Search Results (310)

The growing demand for wearable electronics and the Internet of Things (IoT) calls for flexible piezoelectric energy harvesters with substantially improved power output. Polyacrylonitrile (PAN) polymers, with their high polarization and excellent thermal stability, are among the most promising candidates for efficient flexible piezoelectric materials. However, the performance of existing PAN-based harvesters remains limited, and strategies for further enhancing their output are still insufficiently explored. Herein, this study aims to overcome the output bottleneck of PAN-based PENGs by implementing a novel mechanical excitation strategy. Using electrospun flexible PAN-BaTiO₃ nanocomposite films, we systematically compared the electromechanical responses under conventional compression and impact modes. Real-time synchronized force–current measurements in compression mode revealed that the output current increases progressively with drive frequency (2–10 Hz). Specifically, the PENG with PAN-20 wt.% BaTiO₃ achieved a peak current of 0.33 mA at 10 Hz, showing an approximately 7.9-fold enhancement over its pure PAN counterpart. More importantly, under 6 Hz impact excitation, the device exhibited a remarkable output current density of 1.0 mA cm⁻² and a peak power density of 256.5 µW cm⁻². This current density is 95 times higher than that in compression mode at a comparable frequency and surpasses the performance of most recently reported piezoelectric and triboelectric nanogenerators. With an effective area of 16 cm², the PENG could simultaneously illuminate up to 275 commercial LEDs or 100 individual bulbs and maintained stable operation over 63,530 cycles. This work overcomes the output bottleneck in low-frequency energy harvesting and provides an effective pathway toward practical energy-harvesting applications. Full article

Flexible skin electronics are increasingly sought after for their potential in sensing and drug delivery within wearable human–machine interfaces. However, developing multifunctional applications that maintain biocompatibility and stable electrical performance under various mechanical deformations remains a challenge. Here, we introduce tattoo paper-based graphene–gold conductors that are approximately 0.04 mm thick and feature a dual conductive pathway within the graphene–gold film. By integrating a folding structure with this dual conductive pathway, we can mitigate the strain effects on the electrical resistance of film-based conductors, resulting in wider areas of stable resistance. In addition, we have designed film conductors with a kirigami structure, which achieves a high initial conductivity of 1.5 × 10³ S cm⁻¹ and exhibits negligible resistance changes across a broad strain range of 0 to 130%. We utilize these conductors to develop waterproof on-skin patches that incorporate electrically and optically active heaters for body heating and drug delivery. Furthermore, we have created an on-skin dialing interface using these conductors, which enables users to make telephone calls based on triboelectric nanogenerators. Full article

The rising demand for wireless electronics and sustainable energy solutions drives the search for alternatives to conventional batteries. Triboelectric nanogenerators (TENGs) offer a promising route by converting mechanical energy into electricity via frictional events between two different material surfaces. Here, a simple and scalable surface modification method using conventional laser printing was applied to investigate the effect on triboelectric performance of cellulose-based materials against polytetrafluoroethylene (PTFE). Regenerated cellulose (RC) and cellulose acetate (CA) films were print patterned with black toner in a conventional laser printer at different surface coverages from 0% to 100%. The measured power output for RC films against PTFE showed minimal response from the patterning over the whole range and could be considered as constant with an average of 52 ± 2 W m⁻². On the other hand, the CA sample films showed a significant and gradual increase in power output from 45 to 65 W m⁻² as the toner print coverage increased from 0% to 100%. These results demonstrate that synergistic interactions between the printed toner and the substrate can strongly influence TENG performance and are highly dependent on the physical and chemical properties of the underlying material. In CA, toner–substrate intermixing enabled by laser printing temperatures exceeding the glass transition temperature provides a proof-of-concept for enhancing triboelectric performance through controlled surface–bulk interactions. Full article

Vibration signals generated during hydraulic fracturing drilling in coal mining are critical dynamic indicators for revealing borehole conditions and evaluating drilling efficiency and safety. However, the power supply methods of existing vibration sensors limit the practical application of this technology. To address this, this study was inspired by the African drum and developed a vibration sensor based on a triboelectric nanogenerator (TENG), enabling simultaneous measurement of vibration frequency and acceleration in a self-powered mode. Tests demonstrate that the device measures vibration frequencies from 0 to 9 Hz with an error below 3%. It achieves vibration acceleration measurements at thresholds of 1 g and 2 g with an error less than 4%. The sensor operates effectively at temperatures range of 15 °C to 75 °C and relative humidity below 90%. Additionally, the device possesses energy-harvesting capabilities, delivering a maximum power output of 72 nW at a load resistance of 1000 MΩ and a vibration frequency of 9 Hz. Unlike existing underground vibration sensors, this sensor’s high redundancy design and self-power generation features make it particularly suitable for the practical working conditions of upward drilling in coal mines. Full article

Triboelectric nanogenerators (TENGs) are a newly adopted technology designed to harvest freely available mechanical energy from the environment and convert it into electricity that can help to meet future demands for clean and sustainable energy. TENGs represent a promising next-generation renewable energy technology, an alternative to traditional non-renewable fossil fuel sources, with a wide range of applications, including smart sensors, wearable devices, internet of things (IoT), and portable electronics. Through contact/triboelectrification and electrostatic induction, TENGs convert mechanical energy into electrical energy. Broadly, TENGs are classified into contact–separation mode and sliding mode. In contact–separation mode, the electric output is achieved through the contact and separation of triboelectric layers, while in the sliding mode, it is generated by the sliding of one triboelectric layer over another. Sliding-mode TENGs have demonstrated better electrical output compared to the contact–separation mode; however, they suffer low durability and cannot operate for long periods due to severe wear. In addition, their electrical output performance is reduced owing to air breakdown. Lubricants have demonstrated their potential in TENGs by overcoming these limitations and improving both tribological and triboelectric performance. This review provides a discussion on the fundamental modes of TENGs, followed by a comprehensive summary of the tribological and triboelectrical performance of existing TENGs under liquid lubrication, along with a comparison of their performance under dry conditions. The effects of load, frequency, mass fraction, and volume of the liquid lubricant on both tribology and electrical output are examined. Durability is identified as a key factor for the long-term practical application of TENGs; hence, this paper also focuses on it. Furthermore, strategies for improving TENG performance and the working mechanisms under liquid lubrication are discussed. Finally, the paper summarizes demonstrations of TENG applications based on various TENG designs. Full article

Triboelectric nanogenerators (TENGs) have gradually been applied in various practical scenarios, mainly focusing on core areas such as wearable motion monitoring devices, medical security systems, and natural resource exploration technology. However, they have the problem of low output energy and have not yet formed effective integration with mature commercially available products, which has hindered the industrialization process. This situation still significantly limits its global promotion and application. In this study, TENG was used as the sensing module for intelligent automotive airbags. We tested the voltage and current output characteristics of the system under different impact forces and frequency conditions. During the testing process, the electrical energy generated under different operating conditions is transmitted to the control system via Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) circuits. The system will quickly determine whether to trigger the airbag deployment based on the received electrical signals, and activate the ignition device when necessary to achieve rapid inflation and deployment of the airbag. Compared with traditional triggering mechanisms, the airbag system based on this designed sensor has higher sensitivity and reliability. The sensor can stably capture collision signals, and experiments have shown that as the collision speed increases, the slope of its open-circuit voltage gradually approaches infinity. Applying TENG to automotive airbags not only effectively improves the triggering efficiency and accuracy of airbags, but also provides more reliable safety protection for drivers and passengers. Finite element simulation of the automotive airbag was conducted to provide specific data support for evaluating its safety performance. With the continuous advancement of TENG technology and further expansion of its application scenarios, we believe that such innovative safety technologies will play a more critical role in the future automotive industry. Full article

The growing demand for smart electronic devices in daily life requires sustainable, renewable energy sources that reliably power portable and wearable systems. Triboelectric nanogenerators (TENGs) have emerged as a promising platform for smart textile-based energy harvesting due to their material versatility and mechanical compliance. In this work, electrospun poly (vinylidene fluoride) (PVDF) fiber mats incorporating boron nitride (BN) nanoparticles and reduced graphene oxide (rGO) were investigated to elucidate the roles of insulating and conductive nanofillers in governing the structural and electroactive properties of PVDF-based triboelectric materials. Electrospun PVDF mats containing 5 wt.% BN exhibited enhanced β-phase content (82%), attributed to the nucleating effect of BN and strong interfacial interactions between the nanofiller and the PVDF matrix. In contrast, 7 wt.% rGO demonstrated a high electroactive β-phase fraction (81%), arising from filler-induced dipole alignment and enhanced charge transport within the fibrous network. A comparative analysis of BN and rGO highlights filler-driven mechanisms influencing the electroactive phase formation and triboelectric charge generation in PVDF mats. The corresponding triboelectric power density reached 231 μWcm⁻² for the 7 wt.% rGO/PVDF and 281 μWcm⁻² for the 5 wt.% BN/PVDF-based TENGs, providing valuable insights for the rational design of high-performance, flexible triboelectric materials for wearable energy-harvesting applications. Full article

The combination of nanogenerator technology and traditional textile materials has given rise to textile-based triboelectric nanogenerators (T-TENGs) structured from fibers, yarns, and fabrics. Due to their lightweight, flexibility, washability, and cost-effectiveness, T-TENGs offer a promising platform for powering and sensing in next-generation wearable electronics, with particularly significant potential in smart healthcare and sports monitoring. However, the inherent electrical and structural limitations of textile materials often restrict their power output, signal stability, and sensing range, making it challenging to achieve both high electrical performance and high sensing sensitivity. This review focuses on the application of T-TENGs in smart healthcare and sports. It systematically presents recent developments in textile material selection, sensing structure, fabric design, working mechanisms, accuracy optimization, and practical application scenarios. Furthermore, it provides a critical analysis of the recurring structural and material limitations that constrain performance and offers constructive pathways to address them. Key challenges such as the low charge density of textile interfaces may be mitigated by selecting low-hygroscopicity materials, applying hydrophobic treatments, and optimizing textile structures to enhance contact efficiency and environmental stability. Issues of signal instability under dynamic deformation call for advanced structural designs that accommodate strain without compromising electrical pathways, coupled with robust signal processing algorithms. By providing a comparative analysis across materials and structures, this review aims to inform future designs and accelerate the translation of high-performance T-TENGs from laboratory research to real-world implementation. Full article

This paper presents the design and fabrication of a triboelectric nanogenerator based on a Quadruple Parallel-cavity Helmholtz Resonator (4C–HR TENG) for the efficient harvesting of noise energy in marine engine room environments. The device utilizes sound waves to drive periodic contact and separation between polytetrafluoroethylene (PTFE) particles in the resonant cavity and the vibrating diaphragm as well as the upper electrode plate, thereby converting sound energy into mechanical energy and finally into electrical energy. The device consists of an acoustic waveguide with a length of 350 mm and both width and height of 60 mm, along with a Helmholtz Resonator with a diameter of 60 mm and a height of 40 mm. Experimental results indicate that under resonance conditions with a sound pressure level of 109.8 dB and a frequency of 110 Hz, the device demonstrates excellent output performance, achieving a peak output voltage of 250 V and a current of 4.85 μA. We analyzed and investigated the influence mechanism of key parameters (filling ratio, sound pressure level, the height between the electrode plates, and particle size) on the output performance. Through COMSOL Multiphysics simulation analysis, the sound pressure enhancement effect and the characteristic of concentrated diaphragm center displacement at the first-order resonance frequency were revealed, verifying the advantage of the four-cavity structure in terms of energy distribution uniformity. In practical applications, the minimum responsive sound pressure level corresponding to the operating frequency range of the 4C–HR TENG was determined. The output power reaches a maximum of 0.27 mW at a load resistance of 50 MΩ. At a sound pressure level of 115.1 dB, the device can charge a 1 μF capacitor to 4.73 V in just 32 s and simultaneously illuminate 180 LEDs in real-time, demonstrating its potential for environmental noise energy harvesting and micro-energy supply applications. This study provides new insights and experimental evidence for the efficient recovery of noise energy. Full article

The growing need for self-powered Internet of Things networks has raised interest in converting abundant waste into reliable energy harvesters despite long-standing material and technology challenges. As demand for environmentally friendly self-powered IoT devices continues to rise, attention toward green waste as an eco-friendly energy source has strengthened. However, its direct utilisation in high-performance energy harvesters remains a significant challenge. Driven by the growing need for renewable sources, the triboelectric nanogenerator has emerged as an innovative technology for converting mechanical energy into electricity. In this work, the design, fabrication, and characterisation of a rotating triboelectric energy harvester as a prototype device employing date seed waste as the tribopositive layer are presented. The date seeds particles, measuring 1.2 to 2 mm, were pulverised using a grinder, mixed with epoxy resin, and subsequently applied to the grating-disc structure. The coated surface was machined on a lathe to provide a smooth surface facing. The performance of the prototype was evaluated through a series of experiments to examine the effects of rotational speed, the number of grating-disc structures, the epoxy mixing process, and the prototype’s influence on the primary system, as well as to determine the optimal power output. An increase in rotational speed (RPM) enhanced power generation. Furthermore, increasing the number of gratings and pre-mixing of epoxy with the biomaterial resulted in enhanced output power. Additionally, with 10 gratings, operating at 1500 rpm, and a 24 h pre-mixing method, the harvester achieved maximum voltage and power outputs of 129 volts and 1183 μW at 7 MΩ. Full article

With the rapid development of the Internet of Things, self-powered sensing technology has become a crucial solution for scenarios where an external power supply is inconvenient or unavailable, such as wild monitoring and flexible wearables. The triboelectric nanogenerator (TENG)—an excellent self-powered sensor, particularly in the single-electrode mode—demonstrates broad application prospects due to its simple structure and ease of integration. However, a comprehensive understanding of the electron transfer behavior of TENGs for performance optimization remains insufficient. Here, we investigate such behaviors from three key aspects—the polymer functional groups, the configurations of TENGs, and corona polarization. It is found that polymer functional groups critically determine electron transfer ability, with fluorinated polymers exhibiting superior performance across all configurations. Moreover, the configuration significantly influences electron transfer efficiency, where the sliding configuration vastly outperforms contact–separation configurations. Furthermore, the effect of corona polarization is highly configuration-dependent, improving performance in contact–separation configurations while generally reducing it in sliding configuration. These findings provide valuable theoretical guidance and practical strategies for optimizing the design and selecting appropriate materials and configurations of TENG-based self-powered sensors. They also pave the way for a new generation of highly efficient, miniaturized, and adaptive self-powered systems. Full article

This review explores the pervasive role of water in generating, storing, and mediating electric charge across natural and artificial systems. Far from being a passive medium, water actively participates in electrostatic and electrochemical processes through its intrinsic ionization, interfacial polarization, and charge separation mechanisms. The Maxwell–Wagner–Sillars (MWS) effect is presented as a unifying framework explaining charge accumulation at air–water, water–ice, and water–solid interfaces, forming dynamic “electric mosaics” across Earth’s environments. The authors integrate diverse phenomena—triboelectricity, hygroelectricity, hydrovoltaic effects, elastoelectricity, and electric-field-driven phase transitions—showing that ambient water continually shapes the planet’s electrical landscape. Electrostatic shielding by humid air and hydrated materials is described, as well as the spontaneous electrification of sliding or dripping water droplets, revealing new pathways for clean energy generation. In addition, the review highlights how electric fields and interfacial charges alter condensation, freezing, and chemical reactivity, underpinning discoveries such as microdroplet chemistry, “on-water” reactions, and spontaneous redox processes producing hydrogen and hydrogen peroxide. Altogether, the paper frames water as a universal electrochemical medium whose interfacial electric imprint influences atmospheric, geological, and biological phenomena while offering novel routes for sustainable technologies based on ambient charge dynamics and water-mediated electrification. Full article

At present, there are some devices for muscle strength training after knee surgery, such as elastic bands and isokinetic muscle strength training instruments, but most of them are expensive or cannot monitor training progress. Triboelectric nanogenerators (TENGs) have proven to be reliable self-sensing devices. There have been some applications in the field of rehabilitation, but few have been used for muscle strength training. Our team has innovatively applied the TENG self-sensing device to the self-rehabilitation management of the knee joint post-surgery. We have developed the “Triboelectric Nanogenerator for Muscle Strength Training of Knee Joint after Surgery” (MSTKJS-TENG), which is significantly more integrated than traditional instruments (volume: 120 mm × 100 mm × 100 mm) and can real-time track the number and quality of movements completed by patients during muscle strength training. The development of this device has made up for the deficiencies of traditional instruments. It can assist medical staff in remotely evaluating the recovery of patients’ postoperative muscle strength to a certain extent, thereby adjusting training intensity in a timely manner and providing personalized guidance. Meanwhile, the research on this device provides effective technical support and innovation for the development of smart rehabilitation medicine. Full article

Self-powered microfluidic systems represent a promising direction toward autonomous and portable lab-on-chip technologies, yet conventional electrowetting platforms remain constrained by bulky high-voltage supplies and intricate control circuitry. In this work, we design a triboelectric nanogenerator (TENG)-based microfluidic system that harvests mechanical energy for droplet manipulation without any external electronics. The TENG integrates two triboelectric units with a 25° phase offset, enabling periodic high-voltage generation. Finite element simulations elucidate the electric field distributions of the TENG and microfluidic chip, validating the operating principle of the integrated microfluidic system. Experimental studies further quantify the effects of electrode geometry and rotational speed on the critical drivable droplet volume, demonstrating stable transport over linear, S-shaped, and circular trajectories. Remarkably, the droplet motion direction can be instantaneously reversed by reversing the TENG rotation direction, achieving bidirectional control without auxiliary circuitry. This work establishes a voltage-optimized, structurally tunable, and fully self-powered platform, offering a new paradigm for portable digital microfluidics. Full article

In this study, we explore the integration of a cost-effective triboelectric nanogenerator (TENG) with an large silicon PIN detector (diameter: 12 mm) for intelligent wireless recognition applications. Wireless communication eliminates the need for physical connections, enabling greater flexibility and scalability in deployment. It allows for seamless integration of AI systems into a wide range of environments without the constraints of wiring, reducing installation complexity and enhancing mobility. Additionally, we demonstrate the TENG’s functionality as an autonomous communication unit. The TENG is employed to convert various environmentally triggered signals into digital formats and to autonomously power optoelectronic devices, thus eliminating the need for an external power supply. By integrating optoelectronic components within the self-powered sensing system, the TENG can identify specific trigger information and reduce extraneous noise, thereby improving the accuracy of information transmission. Moreover wireless technology facilitates real-time data transmission and processing. This setup not only enhances the overall efficiency and adaptability of the system but also supports continuous operation in diverse and dynamic settings. This paper introduces a novel convolutional neural network-long short-term memory (CNN-LSTM) fusion neural network model. Utilizing the sensing system in combination with the CNN-LSTM neural network enables the collection and identification of variations in the flicker frequency and luminosity of optoelectronic devices. This capability allows for the recognition of environmental trigger signals generated by the TENG. The classification and recognition results of human body trigger signals indicate a recognition accuracy of 92.94%. Full article