained functionality. The review further explores the synthesis, fabrication techniques, properties, and types of hydrogels tailored for wearable technologies, followed by a detailed discussion of their applications in smart batteries, supercapacitors, sensors, nanogenerators, fabrics and hybrid systems. It also highlights integrating artificial intelligence (AI) and the Internet of Things (IoT) to improve designs; enhance performance through real-time monitoring, data analytics, and user interaction; and expand functionality. Also, it analyzes key limitations of current hydrogels—particularly in energy density, dehydration resistance, fatigue behaviour, and large-scale reproducibility—and outlines strategies based on hierarchical material design, sustainable and biodegradable formulations, and standardized testing and regulatory alignment. The review concludes by affirming the role of hydrogel-based technologies in shaping the future of wearable innovations across healthcare, lifestyle, and beyond and outlines promising research directions. Full article

This work presents the design, fabrication and characterisation of an improved textile energy storage device implemented in a single layer of polyester cotton and silk fabric. To achieve this, the energy storage device has evolved from an electrical double-layer (EDL) supercapacitor to a zinc-ion supercapacitor (ZHSC) with an optimised co-polymer membrane containing a polyethene oxide (PEO) additive and a polyvinylidene (PVDF)-based organic electrolyte. The flexible textile ZHSC achieved an areal capacitance of 159.5 mF cm⁻² and an energy density of 52.3 µWh cm⁻² (increasing by a factor of 4 and 1.8, respectively, on the previous work) with a power density of 0.27 mW cm⁻² and good bending stability. Full article

Filtration of submicron particles and nanoparticles is an important problem in nano-industry and in air conditioning and ventilation systems. The presence of submicron particles comprising fungal spores, bacteria, viruses, microplastic, and tobacco-smoke tar in ambient air is a severe problem in air conditioning systems. Many nanotechnology material processes used for catalyst, solar cells, gas sensors, energy storage devices, anti-corrosion and hydrophobic surface coating, optical glasses, ceramics, nanocomposite membranes, textiles, and cosmetics production also generate various types of nanoparticles, which can retain in a conveying gas released into the atmosphere. Particles in this size range are particularly difficult to remove from the air by conventional methods, e.g., electrostatic precipitators, conventional filters, or cyclones. For these reasons, nanofibrous filters produced by electrospinning were developed to remove fine particles from the post-processing gases. The physical basis of electrospinning used for nanofilters production is an employment of electrical forces to create a tangential stress on the surface of a viscous liquid jet, usually a polymer solution, flowing out from a capillary nozzle. The paper presents results for investigation of the filtration process of metal oxide nanoparticles: TiO₂, MgO, and Al₂O₃ by electrospun nanofibrous filter. The filter was produced from polyvinylidene fluoride (PVDF). The concentration of polymer dissolved in dimethylacetamide (DMAC) and acetone mixture was 15 wt.%. The flow rate of polymer solution was 1 mL/h. The nanoparticle aerosol was produced by the atomization of a suspension of these nanoparticles in a solvent (methanol) using an aerosol generator. The experimental results presented in this paper show that nanofilters made of PVDF with surface density of 13 g/m² have a high filtration efficiency for nano- and microparticles, larger than 90%. The gas flow rate through the channel was set to 960 and 670 l/min. The novelty of this paper was the investigation of air filtration from various types of nanoparticles produced by different nanotechnology processes by nanofibrous filters and studies of the morphology of nanoparticle deposited onto the nanofibers. Full article

Graphene has emerged as a promising material for transforming conventional textiles into smart, multi-functional platforms due to its exceptional electrical, thermal, and mechanical properties. This review aims to provide a comprehensive overview of the latest advances in graphene-enhanced fabrics over the past ten years, focusing on their functional properties and real-world applications. This article examines the main strategies used to incorporate graphene and its derivatives—such as graphene oxide and reduced graphene oxide—into textile substrates through coating, printing, or composite formation. The structural, electrical, thermal, mechanical, and electrochemical properties of these fabrics are discussed based on characterization techniques including microscopy, Raman spectroscopy, and cyclic voltammetry. Functional evaluations in wearable strain sensors, biosignal acquisition, electrothermal systems, and energy storage devices are highlighted to demonstrate the versatility of these materials. Although challenges remain in scalability, durability, and washability, recent developments in fabrication and encapsulation methods show significant potential to overcome these limitations. This review concludes by outlining the major opportunities and future directions for graphene-based textiles in areas such as personalized health monitoring, active thermal wear, and integrated wearable electronics. Full article

The design and investigation of electrochromic devices have advanced significantly, including distinct applications such as self-charged smart windows, aerospace interactive windows, low power flexible and ecofriendly displays, automatic dimming rearview, wearable smart textiles, military and civilian camouflage systems, electrochromic sensors, among others. Although significant progress has been made in related fields, achieving the full potential of electrochromic devices to meet the standards of maturity and practical applications remains a persistent challenge. Electrochromic devices are typically multilayered structures that can be designed as either rigid or flexible systems, depending on the type of substrate employed. Conventional electrochromic devices comprise layered structures that include transparent electrodes, electrochromic materials, ionic conductors, and ion storage materials. On the other hand, multifunctional systems integrate bifunctional materials or distinct functional layers to simultaneously achieve optical modulation and additional capabilities such as energy storage. The development of advanced materials, comprehensive electrochemical kinetic analysis, the optimization and advancement of process techniques and deposition methods, and innovative device designs are active areas of extensive global research. This review focuses on the recent advances in multifunctional electrochromic materials and devices with particular emphasis on the integration of electrochromic technology with other functional technologies. It further identifies current challenges, proposes potential solutions, and outlines future research directions focused on advancing this technology in both niche and scalable applications. Full article

Printed electronics employ established printing methods to create low-cost, mechanically flexible devices including batteries, supercapacitors, sensors, antennas and RFID tags on plastic, paper and textile substrates. This review focuses on the specific contribution of screen printing to that landscape, examining how ink viscosity, mesh selection and squeegee dynamics govern film uniformity, pattern resolution and ultimately device performance. Recent progress in advanced ink systems is surveyed, highlighting carbon allotropes (graphene, carbon nano-onions, carbon nanotubes, graphite), silver and copper nanostructures, MXene and functional oxides that collectively enhance mechanical robustness, electrical conductivity and radio-frequency behavior. Parallel improvements in substrate engineering such as polyimide, PET, TPU, cellulose and elastomers demonstrate the technique’s capacity to accommodate complex geometries for wearable, medical and industrial applications while supporting environmentally responsible material choices such as water-borne binders and bio-based solvents. By mapping two decades of developments across energy-storage layers and functional electronics, the article identifies the key process elements, recurring challenges and emerging sustainable practices that will guide future optimization of screen-printing materials and protocols for high-performance, customizable and eco-friendly flexible devices. Full article

Chemical vapor deposition (CVD) is a highly adaptable manufacturing technique used to fabricate high-quality thin films, making it essential across numerous industries. As materials fabrication processes progress, CVD has advanced to enable the precise deposition of both inorganic 2D materials, such as graphene and transition metal dichalcogenides, and high-quality polymeric thin films, offering excellent conformality and precise nanostructure control on a wide range of substrates. Conjugated conducting polymers have emerged as promising materials for next-generation electronic, optoelectronic, and energy storage devices due to their unique combination of electrical conductivity, optical transparency, ionic transport, and mechanical flexibility. Oxidative CVD (oCVD) involves the spontaneous reaction of oxidant and monomer vapors upon their adsorption onto the substrate surface, resulting in step-growth polymerization that commonly produces conducting or semiconducting polymer thin films. oCVD has gained significant attention for its ability to fabricate conjugated conducting polymers under vacuum conditions, allowing precise control over film thickness, doping levels, and nanostructure engineering. The low to moderate deposition temperature in the oCVD method enables the direct integration of conducting and semiconducting polymer thin films onto thermally sensitive substrates, including plants, paper, textiles, membranes, carbon fibers, and graphene. This review explores the fundamentals of the CVD process and vacuum-based manufacturing, while also highlighting recent advancements in the oCVD method for the fabrication of conjugated conducting and semiconducting polymer thin films. Full article

The production of nanofibers has become a significant area of research due to their unique properties and diverse applications in various fields, such as biomedicine, textiles, energy, and environmental science. Electrospinning, a versatile and scalable technique, has gained considerable attention for its ability to fabricate nanofibers with tailored properties. Among the wide array of conductive polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) has emerged as a promising material due to its exceptional conductivity, environmental stability, and ease of synthesis. The electrospinning of PEDOT-based nanofibers offers tunable electrical and optical properties, making them suitable for applications in organic electronics, energy storage, biomedicine, and wearable technology. This review, with its comprehensive exploration of the fabrication, properties, and applications of PEDOT nanofibers produced via electrospinning, provides a wealth of knowledge and insights into leveraging the full potential of PEDOT nanofibers in next-generation electronic and functional devices by examining recent advancements in the synthesis, functionalization, and post-treatment methods of PEDOT nanofibers. Furthermore, the review identifies current challenges, future directions, and potential strategies to address scalability, reproducibility, stability, and integration into practical devices, offering a comprehensive resource on conductive nanofibers. Full article

This work reports an encapsulated and flexible solid-state AIC screen printed on top of a polyester–cotton textile. The proposed zinc-ion capacitor (ZIC) arrays were fabricated on top of a polymer-coated polyester–cotton textile with solution-based processes and inexpensive electrodes and electrolyte materials. This battery achieved an energy density of 0.47 μWh·cm⁻² (per device area) or 0.51 mWh·cm⁻² (per active material area) in a galvanostatic cycling test between 0.1 V and 1.8 V. Full article

Shape memory and self-healing polymer nanocomposites have attracted considerable attention due to their modifiable properties and promising applications. The incorporation of nanomaterials (polypyrrole, carboxyl methyl cellulose, carbon nanotubes, titania nanotubes, graphene, graphene oxide, mesoporous silica) into these polymers has significantly enhanced their performance, opening up new avenues for diverse applications. The self-healing capability in polymer nanocomposites depends on several factors, including heat, quadruple hydrogen bonding, π–π stacking, Diels–Alder reactions, and metal–ligand coordination, which collectively govern the interactions within the composite materials. Among possible interactions, only quadruple hydrogen bonding between composite constituents has been shown to be effective in facilitating self-healing at approximately room temperature. Conversely, thermo-responsive self-healing and shape memory polymer nanocomposites require elevated temperatures to initiate the healing and recovery processes. Thermo-responsive (TRSMPs), light-actuated, magnetically actuated, and Electrically actuated Shape Memory Polymer Nanocomposite are discussed. This paper provides a comprehensive overview of the different types of interactions involved in SMP and SHP nanocomposites and examines their behavior at both room temperature and elevated temperature conditions, along with their biomedical applications. Among many applications of SMPs, special attention has been given to biomedical (drug delivery, orthodontics, tissue engineering, orthopedics, endovascular surgery), aerospace (hinges, space deployable structures, morphing aircrafts), textile (breathable fabrics, reinforced fabrics, self-healing electromagnetic interference shielding fabrics), sensor, electrical (triboelectric nanogenerators, information energy storage devices), electronic, paint and self-healing coating, and construction material (polymer cement composites) applications. Full article

Efficient energy storage is becoming a serious niche area nowadays due to exponential growth in energy consumption. Different approaches have been developed and implemented to improve the performance of the devices, in which improving conductivity is a major issue. In the present work, cotton fabric was converted into a conductive material by incorporating graphene, using the Layer-by-Layer (LBL) method, followed by heating at 100 °C. The electrical conductivity of the cotton using different concentrations of graphene was studied. The graphene-coated cotton, at the 17th layer, with a concentration of 168.36 wt.% resulted in a surface resistance of 0.644 Ω/sq and retained the maximum resistance even after two months. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy analysis (EDX) were employed to comprehend the surface morphology and elemental compositions. Fourier transform infrared (FTIR) spectroscopy, UV-vis absorption, and X-ray diffraction (XRD) were used to determine the structural analysis, which revealed a good dispersion of graphene in the cotton samples obtained through dimethyl sulfoxide (DMSO) doping, which reduced the ripple of the cotton. The cotton fabric treated with graphene was thermally stable, as shown through thermal analysis. From the results obtained, it is evident that graphene-treated cotton fabric materials show tremendous potential for use in smart textiles and also as protective clothing. Full article

Aerogels, due to their unique features like lightweight, ultra-low thermal conductivity, and design variations, have gotten a lot of interest in thermal insulation, photocatalysis, and protective areas. Besides their superior thermal properties, aerogel thermal insulation and photocatalyst materials also possess many inherent flaws, such as handling issues, high manufacturing costs, and low strength as well as toughness. The most persuasive and successful ways to improve photocatalytic and thermal insulating qualities while lowering costs are composition optimization and microstructure reconstruction. Their high surface area and porosity make them ideal for enhancing the efficiency and capacity of these devices. Research may lead to more efficient and longer-lasting energy storage solutions. This review describes the characteristics, microstructural reconstruction, design variation, and properties of all aerogel fabrication techniques and provides a comprehensive overview of scientific achievements linked to them. The effectiveness of raw material compositions, properties, and mechanical parameters are also discussed. The major goal of this review is to highlight the aerogel-based materials and design variations and to explore the most potential development trends for photocatalysis and thermal applications. The industrial as well as technical applications of silica aerogels are also highlighted. This review highlights futuristic applications of aerogel-based textile materials to alleviate the CO₂ burden on our atmosphere, either by providing next-level thermal insulation or by employing them in CO₂ mitigating technologies such as CO₂ capture. Full article

Future wearable electronics and smart textiles face a major challenge in the development of energy storage devices that are high-performing while still being flexible, lightweight, and safe. Fiber supercapacitors are one of the most promising energy storage technologies for such applications due to their excellent electrochemical characteristics and mechanical flexibility. Over the past decade, researchers have put in tremendous effort and made significant progress on fiber supercapacitors. It is now the time to assess the outcomes to ensure that this kind of energy storage device will be practical for future wearable electronics and smart textiles. While the materials, fabrication methods, and energy storage performance of fiber supercapacitors have been summarized and evaluated in many previous publications, this review paper focuses on two practical questions: Are the reported devices providing sufficient energy and power densities to wearable electronics? Are the reported devices flexible and durable enough to be integrated into smart textiles? To answer the first question, we not only review the electrochemical performance of the reported fiber supercapacitors but also compare them to the power needs of a variety of commercial electronics. To answer the second question, we review the general approaches to assess the flexibility of wearable textiles and suggest standard methods to evaluate the mechanical flexibility and stability of fiber supercapacitors for future studies. Lastly, this article summarizes the challenges for the practical application of fiber supercapacitors and proposes possible solutions. Full article

Rechargeable sodium seawater batteries (SWBs) are gaining the world leadership of high voltage energy storage devices for marine environments. With natural seawater as the source of active material, SWBs can be supplied infinitely with Na cations. Because of their open-structured cathode, the cathode material’s specific surface area, porosity and wettability need to be optimized to achieve a high-performance cell. In this work, activated textile polyacrylonitrile (PAN) fibers were used to produce an activated carbon felt with a facile manufacturing process. The easy and low-cost production of these fibers makes them excellent candidates for energy storage applications involving oxygen evolution and reduction reactions. The electrochemical performance results of the fabricated activated PAN fibers and of commercial carbon felts were measured and compared, being characterized through galvanostic charge discharge cycles, electrochemical impedance spectroscopy and cyclic voltammetries. A performance improvement was observed with PAN activated carbon felt as half cell with a capacitance increase (about 9000%), and as full cell with a smaller voltage gap (about 10%) and increased gravimetric capacitance (about 260%) when compared to the commercial carbon felt. The successful implementation of PAN activated carbon felts in an aqueous environment opens new paths toward high performance seawater battery’s cathodes. Full article

The emerging wearable electronics integrated into textiles are posing new challenges both in materials and micro-fabrication strategies to produce textile-based energy storage and power source micro-devices. In this regard, inkjet printing (IJP) offers unique features for rapid prototyping for various thin-film (2D) devices. However, all-inkjet-printed capacitors were very rarely reported in the literature. In this work, we formulated a stable Ti₃C₂ MXene aqueous ink for inkjet printing current-collector-free electrodes on TPU-coated cotton fabric, together with an innovative inkjet-printable and UV-curable solvent-based electrolyte precursor. The electrolyte was inkjet-printed on the electrode’s surface, and after UV polymerization, a thin and soft gel polymer electrolyte (GPE) was obtained, resulting in an all-inkjet-printed symmetrical capacitor (a-IJPSC). The highest ionic conductivity (0.60 mS/cm) was achieved with 10 wt.% of acrylamide content, and the capacitance retention was investigated both at rest (flat) and under bending conditions. The flat a-IJPSC textile-based device showed the areal capacitance of 0.89 mF/cm² averaged on 2k cycles. Finally, an array of a-IJPSCs were demonstrated to be feasible as both a textile-based energy storage and micro-power source unit able to power a blue LED for several seconds. Full article