Triboelectric Nanogenerator Research Articles

Enhanced Positive Charge Performance in Triboelectric Series: Molecular Engineering of Conjugated Mesoporous Fibers for Machine Learning-Based Wearable Sensors.

With the increasing focus on triboelectric-based sensors, research on synthesizing dielectric layers from specific substances is gradually emerging. Despite numerous negatively-charged triboelectric materials, there is a scarcity of synthesizable positively-charged materials, creating a research gap. This study demonstrates the molecular design of a conjugated, mesoporous, self-assembled sheet via bottom-up synthesis. The synthesized sheet is functionalized to create a triboelectric nanogenerator. Its large specific surface area, softness, and internal space increase the actual contact area and provide adsorption sites for polypyrrole nanoparticles. The incorporation of -COO functional group enhances positive triboelectric performance, forming a dielectric layer with charge-trapping capabilities. When contact with polytetrafluoroethylene (PTFE), this structure boosts the output voltage, showing significant amplification after charge injection with minimal decay. As a demonstration, the bilayer structure is applied as a touchpad on the experimenter's arm to write symbols. The signals are input into an innovative machine-learning model to interpret the writer's intent. Additionally, the device connects to a terminal for real-time medical services, suggesting practical applications for wearable triboelectric sensors with artificial intelligence.

Advances in Intelligent Sports Based on Triboelectric Nanogenerators

In the realm of intelligent sports, the integration of triboelectric nanogenerators (TENGs) marks a transformative approach toward energy sustainability and more advanced athletic monitoring. By leveraging the principle of triboelectricity, TENGs ingeniously convert mechanical energy from athletes’ movements into electrical energy, which offers a green and efficient power solution for wearable technology. This paper presents an innovative study on the application of TENG technology in sports science, with the results illustrating the potential utility of TENGs in revolutionizing the way we monitor, analyze, and enhance athletic performance. Through the development of self-powered wearables and equipment, TENGs facilitate real-time data collection on physiological and biomechanical parameters, ultimately enabling personalized training adjustments and injury prevention strategies. Our findings underscore the dual benefit of TENGs in promoting environmental sustainability by reducing the overall reliance on traditional energy sources and growing the capabilities of intelligent sports systems. This research contributes to the burgeoning field of nano-energy sports applications while setting the stage for future explorations into the optimization of TENG integration in athletic performance enhancement. Finally, the paper concludes by discussing remaining challenges in this area and opportunities for further research.

Conductive, biodegradable multi-array smart bandage for gesture recognition and motion detection

Triboelectric nanogenerator (TENGs), which are capable of capturing high-entropy energy dispersed in the environment and converting it into electricity, have received significant attention for their potential as power sources for sensing networks and wearable portable electronics. Conventional triboelectric materials have serious limitations, which can be overcome by using nanostructured materials. Conductivity and semiconductor nanomaterials have been extensively studied as active components for this type of application, but need to be coupled to an elastic matrix, in order to be functional in flexible technologies. In this study, we prepared MWCNTs/PEO (MCP) films with conductive and biodegradable properties. MCP can be used as conductive ink printed on flexible substrates to fabricate flexible circuits. MCP is utilized as a high-performance positively charged material to construct a TENG (KMCP-TENG) with a maximum power density of 593 mW/m2. Furthermore, MCP can be degraded and recycled, and the output performance of the KMCP-TENG prepared using recycled MCP reaches 90 % of the original TENG. Additionally, the multi-array smart bandage (MASB) is designed and fabricated based on KMCP-TENG, which exhibits high sensitivity and stability. This MASB offers broad applications in health monitoring, motion tracking and human–computer interaction.

Analysis and Application of Poly(vinyl alcohol) (PVA) and Polyacrylonitrile (PAN) Nanofiber Membrane-Based Triboelectric Nanogenerators.

The triboelectric property of materials is used to harvest energy from intentional or nonintentional sources of vibration. Contact mode freestanding dielectric based nanogenerators (CFTENGs) have many advantages when compared with other modes of triboelectric nanogenerators. The property of dielectric materials plays an important role in the energy harvesting process. In this work, we aim to fabricate nanofiber membranes of poly(vinyl alcohol) (PVA) and polyacrylonitrile (PAN) and study their properties for CFTENGs. The morphology and porosity of both membranes were tested experimentally. The mechanical property is modeled with a representative volume element (RVE) technique to understand its deflection behavior. In addition, an electromechanical model is developed to predict and analyze the behavior of those membranes in the energy conversion process. Our research reveals that the PAN dielectric layer achieves a maximum open circuit voltage of 192 kV compared to the PVA dielectric layer (2.2 kV) in the CFTENG system. In comparison, the dielectric layer of the PAN nanofiber membrane reflects its flexibility to generate electrical energy in a CFTENG with the effect of contact electrification and electrostatic induction under various sources of unused energies for a wide range of applications. Moreover, the same methodology is applied to various sources of vibration, and their performance is reported. With an appropriate power management circuit, we can design a PAN membrane-based TENG for various applications.

Oxime-Based Dielectric Polymer with Robust Tailored Cross-Linking for Self-Healing Triboelectric Nanogenerators

Oxime-Based Dielectric Polymer with Robust Tailored Cross-Linking for Self-Healing Triboelectric Nanogenerators

High Performance Rotary Triboelectric Nanogenerator in Weak Wind Conditions through Soft Contact Utilization

High Performance Rotary Triboelectric Nanogenerator in Weak Wind Conditions through Soft Contact Utilization

Aurivillius-Type SrBi4Ti4O15/PGA Composite Film-Based Flexible Triboelectric Nanogenerators for Energy Harvesting/Storage and Multipurpose Tap-Indication Transducer Applications.

Recent advancements in flexible triboelectric nanogenerators (TENGs) have widely focused on converting mechanical energy into electrical energy to power small wearable electronic gadgets and sensors. To effectively achieve this, an efficient energy-converted power management circuit is required. Herein, we report on Aurivillius-type strontium bismuth titanate (SrBi4Ti4O15) nanoparticles (SBT NPs)-loaded polyglucosamine (PGA) composite film-based flexible TENG to be used for energy harvesting/storage and biomechanical applications. Initially, SBT NPs were synthesized and then, different weight concentrations were loaded into PGA. The TENG devices were fabricated using different wt % composite films (SBT/PGA) and polydimethylsiloxane as positive and negative triboelectric layers, respectively, and aluminum was used as a conductive electrode attached to two tribo films. To evaluate the electrical output from the device, contact-separation operation mode was used. An optimized TENG consisting of 2 wt % SBT/PGA composite film produced the maximum electrical output voltage and current of approximately ∼239 V and ∼7.5 μA, respectively. Efficient TENG energy harvesting and storage circuits have been proposed for storing charges in capacitors and for operating electronic gadgets. The optimized TENG was employed to generate electrical energy from various biomechanical movements. Thereafter, the biodegradability of the composite film was also tested. The fabricated films were completely biodegraded within a few hours. Furthermore, the TENG was utilized as a tap-indication transducer for multipurpose switching applications.

A Triboelectric Nanogenerator Based on TPU/MXene/Carbon for Heart Rate and Tai Chi Posture Monitoring

AbstractRecently, the electronic skin (E‐skin) based on triboelectric nanogenerators (TENGs) has exhibited enormous potential in smart sports. However, TENGs device installed on human body usually faces challenges in complex mechanical environments. Here, we proposed a flexible TPU/MXene/carbon conductive electrode and combined with PDMS to prepare triboelectric nanogenerator (PT‐TENG) to harvest mechanical energy. Moreover, to demonstrate the application of PT‐TENG in smart sports, we can use it to monitor the posture changes of human joints during Tai Chi exercise and heart rate. The transfer charge (Qsc) of PT‐TENG can arrive at 104.65 nC, which is superior to the output performance produced by using traditional metal aluminum foil to prepare TENG device. The PT‐TENG can obtain the maximum output power of 132.34 μW under the working frequency 2 Hz. The experimental results show that PT‐TENG installed on the fingers, wrists, and knees of the human body can effectively perceive the bending angle of joints, which is very meaningful for evaluating the posture of movements in Tai Chi training. This research provide an effective path to promote the application of the self‐powered E‐skin based on TENG device on the smart sport field.

Recent Advances in Flexible Self-Powered Sensors in Piezoelectric, Triboelectric, and Pyroelectric Fields

The rise of the Internet of things has catalyzed extensive research in the realm of flexible wearable sensors. In comparison with conventional sensor power supply methods that are reliant on external sources, self-powered sensors offer notable advantages in wearable comfort, device structure, and functional expansion. The energy-harvesting modes dominated by piezoelectric nanogenerators (PENGs), triboelectric nanogenerators (TENGs), and pyroelectric nanogenerators (PyENGs) create more possibilities for flexible self-powered sensors. This paper meticulously examines the progress in flexible self-powered devices harnessing TENG, PENG, and PyENG technologies and highlights the evolution of these sensors concerning the material selection, pioneering manufacturing techniques, and device architecture. It also focuses on the research progress of sensors with composite power generation modes. By amalgamating pivotal discoveries and emerging trends, this review not only furnishes a comprehensive portrayal of the present landscape but also accentuates avenues for future research and the application of flexible self-powered sensor technology.

Frequency Detection for String Instruments Using 1D-2D Non-Contact Mode Triboelectric Sensors.

The proliferation of small electronic devices has significantly increased the demand for self-powered sensors. This study introduces a triboelectric frequency sensor (TFS) that combines the frequency-responsive characteristics of triboelectric nanogenerators with a simple one-dimensional structure for sustainable vibration measurement. This sensor is specifically designed to aid in the tuning of string instruments, capable of detecting frequency responses up to 330 Hz generated by string vibrations. Structural optimization was achieved by setting a non-contact mode with a gap distance of 3 mm and utilizing perfluoroalkoxy alkane (PFA) as the contact dielectric material. The TFS exhibits dynamic response characteristics by varying the vibrating frequency and the tension of the string, facilitated by a custom-built testing setup. Frequency data captured by the sensor can be visualized on a monitor through the integration of a microcontroller unit (MCU) and dedicated coding. The practical applicability and effectiveness of this sensor in real-world scenarios are demonstrated experimentally. This innovation represents a significant step forward in the development of self-sustaining sensing technologies for precision instrument tuning.

A True Random Number Generator Design Based on the Triboelectric Nanogenerator with Multiple Entropy Sources.

The triboelectric nanogenerator (TENG) has the potential to serve as a high-entropy energy harvester, enabling the self-powered operation of Internet of Things (IoT) devices. True random number generator (TRNG) is a common feature of encryption used in IoT data communication, ensuring the security of transmitted information. The benefits of multiplexing TENG and TRNG in resource-constrained IoT devices are substantial. However, current designs are limited by the usage scenarios and throughput of the TRNG. Specifically, we propose a structurally and environmentally friendly design based on the contact-separation structure, integrating heat fluctuation and charge decay as entropy sources. Furthermore, filtering and differential algorithms are recommended for data processing based on TENG characteristics to enhance randomness. Finally, a TENG-based TRNG is fabricated, and its performance is verified. Test results demonstrate a random number throughput of 25 Mbps with a randomness test pass rate approaching 99%, demonstrating suitability for resource-constrained IoT applications.

Thermal-driven self-healing and recyclable thermosetting polyurethane resins for energy harvesting

Improving the mechanical properties, self-healing capabilities, and recyclability of friction layer materials is crucial for the advancement of high-performance triboelectric nanogenerators (TENG). In this study, self-healing cross-linked polyurethanes were synthesized through the prepolymer technique, employing the Diels-Alder (D-A) reaction between the furan ring and Bismaleimide (BMI). The tensile strength of PU film with 10 wt% MBI is 54 MPa, and the shape recovery rate is 96.99 %. Moreover, it exhibits excellent self-healing and recyclable characteristics. Surface cracks can be healing within 10 min under heat, reshaped through hot pressing, while retaining 93.3 % of its mechanical properties. Additionally, the 2 cm × 2 cm area PU-based TENG can generate a short-circuit current, open-circuit voltage, transferred charge, and power density of 3.6 μA, 89 V, 29 nC, and 2.5 W/m2, respectively, at a frequency of 1 Hz. Futhermore, the self-healing efficiency of mechanical properties and the triboelectric output performances were found to reach 93.3 % and 98 %, respectively, after reprocessing. This study introduces a promising method for enhancing self-healing, shape memory characteristics, and the design of wearable TENG devices.

Bio-inspired vibration isolator with triboelectric nanogenerator for self-powered monitoring

Vibration isolators are used in many engineering projects, but their real-time monitoring and early warning still a challenge. This paper presents a novel bio-inspired vibration isolator with triboelectric nanogenerator (BVI-TENG), which can be applied on vibration isolation and structural health monitoring. To find the optimal combination of parameters to achieve quasi-zero stiffness, the relationships between the force–displacement and the stiffness-displacement are investigated. After establishing the dynamic model, the effects of the different parameters on the amplitude-frequency are explored by using the harmonic balanced method. To explore the vibration isolation performance, the force transmissibility is analyzed. It was found that BVI-TENG can isolate the low-frequency and even ultra-low frequency vibration. By setting up and testing the experimental prototype, the theoretical results are verified. The energy harvesting performance of BVI-TENG is investigated by analyzing the output current, output voltage and transfer charge under different frequency. By tuning the loading resistance, the maximum output power of BVI-TENG is found. More importantly, the structural health monitoring part of the BVI-TENG produces AC signal in the safe region, which can be harvested and stored, and the signal transforms immediately into DC signal when out from this region. The performances demonstrate that the BVI-TENG can be applied to vibration isolation and serves as a self-powered structural health monitoring device to meet the needs of the civil engineering, ocean platform, and industrial robot.

Highly Porous, Ultralight, Biocompatible Silk Fibroin Aerogel-Based Triboelectric Nanogenerator.

This study presents the fabrication of an ultralight, porous, and high-performance triboelectric nanogenerator (TENG) utilizing silk fibroin (SF) aerogels and PDMS sponges as the friction layer. The transition from two-dimensional film friction layers to three-dimensional porous aerogels significantly increased the specific surface area, offering an effective strategy for designing high-performance SF aerogel-based TENGs. The TENG incorporating the porous SF aerogel exhibited optimal output performance at a 3% SF concentration, achieving a maximum open circuit voltage of 365 V, a maximum short-circuit current of 11.8 μA, and a maximum power density of 7.52 W/m2. In comparison to SF-film-based TENGs, the SF-aerogel based TENG demonstrated a remarkable 6.5-fold increase in voltage and a 4.5-fold increase in current. Furthermore, the power density of our SF-based TENG surpassed the previously reported optimal values for SF-based TENGs by 2.4 times. Leveraging the excellent mechanical stability and biocompatibility of TENGs, we developed an SF-based TENG self-powered sensor for the real-time monitoring of subtle biological movements. The SF-based TENG exhibits promising potential as a wearable bioelectronic device for health monitoring.

Robust Ag-Co bimetallic nanoparticles: Dual role in catalytic and triboelectric performance

Bimetallic nanoparticles are of great significance in numerous areas due to their unique properties and diverse applications. In the present study, silver (Ag) and cobalt (Co) monometallic nanoparticles (MNPs) and AgCo bimetallic nanoparticles (BNPs), are synthesized using a simple wet chemical route. Various analytical techniques are adopted for the confirmation of the BNPs. Powder X-ray diffraction (PXRD) analysis revealed the formation of FCC-structure. Transmission Electron Microscopy (TEM) micrographs confirmed the bimetallic nature and Janus structure. The synthesized nanoparticles exhibit higher catalytic activity for degrading 4-nitrophenol dye. Recognizing the potential of metal nanoparticles to significantly boost the efficiency of triboelectric nanogenerators (TENG), the synthesized AgCo bimetallic nanoparticles are incorporated into polymer matrix to meticulously analyze the impact on the triboelectric performance. Interestingly, TENG with a higher composite quantity of 8 ml BNPs exhibited greater performance, generating an output voltage of about 270.52 V and a current of 5.24 µA. Hence, the procured synergistic BNPs show their promising avenue towards both water treatment and energy harvesting applications.

Van der Waals interactions enhanced multiple-times all-waste-recycled triboelectric nanogenerator for ultra-high lifetime stability

To mitigate the ever-increasing waste problem, utilization of recycled waste to fabricate energy harvesting devices has emerged as a propitious alternative. Despite several efforts, it is still a daunting challenge to sustain the properties of recycled-plastic-waste after multiple rounds of recycling. We address the above challenges by developing an industry-viable universal framework to recycle plastic-waste multiple-times without significant degradation in its properties. A multiple-times all-recycled triboelectric nanogenerator (MR-TENG) was demonstrated with high performance and record-high overall operational lifetime stability for 5 million cycles of mechanical impact. To the best of our knowledge, this is the first report of a nanogenerator made completely from recycled mixed-plastic-waste, which can sustain its energy-harvesting performance even after ten rounds of recycling. The multiple-times recyclability can be attributed to the improved van der Waals interactions between the polymeric blends at the macromolecular level facilitated by incorporating a mixed-plastic waste-derived compatibilizing agent, which is validated by molecular dynamics simulation. The adopted industry-viable reactive extrusion to fabricate the materials facilitates easy adaptability and commercialization. The practical application was demonstrated by utilizing it for deep learning-enabled MR-TENG-based advanced cognitive waste sorting and segregation, facilitating digitalized-waste-management, thus facilitating a major step towards upcycling of plastic-waste for circular economy.

A self-integration via dual-active mode structural-SC-TENG energy device for electrochemical energy storage and triboelectric energy harvesting

The structural supercapacitor with triboelectric nanogenerator (structural-SC-TENG) is a remarkable integrated energy device utilized for clean energy storage and harvesting. Here, we demonstrated the structural-SC-TENG device based on a multifunctional storage and harvester using dual-functional MoO3 grown on a carbon cloth electrode (CC) via hydrothermal technique and physiochemical characterization revealed the formation of an orthorhombic phase of MoO3. The FE-SEM morphological analysis confirms that the cubes-like peals were uniformly decorated on the CC surface in an upward and downward direction. The dual-functional MoO3 grown on the CC electrode was used for the construction of the supercapacitor and TENG device which will act as a charge-storing electrode in the supercapacitor and charge-sharing electrode in TENG. The constructed MoO3 SSC provides an excellent device capacitance of 97.86 F g−1, energy density of 40.50 Wh kg−1, and a high-power density of 28,125 W kg−1 with remarkable cyclic life modeled/predicted via time series analysis (TSA) technique. On the other side, the TENG device constructed using MoO3 on CC as the positive electrode (confirmed through KPFM analysis) and PDMS as the negative electrode exhibited a better electrical response with a high voltage and current of 55 V and 0.19 μA and delivered a peak power of 4.17 μW. This type of integrated device is splendid and possibly be used for self-powered sensors, smart IoTs, self-charging power systems, low-power electronics, and various indoor/outdoor environments.

High-output solid[sbnd]liquid triboelectric nanogenerator enhanced by the regulation of interfacial wettability

Triboelectric nanogenerators (TENGs), as a new strategy for harvesting energy from nature, have attracted widespread attention in the field of water droplet energy capture. As a friction layer material, the solidliquid electrification phenomenon of coatings has been studied. However, little attention is paid to the influence of the surface wettability of the coating itself on the electrical signal of the droplet generator. In this study, alkyl/phenyl pure silicone resin was utilized as a substitute for fluorine-containing polymer materials. This substitution not only mitigated the risk of environmental pollution from TENG friction materials but also resulted in varying wettability of the silicone resin coating through plasma and surface structure treatment. The droplet-based Double-electrode (D-TENG) and Single-electrode (S-TENG) coating-based triboelectric nanogenerators were fabricated. Through the integration of a high-speed camera and ammeter, the motion state of water droplets on surfaces with different wettability closely correlates with their charged behavior. This correlation is utilized to observe the motion state of water droplets on hydrophilic-hydrophobic surfaces in four stages: contact, spreading, contraction, and sliding. Under the double-electrode structure, as the water contact angle of the coating increased from 6.84° to 139.77°, the short-circuit current initially increased and then decreased, peaking at 466 µA when the contact angle was 98.48°, representing a 677-fold increase from the initial 0.689 µA. In the single electrode structure, the short-circuit current increased from 2.66 nA to 700 nA, indicating a 263-fold increase. Studying the varied wettability of the surface of silicone resin coating aids in comprehending the application of the coating material in solid-liquid friction electrification for energy collection. Furthermore, it offers insight into selecting appropriate coating materials for friction coatings in future applications.

Bio-based polyurethane triboelectric nanogenerator with superior low-temperature self-healing performance for unmanned surveillance

Damaged flexible triboelectric nanogenerators face difficulties in autonomous healing at low temperatures, limiting their application range. Impeded dynamic network reconstruction presents a challenge in developing materials for autonomous low-temperature healing. This study constructed a multi-dynamic network utilizing both strong and weak hydrogen and disulfide bonds to develop a biobased polyurethane elastomer (PBES-U, prepared from biobased monomers such as itaconic acid, sebacic acid, etc.), featuring a cross-linked network capable of cryogenic self-healing, superior toughness, and reprocessability. This elastomer extends to 1100 % of its original length, achieving 90 % self-healing efficiency at temperatures down to −10 °C due to the low glass transition temperature (Tg, −30 ℃) achieved by modulating the flexibility of chain segments. Consequently, a bio-based TENG (LS-TENG) was produced using this elastomer as a positive friction layer through a dynamic interfacial interlocking method. The results reveal that LS-TENG achieves a notable power density of 12.2 mW/m2, an output voltage reaching 160 V, and a 98 % output voltage recovery post-low-temperature self-healing. Furthermore, a non-contact LS-TENG-based monitoring system was developed with significant potential for applications in battlefield sensing, wildlife monitoring, and intelligent driving.

Directional Adaptive Triboelectric Nanogenerator with Wind-Wave Synergy.

To enhance the adaptability and synergy of the triboelectric nanogenerator (TENG) in a wave environment, this paper introduces a directional adaptive triboelectric nanogenerator (DA-TENG) with wind-water synergistic action for wave energy collection. An innovative design combining a wind vane on the top and fan-shaped blade electrodes internally allows the DA-TENG to adjust its swinging direction adaptively to align with the direction of wave motion. The internal multiple power generation units work in coordination, effectively addressing the issues of low efficiency associated with spherical TENGs in capturing multidirectional wave energy. The DA-TENG demonstrates superior performance under various wind speed conditions, showcasing its practical application potential. Experimental results show that the DA-TENG, equipped with a single tail wind vane and a 700 g mass block, can achieve an output voltage, current, and charge of 374.97 V, 84.77 μA, and 622.69 nC under a mild wind environment. Its peak power density reaches 7.51 W m-3, enabling successful data transmission for a wireless temperature and humidity sensor and powering 248 light-emitting diodes (LEDs). This research expands the possibilities of omnidirectional wave energy collection and the collaborative operation of multiple power generation units, offering an effective method for powering low-power maritime devices.