Output Power Of Triboelectric Nanogenerator Research Articles

Bulk Schottky Junctions-Based Flexible Triboelectric Nanogenerators to Power Backscatter Communications in Green 6G Networks.

This work introduces a novel method to construct Schottky junctions to boost the output performance of triboelectric nanogenerators (TENGs). Perovskite barium zirconium titanate (BZT) core/metal silver shell nanoparticles are synthesized to be embedded into electrospun polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) nanofibers before they are used as tribo-negative layers. The output power of TENGs with composite fiber mat exhibited >600% increase compared to that with neat polymer fiber mat. The best TENG achieved 1339V in open-circuit voltage, 40µA in short-circuit current and 47.9Wm-2 in power density. The Schottky junctions increased charge carrier density in tribo-layers, ensuring a high charge transfer rate while keeping the content of conductive fillers low, thus avoiding charge loss and improving performance. These TENGs are utilized to power radio frequency identification (RFID) tags for backscatter communication (BackCom) systems, enabling ultra-massive connectivity in the 6G wireless networks and reducing information communications technology systems' carbon footprint. Specifically, TENGs are used to provide an additional energy source to the passive tags. Results show that TENGs can boost power for BackCom and increase the communication range by 386%. This timely contribution offers a novel route for sustainable 6G applications by exploiting the expanded communication range of BackCom tags.

Nano Groove and Prism-Structured Triboelectric Nanogenerators.

Enhancing the output power of triboelectric nanogenerators (TENGs) requires the creation of micro or nano-features on polymeric triboelectric surfaces to increase the TENGs' effective contact area and, therefore, output power. We deploy a novel bench-top fabrication method called dynamic Scanning Probe Lithography (d-SPL) to fabricate massive arrays of uniform 1 cm long and 2.5 µm wide nano-features comprising a 600 nm deep groove (NG) and a 600 nm high triangular prism (NTP). The method creates both features simultaneously in the polymeric surface, thereby doubling the structured surface area. Six thousand pairs of NGs and NTPs were patterned on a 6×5 cm2 PMMA substrate. It was then used as a mold to structure the surface of a 200 µm thick Polydimethylsiloxane (PDMS) layer. We show that the output power of the nano-structured TENG is significantly more than that of a TENG using flat PDMS films, at 12.2 mW compared to 2.2 mW, under the same operating conditions (a base acceleration amplitude of 0.8 g).

Output characteristics of series-parallel triboelectric nanogenerators

To tackle the problem of the low output power of triboelectric nanogenerators (TENGs), the output characteristics of multiple TENGs in series and parallel were explored. An experimental device for multilayer TENGs was developed. Through the method of experimental modeling, the equivalent circuits and mathematical models in series and parallel are established respectively, and the working principle is expounded. The experiment found that when multiple TENGs are connected in parallel, the voltage, current, and output power can be regularly increased. When the TENGs are connected in series, the output power is only related to the performance of the first and last two triboelectric generators and has nothing to do with the number of series-connected TENGs. This finding has a certain reference value for the design of high-efficiency triboelectric nanogenerators.

A nonlinear triboelectric nanogenerator with a broadened bandwidth for effective harvesting of vibration energy

A narrow resonance bandwidth of an energy harvesters limits its response to the wide frequency spectrum in ambient environments. This work proposes an addition of a nonlinear restoring force applied to a triboelectric nanogenerator (TENG) to tune and broaden the resonance bandwidth. This restoring force is applied by permanent magnets at both sides of the slider and two external magnets. The noncontact strategy is adopted between the slider and the grating electrodes to avoid the wear of electrodes and energy loss caused by friction. The results show that compared with the linear system, the nonlinear noncontact TENG (NN-TENG) can increase the peak current from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$6.3\ \mu\mathrm{A}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$7.89\ \mu\mathrm{A}$</tex> , with an increment of about 25%, increase the peak power from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$650\ \mu\mathrm{W}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$977\ \mu\mathrm{W}$</tex> , increasing by about 50%, and increase the bandwidth from 0.5 Hz to 7.75 Hz, increasing by about 1400%. This work may enable a new strategy to boost the bandwidth and output power of TENG through nonlinear oscillators.

Influence of mechanical motions on the output characteristics of triboelectric nanogenerators

Triboelectric nanogenerator (TENG) as an energy harvesting device, the output characteristics also affect its applications. Usually, the output characteristics of TENG are considered to be influenced by environmental factors, triboelectric materials, and surface morphology. Here we explore the output characteristics are also influenced by the mechanical motions of friction interfaces for the first time. And two new mechanical motions of TENG are proposed: coupling rotation contact-separation (CRCS) motion and independent rotation contact-separation (IRCS) motion. In addition, the output characteristics of TENG under different mechanical motions are investigated and revealed. It is a universal phenomenon that mechanical motions can affect the output characteristics of TENG verified by different types, different materials, and even different parameters of TENG. Compared with contact-separation (CS) motion, the transferred charges and output power of TENG under CRCS motion and IRCS motion realize 397%, 483% and 440%, 660% enhancement, respectively. Furthermore, the theoretical models describing dynamic charging and discharging under different mechanical motions are established. Finally, it is proved that changing mechanical motions can affect the collection of energy. This study provides a new factor to influence the output characteristics of TENG, which can guide the design and accelerate the practical applications of TENG.

A Hybrid Generator with Electromagnetic Transduction for Improving the Power Density of Triboelectric Nanogenerators and Scavenging Wind Energy

AbstractDue to the low output power of triboelectric nanogenerators (TENGs) in harvesting wind energy, this work proposes a hybridization scheme with electromagnetic generators (EMGs) to improve the power density of TENGs. Then, a novel configuration is designed and experiments of impedance matching and output power are conducted to compare the power density of triboelectric nanogenerators with/without electromagnetic generators under a wind speed of 5.5 m s−1. According to the experimental results, the power density of the hybrid generator is 29.8 times higher than that of the triboelectric nanogenerator without electromagnetic generators (TENG‐WEMGs). To further demonstrate the output performance of the hybrid generator, experiments of charging capacitors and powering electronics are implemented at the same wind speed. Based on the experimental results, a capacitor of 2.2 mF is charged to 25.7 V within 20 s, 170 LEDs are lit, and the Bluetooth tracker is driven to transmit signals in real time. In addition, this work investigates the influences of different resistant loads of EMG on the average power of TENGs. This work can be of great significance to further develop self‐powered sensors.

Dual output from unitary input for a hybrid coaxial triboelectric nanogenerator inspired by a crank engine

Energy conversion cannot be sufficiently achieved from a single output device having a single input. Energy conversion efficiency and output power of triboelectric nanogenerator (TENG) can be enhanced by increasing the contact area or the number of devices. Especially, combining two or more of the four operational mode (contact-separation, lateral sliding, single electrode, freestanding) of triboelectric nanogenerator would be more efficient to harvest mechanical energy than with singleharvesting mode. In this paper, a hybrid coaxial triboelectric nanogenerator (HC-TENG) can generate electrical output from dual outputs. This HC-TENG consists of a disk-TENG and LS-TENG so that a large current can be harvested from the rotating movement of disk-TENG at a high frequency input and an additional output can be generated from the LS-TENG by adding one axis. The structure of device with one axis was inspired by the structure of crank engine, which can convert linear motion into rotational motion. When applying the structure of HC-TENG to an application, the input-output efficiency was calculated by using the rotational kinetic energy formula with the value of 16.66%. Moreover, the efficiency of HC-TENG was verified by comparing experimental values with theoretical calculations for the presence of the dual outputs. This combination of multiple TENGs can be adopted for enhancing efficiency from every ambient rotational movement in real life.

Dynamical charge transfer model for high surface charge density triboelectric nanogenerators

Triboelectric nanogenerators have made great progress and paved the way for green energy, self-powered implantable medical devices and a large number of sensors in the Internet of Things. Maxwell's displacement current is the fundamental theoretical framework of nanogenerators. Quantum model of charge transfer between atoms have been devoted to understanding the triboelectric effect. Increasing the output power of triboelectric nanogenerators is one of the most important subjects for practical application. Here, we study the charge transfer process in triboelectric materials and propose a triboelectric material charge transfer dynamic model. Dynamic charge transfer enables triboelectric nanogenerators to achieve high surface charge density and the superior device robustness, which can significantly improve the output power and life time of triboelectric nanogenerators. The charge transfer model provides not only deeply understanding for high performance of triboelectric nanogenerator, but also a useful guide for the optimization and design of high performance triboelectric materials.

Managing and maximizing the output power of a triboelectric nanogenerator by controlled tip–electrode air-discharging and application for UV sensing

Using a switch has been verified as a promising strategy for managing and enhancing the output performances of a triboelectric nanogenerator (TENG). How to design a switch without external triggering is still a challenge. Here, a self-powered air discharge switch with a tip-plate configuration is developed, in which the switch's on/off state is controlled by the voltage of the TENG itself. The electric output of the TENG can be enhanced and modulated by changing the tip-plate distance of the switch. Compared with the same TENG without a switch, the instantaneous power peak and the total output energy on a load resistance lower than 2MΩ are increased by 1600 times and 31 times, respectively, as the switch works in an arc discharge mode. It is found that the UV light can change the switch from an arc discharge mode to a corona discharge mode, which increases the equivalent resistance of the switch and decreases the output current of the TENG. The current ratio of this UV detector reaches 18.6, and the lowest detectable light intensity is 26.2 μW/cm2. Using air discharge switch is a promising route for managing TENG's output power and developing active self-powered UV sensor.

Maximum surface charge density for triboelectric nanogenerators achieved by ionized-air injection: methodology and theoretical understanding.

For the maximization of the surface charge density in triboelectric nanogenerators, a new method of injecting single-polarity ions onto surfaces is introduced for the generation of surface charges. The triboelectric nanogenerator's output power gets greatly enhanced and its maximum surface charge density is systematically studied, which shows a huge room for the improvement of the output of triboelectric nanogenerators by surface modification.

High-performance triboelectric nanogenerator with enhanced energy density based on single-step fluorocarbon plasma treatment

Recently triboelectric nanogenerator (TENG) devices that transform environmental mechanical energy to electric power have been demonstrated as a renewable, clean and usable power source. However, the TENG output power still should be enhanced to better meet practical needs, and the working ability for practical applications should be further investigated. Here, we demonstrate a novel high-performance TENG by using a single-step fluorocarbon plasma treatment, which can significantly strengthen the TENG output performance. After the optimization of plasma treatment, the maximum instantaneous energy area density of the TENG with micro/nano hierarchical structures is enhanced by 278% to 4.85mW/cm2, with a peak output voltage of 265V and current density of 18.3μA/cm2. The reliability and stability of this single-step fluorocarbon plasma enhancement process were widely and deeply investigated by systematically comparative experiments. The density functional theory (DFT) is employed to analyze the chemical modification mechanism of this fluorocarbon plasma treatment, modeling for the first time the energy required for electron transfer for different friction materials at molecular level based on first-principle calculations. The ability of this TENG to work in the practical environmental, especially in the biomedical field, has been demonstrated by the investigation of the effect of the key environmental factor (i.e., humidity) on the TENG output performance, and a quantitative relation has been figured out. Based on this relation, humidity is established as a new consideration for future studies of TENG performance, and a novel self-powered humidity monitoring sensor is proposed. This high-output TENG is also successfully applied to drive an implantable microneedle electrode array to stimulate a frog's sciatic nerve. This represents the first application of a TENG for sustainably powering a biomedical microsystem implanted in real biological tissue, moving closer to practical biomedical applications of TENGs.