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Monitoring and controlling the concentration of nanocellulose suspensions is crucial for various industrial processes. Because of the high complexity of traditional concentration measurement devices, new techniques that offer simple, reliable, and real-time concentration monitoring have been developed. Here, we report a method for real-time concentration monitoring using a tubular structured liquid–solid triboelectric nanogenerator (LS-TENG). The LS-TENG was operated in single-electrode mode with a triboelectric layer comprising a polytetrafluoroethylene tube. Further, we systematically investigated the dependence of the device output performance on variables such as concentration, flow rate, tube diameter, and tube material, finding it to be directly proportional to the flow rate and tube diameter and inversely proportional to the concentration. Furthermore, the output current of the LS-TENG exhibited an exponential relationship with the concentration of the nanocellulose suspension and the Reynolds number, achieving a correlation coefficient above 0.94 for the corresponding regression equation. This study provides a direct, accurate, real-time, and self-powered method for monitoring nanocellulose suspension concentrations. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG), as a novel energy harvesting technology, has garnered widespread attention. As a relatively young field in nanogenerator research, investigations into various aspects of the TENG are still ongoing. This review summarizes the development and dissemination of the fundamental principles of triboelectricity generation. It outlines the evolution of triboelectricity principles, ranging from the fabrication of the first TENG to the selection of triboelectric materials and the confirmation of the electron cloud overlapping model. Furthermore, recent advancements in TENG application scenarios are discussed from four perspectives, along with the research progress in performance optimization through three primary approaches, highlighting their respective strengths and limitations. Finally, the paper addresses the major challenges hindering the practical application and widespread adoption of TENGs, while also providing insights into future developments. With continued research on the TENG, it is expected that these challenges can be overcome, paving the way for its extensive utilization in various real-world scenarios. [ABSTRACT FROM AUTHOR]

[Display omitted] Carbon nanostructures derived from human hair biowaste are incorporated into polyvinylidene fluoride (PVDF) polymer to enhance the energy conversion performance of a triboelectric nanogenerator (TENG). The PVDF filled with activated carbon nanomaterial from human hair (AC-HH) exhibits improved surface charge density and photoinduced charge generation. These remarkable properties are attributed to the presence of graphene-like nanostructures in AC-HH, contributing to the augmented performance of PVDF@AC-HH TENG. The correlation of surface morphologies, surface charge potential, charge capacitance properties, and TENG electrical output of the PVDF composites at various AC-HH loading is studied and discussed. Applications of the PVDF@AC-HH TENG as a power source for micro/nanoelectronics and a movement sensor for detecting finger gestures are also demonstrated. The photoresponse property of the fabricated TENG is demonstrated and analyzed in-depth. The analysis indicates that the photoinduced charge carriers originate from the conductive reduced graphene oxide (rGO), contributing to the enhanced surface charge density of the PVDF composite film. This research introduces a novel approach to enhancing TENG performance through the utilization of carbon nanostructures derived from human biowaste. The findings of this work are crucial for the development of innovative energy-harvesting technology with multifunctionality, including power generation, motion detection, and photoresponse capabilities. [ABSTRACT FROM AUTHOR]

In recent years, there has been a surge in interest surrounding the development of chitosan (CS)-based triboelectric nanogenerators (TENG) for powering attachable/portable devices. Despite numerous strategies aimed at enhancing their efficiency, the selection of acid solvent has remained largely unexplored. In this study, various acids, including acetic (CH3COOH), succinic (C4H6O4), and citric (C6H8O7) acids, were investigated for their impact on mechanical and electrical output signals. Remarkably, the choice and concentration of acid were found to significantly influence performance. Specifically, employing citric acid rendered the CS solid film more pliable and yielded the highest output signal at optimal concentration levels. Under optimized conditions, the CS-TENG exhibited an open-circuit voltage output (VOC) of 157 V and short-circuit current output (ISC) of 53 µA—more than triple that of pristine CS-TENG. Mechanistic insights into electrical generation have been elucidated, underscoring the importance of solvent selection in CS TENG fabrication. These findings underscore the potential for tailored acid solvent selection to advance specialized applications in the field. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) have emerged as promising candidates for integrating with flexible electronics as self‐powered systems owing to their intrinsic flexibility, biocompatibility, and miniaturization. In this study, an improved flexible TENG with a tile‐nanostructured MXene/polymethyl methacrylate (PMMA) composite electrode (MP‐TENG) is proposed for use in wireless human health monitor. The multifunctional tile‐nanostructured MXene/PMMA film, which is self‐assembled through vacuum filtration, exhibits good conductivity, excellent charge capacity, and high flexibility. Thus, the MXene/PMMA composite electrode can simultaneously function as a charge‐generating, charge‐trapping, and charge‐collecting layer. Furthermore, the charge‐trapping capacity of a tile nanostructure can be optimized on the basis of the PMMA concentration. At a mass fraction of 4% PMMA, the MP‐TENG achieves the optimal output performance, with an output voltage of 37.8 V, an output current of 1.8 μA, and transferred charge of 14.1 nC. The output power is enhanced over twofold compared with the pure MXene‐based TENG. Moreover, the MP‐TENG has sufficient power capacity and durability to power small electronic devices. Finally, a wireless human motion monitor based on the MP‐TENG is utilized to detect physiological signals in various kinematic motions. Consequently, the proposed performance‐enhanced MP‐TENG proves a considerable potential for use in health monitoring, telemedicine, and self‐powered systems. [ABSTRACT FROM AUTHOR]

The present research offers an innovative approach to enhance the safety and mobility of people with visual impairments by using a smart white cane sensor. Herein, an aluminum electrode, Kapton film, and an inexpensive PET substrate are employed to develop an origami‐shaped multilayered triboelectric nanogenerator (TENG) device. The multilayered integration of three‐unit TENGs produces output with a high power of 51 μW at 50 MΩ, along with 155 V and 4.5 μA. Capacitor charging, low‐power electronics powering, and the integration of mechanoluminescent materials are demonstrated. The integration of mechanoluminescent materials enables efficient identification of visually impaired people in regions with poor lighting. A single‐electrode TENG is also implemented for successful surface material detection. To further enhance the sensor's capabilities, digital signal processing techniques are employed for obstacle recognition on their route. The intelligent white cane sensor effectively detects obstructions, offering the user instantaneous feedback and enabling more secure navigation in sophisticated environments. This study highlights the possibility of integrating TENG technologies to provide a complete solution for people with visual impairments. The smart white cane sensor has the potential to greatly increase the safety and independence of visually impaired people in a variety of outdoor and public spaces. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) are promising potential sustainable power sources for wireless sensing networks within the Internet of Things (IoT) realm. Developing an efficient TENG evaluation model, characterized by high speed, accuracy, and representativeness, facilitates its integration into practical applications, which is urgent and lack of investigation currently. Herein, an artificial intelligence (AI) based evaluation model is developed to predict the performance of freestanding rotational TENGs (FR‐TENGs) for demonstration. An accurate and representative train dataset is essential for development of AI‐based evaluation model, which has been generated using finite element analysis and equivalent circuit simulation alongside the non‐dominated sorting genetic algorithm II. Through comprehensive experiments and simulations, the accuracy of the model has been verified in predicting the power output performance of FR‐TENGs, which has 99.6% (three design parameters) and 99.2% (seven design parameters) maximum train set accuracy. More importantly, the predicted results from the AI‐based evaluation model have notably expanded the coverage of data and significantly expedited the generation time from days to seconds. Herein, the use of AI in assessing the performance of TENGs is enhanced. The TENG design process can be significantly simplified, while maintaining a high evaluation model accuracy, thus promising advancements of IoT applications in future. [ABSTRACT FROM AUTHOR]

The emergence of the intelligent society presents a significant challenge with regard to distributed energy. One potential solution is to harvest energy from the environment to power micro/nano systems. Herein, an electric‐triboelectric hybrid generator (ETMHG) supported by magnetic springs is presented that operates in the contact‐separation mode. The traditional mechanical springs in the triboelectric nanogenerators are replaced by magnetic springs, and solenoid coils are added. This structure can achieve electromagnet‐triboelectric hybrid generation without significantly increasing the volume of the generator, and the use of magnetic springs offers a solution to the issues of difficult installation and mechanical wear and tear that are inherent in mechanical spring‐based triboelectric nanogenerators. The proposed hybrid generation ETMHG is shown to increase the output capacity of the generator, improve the efficiency of environmental energy harvesting, and achieve an instantaneous maximum power of 4.75 mW and instantaneous maximum power density of 95 W m−3. The ETMHG can charge a 10 μF capacitor that improves efficiency by 52.6% compared to an electromagnetic generator. The output surface power density of TENG in ETMHG can reach 1.12 W m−2. [ABSTRACT FROM AUTHOR]

The stay cable is susceptible to external loads resulting in vibration. Aiming at the large variation of vibration amplitude of stay cable, a damping structured triboelectric nanogenerator (DS‐TENG) for stay cables vibration energy graded harvesting is proposed. The DS‐TENG can not only achieve the graded harvesting of vibration energy, but also provide adjustable additional damping for the cable by utilizing the friction force generated by the wavy center pole and the moving block. With a vibration magnitude of 24 mm as the limit, the DS‐TENG is divided into two order states. The experimental results suggest that the output of the DS‐TENG is 250 V and 42 μA of unit I, and 440 V and 110 μA of unit II. Application demonstration experiments show that the DS‐TENG can power a thermohygrometer and can generate a maximum additional damping force of 91.8 N. In the second‐order state, the DS‐TENG illuminates twice as many light‐emitting diodes as it does in the first‐order state. And experiments demonstrate the ability of the DS‐TENG to operate in harsh environments such as bridges. This work provides important guidance and reference for vibration energy harvesting and cable vibration reduction of stay cable bridges. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) are recognized for energy conversion efficiency and applications including electronics and energy storage devices. This study introduces a groundbreaking development in TENG by incorporating negative Poisson's ratio metamaterials to fabricate auxetic‐assisted triboelectric nanogenerators (Auxetic‐TENG), subversively overcoming the low power density of traditional materials. Subtly, an integrated layer‐by‐layer‐assembly and core–shell accumulation strategy is employed to create a synclastic polytetrafluoroethylene negative friction shell‐skeleton, into which positive Poisson's ratio nature collagen aggregate (CA) foam is inwardly embedded as the positive friction core‐material. Surprisingly, the on‐demand introduction of metamaterials in synergy with CA significantly increases the contact area and mechanical energy absorption of the Auxetic‐TENG under pressure. This enhancement in the conversion efficiency of mechanical to electricity capitalizes on the contraction origins of negative Poisson's ratio metamaterials, integrated with the expansion characteristics of the positive Poisson's ratio materials within the structure, facilitating the synergistic compression of the positive and negative friction stratum. Consequently, Auxetic‐TENG achieves an open‐circuit voltage of 85 V, an overturning four times compared to conventional contact–separation TENG, and a power density of 4.2 W m−2. Application experiments demonstrate the superior performance of auxetic‐TENG under various compression ratios and stress conditions, highlighting its potential for real‐time monitoring in healthcare applications. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG) holds significant potential for applications in energy harvesting and environment monitoring. However, a notable challenge lies in developing a combined system capable of efficiently harvesting energy and providing real‐time self‐powered sensing. Here, a combined wind energy harvesting and speed sensing (EHSS) system is constructed based on a noncontact electricity‐induced constant‐voltage TENG (EICV‐TENG) that achieves constant output by coupling two different phases and incorporates a parasitic sensing module in a single phase. Through the optimization of system integration, the EICV‐TENG achieves a current density of 28.7 mA m−2 and an average power density of 0.26 W m−2 Hz−1. With an optimal power management, the energy output efficiency of the EICV‐TENG reaches up to 96%. And EICV‐TENG can stably power 32 commercial hygrothermographs connected in parallel with the PMC at a wind speed of 7 m s−1. In addition, the EHSS system demonstrates excellent real‐time sensing performance based on the correlation between the peak number of pulse output in a single phase and wind speeds. This work contributes to the advancement of TENG technology for a combined energy harvesting and self‐powered sensing system in the context of the Internet of Things (IoTs). [ABSTRACT FROM AUTHOR]

The appearance of triboelectric nanogenerators (TENG) provides a promising energy technology for harvesting abundant water wave energy. Here, the design and fabrication of a swinging origami‐structured TENG (SO‐TENG) tailored specifically for water wave energy harvesting are presented. The design incorporates an oscillating structure weighted at the bottom, inducing reciprocating motion propelled by the inertia of passing water waves. This reciprocating motion efficiently converts mechanical into electrical energy through the origami structure. By employing origami as the monomer structure, the surface contact area between friction layers is enhanced, thereby optimizing output performance. the swinging structure, combined with the placement of heavy objects, enhances the folding and contact of the origami, allowing it to operate effectively in low‐frequency water wave environments. This configuration exhibits robust power generation capabilities, making it suitable for powering small electronic devices in water wave environments. Furthermore, when applied to metal corrosion protection, the SO‐TENG demonstrates notable efficacy. Compared to exposed Q235 carbon steel, Q235 carbon steel protected by SO‐TENG exhibits a significant reduction in open‐circuit potential drop, approximately 155 mV, indicative of superior anti‐corrosion properties. It lays a solid foundation for water wave energy collection and self‐powered metal corrosion protection in marine environments. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerator (TENG), an emerging energy conversion technology, offers innovative pathways for energy harvesting and self‐powered sensing. To achieve superior performance, researchers commonly employ substantial quantities of original or treated polymers, resulting in high energy and precise sensing. Nevertheless, the sustainable development of TENGs faces significant challenges related to environmental compatibility, pollution hazards, and high production and disposal costs. To address this issue, numerous green materials for diverse TENGs are introduced and advanced. These materials may encompass natural resources, household waste, and recyclable materials, among others. Consequently, a review of the progress in TENGs based on green materials, which can be called green TENGs, becomes imperative to advance its sustainable development. To this end, this work comprehensively elucidates the development of green TENGs from the perspective of materials processing and treatment degree for the first time. Various green TENGs, including food waste, discarded daily‐use items, plant organs, biodegradable industrial products, and natural cellulose, are meticulously categorized. This review not only systematically synthesizes the latest research advancements in green TENGs, but also offers insight into their processing methodologies, working characteristics, and potential application scenarios. Finally, it envisions the challenges, proposed solutions, and future research directions for the development of green TENGs. [ABSTRACT FROM AUTHOR]

Accurately predicting the distance an object will travel to its destination is very important in various sports. Acceleration sensors as a means of real-time monitoring are gaining increasing attention in sports. Due to the low energy output and power density of Triboelectric Nanogenerators (TENGs), recent efforts have focused on developing various acceleration sensors. However, these sensors suffer from significant drawbacks, including large size, high complexity, high power input requirements, and high cost. Here, we described a portable and cost-effective real-time refreshable strategy design comprising a series of individually addressable and controllable units based on TENGs embedded in a flexible substrate. This results in a highly sensitive, low-cost, and self-powered acceleration sensor. Putting, which accounts for nearly half of all strokes played, is obviously an important component of the golf game. The developed acceleration sensor has an accuracy controlled within 5%. The initial velocity and acceleration of the forward movement of a rolling golf ball after it is hit by a putter can be displayed, and the stopping distance is quickly calculated and predicted in about 7 s. This research demonstrates the application of the portable TENG-based acceleration sensor while paving the way for designing portable, cost-effective, scalable, and harmless ubiquitous self-powered acceleration sensors. [ABSTRACT FROM AUTHOR]

Marine pipeline vibration condition monitoring is a critical and challenging issue, on account of the complex marine environment, while powering the required monitoring sensors remains problematic. This study introduces a vibration sensor based on a ball triboelectric nanogenerator (B-TENG) for marine pipelines condition monitoring. The B-TENG consists of an acrylic cube, polyester rope, aluminum electrodes, and PTFE ball, which converts vibration signals into electrical signals without the need for an external energy supply. The experimental results show that B-TENG can accurately monitor the frequency, amplitude, and direction of vibration in the range of 1–5 Hz with a small error of 0.67%, 4.4%, and 5%, and an accuracy of 0.1 Hz, 0.97 V/mm, and 1.5°, respectively. The hermetically sealed B-TENG can monitor vibration in underwater environments. Therefore, the B-TENG can be used as a cost-effective, self-powered, highly accurate vibration sensor for marine pipeline monitoring. [ABSTRACT FROM AUTHOR]

Ferroelectric materials, with their spontaneous electric polarization, are renewing research enthusiasm for their deployment in high-performance micro/nano energy harvesting devices such as triboelectric nanogenerators (TENGs). Here, the introduction of ferroelectric materials into the triboelectric interface not only significantly enhances the energy harvesting efficiency, but also drives TENGs into the era of intelligence and integration. The primary objective of the following paper is to tackle the newest innovations in TENGs based on ferroelectric materials. For this purpose, we begin with discussing the fundamental idea and then introduce the current progress with TENGs that are built on the base of ferroelectric materials. Various strategies, such as surface engineering, either in the micro or nano scale, are discussed, along with the environmental factors. Although our focus is on the enhancement of energy harvesting efficiency and output power density by utilizing ferroelectric materials, we also highlight their incorporation in self-powered electronics and sensing systems, where we analyze the most favorable and currently accessible options in attaining device intelligence and multifunctionality. Finally, we present a detailed outlook on TENGs that are based on ferroelectric materials. [ABSTRACT FROM AUTHOR]

The vibration parameters during drilling play a critical role in enhancing drilling speed and ensuring safety. However, traditional downhole vibration sensors face limitations in their power supply methods, hindering widespread adoption. To address this challenge, our research introduces a novel solution: a hybrid downhole vibration sensor (HDV-TENG) utilizing triboelectric nanogenerators. This sensor not only enables the measurement of low- to medium–high-frequency vibrations using self-power but also serves to energize other downhole devices. We utilized a self-constructed vibration simulator to replicate downhole drilling tool vibrations and conducted a comprehensive series of sensor tests. The test results indicate that the frequency measurement bandwidth of the HDV-TENG spans from 0 to 200 kHz. Especially, the measurement errors for vibrations within the low-frequency range of 0 to 10 Hz and the high-frequency range of 10 to 200 k Hz are less than 5% and 8%, respectively. Additionally, the experimental findings regarding load matching demonstrate that the HDV-TENG achieves an output power level in the milliwatt range, representing a significant improvement over the output power of traditional triboelectric nanogenerators. Unlike traditional downhole vibration measurement sensors, HDV-TENG operates without requiring any external power supply, thereby conserving downhole space and significantly enhancing drilling efficiency. Furthermore, HDV-TENG not only offers a broad measurement range but also amplifies output power through the synergy of a triboelectric nanogenerator (TENG), piezoelectric nanogenerator (PENG), and electromagnetic power generator (EMG). This capability enables its utilization as an emergency power source for other micropower equipment downhole. The introduction of HDV-TENG also holds considerable implications for the development of self-powered underground sensors with high-frequency measurement capabilities. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG) has been considered as an effective way to convert various mechanical energies into electrical energy. However, the energy output needs continuous improvement for potential applications. In this study, triboelectric layers composed of polyimide (PI) matrix and carbon nanotube@barium titanate (CNT@BTO) nanoparticles were developed to achieve the performance enhancement through the synergistic coupling of piezoelectric and triboelectric effects as well as the microcapacitor function. To achieve the purpose, CNT@BTO nanoparticles were synthesized by the chemical vapor deposition method and then incorporated into a flexible PI triboelectric layer prepared using electrospinning technology and thermal imidization. The results showed that when the BTO content was 26 wt % and the CNT content was 2 wt %, the open-circuit voltage and short-circuit current of a TENG based on a PI/CNT@BTO nanofiber membrane reached 305 V and 104 μA, which were 3 times higher than those of a pure PI-based TENG. The TENG demonstrated sufficient power to drive small electronic devices, such as calculators, and to light up 124 commercial green LED and 18 blue COB light sources. Additionally, the TENG was integrated into a real-time temperature-sensing alarm system, showcasing its potential application in safety-related fields. The study demonstrated the feasible methods for TENGs' performance enhancement and provided potential application fields of energy-harvesting and self-powered sensing systems. [ABSTRACT FROM AUTHOR]

Precise agriculture based on intelligent agriculture plays a significant role in sustainable development. The agricultural Internet of Things (IoTs) is a crucial foundation for intelligent agriculture. However, the development of agricultural IoTs has led to exponential growth in various sensors, posing a major challenge in achieving long‐term stable power supply for these distributed sensors. Introducing a self‐powered active biochemical sensor can help, but current sensors have poor sensitivity and specificity making this application challenging. To overcome this limitation, a triboelectric nanogenerator (TENG)‐based self‐powered active urea sensor which demonstrates high sensitivity and specificity is developed. This device achieves signal enhancement by introducing a volume effect to enhance the utilization of charges through a novel dual‐electrode structure, and improves the specificity of urea detection by utilizing an enzyme‐catalyzed reaction. The device is successfully used to monitor the variation of urea concentration during crop growth with concentrations as low as 4 µm, without being significantly affected by common fertilizers such as potassium chloride or ammonium dihydrogen phosphate. This is the first self‐powered active biochemical sensor capable of highly specific and highly sensitive fertilizer detection, pointing toward a new direction for developing self‐powered active biochemical sensor systems within sustainable development‐oriented agricultural IoTs. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerator (TENG) has emerged as a novel nanotechnology for energy harvesting and self‐powered sensing via utilizing various low‐frequency mechanical energies throughout the surrounding environment. However, designing TENG with high physical robustness, flexibility, and output performance is rather challenging. This study develops monolithic conjugated microporous polymer aerogel (CMPA) with delocalized π‐conjugation to construct TENG with a robust porous structure. The as‐produced CMPA is composed of hollow intertwined nanotubes with a high degree of flexibility and high specific surface area (up to 528 m2 g−1). Due to its intrinsic nature of conjugated electron transfer and architectural characteristics, the CMPA‐based TENG (effective area: 4.9 cm2) shows a high sensitivity to mechanical force and excellent electric output (open‐circuit voltage: 72 V, short‐circuit peak current: 3.2 µA and transferred charge: 48 nC). Moreover, the CMPA‐based TENG can charge micro‐electronic devices and sense human motions. This work will inspire the design of aerogel‐based electronic devices and the management of renewable energy resources. [ABSTRACT FROM AUTHOR]

This paper systematically investigates the effective parameter on the performance of polydimethylsiloxane/graphene (PDMS@Gr)-based triboelectric nanogenerators (TENGs) as well as their applications. PDMS@Gr films containing 0, 0.05, 0.5, 1, and 1.5 wt.% graphene are synthesized, and their surface characteristics, mechanical behavior, and electrical properties are characterized. Vertical contact-separation mode TENGs are fabricated, and their performance is evaluated. The results demonstrate that the surface roughness and surface charge density are the most critical parameters for the performance of PDMS@Gr-based TENGs compared to the electrical and mechanical properties of the friction layers. The PDMS@Gr-based TENG with 1 wt.% graphene shows the highest power output of 2.6 W/m2 at an optimized working condition (5 Hz and 15 N). It also exhibits stable power output until 15,000 working cycles and displays battery-free applications by powering a light-emitting diode (LED) array, a calculator, a digital watch, and a digital thermometer. [ABSTRACT FROM AUTHOR]

Harvesting the omnipresent mechanical energy emerges as an essential solution in combating environmental pollution and alleviating energy deficits. However, the ultra‐low frequencies and variable amplitudes of most ambient mechanical energy pose significant challenges to effective energy harvesting. To address this issue, this paper reports an innovative triboelectric nanogenerator based on pendulum‐rotation transmission mechanism (PR‐TENG) designed for efficacious harvesting of continuous low‐frequency mechanical energy. It comprises two synergistic units: a transmission unit and a power‐generating unit. The transmission unit is capable of converting external low‐frequency mechanical excitations into unidirectional rotation. Through an internal speed‐increasing mechanism, the rotational speed of the rotor can be further elevated, thereby enabling the power‐generating unit to produce a frequency‐multiplied output and markedly improving the energy transduction efficiency. The mechanism of triboelectrification employed by the power‐generating unit further reduces the total weight of the device, thus advancing its portability. In addition, the coherent coaxial configuration of the device's components significantly enhances compactness and optimizes spatial efficiency. As a practical power source, the PR‐TENG is shown to be capable of directly powering LEDs. Owing to its distinctive operational mechanism and structural innovation, the PR‐TENG is a promising method to efficiently harvest low‐frequency mechanical energy from the ambient environment. [ABSTRACT FROM AUTHOR]

With the energy crisis and environmental pollution becoming a growing concern worldwide, the development of clean and renewable energy from the environment has become an imperative for human survival and development. However, the equipment used to harvest clean renewable energy is large, subject to environmental impacts and regional differences (such as wind, solar and tidal energy). In this study, a biodegradable eggshell membrane triboelectric nanogenerator (EM-TENG) is introduced for the purpose of harvesting lowfrequency mechanical energy. A Wireless Intelligent Motion Monitoring System (WIMMS) has been created using EM-TENG. It includes a Bluetooth sensor terminal and an intelligent processing terminal for digital signal reception on a host computer. The EM-TENG can be attached to knee and ankle joints to monitor posture. Therefore, for real-time monitoring of joint and kinetic chain changes during land training of ice dance athletes, the intelligent ice dance land training aid system is important. As a wearable motion monitoring sensor, EMTENGs application in intelligent motion monitoring, intelligent wearable devices and big data analytics is being promoted. [ABSTRACT FROM AUTHOR]

Polyvinylidene fluoride/graphene oxide (PVDF/GO) composite nanofibers were fabricated by electrospinning technology, to enhance the output performance of triboelectric nanogenerators (TENG) based on PVDF. These nanofibers were assembled into vertically contact-separate TENG to investigate the influence of GO mass fraction on the output performance of TENG. By utilizing the COMSOL software, the output performance of the TENG was simulated and analyzed, and the variations of electric potential and electric energy density at different electrode distances were observed. This study provides theoretical support for the working principle of TENG. Moreover, the morphology and structure of the PVDF/GO composite nanofibers were characterized using scanning electron microscopy, while the output performance of the TENG based on PVDF/GO composite nanofibers was characterized using a digital oscilloscope. The results indicate that the TENG based on PVDF/GO composite nanofibers exhibits excellent output efficiency when the GO mass fraction is 0.06%. The output voltage is approximately 350 V, and the short-circuit current is around 28 µA, and under impedance matching conditions, the maximum peak power is approximately 9.66 mW, with a power density of approximately 3.86 W/m². The TENG prepared by PVDF/GO composite nanofibers exhibits excellent output performance, capable of powering 120 LEDs, hereby demonstrating potential application prospects in the field of energy harvesting. [ABSTRACT FROM AUTHOR]

Energy-harvesting technology, which converts discarded energy from nature into electric energy, has recently attracted attention as a solution to environmental problems, such as the exhaustion of fossil fuels, climate change, and environmental pollution. A triboelectric nanogenerator (TENG) convert mechanical shaking into electrical signals through triboelectric charging and electrostatic induction in an internal circuit, collecting wasted mechanical kinetic energy from the body, such as walking and breathing. In this study, models of a textile structure and 3D printing were used to verify the applicability of TENG of 3D Printing textile structures by outputting textile structures using 3D Printing, textile structure was modeled and 3D printed to check the TENG applicability of the 3D Printing style structure by outputting the textile structure using 3D Printing, and freestanding mode TENG was manufactured using the fabric structure output as a tribo-layer to evaluate the maximum power voltage under various conditions. The results of this study evaluated the maximum output voltage under various conditions. The thickness and load were also increased. The factors that influence the selection of materials can be identified. [ABSTRACT FROM AUTHOR]

In recent years, electrophoretic display (EPD) attracts great attention for its ultra‐low power consumption, which is suitable for self‐powered applications. In this case, an energy storage system, simple as the capacitor, is essential for the self‐powered driving of EPDs. However, significance on the capacitor‐based driving of EPDs was underestimated in spite of its great practical value. This paper investigated the capacitor‐based driving of EPD for better performances of self‐powered EPDs. Based on this novel scheme, sports shoes with self‐powered EPD patterns were demonstrated as the future wearable applications. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG) offers a novel approach to harness mechanical energy continuously and sustainably. It has emerged as a leading technology for converting mechanical energy into electricity. The demand for self‐powered wearable microelectronics and energy generation in extreme conditions underscores the need for efficient high‐temperature operatable TENGs (HTO‐TENGs). However, the operating environment temperature not only affects the storage and dissipation of electrons during triboelectrification, leading to decreased output performance of TENG and instability at high temperatures, but also damage to the mechanical stability and effective defects in most tribo‐materials, resulting in a further reduction in TENG's effective output power. Moreover, the unstable material properties of the triboelectric layer at high temperatures also restrict the use of the TENG in harsh environments. Therefore, it is imperative to consider the structural durability and electrical output stability of TENG when applying it in challenging working environments. This review aims to bridge this gap by providing a comprehensive overview of the current state and research advancements in HTO‐TENG for the first time. Finally, this review presents insights into future research prospects and proposes design strategies to facilitate the rapid development of the field. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) are an attractive energy harvesting technology due to their high efficiency and vast applications in self-powered sensors. In this work, dielectric–dielectric contact-separation TENGs were modeled with time-dependent finite element simulations with the objective of improving TENG's performance by enhancing the relative permittivity ( ε r ).To achieve this, the chosen material (PDMS, ε r = 2.75 ) was doped with SrTiO3 ( ε r = 300) particles. The open-circuit voltage ( V O C ) and short-circuit current ( I S C ) remained constant as ϵ r increased, as predicted by existent models, but in contradiction with available experimental data. Thus, we introduced a charge correction model relating ϵ r and surface charge density, allowing us to observe an increase in TENG performance output ( V O C and I S C ). This work shows that finite element simulations are suitable for better understanding and optimizing TENGs' performance. [ABSTRACT FROM AUTHOR]

This paper reviews and summarizes recent progress in blue energy harvesting based on a triboelectric nanogenerator (TENG). This review covers TENG-based blue energy harvesters (BEHs) with different inertial units in spherical structures, derivative spherical structures, buoy structures, and liquid–solid contact structures. These research works have paved the way for TENG-based BEHs working under low-frequency waves and harvesting wave energy efficiently. The TENG-based BEH unit design and networking strategy are also discussed, along with highlighted research works. The advantages and disadvantages of different TENG structures with other inertial units are explored and discussed. Meanwhile, power management strategies are also mentioned in this paper. Thus, as a promising blue energy harvesting technology, the TENG is expected to significantly contribute to developing low-cost, lightweight, and high-performance BEHs supporting more frequent marine activities. [ABSTRACT FROM AUTHOR]

To address the problem of frequent battery replacement for wearable sensors applied to fall detection among the elderly, a portable and low-cost triboelectric nanogenerator (TENG)-based self-powered sensor for human gait monitoring is proposed. The main fabrication materials of the TENG are polytetrafluoroethylene (PTFE) film, aluminum (Al) foil, and polyimide (PI) film, where PTFE and Al are the friction layer materials and the PI film is used to improve the output performance. Exploiting the ability of TENGs to monitor changes in environmental conditions, a self-powered sensor based on the TENG is placed in an insole to collect gait information. Since a TENG does not require a power source to convert physical and mechanical signals into electrical signals, the electrical signals can be used as sensing signals to be analyzed by a computer to recognize daily human activities and fall status. Experimental results show that the accuracy of the TENG-based sensor for recognizing human gait is 97.2%, demonstrating superior sensing performance and providing valuable insights for future monitoring of fall events in the elderly population. ARTICLE HIGHLIGHTS: HIGHLIGHTS • A triboelectric nanogenerator (TENG) does not require a power source to convert physical signals into electrical signals. • TENG-based sensors can monitor human gait to identify daily activities and falls. • This work represents an important development of nanotechnology for wearable flexible sensors. [ABSTRACT FROM AUTHOR]

This study presents a novel approach utilizing solvothermal techniques to synthesize zeolitic imidazolate framework (ZIF‐4) particles. Various properties of the ZIF‐4 particles are investigated to shed light on the structural and morphological characteristics. These ZIF‐4 particles act as a positive triboelectric layer in the fabrication of a triboelectric nanogenerator (TENG) designed for powering electronic devices. The solvothermal‐assisted synthesis ensures the controlled and efficient production of ZIF‐4, optimizing its characteristics for enhanced performance in the TENG. The generated TENG, based on ZIF‐4 particles, determines promising capabilities in converting mechanical energy into electrical power. The highest power of TENG is obtained to be 18 μW at a load resistance of 50 MΩ. This work contributes major insights to the search for sustainable and effective power solutions for electronic gadgets. It emphasizes the potential of ZIF‐4 as a crucial triboelectric material, demonstrating its importance in the advancement of TENGs. [ABSTRACT FROM AUTHOR]

Serious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing. Significant experimental and theoretical efforts have been achieved toward understanding fundamental behaviors and a wide range of demonstrations since its report in 2012. As a result, considerable technological advancement has been exhibited and it advances the timeline of achievement in the proposed roadmap. Now, the technology has reached the stage of prototype development with verification of performance beyond the lab scale environment toward its commercialization. In this review, distinguished authors in the world worked together to summarize the state of the art in theory, materials, devices, systems, circuits, and applications in TENG fields. The great research achievements of researchers in this field around the world over the past decade are expected to play a major role in coming to fruition of unexpectedly accelerated technological advances over the next decade.

Abstract Triboelectric nanogenerators (TENGs) combine contact electrification and electrostatic induction effects to convert waste mechanical energy into electrical energy. As conventional devices contribute to electronic waste, TENGs based on ecofriendly and biocompatible materials have been developed for various energy applications. Owing to the abundance, accessibility, low cost, and biodegradability of biowaste (BW), recycling these materials has gained considerable attention as a green approach for fabricating TENGs. This review provides a detailed overview of BW materials, processing techniques for BW‐based TENGs (BW‐TENGs), and potential applications of BW‐TENGs in emerging bioelectronics. In particular, recent progress in material design, fabrication methods, and biomechanical and environmental energy‐harvesting performance is discussed. This review is aimed at promoting the continued development of BW‐TENGs and their adoption for sustainable energy‐harvesting applications in the field of bioelectronics.

Abstract Metal‐organic frameworks (MOFs) are nanomaterials with engineered chemical structures, offering remarkable properties. However, their limited film‐formation capability hinders their integration into triboelectric nanogenerators (TENGs). This study proposes a simple yet effective solution to overcome this challenge by employing electrospinning techniques to integrate the zeolitic imidazolate framework (ZIF‐8) into an easy‐to‐use nanofibrous mat. ZIF‐8 has high surface potential, a unique cubical structure, and an easy fabrication process that makes it an ideal material for TENGs. By incorporating ZIF‐8 into the electrospinning solution, significant improvements are achieved in the electropositivity of the resulting nanofibers. It leads to notable changes in the shape, morphology, and roughness of electrospun fibers, consequently enhancing the overall performance of the TENG. The results indicate that utilizing the ZIF‐based electrospun mat as a tribo‐positive material can increase transferred charges between electrodes by more than 100%. Utilizing the MOF‐based nanofibrous mat, this study also introduces a novel rotary TENG that works based on a mode of TENG operation called rolling mode. The reliable charge generation by the proposed rolling system reveals that this mode of TENG operation could be a superb alternative for traditional TENG modes, like contact/separation or sliding, which cause high levels of mechanical stress due to harsh physical impact or friction.

Abstract The floor constitutes one of the largest areas within a building with which users interact most frequently in daily activities. Employing floor sensors is vital for smart‐building digital twins, wherein triboelectric nanogenerators demonstrate wide application potential due to their good performance and self‐powering characteristics. However, their sensing stability, reliability, and multimodality require further enhancement to meet the rapidly evolving demands. Thus, this work introduces a multimodal intelligent flooring system, implementing a 4 × 4 floor array for multimodal information detection (including position, pressure, material, user identity, and activity) and human–machine interactions. The floor unit incorporates a hybrid structure of triboelectric pressure sensors and a top‐surface material sensor, facilitating linear and enhanced sensitivity across a wide pressure range (0–800 N), alongside the material recognition capability. The floor array is implemented by an advanced output‐ratio method with minimalist output channels, which is insensitive to environmental factors such as humidity and temperature. In addition to multimodal sensing, energy harvesting is co‐designed with the pressure sensors for scavenging waste energy to power smart‐building sensor nodes. This developed flooring system enables multimodal sensing, energy harvesting, and smart‐sport interactions in smart buildings, greatly expanding the floor sensing scenarios and applications.

Incorporating self-powered devices with flexible sensors not only tackles the power obstacles linked to wearable electronics but also greatly broadens their capability and application fields. Triboelectric nanogenerator (TENG) have garnered significant interest in the wearable electronics sector because of their distinct ability to harness ambient energy. Several techniques have been suggested to improve the efficiency of TENG, but these strategies often result in higher intricacy and manufacturing expenses. This study presents an interlayer structure that efficiently increases the surface contact area of TENG, consequently improving their output performance. Using this structure, a cost-effective, highly sensitive, and easily manufacturable sensor called the Ecoflex-encapsulated interlayered triboelectric nanogenerator (EI-TENG), has been developed. The EI-TENG demonstrates superior performance compared to a monolayer TENG (M-TENG) of identical dimensions, exhibiting a 1.6-fold increase in voltage output, a fivefold enhancement in minimum measurement precision, and a 2.29-fold increase in sensitivity. In addition, the EI-TENG exhibits exceptional endurance, as it maintains a consistent output even after undergoing 10,000 cycles. Furthermore, it reliably functions under different temperature and humidity situations. The energy produced by the EI-TENG is adequate to power 45 LED lamps directly. The EI-TENG, when affixed to an athlete’s hand, is capable of sensing the distribution of pressure while dribbling and shooting a ball, which assists athletes in honing their methods and making necessary adjustments to their hand strength. This study not only demonstrates the creation of interlayer-structured TENG, which produces a high amount of electrical energy and is durable and stable in many environments, but also provides valuable information for the future advancement of affordable, self-sustaining electronic devices.

Abstract The greener alternatives to tactile‐integrated multimodal sensors with self‐powered and self‐healing abilities are highly desirable for all‐in‐one autonomous sensing systems, particularly impressive in diverse application ranges including smart home, healthcare, and e‐skin. The dynamically self‐healable, stretchable piezoresistive sensors, and triboelectric nanogenerators (TENGs) reported herein are constructed by a facile, industrially viable method of grafting imidazolium ions on epoxidized natural rubber (ENR) backbone. Owing to cation‐π and π–π interaction between the percolated carbon nanotubes (CNTs)‐network and the imidazolium ions formed by non‐covalent interactions, the interfacial adhesion between the filler and elastomer is shown to improve considerably. The sensors show high piezoresistive strain sensitivity, reversible ionic network‐assisted self‐healability (efficiency ≈80%) and wide‐ranging detectability for precise monitoring of human movements. Both the healed and pristine sensors feature low hysteresis and stable electrical outputs over a wide strain range (≤200%). While achieving rapid self‐healing efficiency, the substrates are shown to exhibit remarkable robustness for harsh climates owing to significant mechanical toughness. Supported by excellent triboelectric tactile sensitivity (2.12 V N−1), the multifunctional TENG‐enabled sensor yields superior power density (0.16 mW cm−2). Moreover, the TENG module exhibits high force sensitivity and ease of operation that are considered versatile for all‐weather integrated tactile solutions for future technology.

Abstract The long‐term durability of triboelectric nanogenerators (TENGs) remains a main challenge for practical applications because of inevitable material abrasion and wear, especially for sliding TENGs. Herein, an inorganic triboelectric pair composed of diamond‐like carbon (DLC) and glass with excellent durability and triboelectric output for sliding‐mode TENGs is proposed. This triboelectric pair possesses a low coefficient of friction and little abrasion and accordingly excellent durability (>500 000 cycles). Moreover, compared with the traditional copper‐polytetrafluoroethylene (Cu‐PTFE) TENG with maximum transferred charges of 50 nC, those of the DLC‐glass TENG reaches 141 nC. Due to the low‐friction and high hardness of the triboelectric pair, the output quickly recovers after simply cleaning wear debris. The DLC‐glass TENG demonstrates an output power density of 530 mW m−2 and a fourfold faster capacitor charging speed than the Cu‐PTFE TENG. Compared to the reported durable TENGs via structure optimization and interface lubrication, the DLC‐glass TENG shows higher outputs and simpler structure. This DLC‐glass pair structure is also introduced into a spherical TENG for blue energy harvesting with excellent durability. The inorganic triboelectric pair with excellent mechanical durability and electrical performance proposed in this work shows huge prospects for practical applications of TENGs.

Abstract Metal–organic frameworks (MOFs) have emerged as promising materials for triboelectric nanogenerators (TENGs), but the effects of ligand choice on triboelectric charge remain underexplored. Hence, this paper demonstrates the effect of single, binary, and ternary ligands on TENG performance of cobalt/cerium‐based (Co─Ce) bimetallic MOFs utilizing 2‐methylimidazole (2Melm), terephthalic acid (BDC), and benzene tricarboxylic acid (BTC) as ligands. The detailed structural characterization revealed that varying ligand chemistries led to distinct MOF features affecting TENG performance. Single ligand bimetallic MOFs (designated as CoCe‐2MeIm, CoCe‐BDC, CoCe‐BTC) has lower performance than binary ligand (designated as CoCe‐2MeIm‐BDC, CoCe‐2MeIm‐BTC, CoCe‐BDC‐BTC) and ternary ligand MOFs (designated as CoCe‐2MeIm‐BDC‐BTC). Among all, the binary ligand MOF, CoCe‐2MeIm‐BTC, shows the best results (598 V, 26.7 µA) due to the combined effect of imidazole ring and (─COO─) groups. This is attributed to lone pairs on nitrogen atoms and a delocalized π‐electron system in imidazole system in this material. CoCe‐BTC has the lowest results (31 V, 3.2 µA) due to the bulkier nature of the electron‐withdrawing (─COO─) groups and their impact on the π‐electron system of the benzene ring. This study showcases the potential of ligand chemistry manipulation to control triboelectric charge and thereby enhance MOF‐based TENG performance.

Abstract Triboelectric nanogenerators (TENGs) have become reliable green energy harvesters by converting biomechanical motions into electricity. However, the inevitable charge leakage and poor electric field (EF) of conventional TENG result in inferior tribo‐charge density on the active layer. In this paper, TiO2‐MXene incorporated polystyrene (PS) nanofiber membrane (PTMx NFM) charge trapping interlayer is introduced into single electrode mode TENG (S‐TENG) to prevent electron loss at the electrode interface. Surprisingly, this charge‐trapping mechanism augments the surface charge density and electric output performance of TENGs. Polyvinylidene difluoride (PVDF) mixed polyurethane (PU) NFM is used as tribo‐active layer, which improves the crystallinity and mechanical property of PVDF to prevent delamination during long cycle tests. Herein, the effect of this double‐layer capacitive model is explained experimentally and theoretically. With optimization of the PTMx interlayer thickness, S‐TENG exhibits a maximum open‐circuit voltage of (280 V), short‐circuit current of (20 µA) transfer charge of (120 nC), and power density of (25.2 µW cm−2). Then, this energy is utilized to charge electrical appliances. In addition, the influence of AC/DC EF simulation in wound healing management (vitro L929 cell migration, vivo tissue regeneration) is also investigated by changing the polarity of trans‐epithelial potential (TEP) distribution in the wounded area.

This paper reviews and summarizes recent progress in blue energy harvesting based on a triboelectric nanogenerator (TENG). This review covers TENG-based blue energy harvesters (BEHs) with different inertial units in spherical structures, derivative spherical structures, buoy structures, and liquid–solid contact structures. These research works have paved the way for TENG-based BEHs working under low-frequency waves and harvesting wave energy efficiently. The TENG-based BEH unit design and networking strategy are also discussed, along with highlighted research works. The advantages and disadvantages of different TENG structures with other inertial units are explored and discussed. Meanwhile, power management strategies are also mentioned in this paper. Thus, as a promising blue energy harvesting technology, the TENG is expected to significantly contribute to developing low-cost, lightweight, and high-performance BEHs supporting more frequent marine activities.

Triboelectric nanogenerators (TENGs) are an attractive energy harvesting technology due to their high efficiency and vast applications in self-powered sensors. In this work, dielectric–dielectric contact-separation TENGs were modeled with time-dependent finite element simulations with the objective of improving TENG’s performance by enhancing the relative permittivity (εr).To achieve this, the chosen material (PDMS, εr=2.75) was doped with SrTiO3 (εr = 300) particles. The open-circuit voltage (VOC) and short-circuit current (ISC) remained constant as ϵr increased, as predicted by existent models, but in contradiction with available experimental data. Thus, we introduced a charge correction model relating ϵr and surface charge density, allowing us to observe an increase in TENG performance output (VOC and ISC). This work shows that finite element simulations are suitable for better understanding and optimizing TENGs’ performance.

This paper systematically investigates the effective parameter on the performance of polydimethylsiloxane/graphene (PDMS@Gr)-based triboelectric nanogenerators (TENGs) as well as their applications. PDMS@Gr films containing 0, 0.05, 0.5, 1, and 1.5 wt.% graphene are synthesized, and their surface characteristics, mechanical behavior, and electrical properties are characterized. Vertical contact-separation mode TENGs are fabricated, and their performance is evaluated. The results demonstrate that the surface roughness and surface charge density are the most critical parameters for the performance of PDMS@Gr-based TENGs compared to the electrical and mechanical properties of the friction layers. The PDMS@Gr-based TENG with 1 wt.% graphene shows the highest power output of 2.6 W/m2 at an optimized working condition (5 Hz and 15 N). It also exhibits stable power output until 15,000 working cycles and displays battery-free applications by powering a light-emitting diode (LED) array, a calculator, a digital watch, and a digital thermometer.

Highlights A bionic phase-locked structure-inspired iontronic triboelectric gel is proposed with good mechanical compliance for wearable haptic sensing applications. Competitive hydrogen bonding systems are constructed through polymer-solvent-nonsolvent interactions, and regeneration of polymers with weak hydrogen bond donors triggers controlled phase separation. Self-powered haptic skin constructed with iontronic triboelectric gel has a modulus (150.6 kPa) and stretchability (> 400%) similar to that of the human body, enabling fidelity transmission of haptic signals and precise recognition of sensing objects.

Abstract We investigated the polarity dependence of a capacitive energy management circuit in a triboelectric nanogenerator (TENG) power system. In a half-wave rectifying circuit, the Simulation Program with Integrated Circuit Emphasis and analytical models show that the charge dump to the load varied depending on the polarity of the rectifying circuit even with the same charge output from TENG. Depending on the polarity of the rectifying circuit, a fast saturation of the direct current (DC) output voltage or a high DC output voltage was obtained. Experiments with a half-wave rectifier and Bennet doubler confirmed our simulation and theoretical results. The charge dump from the minimum capacitance of the separated TENG to the load capacitance and the charge dump from the maximum capacitance of the contacted TENG to the load resulted in asymmetric charging behavior. We concluded that it is necessary to analyze the TENG and the capacitive energy management circuit as a single system rather than considering them as independent units in the rectifying circuit of the TENG. This work can provide insights for the design of triboelectric energy harvesting systems.