Polymer-based flexible batteries have been long awaited for wearable electronics and smart textiles thanks to their inherent flexibility and processibility. An all-polymer aqueous battery was reported by integrating symmetric polyaniline (PANI) electrodes with a polymer aqueous electrolyte, revealing a new paradigm of the flexible battery. Based on this energetic and durable energy system, all-polymer aqueous flexible batteries were fabricated and successfully integrated into wearable electronics. Thanks to the use of renewable and recyclable polymeric electrode materials as well as a green and safe polymer aqueous electrolyte, these batteries are expected to propel flexible power toward a sustainable future, potentially transforming the landscape of wearable electronics.
Rechargeable aluminum-ion batteries (AIBs) possess a higher theoretical volumetric capacity than lithium-ion batteries (LIBs) and offer a sustainable, low-cost alternative. However, the performance of AIBs fails to meet commercial standards due to the challenges experienced including volume changes caused by interfacial issues, side reactions of the electrolyte with electrode, and low cyclic stability. These issues are attributed to the inability of existing cathode materials to perform effectively. To address these challenges, 1-dimensional (1D) structures, especially nanofiber (NF) cathodes offer a promising solution due to their higher aspect ratios, specific surface area, flexibility, and quantum scale effects. To date, there has been no comparative analysis of the electrochemical and structural performances of NF based cathodes in AIBs. Thus, this review focuses on the recent developments in various transition metal oxides and chalcogenides of (Mo, V, Mn, Ni, Cu, W, Se, and Co) along with carbon-based NFs as cathodes for AIBs. Challenges were observed in adopting trivalent Al3+ cations as charge carriers and maintaining the structural integrity of the cathode. Several novel approaches have been developed to enhance electrical conductivity, including the incorporation of the metal oxides/chalcogenides with the carbon NF substrates, crystallizing the nanoparticles at high temperatures, and using self-assembly and templating techniques to create multi-dimensional NF films. Other battery components such as separators were replaced with carbonaceous structures in the MnSe based cathodes to increase ion mobility, and Mo current collectors to prevent dendrites. This review includes prospects aimed at improving performance and functionality, based on observations from the discussed work and innovations in AIBs such as compositing, surface functionalization, and defect engineering through ion doping.
Graphene fiber materials have emerged as key enablers in the advancement of wearable electronics due to their outstanding electrical conductivity, mechanical strength and flexibility. This review explores the fabrication techniques of graphene fibers, including wet spinning, electrospinning and dry spinning, which have been refined to produce high-performance fibers tailored for various wearable applications. Graphene fibers demonstrate exceptional functionality in wearable sensing technologies, such as strain, pressure and humidity sensors, while also showing promises in flexible energy storage devices like supercapacitors and batteries. Moreover, fabrication techniques like weaving, spinning and additional encapsulations have enabled the integration of graphene fibers into smart textiles, enhancing flexibility and durability. These methods ensure seamless electronic integration into fabrics for applications in flexible displays and wearable systems. By summarizing all the advances of graphene fibers in wearable electronics, this review provides a roadmap for future research directions. Future developments will focus on enhancing structural performance, hybridization with other materials and scalable fabrication techniques to support commercialization. These advancements position graphene fibers as a critical material for next-generation wearable electronics, offering seamless integration of functionality, comfort and durability.
Water and energy scarcity present significant global challenges in arid and remote regions, therefore, it is imperative to develop a sustainable approach that harnesses atmospheric moisture and sunlight to generate both water and energy. A portable system was presented, which directly harvests water from atmospheric moisture and generates energy using cellulose aerogels–high-entropy perovskite La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3–lithium chloride (CA–LB5O3–LiCl). The system captures water from moist air during the night and facilitates solar-driven water evaporation and electrocatalytic water splitting during the day. The CA integrated with LiCl achieves efficient moisture absorption even in arid conditions due to its combined hydrophilic structure and entrapped water. The high-entropy perovskite LB5O3 promotes the lattice oxygen mechanism by weakening the metal–oxygen bond, resulting in an overpotential of 290 mV at 10 mA·cm−2. Furthermore, its excellent solar absorption and photothermal conversion enhance water uptake to 1.01 g·g−1 at 60% relative humidity (RH) as well as increase water evaporation rates to 2.1 kg·h−1·m–2. This process simultaneously generates O2 and H2 from moist airflow, providing both clean water and green fuel. This flexible and sustainable system offers a new pathway for producing water and energy in resource-scarce environments with potential applications in arid and remote regions.
Conformable and breathable textile structures are ideal for flexible wearable pressure sensors, yet challenges remain in scalable fabrication, easy integration, and programmability. This study presents a cost-effective and customizable method to create fully textile-based pressure sensors using machine embroidery, enabling seamless integration into smart wearable systems. Two sensing configurations were developed: a single-layer satin block embroidered with conductive yarn, which exhibited high piezoresistivity, fast response (35 ms), quick recovery (16 ms), and robust durability over 5000 press-and-release cycles, proven effective for monitoring activities such as plantar pressure and muscle contraction, and making it suitable for personalized health and fitness applications. The second configuration, a double-layer embroidery sensor with a conductive path and two parallel spacers anchored beneath a satin block, allows for array integration with minimal wiring, demonstrated by a 3 × 3 sensing array that, with the help of a convolutional neural network (CNN) machine learning model, accurately recognized handwritten numbers (0–9) with a 98.5% accuracy, showing its potential for user authentication and secure passcode entry. These findings underscore the potential of machine embroidery for developing scalable, integrated, and high-performance intelligent textile systems, paving the way for wearable technologies that are customizable, comfortable, and aesthetically appealing for a wide range of applications.
Chronic hypoxia affects stem cell function during tissue repair. Thus far, the hypoxia-associated impact on periosteal stem cells (PSCs), the main contributor to bone repair, remains unknown, and a tailored oxygen modulation strategy for optimizing PSC function is lacking. Here, PSCs exhibit time-dependent proliferation and survival upon hypoxic exposure and a critical 48-h time-point is identified at which hypoxia transitions from beneficial to detrimental. Then, a photothermal-sensitive coaxial fiber-reinforced membrane containing oxygen and pravastatin is constructed to function as an intelligent oxygen supply system. Leveraging near-infrared light as an ON/OFF switch, the system noninvasively scales up oxygen release beginning 48 h post-implantation, counteracting prolonged hypoxia and mitigating its adverse effects on PSCs. The sustained release of pravastatin from the membrane accelerates early neovascularization both directly through its pro-angiogenic effect and indirectly by stimulating vascular endothelial growth factor secretion from PSCs, ensuring a continuous oxygen supply after exogenous oxygen exhaustion. Notably, pravastatin steers PSCs toward robust osteogenic differentiation and provides multifunctional bioactive cues for advanced bone regeneration in vivo. This time-scheduled approach to modulate oxygen supply noninvasively could be applicable beyond bone regeneration for hypoxia-related diseases and multi-tissue repair.
Passive radiative thermal management holds substantial potential for enhancing energy efficiency and sustainability. However, few research efforts have addressed the integration of mechanical robustness and durability with the distribution and composition of photonic structures within materials. Silk fibers, known for their distinctive hierarchical morphological structure, offer a solution to these challenges by providing exceptional optical and mechanical properties. Inspired by this, we developed a silk-like tough metafiber (PMABF) that incorporated multiple scatterers through a multi-scale structural construction of nanofiber aggregates and molecular interface engineering. We show that fabrics woven with PMABF can provide high mid-infrared (MIR) emissivity (98.6%) within the atmospheric window and 86.7% reflectivity in the solar spectrum, attributed to its ellipsoidal photonic structure featuring by surface micro-/nano-particles and numerous internal voids. Through mature and scalable industrial manufacturing routes, our metafibers show excellent mechanical strength, hydrophobicity and thermal stability while maintaining effective passive radiative cooling. Practical application tests demonstrated that molecules introduced during the heterogeneous composite process significantly enhanced the metafiber’s tensile strength (125%) and compressive stress (261.5%) by forming junction welds among the nanofiber backbones to efficiently distribute the external forces. Furthermore, the superior thermal stability and flexibility of PMABF open abundant opportunities for diverse applications with demanding thermal management requirements, such as thermal protection and multi-scenario thermal camouflage.
Biodegradable polylactic acid (PLA) melt-blown nonwovens (MN) are regarded as the promising alternatives for petroleum-based air filtration mediums. However, the filtration performances of most PLA MN were greatly relied on their electrostatic effects which would suffer from inevitable attenuation caused by environment conditions during long-term storage. Herein, the innovative combination of breath-figure (BF) and melt-blowing technologies was proposed to prepare the hierarchically structured PLA MN-bearing BF net pattern (PMBP) for enhanced air filtration. Initially, melt-blowing technology was employed to conduct large-scale preparation of PLA MN with a low-pressure drop of 25.7 Pa but an unsatisfactory PM2.5 (aerodynamic diameter below 2.5 μm) filtration efficiency of 59.5%. At the optimized BF processing conditions involving polymer concentration of 0.5 wt% in hexafluoroisopropanol and relative humidity of 50%, the resultant BF net pattern exhibited uniformly microporous structure with the average pore size low to 1.02 μm. The integration of large-pore PLA MN and small-pore net pattern endowed PMBP with hierarchical structures, which induced PMBP displaying excellent filtration performances (filtration efficiency of 95.8% and pressure drop of 39.3 Pa), and eliminating over 99% of PM2.5 particles within 3 min in the actual smoke test, even without the benefit of static charges. The filtration performances of the PMBP remained stable in high-humidity environments and during long-term storage. Furthermore, the PMBP also exhibited exceptional self-cleaning properties. Overall, this work opens up a promising approach to develop fully bio-based and high-performance filtration materials with hierarchical structures.
Liquid metal (LM) dielectric elastomers with high flexibility and excellent dielectric properties are ideal for flexible capacitive pressure sensors. However, the development of LM dielectric elastomers is hindered by the challenge of unavoidable percolation at high LM fill ratios. Inhomogeneous distribution is an effective strategy to manipulate the percolation threshold. Herein, thermoplastic polyurethane (TPU) fiber mats featuring a unique rapeseed-shaped structure were designed for high LM content filling (up to 90 vol%) and prepared with the aid of an electrospinning technique, in which LM was locally concentrated in the TPU fibers of the composite mats to form isolated clusters, leading to an incredible improvement in the percolation threshold surpassing our calculated theoretical prediction (>90 vol% vs. 83 vol%). The LM/TPU-Fiber mats are proven to be recyclable, temperature-insensitive, and waterproof, making them suitable for multiple usage environments. A flexible capacitive sensor prepared with LM/TPU-Fiber mats, capable of exceptional relative capacitance change (Max. ΔC/C0 = 6.32), an impressive pressure range of 0–550 kPa with a sensitivity of 55 MPa−1, and high cyclic stability (>6000 cycles). With these outstanding attributes, the sensor holds great promise for applications in intelligent sorting, pressure distribution monitoring, and human–machine interaction.
After peripheral nerve injury, disruption of immune homeostasis retards the repair process of peripheral nerves. Piezoelectric materials are the latest paradigm used to address the electrical and energy deficiencies of peripheral nerves. However, the effects and mechanism by which piezoelectric materials regulate immune homeostasis and promote peripheral nerve regeneration remain unclear. We developed a self-powered nerve-bridging scaffold by adding polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) and reduced graphene oxide (rGO) nanoparticles to a polycaprolactone (PCL) substrate. This electrical stimulation reduces high levels of inflammatory cytokines in damaged nerve tissue, controls abnormal neutrophil activity, and promotes quick revascularization. By providing energy, immune balance, and angiogenesis, this electroactive scaffold significantly enhances peripheral nerve regeneration. The recovery of the disintegrated myelin sheath was comparable to that observed after autologous nerve transplantation, and neuromuscular function was significantly restored after implantation of the self-generating electrical stimulation material. This multifunctional fibrous material has promise for clinical translation for the treatment of peripheral nerve injuries.
Due to the shortage of rational waste management, plastic waste has become increasingly serious, posing a serious threat to the environment and humans. The catalytic oxidation of polyethylene terephthalate (PET) waste has been reported to reduce environmental stress and produce valuable products. However, obtaining valuable chemicals from waste plastics under mild conditions driven by specific reactive oxygen species is a great challenge. Herein, N, P-doped Mo2C@porous carbon was designed and employed in the peroxymonosulfate-based advanced oxidation reforming of PET hydrolysate. The ethylene glycol (EG) derived from PET fiber was catalytically oxidized to formate via singlet oxygen activation during the peroxymonosulfate-based advanced oxidation process. Compared with Mo2C, the N, P-doped Mo2C@porous carbon catalyst with a large specific surface area provides more active sites, which has the characteristic of high catalytic activity. It presents the tetracycline degradation efficiency of ~ 80% under a wide pH range (6.8–10.6) and, further, the formate generation rate of ~ 56.5 mmol gcat−1 in the advanced oxidation reforming process of EG in 8 h. The detection and quenching experiments on the oxygen active species comprehensively confirmed that singlet oxygen is the key reactive oxygen species during the advanced catalytic oxidation reactions. This work provided a constructive demonstration for designing advanced oxidation catalysts to catalyze the reforming of waste PET fiber plastics into valuable chemicals.
The catalytic reforming of polyethylene terephthalate (PET) waste and proper treatment of fiber-based microplastics have emerged as critical areas of research and innovation to alleviate environmental stress and generate valuable products. This work sheds light on the efficient Mo2C@porous C catalyst design via singlet oxygen activation for persulfate-based advanced oxidation reforming of EG from PET fiber waste, providing a potential countermeasure to address plastic waste pollution and achieve carbon neutrality