To address the challenges of low surface charge density, poor stability in humid conditions and unstable performance in polymer electret triboelectric nanogenerators (TENGs), this study presents a synergistic enhancement strategy combining electrospinning and corona charging. The PAN-PVDF composite nanofiber membrane prepared via electrospinning achieves an initial surface potential of -3.2kV. Following secondary corona electret treatment, the surface potential significantly increased to -12.3kV. In contact-separation mode, this electret demonstrated outstanding output performance: within an operating frequency range of 2-4Hz and a separation distance of 4-5mm, its maximum power density reached 12 mu Wcm(-2) (under matched load). Furthermore, the device charged a 47 mu F commercial capacitor to 12V within 15min at 2.5Hz, demonstrating practical energy storage and driving capabilities. Compared to conventional materials such as PTFE and pure PVDF, the PAN-PVDF composite fiber membrane exhibits a high initial potential, a slow charge decay rate and good mechanical stability after electret processing. This research provides a highly viable material and process pathway for high-performance self-powered devices in wearable technology and IoT applications.

Flexible strain sensors hold considerable potential for human-machine interaction and health monitoring, yet conventional single-network systems often suffer from brittleness, limited durability, and insufficient multifunctionality. Herein, a multifunctional polyacrylamide (PAAm)/polyvinyl alcohol (PVA) composite hydrogel incorporating tannic acid-modified lignin (TA@AL) is developed via a simple one-pot polymerization followed by Fe3+ post-impregnation. A hierarchical triple-network structure is constructed, consisting of (i) a covalent PAAm backbone, (ii) a physically interpenetrated PVA network stabilized by hydrogen bonding, and (iii) a dynamic metal-phenol coordination network between TA@AL and Fe3+. Owing to this synergistic architecture, the hydrogel exhibits a high tensile strength of 115 kPa, a fracture strain of ∼900%, and a toughness of 0.45 MJ m-3, together with robust adhesion and high ionic conductivity (0.75 S m-1). Density functional theory (DFTD3) calculations further reveal the coordination energetics between FeCl3 and different polymer ligands, demonstrating that multidentate coordination in the PAAm/PVA/TA system provides strong yet dynamic binding, which underpins efficient energy dissipation and mechanical robustness. Benefiting from the coupled mechanical and electrical properties, the hydrogel functions as a high-performance strain sensor with high sensitivity, fast response, and excellent cycling stability, enabling accurate detection of both large-amplitude joint motions and subtle physiological signals such as swallowing and handwriting. This work not only offers an effective strategy for lignin valorization but also provides a molecular-to-macroscopic design framework for high-strength, conductive, and multifunctional hydrogels for wearable and biomedical applications.

Intervertebral disc degeneration (IVDD), a prevalent degenerative spinal disorder, arises from a complex pathological microenvironment. Consequently, current clinical therapies primarily relieve symptoms and often fail to arrest disease progression. Herein, we developed an injectable anti-inflammatory and antioxidant piezoelectric hydrogel (F127DA@alpha-TOH/NF-sPLLA) loaded with alpha-tocopherol (alpha-TOH) and short poly (L-lactic acid) nano-fibers (NF-sPLLA). The self-assembly properties of the amphiphilic copolymer F127DA facilitated efficient encapsulation and controlled release of hydrophobic alpha-TOH. The incorporation of NF-sPLLA enabled the hydrogel to generate in situ electrical stimulation under ultrasound activation. The precise implantation and in situ treatment were achieved through localized micro-injection and photocuring techniques. Experimental results revealed that F127DA@alpha-TOH/NF-sPLLA hydrogel exhibits good piezoelectric properties and drug-sustained-release ability. This system enhances the proliferation of nucleus pulposus cells, improves cellular functions, inhibits the inflammatory response, and restores the extracellular matrix homeostasis by regulating various metabolic pathways, including nucleotide, lipid, and amino acid metabolism, while modulating the local immune microenvironment. In vivo experiments confirmed that a single in situ injection of this hydrogel effectively preserves the disc height and nucleus pulposus tissue structure. This study presents a novel treatment strategy that integrates self-generating piezoelectric tissue engineering scaffolds with anti-inflammatory and antioxidant drugs, offering a potential treatment option for reversing IVDD progression and enhancing inter-vertebral disc (IVD) regeneration.

In recent years, with the advancement of precision medicine, oral health monitoring has become an important component in assessing human physiological indicators. However, due to the unique characteristics of the oral environment, such as high humidity, confined space, and complex conditions, traditional sensors often face challenges, including poor biocompatibility, frequent battery replacement, and size limitations. Moreover, high energy consumption in intraoral monitoring sensors leads to substantial maintenance costs for long-term wear. Therefore, the development of sensing systems with excellent biocompatibility, miniaturization, and self-powering capability has become a core requirement in long-term monitoring of the oral cavity and teeth. Compared with conventional sensors reliant on external power supplies, nanogenerators (NGs) based on triboelectric, piezoelectric, and pyroelectric effects can harvest oral biomechanical or environmental energy for continuous operation, thereby exhibiting immense potential and clinical value for frontier applications, such as critical care vital sign monitoring, exhaled gas analysis, and long-term stable monitoring of human organs. Despite the rapid development of NGs in oral and respiratory applications, there is still a distinct lack of a systematic review that bridges tailored material choices and structural designs with the specific and harsh clinical demands of the oral-respiratory environment. This review summarizes the functional implementation and self-powered sensor applications of NGs in areas such as respiratory monitoring, gas sensing, medical diagnostics, and electronic skin. Based on a summary of these categorized applications, the review concludes with a discussion of the application prospects and current challenges of NGs in the oral field.

Passive daytime radiative cooling (PDRC) materials require high solar reflectance and high atmospheric window emissivity. However, high solar reflectance achieved by scattering strategies often relies on porous structures, which can compromise the material’s mechanical reliability. To address this trade-off, we develop a layered alumina nanofiber membrane (LANM) by dual-nozzle electrospinning with programmed alternating deposition, in which alternating deposition and subsequent removal of alumina precursor layers and sacrificial polyvinyl alcohol (PVA) interlayers generate a continuously layered architecture with periodic interfaces and interlayer air gaps. This interfacial geometric design enables simultaneous regulation of solar-band scattering and bending load transfer within a single alumina system. Because photon flux attenuates with depth, shallow interfaces contribute more strongly than deeper ones; therefore, the micro-layered architecture enhances scattering while maintaining high emissivity in the atmospheric window. In outdoor testing, LANM achieved a maximum sub-ambient temperature reduction of ~5.8 °C, representing a further improvement of about 2.4 °C compared to Monolithic alumina nanofiber (ANM). Moreover, interlayer interfaces induce a multiple-neutral-axis mechanism and segmented stress transfer, thereby improving bending deformability rather than load-bearing strength.

ZnO is considered as an ideal material for preparing ultraviolet emitting devices and ultraviolet detectors. At present, how to obtain high-quality ZnO thin films by a simple technology has become an important research topic. In this paper, the authors report a simple and effective method for growing high-quality ZnO nanocolumnar thin films and propose the growth mechanism of ZnO nanocolumns using this method. We found that high-quality nanocolumns were formed on the surface of ZnO films deposited by cerium chloride doped zinc acetate sol, which greatly improved the ultraviolet emission performance of ZnO films. High-resolution TEM and selected area electron diffraction reveal that the nanocolumns are single crystals with high crystallization quality. EDX and XPS spectra exhibit that the doped Ce and cl are mainly distributed in the bottom film, while there are almost no doped ions in the nanocolumns. With the rise of cerium chloride doping level, the surface density and length of nanocolumns is first increased and then decreased. We think this is due to the different growth modes of nanocolumns. When the doping concentration of cerium chloride in the sol reaches 12%, a second phase cerium oxide (CeO2) appears in the film, which inhibits the growth of ZnO nanocolumns. Via comparing ZnO films prepared with cerium nitrate and cerium chloride as doping sources, we found that Ce-doping does not contribute to the growth of nanocolumns on the surface of ZnO films; instead, it is the doped cl ions that play the key role. The Cecl incorporated ZnO thin films are suitable for preparing ultraviolet emission devices

Triboelectric nanogenerators (TENGs), which operate independently of sunlight or fuel, can effectively harvest deep-sea mechanical energy (such as ocean currents and fluctuations) to power long-term low-energy electronic devices, forming self-powered systems. However, structural design for deep-sea equipment remains a significant challenge due to extreme depth and pressure conditions. Here, we demonstrate that a simple balloon structure can meet the corresponding design requirements in a low-cost manner. Through the expansion and contraction of the balloon in response to pressure variations, the nanogenerator integrated on the inner surface of the balloon achieves contact-separation motion. Quasi-hydrostatic pressure introduces no additional shear stress, and the normal stresses cancel each other out, enabling the thin-walled balloon to withstand immense water pressure. By presetting the gas volume, the operating depth of the device can be tuned, while reducing buoyancy-induced restraint requirements, thereby enhancing deployment stability. The excellent airtightness of the balloon ensures that humidity does not interfere with TENG operation. The device has been demonstrated to effectively harvest energy over short-term tests. This study provides a proof-of-concept validation of a pressure-adaptive balloon TENG for underwater energy harvesting at moderate pressures. Finite element simulations suggest the potential scalability of this design to greater depths, contributing to the advancement of TENGs for extreme marine environments.

To address the rising need for multifunctional integration in core materials for flexible wearable electronics, this study presents a composite hydrogel that combines high mechanical strength, sensitive sensing capabilities, and efficient electromagnetic interference (EMI) shielding. By incorporating hydroxylated multi-walled carbon nanotubes (OH-MWCNTs) as nano-conductive fillers into a polyacrylamide/quaternary ammonium chitosan (PAM/HACC) dual-network matrix, a multifunctional composite material was successfully fabricated. The PAM/ HACC dual-network structure provides remarkable mechanical properties through synergistic energy dissipation, achieving a tensile strength of 435 kPa and an elongation at break exceeding 2500%. Uniformly dispersed OH-MWCNTs establish a robust and stable three-dimensional conductive network within the hydrogel, enabling the material to function as a highly sensitive strain sensor (with GF up to 16.04 at 200%-300%) for reliably monitoring diverse human physiological activities-from large-scale joint movements to subtle motions such as speech and coughing. Moreover, the hydrogel exhibits an electromagnetic shielding effectiveness exceeding 30 dB, and the average effectiveness is stable at more than 25 dB across the X-band (8.2-12.4 GHz). This work offers an innovative and promising material platform for next-generation flexible electronics that integrate sensing and shielding functionalities.

Incorporating inorganic electrolyte fillers within solid polymer electrolytes (SPEs) is generally considered an efficient strategy for constructing rapid Li+ transport channels, thereby markedly enhancing ionic conductivity. However, the relatively low specific surface areas of traditional fillers, along with their inherently weak interfacial affinity toward polymer matrices, hamper effective Li+ transport across polymer-filler interfaces. Consequently, Li+ migration from the polymer domain into the filler phase remains kinetically unfavorable, which ultimately limits further improvement in the overall electrochemical performance of SPEs. Here, we report a scalable porosity-interface co-engineering strategy to overcome these limitations. First, a three-dimensional, percolating porous Li0.33La0.557TiO3 (PLLTO) framework is constructed to significantly enlarge the solid-solid contact area and promote continuous Li+ percolation pathways. Second, surface functionalization is carried out using 3-glycidoxypropyltrimethoxysilane (KH560) to form silicon-coated PLLTO (Si-PLLTO) with a silane-mediated interfacial layer. This interfacial layer enhances polymer/ceramic bonding through hydrogen bonding and possible covalent linkage formation, decreases interfacial Li+ transfer resistance, and suppresses electron transfer toward titanium centers, thereby mitigating undesirable reduction from Ti4+ to Ti3+. Density functional theory (DFT) calculations reveal that surface silicon modification lowers the Li+ migration energy barrier (1.77 eV) by modulating surface electronic structures and weakening Li-O coordination along interfacial conduction pathways, thus enabling energetically favorable Li+ transport. As a consequence, the resulting SPE exhibits elevated ionic conductivity of 2.37 mS cm-1 at 60 degrees C. It further delivers an ion transfer number of 0.57 and sustained lithium plating/stripping for 4000 h in lithium symmetric batteries. LiFePO4|Li batteries retain 82.4% of their initial capacity after 1200 cycles at 0.2C with 99.9% coulombic efficiency (CE). These results demonstrate that enhancing a porous lithium ceramic framework with a targeted interfacial chemistry approach markedly improves ion transport, interfacial stability, and cycling durability, providing a generalizable strategy for constructing high-performance, safe solid-state lithium batteries.

Triboelectric nanogenerators (TENGs) present a promising route for self-powered tactile sensing, demonstrating considerable potential in wearable electronics and the Internet of Things. Although surface engineering is a critical determinant of TENG output performance, predominant strategies are largely confined to static structural designs. Consequently, effective approaches for the dynamic tuning of the contact interface remain limited. Inspired by the natural venation topology of leaves, this work fabricates a rhombic-patterned array on the surface of triboelectric layers via one-step template-assisted electrospinning, facilitating the formation of moire fringes through interlayer rotation. Rotating the two triboelectric layers to predetermined angles (0 degrees, 45 degrees, and 90 degrees) modulates the period and distribution of the moire fringes, leading to distinct geometric configurations at the contact interface. This angle-dependent variation of the moire geometry enables controllable regulation of the effective interfacial contact area, thereby yielding a tunable electrical output. This direct correlation further validates the device's capability for angle sensing. Compared with the TENG based on flat nanofiber membranes, the patterned TENG exhibited a significant short-circuit current enhancement of approximately 306 %, attributed to the synergistic effect of the bio-inspired microstructure and this tunable moire modulation. The moire-based angular control strategy introduced here establishes a new paradigm for the design of regulated contact interfaces in next-generation TENGs.

Nanogenerators provide important freedom for future electronic system design by collecting dispersed mechanical energy to power devices such as Internet of Things. Although researchers have focused on breaking through the design of high energy density nanogenerators, the whole system energy consumption design can effectively improve the convenience and effectiveness of the self-powered system design by reducing the use area of nanogenerators. In this study, we use the brightness change of an light-emitting device (LED) powered by a nanogenerator to convert the vibration of an instrument into a light signal (LS). This method effectively eliminates the additional phase difference commonly encountered in traditional sound signal (SS) transmission, thereby providing a significant phase verification technique for symphony orchestra coordination and related applications. This system does not rely on chip conversion signals, and does not require a Bluetooth transceiver system, so it can achieve long-distance signal transmission. The system implements a fully self-powered design, so this work has an important impact on the design of related systems in the future.

Compared with the centralized and orderly energy supply system, the distributed energy system has attracted wide attention, although it has the characteristics of high entropy. These new energy sources can effectively solve the problem of global warming and reduce carbon emissions. However, in the high-entropy application environment, the low application frequency of a single device determines that its manufacturing energy consumption and carbon emissions cannot be ignored. Obviously, the secondary utilization of items through a reasonable design route can effectively reduce carbon emissions, and nanogenerators have an excellent advantage in this technical path. Among them, nanogenerators can effectively reduce the additional carbon emissions generated during preparation because they can use waste cloth. At the same time, the recycled battery has been proved to be able to effectively utilize its low-capacity characteristics when collecting the energy of the nanogenerator, accelerating the energy collection process of the nanogenerator so as to change faster from energy collection to energy output. More importantly, this energy system has been proved to be able to be assembled for emergency use in wilderness situations compared to other devices that require standard processing. We suggest that this system-level design inspires designing future energy systems and further reduce carbon emissions from new energy systems.

The electroneutrality assumption has long been adopted by scholars; however, this assumption may lead to an oversight of certain physical effects. Using derivations from a discontinuous medium, we have obtained an expression for the potential and energy of a many-body unipolar charge system, which corresponds well to its counterpart in a continuous medium. The compressed form of this expression suggests that compressing a macroscale charged body to the nanoscale can yield an enormous electric potential and energy, thereby establishing a concrete research framework for third-generation nanogenerators. This effect may serve as a crucial reference for understanding anomalous spatial electromagnetic distributions and divergent energy fields.

Electrostatics was considered to be a negative effect a long time ago, people never used frictional electrification to collect kinetic energy and convert it into electrical energy until the invention of the triboelectric nanogenerator (TENG). Generally speaking, triboelectrification is susceptible to humidity, but this influence mechanism has not yet been fully figured out. In fact, clarifying the physics will be conducive to the design of new devices. In this work, we sort out the influencing mechanisms of humidity on TENG, and differentiate them by their characteristic time. Based on this analysis and the traditional non-contact nanogenerator structure, a screening nanogenerator is designed utilizing the screening effect of water layer. The effects of screening boards in different locations on the system are studied. Surprisingly, the outside screening board can also influence system. Therefore, an outside screening sensor is designed for detecting the charge state of matter and monitoring water levels. This work builds a new mode for further understanding about interaction principle of humidity and surface charge, and presents a different strategy to design humidity-resistant TENG. Meanwhile, the research frontier of many-body charge interaction based on non-Landau system is raised, hoping to inspire more scholars.

With the development of intelligent transportation systems, the requirements for monitoring and sensing systems have become increasingly stringent. This study proposes a novel self-powered sensing system based on triboelectric nanogenerators (TENGs) for vehicle monitoring and energy harvesting in intelligent transportation systems. The system utilizes the friction between vehicle tires and road materials to generate electricity, enabling real-time monitoring and analysis of driving behavior through collected signals. The research designed a road-compatible triboelectric nanogenerator (r-TENG) using common materials such as natural rubber and asphalt as friction layers, successfully achieving identification and differentiation of various vehicle types. Machine learning algorithms were employed to further enhance recognition accuracy, reaching an identification rate of over 80

With the increasing importance of low-frequency signals in underwater monitoring, earthquake early warning, environmental noise analysis, and biomedical imaging, traditional sensor technologies face challenges such as limited flexibility, slow response time, and poor adaptability. Although existing sensors, such as electromagnetic, piezoelectric, and capacitive sensors, have made progress in certain areas, their applications are often restricted by complex environments. This paper innovatively proposes anin-situvibration monitoring method, designing a low-frequencyin-situdetection system based on triboelectric nanogenerator technology. The system not only enables efficient low-frequency signal detection in complex underwater environments but also, by incorporating machine learning algorithms, identifies different signal sources, achieving accurate distinction of intrinsic signals. The application of this technology realizes the concept ofin-situdetection, breaking through the limitations of traditional sensor systems and providing a new solution for real-time monitoring of low-frequency signals.

In recent years, nanogenerators which can convert tiny movements or deformation into electrical energy have been considered as pivotal components in self-powered system due to the advantages of high-efficiency energy conversion, sustainability and miniaturization. Different from traditional semiconductor energies, nanogenerators use dielectric materials, which use electric polarization behavior to induce charge transfer to complete the related energy conversion process. So they are different compared with semiconductor devices. On the one hand, the dielectric device itself is an insulator, combined with its self-powered characteristic, the device has a good anti-short-circuit advantage when the power supply circuit interferes, and the contact resistance interference in a flexible environment will not affect its sensing results. On the other hand, these materials are often commonly used polymer materials without additional modification or design, so they can fully inherit the stability advantages of polymer materials, such as self-healing, radiation stability and corrosion stability. This perspective has been neglected for a long, so the related review will discuss will lead to more research on digging characteristics of nanogenerators.

Flexoelectric effect refers to the phenomenon of electric polarization under the action of material deformation gradient. When the material is strained, the local strain gradient will cause the electric dipole moment to rearrange, thereby generating an electric field in the material. Different from the piezoelectric effect, the flexoelectric effect is not limited by the symmetry of materials. Furthermore, the flexoelectric effect exhibits a significant size effect, allowing for huge flexoelectric signals to be obtained in nanoscale systems. Therefore, the flexoelectric effect has a wider application prospect and development space. There are differences in the number dimension between the flexoelectric coefficient and the piezoelectric coefficient, but both flexoelectric and piezoelectric effects result in the induction of electric dipole moments. In analogy to the piezoelectric effect, the polarization intensity may influence the flexoelectric coefficient. In this study, we selected the typical piezoelectric material barium titanate (BaTiO3) and employed the forward/reverse and continuous polarization method to regulate the dipole moment arrangement. We measured the piezoelectric-like effect and flexoelectriclike effect under different polarization voltages with using a quasi-static d33 measuring instrument and a two-step dot-loop method. The results confirmed that the polarization process intrinsically enhances the flexoelectric coefficient. At a polarization voltage of 600 V, the flexoelectric-like coefficient reached 180 pC/N, which is more than twenty times stronger than that of the non-polarized sample (7 pC/N). This study provides a simple and feasible idea for the enhancement of macroscopic flexoelectric coefficients.

Catalysts for heterogeneous advanced oxidation processes (AOPs) in water remediation face environmental sustainability challenges, due to the intensive production of catalysts and limited stability of catalysts while maintaining high efficiency. Herein, we design a biomimetic carbon catalyst (BCC) inspired by the diatom frustule valve structure, achieving high environmental sustainability while maintaining superior water decontamination performance by a non-radical direct electron transfer (DET) pathway through activating peracetic acid (PAA). Utilizing a hydrogen-bonding strategy, BCC features pillared layered hierarchical pores with an ultrahigh specific surface area of 2710.35 m2 g-1. The nitrogen-doped carbon network combined with the unique diatom-like structure facilitates key DET steps by enhancing PAA adsorption and increasing the oxidation potential of the subsequent surface complex, thereby lowering the DET energy barrier. Additionally, this structure allows target pollutants to deeply penetrate into the hierarchical pores, facilitating enhanced mass transfer and thus reducing catalyst deactivation. Consequently, the BCC/PAA filtration system achieves complete bisphenol A removal with over 50 h of continuous operation under a high membrane permeance (1572 L m-2 h-1 bar-1). Further, BCC demonstrates a notably reduced global warming potential than state-of-the-art carbon catalysts from a "cradle-to-grave" life cycle assessment, with reductions of 74.9 % in catalyst production and 85.9 % in phenol removal. Our findings offer a facile strategy for designing hierarchical bio-inspired catalysts to boost the environmental sustainability of heterogeneous AOPs.