Amplitude‐Amplified Triboelectric Nanogenerators Enabled by Fluid‐Structure Coupling for Efficient Ocean Wave Energy Conversion

A high-performance triboelectric nanogenerator (TENG) has been developed for breath sensing applications, utilizing tribopositive electrospun nylon-6 nanofibers and tribonegative fluorinated ethylene propylene (FEP). The optimization toward the development of electrospun nylon-6-based TENG includes a range of factors such as the applied force and frequency on tribo responses, the thickness of the fiber mat, the concentration of nylon-6 in the fiber mats, and the selection of the tribonegative material for pairing with nylon-6 nanofiber. Among these parameters, the nanofiber prepared with 18 wt% nylon-6, characterized by a uniform fiber distribution, the highest surface area of 55.69 m2 g−1, and an optimal thickness of 0.169 mm, demonstrated excellent TENG performance, among others. The TENG module constructed using nanofiber in a 4 cm2 area showed the TENG responses of more than 30 μA short-circuit current, 200 V open-circuit voltage, and 90 nC charge when hand-pressed. It achieved a substantial power density of 890 mW m−2 at 20 MΩ by applying a constant force of 10 N at a 10 Hz frequency. Charging a 1 μF capacitor to approximately 30.1 V in just 30 s highlights the potential of electrospun nylon-6 as a promising material for nanogenerator energy harvesting and sensing applications. The TENG device was found to be sufficient to power small, portable electronics such as LEDs and digital watch displays. A wearable belt was fabricated to showcase its breath-sensing capabilities by pairing it with FEP. The microcontroller connected to the TENG in the wearable belt is used to analyze the output produced through breathing patterns, subsequently activating a buzzer and LED by the nature of the breathing.

Sustainable energy harvesting from medical waste: Utilizing discarded ointment tubes in triboelectric nanogenerators

In recent years, wearable technology designed for tracking human motion has garnered significant interest. In this study, we developed a wire-structured triboelectric nanogenerator (W-TENG) incorporating polytetrafluoroethylene and nylon wires, designed for both mechanical energy harvesting and real-time monitoring of jumping motion. The rough-textured, wear-resistant triboelectric layers enhance durability and lifespan. Unlike thin-film counterparts, the wire-based structure adapts better to dynamic deformations, ensuring robustness and efficiency. The W-TENG achieved outstanding performance metrics, including an open-circuit voltage (VOC) of 847 V, a short-circuit current (ISC) of 80 μA, and a transferred charge (QSC) of 165 nC, with a peak output power of 4.56 mW at an optimal load resistance of ∼60 MΩ. With its high sensitivity and precision, the W-TENG enables detailed posture monitoring during jumping activities, effectively capturing lower-limb dynamics, such as take-off, mid-air motion, and landing impact. The W-TENG effectively tracks voltage fluctuations from jump intensities, optimizing performance, assessing landing stability, and preventing injuries. This versatile, sustainable sensor advances energy harvesting and jumping motion sensing in fitness, sports science, and rehabilitation.

Hybrid harvesting of wind and wave energy based on triboelectric-piezoelectric nanogenerators

The conversion of water energy into sustainable electricity has attracted more and more attention. Conventional water energy harvesting technologies are limited by manufacturing materials and output performance. The triboelectric nanogenerator (TENG) shows good performance in mechanical energy harvesting, while it has a relatively low short-circuit current and large inherent impedance. A novel high DC current output salt battery (SB) hybrid and enhanced by TENG (DC-SBHET) is proposed in this paper. The high open-circuit voltage generated by TENG can accelerate the velocity of mobile ions in the SB. The combination of TENG and SB can successfully increase the DC short- circuit current up to 18.1mA. Nano-foam electrodes were also chosen to further increase the battery performance.

Water wave energy is a promising renewable energy source that may alleviate the rising concerns over current resource depletion, but it is rarely exploited due to the lack of efficient energy harvesting technologies. In this work, a hybrid system with a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG) based on an optimized inner topological structure is reported to effectively harvest water wave energy. The TENG with etched polytetrafluoroethylene films and Cu electrodes utilizing the contact‐freestanding mode is designed into a cubic structure, in which the EMG is well hybridized. An integration of TENG and EMG achieves mutual compensation of their own merits, enabling the hybrid system to deliver satisfactory output over a broad range of operation frequency. The output performance of TENG with varied inner topological structures is experimentally and theoretically compared, and a concept is proposed to further clarify the energy conversion efficiency, which should be considered in designing energy harvesting devices. The influences of oscillation frequency, amplitude, and dielectric materials on the output performance of the hybrid system are comprehensively studied on different platforms. Furthermore, the optimum operation frequency ranges for TENG and EMG are concluded. The proposed hybrid nanogenerator renders an effective approach toward large‐scale blue energy harvesting over a broad frequency range.

Environmental degradation and the depletion of fossil fuels have emerged as pressing issues that must be addressed for progressing sustainable life. Reducing the usage of the fossil fuels and exploring different eco-friendly resources and energy are in highly valued. The abundant mechanical energy is the most promising source of accessible alternative energy in our daily lives. Harvesting energy from bodily movements such as running, jogging, shaking, and so on enabled to power low-power electronics using nanogenerators (NGs) and has recently emerged as an important area of study due to their diverse applicability in practical scenarios. To obtain highest mechanical energy optimization and greater voltage outputs from NGs, scientists all over the globe have put forward potential options of hybrid NGs with numerous and unique designs utilizing a combination of more than one of the following pyroelectric, triboelectric, piezoelectric, thermoelectric, and other NGs. In large-scale operations, hybridization of NGs has proven to be an effective approach for mechanical energy harvesting and sensing applications. This book chapter focuses on major types of NGs for energy harvesting, such as piezoelectric NG (PENG), triboelectric NG (TENG), and hybrid NGs. The emphasis is primarily on the fundamental working mechanisms of three types of NGs, newly developed materials, and typical applications for energy harvesting in fields such as wearable and human monitoring, implementable devices, and artificial intelligence. Finally, we summarize recent advancements in this field and describe future opportunities for improving energy harvester performance.

The design of energy harvesting (EH) scheme is one of important issues in energy-constrained relaying networks. Since most of the existing EH schemes assume a linear EH model, which cannot capture the properties of EH circuits, the EH schemes dedicated for a practical EH model should be redesigned. Based on the time switching (TS) and power splitting (PS) receiver architectures, we study two EH schemes, namely, PS scheme and TS scheme, in an amplify-and-forward (AF) energy-constrained relaying network under a non-linear EH model. Two problems are formulated to maximize the achievable throughput based on the instantaneous channel state information by optimizing the PS ratio and TS ratio, respectively. The solutions for both EH schemes are obtained. Numerical results are presented to show that the designed EH schemes based on the non-linear EH model are able to achieve a higher throughput than those based on the existing linear model. It is found that employing a non-linear energy harvester instead of the linear one into AF relaying network, and the PS scheme still outperforms the TS scheme in general.

Triboelectric nanogenerators (TENGs) are emerging as a sustainable and environmentally friendly approach for energy harvesting and self-powered sensing, because of their diverse material options, simple structure, and efficient energy conversion. However, developing tribopositive materials with both high-charge-inducing and high-charge-trapping capabilities remains a significant challenge. Herein, a high-performance TENG is developed based on a polyaniline (PANI) embedded polyacrylonitrile (PAN) nanofiber membrane (NM) (P/P NM) for energy harvesting and self-powered wireless sensing. The incorporation of PANI significantly enhanced the electrical performance, mechanical properties, and thermal stability of P/P NMs. The P/P NM-based TENG achieved an output voltage of 726 V, a short-circuit current density of 32 μA/cm2, and a peak power density of 23.3 W/m2, which were approximately 2.3, 3.6, and 4.6 times higher than those of the pristine PAN NM-based TENG, respectively. Detailed investigations revealed that the embedded PANI improved the electron-donating ability and dielectric constant (by 4.25 times) of P/P NMs, thereby significantly boosting the electrical output of the TENG. The mechanical energy harvesting ability was elucidated through capacitor charging and the operation of low-power devices. Furthermore, the P/P NM-based TENG was integrated into a self-powered wireless sensing system, which enabled the cross-scale monitoring of human signals ranging from tiny pulses to large-scale movements. The introduction of PANI nanofillers provides a simple, effective, and scalable strategy for developing high-performance positive tribomaterials, thus, advancing the practical application of TENGs in energy harvesting and self-powered sensing.

The growing demand for sustainable and distributed energy solutions has driven increasing interest in triboelectric nanogenerators (TENGs) as platforms for energy harvesting and self-powered sensing. Biowaste-based triboelectric nanogenerators (BW-TENGs) represent an attractive strategy by coupling renewable energy generation with waste valorization under the principles of the circular bioeconomy. This review provides a comprehensive overview of BW-TENGs, encompassing fundamental triboelectric mechanisms, material categories, processing and surface-engineering strategies, device architectures, and performance evaluation metrics. A broad spectrum of biowaste resources-including agricultural residues, food and marine waste, medical plastics, pharmaceutical waste, and plant biomass-is critically assessed in terms of physicochemical properties, triboelectric behavior, biodegradability, biocompatibility, and scalability. Recent advances demonstrate that BW-TENGs can achieve electrical outputs comparable to conventional synthetic polymer TENGs while offering additional advantages such as environmental sustainability, mechanical compliance, and multifunctionality. Key application areas, including environmental monitoring, smart agriculture, wearable and implantable bioelectronics, IoT networks, and waste management systems, are highlighted. The review also discusses major challenges limiting large-scale deployment, such as material heterogeneity, environmental stability, durability, and lack of standardization, and outlines emerging solutions involving material engineering, hybrid energy-harvesting architectures, artificial intelligence-assisted optimization, and life cycle assessment frameworks.

Highly electronegative borophene/PVDF composite hybrid nanofibers based triboelectric nanogenerator for self-powered sensor for human motion monitoring and energy harvesting from rain

A one-structure-layer PDMS/Mxenes based stretchable triboelectric nanogenerator for simultaneously harvesting mechanical and light energy

Exploring liquid-solid interface based triboelectrification, structures, and applications

Constructing a micro-water energy-harvesting system for the power supply of micro-nano sensors in pipeline liquid transmission networks is of great significance. In this study, a micro water energy harvesting system based on a tubular triboelectric nanogenerator was designed, which achieves efficient energy harvesting and conversion by directly collecting the charge of the friction layer without the electrostatic induction effect. First, the working principle of the liquid–solid triboelectric nanogenerator is analyzed based on multi-physic coupling, and the potential distribution in the charge transfer process is analyzed. Second, the effects of liquid flow, pipe length, inner diameter, and material on the output characteristics of the triboelectric nanogenerator were investigated. Finally, the load power supply characteristics of the triboelectric nanogenerator were presented. The output characteristics of the liquid–solid triboelectric nanogenerator were proportional to the flow rate and inversely proportional to the inner diameter of the pipe. The output power of the liquid–solid triboelectric nanogenerator can be charged and stored by the capacitor through the rectifier bridge, and at least 30 LED lamp beads can be driven at a flow rate of 650 ml·min-1. This research has the potential to be applied to the construction of self-powered liquid-state monitoring intelligent sensors in pipeline networks.

Energy harvesting technologies, which scavenge and capture various types of abandoned energies from an ambient environment, have grown more comprehensive and crucial as they play a role to power the emerging mobile electronic systems and micro devices. Lots of energy harvesting technologies have been successfully demonstrated and explored based on photovoltaic effect, piezoelectric effect, electromagnetic effect and so forth. Recently, the eminent concept of the triboelectric nanogenerator (TENG), where operation mechanism is coupling of triboelectricity and electrostatic induction, has been proposed. The TENG is mainly composed of 1) the contact layer, where the triboelectric effect occurs, and 2) the electrode layer inducing movement of the electrical charges to generate electric current and power. Since its first demonstration, the TENG has been proven as one of the promising energy harvesting platforms due to its high accessibility, low manufacturing cost and high energy conversion efficiency compared with the other existing energy harvesting platforms. With those advantageous aspects, so far, the TENG has been widely applied to versatile applications such as biomedical monitoring system, self-powered sensor and portable power supply to drive wearable electronics. As above mentioned, although lots of potential applications of TENGs have been successfully demonstrated, for their reliable utilization as a practical power source, the electrical output performance of TENGs still needs to be further increased. From this point of view, enhancing the electrical output performance of the TENG has been one of the important issues in research fields from its first proposal to present. The simplest and most powerful way to enhance the electrical output performance of the TENG is based on formation of micro/nanoscale surface topographies on its contact layer inducing localized concentration of contact forces, which generates higher electrical charge amounts on its surface. As well as formation of topographies on its external surface, recently, the concept of modifying internal molecular arrangement has been suggested. For example, the synthesis of material where important derivatives are carbon increased the interface for charge storage by acting charge trapping sites. On top of that, the alignment of positive and negative charges referred to as poling process has been reported. During this poling or dipolar alignment, a large electric potential is applied across the material which induces the alignment of dipole and production of net positive charge. To be detailed, the maximized surface charge and charge difference between upper and bottom surface of material can produce the developed electrical energy compared with that of non-aligned material. In this respect, it has been considered as a potent strategy to increase the energy output of the TENG. Previously, we reported the one-step simple method to fabricate the advanced energy output TENG by using nanoimprinting process. Through thermal nanoimprint process, there are obvious advantages in terms of increasing energy output of the TENG, and practical commercialization. Firstly, the energy output of the TENG can be enhanced due to the formation of nano topographies on the contact layer of thermoplastic fluoropolymer. Secondly, in viewpoint of commercialization, the thermal nanoimprint is one-step fabrication, with coincidently replication of nano structure and integration of contact later with the electrode layer which are essential prerequisite components of TENG. Besides these merits, low cost and mass producible nanofabrication process present the application of practical commercialization. In this study, we first introduced the innovative strategy which is coupling process between nano imprint and poling process to maximize the electrical energy output performance of TENG based on the formation of nano-topographical surface on contact layer and modulation of the internal dipole moments of ferroelectric thermoplastic polymer. The most remarkable novelties are shown that energy output of TENG can be enhanced by achieving the alignment of dipole moments of polymer while taking advantages of fabricating the TENG by using the nanoimprint process. In aspects of the modulation of internal moments, the degree of alignment dipole moments is higher than when the conventional poling method is used. Compared with the conventional poling process, the method we suggested has distinct advantages. Given that the flexibility of thermoplastic polymer increased due to the elevated temperature, the alignment of dipole moments can be achieved more effectively. In addition, the electric field concentrated on each nano structure contributes to obtain the high portion of dipole moments alignment due to their higher electric field in comparison with when the electrode which has no nano-topograpies on surface is used to poling process. Lastly, based on these effects, the overall poling period is much shorter than that of conventional poling. Figure 1