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Triboelectric nanogenerators (TENGs) based on water droplets can harvest water kinetic energy using triboelectrification and electrostatic induction mechanisms. However, the development of traditional liquid–solid TENGs (L–S TENGs) is severely limited due to their low‐performance output and high device encapsulation requirements for preparation technology. In this work, a single‐electrode mode droplet‐based TENG (D‐TENG) is devised to effectively harvest water kinetic energy by optimizing the interface contact behavior of droplets, increasing the short‐circuit current (ISC) of one drop of water from microamperes to milliamperes levels. In the D‐TENG configuration, the electrode is positioned above the dielectric rather than at the bottom, allowing efficient utilization of generated friction charges and reducing the dissipation of these charges, thereby enhancing the output performance of the TENG. The influencing factors and operational mechanisms of D‐TENG are studied to obtain optimized working conditions to improve its output performance. Under optimal conditions, the D‐TENG can saturate the charge of the PTFE surface with only 8 droplets, achieving an ISC of up to 3.51 mA and an output voltage (VO) of 298.27 V. This work provides a convenient method for efficiently harvesting water kinetic energy based on interfacial behavior control. [ABSTRACT FROM AUTHOR]

Metal substrate at the damaged coating, exposed directly to the corrosive medium, is susceptible to the localized corrosion, due to the formation of occluded corrosion cells. Herein, a new facile strategy for addressing the localized corrosion issue at damaged coating using a triboelectric nanogenerator (TENG) was proposed. The wind-driven TENG with a simple double-layer structure was designed. The output performance of the TENG can be controlled by adjusting structural parameters and the wind speeds, with the maximum short circuit current, output voltage and corresponding power reaching approximately 102.5 μA, 814 V and 7.6 mW, respectively, at a wind speed of 7.5 m/s. The electrons generated by the TENG can be transferred to the metal substrate at the damaged coating, inducing the cathodic polarization of the metal and providing effective cathodic protection. The reduction reaction, with the consumption of O 2 and the formation of OH-, occurs at the metal substrate at the damaged coating. A protective local environment is created by the combination of increased pH and removal of Cl- under the electric field of the TENG. To evaluate the corrosion behavior, immersion experiments and electrochemical measurements were conducted in 3.5 wt% NaCl when the Q235 steels covered the damaged coating were coupled with and without the wind-driven TENG at different wind speeds. Meanwhile, the influence of TENG's output performance on the cathodic protection effect for the metal substrate at the damaged coating is discussed. This study expands the application of the TENG in the field of corrosion resistance. [Display omitted] • A new strategy is proposed for solving the corrosion at damaged coating via TENG. • The wind-driven TENG consists of a stator and a vibrator. • TENG has a maximum current output of 102.5 μA at the wind speed of 7.5 m/s. • TENG provides the cathodic protection for the metal at the damaged coating. • The cathodic protection effect depends on the output performance of TENG [ABSTRACT FROM AUTHOR]

As modern industry evolves, powder technology has become widely used across numerous sectors. However, such extensive utilization has augmented the risk of dust explosions due to electrostatic charges during the production processes. The tiny size of dust particles, along with their tendency to gather static electricity during transportation in pipelines, poses a significant challenge for both observation and analysis. Furthermore, the electrostatic charging mechanisms of dust particles are still not well understood, highlighting the urgent need to clarify how electrification occurs to effectively mitigate electrostatic issues with dust. In this paper, a continuous gas-solid two-phase flow triboelectric nanogenerator (GS-TENG) has been developed to explore the generation mechanism of triboelectrification when flour-air two-phase flow collides with pipeline wall. Furthermore, to comprehensively analyze the relationship between flour movement in the pipeline under the influence of airflow and frictional electric signals, high-speed cameras were employed to record flour motion throughout the process. The findings indicate that flour-air two-phase flow exhibits unidirectional frictional electric signals after friction within PTFE pipelines. The findings reveal that the flow of flour driven by airflow through PTFE pipes produces frictional charges, leading to the formation of charged clusters. Upon contact with a grounded copper mesh, electric current peaks of up to 150 μA can be observed. Since the frictional charges carried by flour primarily originate from wall friction, coating the inner walls of pipelines with silicon-modified acrylic resin significantly reduces the frictional charges carried by flour, effectively suppressing static electricity accumulation and discharge phenomena, thus enhancing the safety of dust transportation. This study offers novel strategies for harnessing frictional electricity in gas-solid two-phase flows and mitigating electrostatics. [Display omitted] • An adjustable gas-solid two-phase flow TENG system was constructed. • GS-TENG can test the charging status of flour particles in situ. • A method to suppress the charging behavior of flour particles is proposed. [ABSTRACT FROM AUTHOR]

Static electricity accumulated on fabrics often causes discharged discomfort, fire, explosion, and cardiovascular diseases. Meanwhile, the electricity can be harvested and used for self-powered wearable devices. Therefore, it is essential to regulate fabric triboelectricity through studying the relationship between friction coefficients and triboelectric charges. In this paper, a reciprocating tribometer coupled with triboelectric testing instruments is designed to collect in-situ tribological and triboelectric properties for laterally sliding fabric based triboelectric nanogenerators (F-TENGs). In this case, the regulation factors involve motion conditions (including load, frequency, friction angle, etc.), surface components and environments. The results show that faster sliding speed and lower humidity produce higher triboelectric outputs of F-TENGs. Especially, amino groups modified silk shows an extremely strong electron-donating ability and achieves a high triboelectric current of 382.2 nA when paired with polyimide, which is enhanced by 1.67 times compared with silk. Most importantly, the friction coefficient values of F-TENGs show almost the same trend as the triboelectric outputs. Based on this, a sensing system for monitoring comfort level of fabrics is successfully designed through rubbing tested fabrics and observing indicator lamps. This work proposes a tribological approach with valuable insights of the underlying mechanism of triboelectric charging and extended applications. [Display omitted] • An in-situ testing system is fabricated by coupling the reciprocating tribometer and triboelectric testing instruments. • The correlation between fabric friction and electrification is verified for silk/polyimide pair under different conditions. • The monitor of comfort level of fabrics is achieved to provide personal comfort customization for different materials. [ABSTRACT FROM AUTHOR]

In the field of blue energy harvesting, solid-liquid triboelectric nanogenerators (SL-TENG) show significant potential. However, their low output performance in energy applications is limited due to the relatively small contact area and slow separation speed during the friction process. To overcome these limitations, we develop a pneumatic solid-liquid triboelectric nanogenerator (PSL-TENG) with ultrahigh output performance based on pneumatic solid-liquid triboelectrification and electrostatic breakdown. The pneumatic design effectively increases the solid-liquid interface area and the solid-liquid contact and separation rate, which can enhance solid-liquid triboelectrification effect. The synergistic design of the horn and the bent pipe can converge positively charged mist into large droplets, which can enhance electrostatic breakdown effect. This innovative design approach has achieved outstanding output performance, with a peak instantaneous voltage of 6436 V and a peak instantaneous current of 3.05 mA. This exceptional output performance is sufficient to directly power 3000 LED lights or a 55 W commercial lamp. These research achievements provide new insights for SL-TENG in energy harvesting, as significant output can be generated by collecting the inherent charges of liquids themselves. [Display omitted] • A new solid-liquid triboelectric nanogenerator based on pneumatic principles. • The peak voltage of the PSL-TENG can reach 6436 V, and the peak current can reach 3.05 mA. • The PSL-TENG can directly power a 55 W commercial lamp or illuminate 3000 LED lights. • Proposed a new mechanism that can achieve such a large output by relying on the charge of the liquid itself. [ABSTRACT FROM AUTHOR]

With the rapid development of modern industrial processes, electrostatic safety issues caused by powder in production and daily life have attracted people's attention. Since powder is small in size and easily agglomerates, it is difficult to observe or design devices to monitor the electrostatic process generated by powder. Herein, a continuous gas-solid two-phase flow triboelectric nanogenerator (GS-TENG) was developed to harvest triboelectricity from the collision process between the powder-air flow and the solid surface. Compared with the signals under non-continuous airflow, the short-circuit current and output voltage signals generated under continuous airflow impact exhibit an unidirectional direct current peak characteristic. Additionally, in order to analyze the relationship between motion of powder airflow and the triboelectric signals, the two-phase flow more comprehensively, a high-speed camera was used to record motion during the charge generation process. Results showed that 3 mm nylon sphere generated normal alternating current signals upon contact and separation from PTFE, while nylon power with the diameter of about 30 µm produced direct current triboelectric signals owing to the effect of point discharge. At a wind speed of 32 m/s, 5 cm distance, 90° impact angle, the short-circuit current and output voltage can reach the maximum values of 20 µA and 130 V, respectively, which can serve as a power source sufficient to power 63 commercial LEDs. Based on the gas-solid two-phase flow triboelectric nanogenerator, a self-powered road warning lights was designed, indicating application prospects in dusty weather. [Display omitted] • A new single-electrode gas-solid two-phase flow TENG system was constructed. • GS-TENG can form a continuous and uniform powder-air two-phase flow. • The effects of distance and angle on the output performance of GS-TENG were studied. • Powder-air two-phase flow collides with the PTFE film, point discharge phenomena occurs. [ABSTRACT FROM AUTHOR]

Controlling liquid–solid triboelectrification is highly demanded in a wide range of applications, from electrostatic prevention to energy collection and utilization. Except for traditional unidirectional and irreversible ways, smart approaches are required urgently. Here, a novel temperature response liquid–solid triboelectric nanogenerator (TENG) is reported on the basis of a polycaprolactone (PCL) covered fluorinated alumina for tunable triboelectrification. The PCL conformation is regulated by temperature to endow the substrate controllable surface component and interfacial wettability to manipulate the liquid–solid triboelectricity flexibly. As the temperature rises from 20 to 40 °C, the short circuit current and the open‐circuit voltage of the PCL‐based TENG are reduced by more than 40 times. When the temperature drops to 20 °C, the electrical output can return to its original level again. Moreover, after one month, the electrical signal is still reversible and stable. In addition to water, the electrical output of organic liquid, such as ethylene glycol, also responds well to temperature. This work initially provides a new strategy for achieving the customizable manipulation of liquid–solid triboelectrification by polymer surface reorganization, gives a new idea for in situ monitoring the interfacial wettability changes, and configures the reconstruction of amphiphilic polymer using triboelectricity. [ABSTRACT FROM AUTHOR]

The water vapor exhaled by the human body can severely accelerate the charge dissipation of a polypropylene (PP)‐based medical mask, thereby reducing the electrostatic adsorption efficiency to cause infection. To solve this problem, a new type of polyvinyl alcohol (PVA)‐based medical mask through electrostatic spinning to replace the PP melt‐blown layer, which has self‐charging and charge retention performance in a high humidity environment is fabricated. The PVA is rich in hydroxyl groups, which can spontaneously form hydrogen bonds with water vapor molecules exhaled by the human body and fix water molecules to increase the triboelectricity. By analyzing the electrical output performance of PVA‐based triboelectric nanogenerator (TENG), it is shown that the short circuit current is ≈26 times larger than that of PP‐based TENG in 95% relative humidity (RH). Moreover, PVA has a strong charge storage capacity and self‐charging performance, as determined by hand touching under a high humidity environment. The static dissipation rate of PVA is 1.4 times lower than that of PP at a 95% RH. In comparison with PP‐based medical masks, PVA‐based medical masks have a high humidity resistance and self‐charging performance and can be easily recharged in situ by hand slapping without taking it off for many times. [ABSTRACT FROM AUTHOR]

Online measurement of liquid flow rate in high-speed gas-liquid two-phase flow remains a considerable challenge for practical engineering applications. Owing to the non-linear and non-smooth characteristics, it is not easy to achieve effective measurement of liquid-phase flow without separation of gas-liquid two-phase using conventional methods. An alternative, the solid/liquid-based triboelectric nanogenerator, has a great potential for self-powered sensing of liquid states. Herein, a ring-shaped single-electrode triboelectric nanogenerator (RSE-TENG) by combining contact electrification (CE) and electrostatic induction is designed for energy harvesting and parameter monitoring of gas-liquid two-phase flow. The RSE-TENG can achieve stable short-circuit current and open-circuit voltage peaks of 24 µA and 344 V, respectively. And a self-powered real-time liquid-phase flow monitoring system with a measurement range of 4–20 mL/min for gas-liquid two-phase flow is developed based on the RSE-TENG. It has the advantages of simple structure, low cost, fast response time, and can achieve effective non-contact measurement of liquid-phase flow without separation of gas-liquid two-phase. This measurement method based on the electric signal of triboelectricity at the solid-liquid interface can provide guidance and reference for the related research on fluid mechanics. [Display omitted] • A systematic study of the triboelectrification behavior of the high-speed gas-liquid two-phase flow with a solid surface was investigated. • Highlighting the feasibility of using the triboelectricity for parameters monitoring of the gas-liquid two-phase flow system. • Harvesting energy from high-speed gas-liquid two-phase flow in the transportation pipelines. • Proposing a self-powered liquid-phase flow monitoring system with a measurement range of 4-20 mL/min of gas-liquid two-phase flow. [ABSTRACT FROM AUTHOR]

A new repairable water-solid triboelectric nanogenerator (W-TENG) based on superhydrophobic surface is fabricated to harvest water-flow energy. The superhydrophobic triboelectrode with micro- and nanostructures is prepared by adhering polyvinylidene fluorid (PVDF) nanospheres to a polyimide (PI) film through a double-sided adhesive tape followed with a fluorination process. When water flows through the superhydrophobic surfaces with a flow rate of 0.3 m/s, the W-TENGs array could easily harvest water-flow energy to obtain a current output of 20 μA which can light more than 30 commercial LEDs or be used for self-powered sensors to detect concentration change of chemicals pollutants in water. More importantly, when the superhydrophobic surface is damaged during long-term working, it could be self-repaired by releasing the fluorinated alkyl silane packed in pores of adhesive tape surface, and a self-repairable W-TENG is achieved. Given its easy fabrication and self-healing properties, the W-TENG and W-TENGs array have promising practical use in oceans and rivers energies harvesting, especially in some remote areas, for early warning, indicator light and self-powered detection sensors. A water-solid triboelectrification with self-repairable superhydrophobic surfaces is fabricated through simply adhering PVDF nanospheres to a double-sided adhesive tape. Once superhydrophobic property of the triboelectrode surface is destroyed, electrical output property can be conveniently self-repaired by transferring fluorinated alkyl silane to its top surface or replacing the damaged surface with a superhydrophobic tape at mild conditions. Image 1 • A self-repairable water-TENG based on superhydrophobic surface is fabricated. • The superhydrophobic triboelectrode can be prepared in a large area by a simple bonding method. • A self-repairable W-TENG is achieved by restorable superhydrophobicity. • A current output of 30 μA can be obtained with the water flow rate of 0.6 m/s. [ABSTRACT FROM AUTHOR]

Abstract Triboelectric nanogenerators based on biodegradable plant leaf and leaf powder is fabricated through a simple and cost effective method. The short-circuit current (I sc) and output voltage (V o) of fresh leaf can reach 15 μA and 430 V. Dry leaf is grinded into powder to make solve problem of frangibility when contact and make full use of the leaf. Poly- L -Lysine is used to modify leaf powder and enhance the output performance of leaf powder based TENG. After surface modification, the I sc and V o can reach high as 60 μA and 1000 V, respectively, which can easily power a commercial electric watch and 868 LEDs. To extend the drive mode, wind driven TENG (WTENG) based on PLL modified leaf powder is designed for harvesting wind energy and the maximum I sc can reach 150 μA under 7 m/s wind speed. The WTENG is designed to power an "EXIT" LED light for exit passageway in windy weather. Furthermore, TENG tree is designed basing on the live leaves and artificial leaves, which have promising potential use in the remote regions, such as in the mountains or islands, for early warning and indicator light. Graphical abstract Triboelectric nanogenerators based on biodegradable plant leaf and leaf powder was fabricated through a simple and cost effective method. Poly- L -Lysine is used to modify leaf powder and enhanced the output performance of leaf powder based TENG. Moreover, wind driven TENG and TENG tree were designed for harvesting wind energy. fx1 Highlights • TENGs based on biodegradable plant leaf and leaf powder are fabricated. • I sc and V o of plant leave based TENG can reach as high as 60 μA and 1000 V, respectively. • Plant leaves material based TENG can easily power a commercial electric watch and 868 LEDs. • W-TENG and TENG tree are designed for harvesting wind energy. [ABSTRACT FROM AUTHOR]

A new self-powered ammonia (NH 3 ) nanosensor with flexibility, portability, good selectivity and sensitivity has been developed from conducting polyaniline nanofibers (PANI NFs) based triboelectric nanogenerator (TENG). The power supply and gas sensor have been successfully integrated into one device. The PANI NFs with NH 3 sensing property work both as a frictional layer and an electrode in the TENG. The TENG shows high output performance with the maximum short current circuit of 45.70 μA and output voltage of 1186 V in air, while its output voltage is obviously reduced in varying degrees after being exposed to NH 3 with different concentrations, resulting from the change of electroconductivity of PANI, which is the design principle of the NH 3 sensor. Meanwhile, this NH 3 nanosensor exhibits good selectivity and sensitivity with the limit detection of 500 ppm at room temperature. This work proposes a new thought to design the self-powered NH 3 nanosensor, which has the widespread application prospect to harvest ambient energy for detecting toxic NH 3 without any external power sources. [ABSTRACT FROM AUTHOR]

A new smart U-shaped triboelectric nanogenerator (TENG) was reported basing on solid-liquid contact triboelectrification and the Pascal's law, in which the complicated mechanical motions can be transmitted into liquid pressure and electricity signal. The U-shaped TENG driven by inertial force and air flow is designed as an energy harvesting device to collect the mechanical energy with a stable peak output voltage and current of about 20 V and 400 nA, respectively. The relationship between the output performance and the water sliding conditions is investigated in detail with a stable peak output performance at the point of resonance. The U-shaped TENG can also be working as smart multifunctional sensors to detect the displacement, pressure, torsion, and so on. As a self-powered displacement sensor, the U-shaped TENG shows a high sensitivity of 0.91 V mm −1 and 8.50 nA mm −1 . As a pressure sensor, it also exhibits a high sensitivity of 4.41 V kPa −1 and 72.94 nA kPa −1 , respectively. This work expands the practical applications of the solid-liquid triboelectrification based TENGs for energy harvesting and smart sensors in wide fields with advantages of simple fabrication, low cost, portable and self-powered properties. [ABSTRACT FROM AUTHOR]

A new structured triboelectric nanogenerators (TENG) was designed by adding a transition layer between the friction layer and the conduct layer, which could significantly improve the output performance by one order of magnitude. The material of transition layer, such as polyimide, has high ability to store the triboelectrification charges, resulting in more induced charges and higher external current. After adding a polyimide charge storage layer with the thickness of 25 µm, the short-circuit current and output voltage of polyvinylidene fluoride (PVDF) and nylon (NY) based TENG (Cu-PI-PVDF@NY-Cu) increased from 9.2 μA to 65 μA, and 110 V to 1010 V, respectively. The maximum charge density can reach approximately 105 μC/m 2 with the maximum value of the output power of 5.87 mW under 4 MΩ loading resistance, which can instantaneous light up 992 commercial LEDs and charge a capacitor with the speed increased by 10 times. Moreover, the mechanism and influence factors including the surface structure, composition and thickness of the charge keeping layer to enhance the output of TENGs were discussed in detail. The charge decay tests of the transition layers showed that polyimide layer has very good charge keeping ability with a decay rate of only about 20% in 4 h, while the charge of PVDF decrease about 97% in 4 h, which is a key factor for its lower output. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) with sliding-mode have developed rapidly in the field of energy harvesting and sensing. However, its surface wear and low electric output performance usually limit its applicability. Herein, a mixture of hexadecane with onion-like carbon (OLC) lubricant is added to the interface between polytetrafluoroethylene (PTFE) film and steel to enhance the triboelectrical and tribological performance. During dry friction, the friction pair is severely worn and the current output decreases gradually with the transfer of a large amount of PTFE debris in a short period. The introduction of hexadecane partly resolves the problems such as friction and wear with the reduction in the transfer of PTFE material. However, the current output decreases gradually during the friction process because there is still some slight material transfer in the interface. The electrical output of TENG is further enhanced with the addition of OLC, and its tribological properties are comparable or better than oil-based TENG. The short-circuit currents (I sc) of the oil-based TENG and the oil-OLC-based TENG are 1.5 times and 5 times that of the TENG in the dry friction state, respectively. Also, the coefficient of friction (COF) of oil-OLC-based TENG is reduced by about 75.3% compared with dry friction state. The oil-OLC-based lubricant reduces the transfer film formation, increases the effective contact area, and squeezes the air at the interface. Also, part of the OLC rolls between the two friction layers, forming a "micro-bearing", further reducing the generation of transfer film. This study provides a novel way to improve the output efficiency and prolong the service life of TENG. [Display omitted] • Hexadecane-Onion-like carbon (OLC) lubricant further increases the triboelectricity. • The wear resistance of TENG is further improved by using hexadecane-OLC. • OLC doped hexadecane further inhibits material transfer during friction. • Hexadecane-OLC lubrication greatly extends the service life of TENG. [ABSTRACT FROM AUTHOR]

Moisture in environment can severely decrease the output of the solid-solid triboelectric nanogenerators (TENGs) which usually hinders their further practical applications. To solve this problem, we report a modified cellulose material that achieves enhanced electrical output property at high humidity by acquiring universal dual-electric-polarity augmented property. This material shows enhanced contact electrification performance when contacted with different electrode materials. Results show that the electrical output of the TENG composed of cyanoethyl cellulose (CE-cellulose) with poly tetra fluoroethylene (PTFE) and nylon 11 (PA 11) increased by 4 and 8 times. Moreover, the triboelectric charge density (TECD) of CE-cellulose-PTFE based TENG at 95%RH is 533 μC/m2, which is a new record for the electrical output of TENG in high humidity environment. This work opens new avenues to the development of TENGs for energy harvesting and self-powered sensors under the real working conditions, especially in high humidity environments, even in the presence of water droplets. [Display omitted] • Cyanoethyl cellulose (CE-cellulose) has universal dual-electric-polarity augmented property. • CE-cellulose based triboelectric nanogenerator (TENG) has ultra-high moisture resistance performance. • The triboelectric charge density (TECD) of this TENG at 95%RH is 533 μC/m2, which is a new record. [ABSTRACT FROM AUTHOR]

Triboelectricity has demonstrated bright application prospects in the field of blue energy harvesting. However, the low output efficiency of solid-liquid triboelectricity hinders its practical application. This paper proposed a high-efficiency drip nanogenerator with a cambered surface based on the brachistochrone curve principle. In this nanogenerator, a drop of water can achieve an output current of 50 µA and an output voltage of 137 V without pre-charging. The cambered-surface structured triboelectric nanogenerator (C-TENG) enhances the short-circuit current by 30 times compared to the traditional TENG based on flat-surface structure (F-TENG). The output power of C-TENG reaches up to 1.875 mW at the central angle of 60°. The Simcenter STAR-CCM+ Viewer software is utilized to simulate the falling process of water droplets and the dynamics to explain the difference in the falling process of central angle structures at different central angles. The C-TENG characteristics ensure improved energy collection efficiency. Therefore, it is used to design a new droplet energy collection structure for rain energy harvesting. C-TENG has a more significant lighting effect than F-TENG. This new drip generator demonstrates remarkable efficiency in collecting various water energies in nature and has potential applications in device power supply and self-powered sensing. In this work, we creatively designed a cambered-surface based TENG (CS-TENG) with a flexible PTFE filter membrane attached to the inner wall of a cambered-surface device for high drop energy collection efficiency without pre-charging. In this cambered surface contact mode, the CS-TENG has a higher output with short-circuit current of 50 µA than that of the flat-surface structure TENG (in prior investigations most of the water droplets TENG developed were based on the flat-surface structure), with the triboelectric current enhanced dozens of times. This study provides a novel design concept for improving water drop power generation. [Display omitted] • A new droplet TENG (CS-TENG) based on cambered surface has been designed and developed. • A droplet of water can generate power of 50 µA and 137 V on CS-TENG without pre-charging. • It is a simple and efficient development of TENG for harvesting raindrop energy. • A new approach to enhance triboelectric output using simple materials. [ABSTRACT FROM AUTHOR]

In modern times, conventional energy resources are depleting at a rapid pace, and clean renewable energy sources are becoming a research hotspot. In this regard, the triboelectric nanogenerator (TENG) is being used for collecting mechanical energy from the environment. However, the performance of the common solid–solid TENG is often limited by its bulky mechanical structure. Therefore, the present study proposes a novel TENG with the seesaw equal-arm lever structure, which is lightweight and convenient to use. The performance output of the proposed TENG is not limited by its structure. Moreover, it is capable of harvesting the energy of ocean waves in both horizontal and vertical directions. The performance of the proposed TENG was evaluated under different wave conditions using equipment such as motors to simulate the frequency and amplitude of ocean waves. The optimal voltage output achieved using the proposed TENG was up to 1055 V, and the current was up to 72 µA. In addition, a double-sided DSS-TENG was fabricated on the foundation of SS-TENG to exhibit improved energy conversion efficiency. Finally, the SS-TENG was applied successfully to power LED lamps and small hygrometers, which demonstrated that the SS-TENG had good stability and could serve as a feasible tool for large-scale collection of blue ocean energy. [Display omitted] • A novel TENG devices with the seesaw equal-arm lever structure (SS-TENG) was designed. • The generation performance of SS-TENG devices will not limited by its own structure. • The SS-TENG is capable of harvesting the energy of ocean waves in both horizontal and vertical directions. • The SS-TENG can be drove more efficiently by binding heavy objects on both sides to form an inertia difference. • The power harvesting efficiency can be improved by changing the structure of SS-TENG. [ABSTRACT FROM AUTHOR]

We report a new method to fabricate a polypropylene (PP) nanowire array based triboelectric nanogenerator (TENG) with high output through structural control and surface functionalization for harvesting friction mechanical energy. Compared with the smooth PP film based TENG, the short circuit current ( I sc ) and open circuit voltage ( V oc ) of the PP nanowire based TENGs with the nanowire diameter of about 100 nm and length of about 14 μm increase by more than 4 times. More importantly, after surface functionalization with a modifier of 1H,1H,2H,2H-perfluorooctyltrichlorosilane, the output of the PP nanowire based TENG is further increased to a maximum V oc of 1900 V and a short circuit current density of 19 mA/m 2 , increased by more than 100 times than that of the flat PP film based TENG. This TENG can light up 372 commercial LEDs. Furthermore, a self-powered temperature sensor is designed, which shows great potential application in daily life. By taking this simple and effective surface modification strategy, we believe various materials could be used for energy harvesting by TENGs and other devices with high performance. [ABSTRACT FROM AUTHOR]

Peeling the adhesion interface is a common contact-separation process at the interface, but harvesting and effectively regulating the mechanical energy remains a challenge. Herein, we designed a new protocol triboelectric nanogenerator based on interfacial adhesion-peeling behavior (AP-TENG). The basic relationship between adhesion force and peeling current reveals that rapid jumping out of contact of the adhesion interface enhanced peeling electrification. Also, the design of the grid structure allows for rapid separation of the adhesion interface. The current of AP-TENG during peeling is approximately four times larger than that of the flat surface, allowing for the monitoring of interface fracture. In the rolling mode, AP-TENG can peel the adhesive tape from the surface of the substrate at a very small angle, resulting in a shocking current of up to about 15 μA. The present results confirm the role of adhesion in triboelectricity and expand the potential applications of adhesive materials for energy harvesting. [Display omitted] The peeling electrification of adhesive interface is a special case of triboelectrification, which is strongly affected by the peeling condition (contact interface continuity, velocity, angle, etc.) and the energy dissipation during the separation process of adhesive interface. This work successfully converted the mechanical energy into electrical energy during peeling process, and explored the mechanism and influencing factors of peeling electrification at the adhesion interface. • Peeling electrification is a special case of contact electrification. • Peeling electrification is driven by the energy dissipation behavior of adhesive tape. • The adhesion-peeling triboelectric nanogenerators successfully convert the mechanical energy into electrical energy. • Adhesion failure detection is achieved by energy harvesting in peeling-electrification mode. [ABSTRACT FROM AUTHOR]

Rapid developments of artificial intelligence have increasingly necessitated wearable and functionalized fabric-based triboelectric nanogenerators (F-TENGs). However, conventional F-TENGs are limited by low outputs, poor durability and washability. In this study, through simple liquid-phase fluorination with homemade urethane perfluorooctyl silane (NHCOO-PFOTS), functional fabrics were fabricated for highly wearable and machine-washable F-TENGs. By introducing fluorine atoms, the fabrics possess strong electron-accepting ability, excellent waterproof and anti-soil performances. Besides, fluorination provides excellent durability for F-TENGs since chemicals reacted inside the fibers and formed long-chain molecules that will not disappear upon subsequent washing and daily abrasion. F-TENG composed of fluorinated silk and nylon fabrics yielded a maximum output power of 2.08 W·m−2 at 10 MΩ with negligible decay after 45,000 cycles of contact-separation motions and 70 h of washing. Fluorinated silk can maintain hydrophobic (contact angle > 140°) in extreme environments for long durations. In addition, the F-TENG developed herein exhibits excellent anti-wear performances and self-healing of hydrophobicity and triboelectric performances through heating treatment. Further, F-TENGs sewed on clothing can drive a digital watch using electricity generated by arm swinging. A wireless drowning sensor was designed by utilizing human motion energy with a water-conducted switch in the circuit. The sensor gets triggered by water and instantaneously sends out real-time alarms and notifications to mobile devices. The excellent outputs and practicability of fluorinated fabrics make them excellent candidates for self-powered smart clothes and wearable devices for drowning prevention. • A fully fabric-based energy harvester is developed through low-cost NHCOO-PFOTS modification, which shows excellent self-healing, self-cleaning performances and extreme durability. • A self-powered wireless sensor with the ability of drowning warning is demonstrated, which is able to send real-time message to the specified client when connected fabric-based power device falls into the water. [Display omitted] • A fully fabric-based energy harvester is developed through low-cost NHCOO-PFOTS modification. • The fluorinated fabrics show excellent self-healing, self-cleaning performances and extreme durability. • A self-powered wireless drowning sensor with the ability of drowning warning is demonstrated. [ABSTRACT FROM AUTHOR]

A new synergetic anticorrosion system was constructed via combining a self-powered cathodic protection based on triboelectric nanogenerator (TENG) and a green corrosion inhibitor of zinc gluconate (ZnG). Wind-driven TENG with a sandwich-like structure was designed, exhibiting high output performance with the peak values of short circuit current, output voltage and corresponding power reaching about 155 μA, 402 V and 13.5 mW, respectively, under a wind speed of 10 m/s. With the assistance of TENG, the migration of corrosion inhibitor can be accelerated and the formation of the protective layer becomes faster due to the driving force of electric field. The shielding effect of protective layer in turn improves the cathodic protection of TENG. The immersion experiment and electrochemical measurements including Tafel polarization curves and EIS were taken to evaluate the performance of synergetic anticorrosion system. FESEM and EDS measurements were performed to analyze the morphology and composition of the protective layer and confirm the mechanism of synergetic anticorrosion. This work expands the application of TENG in the anticorrosion field and proposes a new thought of synergetic anticorrosion method. A new synergetic anticorrosion system was constructed via combining a self-powered cathodic protection based on triboelectric nanogenerator (TENG) and a green corrosion inhibitor of zinc gluconate (ZnG). [Display omitted] • A new synergetic anticorrosion system is designed via combining TENG and corrosion inhibitor of zinc gluconate. • TENG facilitates the formation of protective layer on the metal surface. • The shielding effect of protective layer improve the cathodic protection of TENG. • The protective layer consists of Zn(OH) 2 nanoparticles and absorbed gluconate complex. • The synergetic anticorrosion system exhibits good performance. [ABSTRACT FROM AUTHOR]

The presence of water in lubricating oil causes the latter's failure and wastage, thus greatly accelerating the corrosion and wear of mechanical equipment. It may even cause mechanical failure, which poses a challenge in water-in-oil (W/O) emulsion separation. In this work, a nylon and polyvinylidene fluoride (PVDF) electrospun nanofiber-based triboelectric nanogenerator (TENG) with an asymmetric AC electric field is designed for efficient W/O emulsion separation. Double polyimide (PI) films are used as the transition layers for charge storage in the TENG to achieve a stable short-circuit current up to 115 μA and output voltage of 2847 V, which help to realize the dehydration and separation of lubricating oil with low energy consumption and effective energy reuse. Under an asymmetric alternating voltage output of 2500 V powered by the proposed TENG, the moisture content of the W/O emulsion can be reduced from 5 wt% to 0.15 wt%, and the W/O emulsion separation rate can reach 96.97% after 30 min. The rapid separation of large amounts of W/O emulsion driven by wind could be also achieved. The working mechanism of high W/O emulsion separation efficiency driven by the asymmetric AC electric field was attributed to the dipole coalescence, oscillation coalescence and electrophoretic coalescence. Moreover, electrical breakdown hardly occurs during the working process of the TENG, and oil-water separation driven by the TENG has the characteristics of high efficiency, low cost and safety, which has promising potential to use triboelectric nanogenerator to treat oily wastewater in the actual industry in the future. An asymmetric AC electric field powered by an electrospun nanofiber-based TENG driven by wind in nature was used for efficient W/O emulsion separation. The working mechanism of the asymmetric AC electric field powered by TENG for W/O emulsion separation has the synergistic effect of dipole coalescence, oscillation coalescence, and electrophoretic coalescence. This research provides a new and effective oil–water separation strategy, which offers great promise in the purification and emulsion separation of industrial lubricants. [Display omitted] • Electrospun nanofibers serve as the triboelectric layer to achieve an asymmetric AC electric field. • The synergistic effect of dipole coalescence, oscillation coalescence and electrophoretic coalescence. • The rapid separation of large amount of W/O emulsion driven by wind could be achieved. • Oil-water separation driven by TENG has effective energy reuse, low cost and safety. [ABSTRACT FROM AUTHOR]

A new type of gas-solid two-phase flow-based triboelectric nanogenerator (WS-TENG) is fabricated for collecting triboelectric energy in wind-blown sand environment, producing direct current output, and harvesting kinetic energy of continuous wind-blown sand flow. A single-electrode mode WS-TENG is designed with polytetrafluoroethylene (PTFE) as friction layer and used to investigate triboelectrification between wind-blown sand flow and friction layer surface using sediment-air injection method. Results showed that both short-circuit current (I sc) and output voltage (V o) are direct current modes that increase with increasing impact angle and sand feed rate and reach 2 µA and 55 V, respectively, at a flow velocity of 18 m·s−1 to charge capacitor and light up five LEDs as a wind-blown sand flow kinetic energy collector. Moreover, output performance of WS-TENG can be improved further by pre-charging the floating sand using a PTFE pipe due to coupling of electrostatic induction and triboelectrification effect. WS-TENG was also applied as a self-powered sensor for aeolian sand transport rate in harsh sandstorm environment, thereby indicating its potential application for tracking the evolution of aeolian desertification and developing practical sensing applications of gas-solid two-phase flow-based TENG. [Display omitted] • A novel wind-blown sand flow-based triboelectric nanogenerator (WS-TENG) has been proposed and developed. • The WS-TENG can efficiently harvest the kinetic energy of wind-blown sand flow in a sandstorm environment. • A self-powered active sand transport rate sensor based on precharged WS-TENG has been developed. • The gas-solid two-phase flow as frictional media has been introduced into the TENG filed. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerator (TENG) based on elastic materials is increasing interests for irregular and random mechanical energies harvesting. However, the conductive design of the elastic materials in TENGs often limits its applications. Herein, a new conductive and elastic sponge-based triboelectric nanogenerator (ES-TENG) is developed for random mechanical energy harvesting, which integrates the elastic material and the conductive material on a flexible sponge to realize the collection of mechanical energies, particularly for irregular and random motions. The conductive elastic sponge is prepared by a simple dilute chemical polymerization of aniline to grow conductive polyaniline nanowires (PANI NWs) on the surface of elastic sponge. Due to the flexible deformation of sponge, it can harvest the kinetic energy of disordered motion with different amplitudes and from variable directions. As the triboelectric layer of ES-TENG, the porous sponge and polyaniline nanowires on its surface can provide a large contact area and improve the triboelectric efficiency. At the same time, the conductive polyaniline coating on the surface of sponge can also be used as the electrode of ES-TENG to conduct electrons and generate an output of 540 V and 6 μA respectively, which can be used on various flexible object surfaces to collect irregular and random mechanical energy ubiquitous in daily life. In addition, based on the NH 3 -sensing performance and the three-dimensional reticular structure of the polyaniline nanowires on the elastic sponge, the ES-TENG can make it work as self-powered sensor for detecting toxic NH 3 with the detection limit up to 1 ppm and the response time less than 3 s. In view of the microporous and nanowire structures, elasticity, conductivity and easy fabrication of the conductive elastic sponge, the ES-TENG has promising applications in various irregular and random mechanical energy harvesting and self-powered NH 3 sensors. ga1 • A new conductive elastic sponge-based triboelectric nanogenerator (ES-TENG) is developed. • The conductive elastic sponge is prepared by a dilute chemical polymerization of aniline on the surface of sponge. • The ES-TENG can conveniently harvest irregular and random mechanical energies. • The ES-TENG based self-powered NH 3 sensor has detection limit up to 1 ppm and fast response of less than 3 s. [ABSTRACT FROM AUTHOR]

Moisture in environment can severely decrease the output of the solid-solid triboelectric nanogenerators (TENGs) which usually hinders their further practical applications. To solve this problem, in this paper we fabricated a new type of biofilm materials based TENG, which can work stably in high humidity environment with high output performance by forming hydrogen bond with water molecules. In high humidity environment the hydroxyl-rich biomaterials, such as starch molecules, and water molecules could form hydrogen bonds spontaneously to fix water molecules on the surface, which allows water molecules to participate in triboelectric charging as a more electropositive material to obtain a higher output of TENG. Different from the traditional polymer materials based TENGs, the output of the starch films based TENG increases with the increase of the environmental humidity. The output current and voltage could increase from 6.2 μA to 110 V to 16.6 μA and 330 V with the ambient humidity increasing from 15% to 95%, respectively, which is about 12 times larger than that of the traditional nylon-11 based TENG in the humidity of 95%. It is an important supplement of TENG family and highly expand application scopes for energy harvesting and self-powered sensors in high humidity environment, especially in cloudy, foggy days or under water and sweat conditions. A new kind of biofilm material based triboelectric nanogenerator (TENG) with high output performance is constructed for energy harvesting in high humidity environment, solving the output reduction of solid-solid TENG with the increase of environmental humidity. This type of TENG has promising potential applications in energy harvesting, self-powered electronic devices early warning devices in fog, ocean, and other high humidity environment. Image 1 • This new type of triboelectric nanogenerator can work stably in high humidity environment with high output performance. • This TENG is fabricated with an environment friendly and biodegradable hydroxyl-rich material without any specific treatment. • Biofilm materials based TENGs have universal characteristics of high output under high humidity. [ABSTRACT FROM AUTHOR]

Recent advances in triboelectric nanogenerator (TENG) by suitable micro/nanostructure fabrication and surface chemical modification have greatly optimized surface charge density and output performance, but poor wear resistance of micro/nanostructure and surface modification composition is still the bottleneck for practical applications. Here, an oleic-acid-enhanced triboelectric nanogenerator (OA-TENG) with high output performance and wear resistance is reported, in which the OA was used to improve the electronegativity of polystyrene (PS) friction pair and also used as lubrication additives to reduce friction coefficient and wear volume. The maximum output power of the PS based TENG doping with oleic acid reached 470.5 μW, which is 79 times larger than the device without doping oleic acid. More importantly, the tribological tests show that the addition of 4.8 wt % OA reduced the wear volume by about 90% comparing to pure PS, which is a key role to ensure the long-term work of TENG. The wear-resistant friction electrode material can be prepared in a large area and used for energy collection to design temperature self-powered sensors or cathodic protection devices. This protocol shows new perspectives for TENG researches in terms of high performance, wear resistance and robustness for green-energy harvesting and applications. An oleic-acid-enhanced triboelectric nanogenerator (TENG) with remarkable characteristics of high output performance and wear resistance is developed. The addition of 4.8 wt % oleic acid increased power density by 79 times and reduced the wear volume by 90%. This protocol opens up new perspectives for TENG researches in terms of excellent robustness and cost efficiency for green-energy applications. Image 1 • An oleic-acid-enhanced triboelectric nanogenerator with high output performance and wear resistance is fabricated. • Oleic acid is used to improve the electronegativity of friction pair and reduce friction coefficient and wear volume. • The power density of the TENG doping with oleic acid is 79 times larger than the device without doping oleic acid. • The addition of 4.8 wt % oleic acid reduced the wear volume by about 90%. [ABSTRACT FROM AUTHOR]