Aerodynamic and aeroelastic flutters driven triboelectric nanogenerators for harvesting broadband airflow energy

Phan, Hai,Shin, Dong-Myeong,Heon Jeon, Sang,Young Kang, Tae,Han, Pyunghwa,Han Kim, Gyu,Kook Kim, Hyung,Kim, Kyujung,Hwang, Yoon-Hwae,Won Hong, Suck Elsevier 2017 Nano energy Vol.33 No.-

<P><B>Abstract</B></P> <P>Aerodynamic and aeroelastic flutter-driven triboelectric nanogenerators are successfully used to harvest broadband airflow energy. The unit component of the flutter membrane consists of thin, free-standing Al foil electrodes covered on both sides with electrospun poly(vinyl chloride) nanofiber-structured mats, which provide advantageous tribo-surfaces specifically to increase the friction area. The airflow-induced triboelectric power generation from a single unit of the flutter-membrane-based triboelectric nanogenerator (FM-TENG) was up to 0.33 μW under a mild airflow condition. The use of a multi-layered triboelectric nanogenerator, fabricated by simply stacking the single units, can improve the output performance of the device. In a separate configuration, we designed a novel FM-TENG structure by mounting an aeroelastic flutter-belt adapted for use with a flutter-membrane energy-harvester. A rubber belt, which was sandwiched between the flutter membranes, created a rapid periodic vibrational mode via aeroelastic fluttering, synergistically harvesting triboelectric energy with the application of a constant air stream through the closed channel of the FM-TENG. Thus, our flutter-membrane-based approach creates a sustainable and cost-efficient energy harvesting system for collecting broadband airflow energy. Furthermore, the aerodynamic and aeroelastic FM-TENG have great potential to be used in numerous areas of self-powered electronic systems and in-situ wireless sensor applications for automobiles or aircraft.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Aerodynamic and aeroelastic flutter-driven triboelectric nanogenerators. </LI> <LI> Multi-layered triboelectric nanogenerators. </LI> <LI> Adapting an aeroelastic flutter to synergistically combine aerodynamic and aeroelastic movement. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The harvest of broadband airflow energy is accomplished using aerodynamic and aeroelastic flutter-driven triboelectric nanogenerators. Multi-layered triboelectric nanogenerators are made by simply stacking single units and can improve the output performance of the device. Adapting an aeroelastic flutter to synergistically combine aerodynamic and aeroelastic movement enables dramatic improvements in the electrical output of the triboelectric nanogenerator.</P> <P>[DISPLAY OMISSION]</P>

Bacterial Nano‐Cellulose Triboelectric Nanogenerator

Kim, Hyun-Jun,Yim, Eun-Chae,Kim, Jong-Hun,Kim, Seong-Jun,Park, Jeong-Young,Oh, Il-Kwon Elsevier 2017 Nano energy Vol.33 No.-

<P><B>Abstract</B></P> <P>Motivated by a desire to resolve the needs of sustainable energy resources, remote sensing electronics, wireless autonomous devices, mobile internet of things (IoT) and portable self-power generators, triboelectric nanogenerators have recently been suggested. However, more specialized target applications to biomedical and wearable devices will require biocompatible and eco-friendly triboelectric materials in power generators. Herein, we report for the first time a bio-triboelectric nanogenerator based on an eco-friendly and naturally abundant biomaterial, bacterial nanocellulose. Initially, bacterial cellulose pellicles were produced in a gel state by <I>Acetobacter xylinum</I> KJ1 in the Glu-Fruc medium and then a bacterial nanocellulose film having transparent and flexible functionalities was regenerated on a current collector <I>via</I> a solubilization process. The bacterial nanocellulose triboelectric nanogenerator was investigated with various input conditions and structural aspects. The working mechanism was also considered by measuring the contact angle and the surface potential of the friction materials. We believe that this study provides new insights to advancing the biocompatible and eco-friendly triboelectric power generator and optimization strategies to achieve high performance of triboelectric nanogenerators.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bio-triboelectric nanogenerator by employing sustainable bacterial nanocellulose. </LI> <LI> Working mechanism investigation by measuring the contact angle and the surface potential. </LI> <LI> New insights to advancing the biocompatible and eco-friendly TENG and optimization strategies. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We report a bio-triboelectric nanogenerator (Bio-TENG) based on the eco-friendly and naturally abundant biomaterial, bacterial nanocellulose (BNC), having unique functionalities such as transparency, flexibility, and biocompatibility. This study provides new insight of biomaterials toward advancing the biocompatible and medical bio-triboelectric power generator and transparent self-power integrated sensing systems.</P> <P>[DISPLAY OMISSION]</P>

All-in-one cellulose based triboelectric nanogenerator for electronic paper using simple filtration process

Kim, Inkyum,Jeon, Hyejin,Kim, Dabum,You, Jungmok,Kim, Daewon Elsevier 2018 Nano energy Vol.53 No.-

<P><B>Abstract</B></P> <P>Cellulose is one of the emerging materials as a natural polymer. In this work, cellulose nanofiber is utilized as a dielectric layer in triboelectric nanogenerator. To retain the flexibility of the fabricated paper, Ag nanowires layer is employed for electrode material and counter triboelectric layer simultaneously. This triboelectric nanogenerator is fabricated by a filtration process with different cellulose nanofiber and Ag nanowire condition. This triboelectric nanogenerator operates by contacting and separating of only two same bilayer paper consisting of cellulose nanofiber and Ag nanowire. Cellulose nanofiber and Ag nanowires layer acting as not only triboelectric layer and counter-triboelectric layer but substrate and electrode respectively. The case of cellulose nanofiber solution homogenized with 20 passes in 1000 bar and Ag nanowire with 0.1 wt% solution shows the optimal peak corresponding to 21 V of open-circuit voltage and 2.5 µA of short-circuit current. The maximum power output represents the value of 693 mW/m<SUP>2</SUP> for a 10 MΩ external resistance. Fabricated device is dispersed and completely dissolved in deionized water by using sonicator for 30 min and returns to original ingredient without producing any pollutant. This nanogenerator plays roles of not only harvesting ambient energy but folding sensor, humidity sensor, and e-paper-like device due to the paper-like characteristics and nano-porous of cellulose nanofiber and Ag nanowires.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cellulose nanofiber (CN) is used for a freestanding paper film acting as a triboelectric dielectric layer and a substrate. </LI> <LI> 'Ag nanowires network is formed onto the CN based freestanding paper, forming electrodes with a high dissolubility of water. </LI> <LI> Increasing the pressure and the number of passes, higher electrical outputs are generated from the CN based TENG (CN-TENG). </LI> <LI> The sheet resistance of the CN-TENG is maintained at a constant value during the several times of high mechanical stress. </LI> <LI> With the writable and erasable characteristics of device, this CN-TENG is expected to be utilized as an electronic paper. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

An electrostatic discharge based needle-to-needle booster for dramatic performance enhancement of triboelectric nanogenerators

Zhai, Cong,Chou, Xiujian,He, Jian,Song, Linlin,Zhang, Zengxing,Wen, Tao,Tian, Zhumei,Chen, Xi,Zhang, Wendong,Niu, Zhichuan,Xue, Chenyang Elsevier 2018 APPLIED ENERGY Vol.231 No.-

<P><B>Abstract</B></P> <P>There is plenty of exploitable energy in the ambient environments. Triboelectric nanogenerator is an innovative electricity generation technology to convert the wasted mechanical energy into electrical energy. However, the output of conventional triboelectric nanogenerators cannot be employed efficiently because their tremendous internal resistance limits the current of electrons. Inspired by the principle of lightning rods, for the first time we propose the utilization of electrostatic discharge to improve the performance of triboelectric nanogenerators, which is realized by an opposite needles structure enclosed in an inert atmosphere. When this structure is connected in series with a vertical contact-separation triboelectric nanogenerator, the strong electric field near tips of two needles ionizes the gas around them, forming a conductive plasma channel between the tips, and releasing a mass of free charges. As a result, some exciting performances are obtained in triboelectric nanogenerator. The output peak-to-peak voltage is increased from 300 V to 1300 V, and the equivalent impedance of energy harvesting circuit is reduced from 100 MΩ to 10 kΩ. Especially in the optimal conditions, the maximum continuous power can even be significantly improved by 330.76%. Therefore, this work provides a new strategy for the energy conversion technology, which is significant for the advancement and application of triboelectric nanogenerators.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A strategy is proposed to improve the performance of triboelectric nanogenerators. </LI> <LI> The maximum continuous power can be boosted dramatically by electrostatic discharge. </LI> <LI> This design reduces the optimal impedance that is important for circuit matching. </LI> <LI> With this design triboelectric nanogenerators can directly drive low-power devices. </LI> <LI> This work is also significant for macro-energy conversion, such as ocean energy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Understanding and modeling of triboelectric-electret nanogenerator

Hinchet, Ronan,Ghaffarinejad, Ali,Lu, Yingxian,Hasani, Javad Yavand,Kim, Sang-Woo,Basset, Philippe Elsevier 2018 Nano energy Vol.47 No.-

<P><B>Abstract</B></P> <P>Recently, electrostatic kinetic energy harvesters regained strong attention through the development of new triboelectric generators for harvesting green and renewable energy. These devices use a triboelectric dielectric layer as electret for polarizing their capacitance and they behave similarly to electret generators. However, triboelectric-based electret nanogenerators (T-ENG) have specificities arising from the contact electrification phenomenon and leading to different performances. For better understanding T-ENG, we investigated their electrical modeling with lumped-elements and multiphysics simulation in light of last researches on electret generators. To take into account T-ENG specificities, we experimentally measured the amplitude of the triboelectric effect on perfluoroalkoxy alkane films. This approach allowed fully simulating T-ENG and the model was found in agreement with experimental results. Understanding and verifying the model is capital, but to go further toward the application of T-ENG, we reused two electret circuits to extract the T-ENG model parameters in view of facilitating their realistic modeling and practical development into application.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report the electrical modeling of gap closing triboelectric-electret nanogenerators (T-ENG) and the study of their performances in the transitory and stationary regimes. </LI> <LI> We achieved multiphysics time dependent finite element method (FEM) simulations of gap closing T-ENG and found that results agree well with the electrical modeling, having less than 3% discrepancy. </LI> <LI> The comparison with T-ENG experimental measurements show very close shapes and amplitudes well synchronized, which validate the T-ENG electrical model. </LI> <LI> We used the T-ENG electrical model to extract the key parameters of a real T-ENG, which offers a way to compare T-ENG independently of mechanical stimulus. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We report the modeling of gap closing triboelectric-electret nanogenerators (T-ENGs) and the study of their performances. The model developed agrees well with multiphysics time dependent finite element method simulations, having less than 3% discrepancy. The comparison with T-ENG experimental measurements shows very close shapes and amplitudes well synchronized, which validates the T-ENG model. This allows to better design T-ENG to maximize their performances. Finally, this model was used to extract the key parameters of a real T-ENG, offering a way to compare T-ENGs independently of mechanical stimulus.</P> <P>[DISPLAY OMISSION]</P>

Interdigital electrode based triboelectric nanogenerator for effective energy harvesting from water

Kil Yun, Byung,Soo Kim, Hyun,Joon Ko, Young,Murillo, Gonzalo,Hoon Jung, Jong Elsevier 2017 Nano energy Vol.36 No.-

<P><B>Abstract</B></P> <P>Despite high voltage output, the low current output of triboelectric nanogenerators (TENGs) limits their expansion into practical applications. The incorporation of additional machinery, such as transformers and gear trains, has been proposed to remove this bottleneck. Here, we report a simple and cost-effective strategy that employs a compact interdigital electrode (IDE) to increase the current output in TENG devices. A foldable, twistable, and rollable IDE-based TENG, comprised of finger-like aluminum electrodes sandwiched between polytetrafluoroethylene and polyester films, was fabricated to harvest triboelectric energy from water. This IDE-based TENG exhibited a triboelectric charge threefold higher than that of a single electrode-based TENG. Triboelectric charge is greatly enhanced when the width of the IDE is comparable to the size of the water droplet being harvested. Using a cone-shaped IDE-based TENG, we showed that the folding angle of the device and the water droplet volume rate are important for enhancing triboelectric currents. Using a cylinder-shaped IDE-based TENG, we demonstrated the powering of 10 light emitting diodes and the charging of a 0.1-μF capacitor to 15V within 20s.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sharp increase of triboelectric current in interdigital electrode based triboelectric nanogenerators. </LI> <LI> Large degrees of freedom in interdigital electrode to harvest triboelectric energy of water. </LI> <LI> Reliable and durable device structure for various kinds of water at diverse places. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Realization of enhanced sound-driven CNT-based triboelectric nanogenerator, utilizing sonic array configuration

M. Javadi,A. Heidari,S. Darbari 한국물리학회 2018 Current Applied Physics Vol.18 No.4

Triboelectric nanogenerators have been emerged as the most promising mechanical energy harvesters, during last few years. Here, a sonic triboelectric nanogenerator with 7-fold enhanced output power is reported, in which carbon nanotubes are utilized to increase the electrode's effective surface area. To improve the efficiency we have taken advantage of acoustic wave localization in a sonic array. For this purpose, first we have studied an array of periodic acoustic scatterers by simulation. Then, we have designed a 1-D phononic crystal consisting of five steel slabs standing in air medium, which leads to resonance of incident acoustic wave at f = 4.34 kHz. We implemented the design, but replaced the middle scatterer by triboelectric nanogenerator. An enhancement factor of about 4 has been measured for the output voltage of the sonic nanogenerator at f = 4.24 kHz, when it is embedded in the sonic array. Also, power enhancement factor of 7-fold has been achieved (Pout≈4 μW/m2), benefiting from the applied sonic cavity. The measured resonance frequency and enhancement factor are in acceptable agreement with the simulation results. The presented enhanced energy harvesting configuration proposes a compact and low cost structure, which allows parallel energy harvesting, and seems promising for realizing sonic harvesters.

A study of sustainable green current generated by the fluid-based triboelectric nanogenerator (FluTENG) with a comparison of contact and sliding mode

Nahian, Syed Abu,Cheedarala, Ravi Kumar,Ahn, Kyoung Kwan unknown 2017 Nano energy Vol.38 No.-

<P><B>Abstract</B></P> <P>Recently, the triboelectric nanogenerator (TENG) has become a well-known energy harvester for ambient-resource energy harvesting for which the contact electrification between two different materials is employed. Alternatively, research has been carried out on the fluid-based TENG (FluTENG) for the replacement of the conventional solid-based TENG due to the destruction of the active surface by a long mechanical rupture that reduces the triboelectrical effect. For the first time, a simple, eco-friendly, very economical, and novel DI (deionized)-water commercial-polytetrafluoroethylene (cPTFE)-based FluTENG with contact-separation (CS-FluTENG) and lateral-sliding (LS-FluTENG) modes has been developed for this paper. Here, we examined the dynamic interaction between water and solid contact for each mode. During the study of the surface morphologies for both the CS-FluTENG and the LS-FluTENG, an FE-SEM analysis showed expansions of the fibril lengths in the film network. Also, the mechanistic approach of water splitting and the way that a chemical reaction occurs with the cPTFE film during the contact electrification that have been proved by UV-spectroscopy, FT-IR, and XRD analyses were investigated in this manuscript. The contact-angle measurements revealed that the surface-hydrophobicity values of the films were decreased after the CS-FluTENG and LS-FluTENG experiments due to a roughness increment, and the fibril distance from the nodes was increased. The triboelectric-power density values reached up to 2.15mW/m<SUP>2</SUP> for the CS-FluTENG and 0.8mW/m<SUP>2</SUP> for the LS-FluTENG, respectively. Moreover, the instantaneous power reached up to 2.4 µW for the CS-FluTENG and 1.85 µW for the LS-FluTENG, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel fluid based TENG(FluTENF) using DI water and cPTFE film is proposed. </LI> <LI> Lateral sliding and contact separation type FluTENG is compared and analyzed by FE-SEM analysis. </LI> <LI> The triboelectric power density is achieved upto 2.15mW/m<SUP>2</SUP> for CS-FluTENG and 0.8mW/m<SUP>2</SUP> for LS-FluTENG. </LI> <LI> The energy loss in CS-FluTENG is significantly higher than LS-FluTENG. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P> <B>Scheme1</B>. Schematic illustration of a fluid triboelectric nanogenerator.</P> <P>[DISPLAY OMISSION]</P>

Piezo/triboelectric nanogenerators based on 2-dimensional layered structure materials

Han, Sang A,Lee, Jaewoo,Lin, Jianjian,Kim, Sang-Woo,Kim, Jung Ho Elsevier 2019 Nano energy Vol.57 No.-

<P><B>Abstract</B></P> <P>Recently, research on energy harvesting has attracted great attention as a solution to energy depletion and environmental problems due to the use of fossil fuels such as coal, natural gas, and oil. To be precise, harvesting technology converts the energy sources around us such as solar, heat, and mechanical energy into electrical energy. It has the advantage of being able to supply and sustain energy on a permanent basis, rather than being non-renewable, and it is also eco-friendly. Among the various energy harvesting techniques, nanogenerators based on piezoelectric and triboelectric phenomena can generate electrical energy based on mechanical energy sources, which are usually ubiquitous, there are no restrictions due to weather, time, or space, and this technology is also user-friendly. Recently, two-dimensional (2D) materials have been chosen for implementing piezo/triboelectric nanogenerators. The 2D materials have transparency, flexibility, and a high surface-to-volume ratio. Owing to the very low thickness of the atomic unit, a stacking structure using 2D materials can be also made to form a very thin device, which is applicable for insertion into the body or wearable electronic devices. In this review, we summarize the characteristics and research results on piezo/triboelectric energy harvesters based on 2D layered structure materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The characteristics of 2D materials are transparency, flexibility, and high surface-to-volume ratio. </LI> <LI> With these advantages, 2D materials with piezo/triboelectric potential can be applied as various electronic devices. </LI> <LI> We summarize the research results on piezo/triboelectric energy harvester based on 2D layered structure materials. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Integrable card-type triboelectric nanogenerators assembled by using less problematic, readily available materials

Wu, Chaoxing,Park, Jae Hyeon,Sung, Sihyun,Koo, Bonmin,Lee, Yong Hun,Kim, Tae Whan Elsevier 2018 Nano energy Vol.51 No.-

<P><B>Abstract</B></P> <P>The development of portable power banks by using triboelectric nanogenerator-based technology has been a subject of great interest. However, when the potential wide range of future applications of such devices is considered, their heavy use of nanomaterials, polymers, and micro/nano fabrication technologies will increase the cost of and the energy consumed during production; moreover, their improper disposal may harm the environment. Here, we demonstrate portable card-type triboelectric nanogenerators (Card-TENGs) assembled by using less problematic, readily available materials through a top-down approach. The Card-TENGs are fabricated mainly from paper, including card paper and printer paper, which can greatly reduce the fabrication cost and the risk to the environment. Electricity can be generated simply by shaking the Card-TENGs, and Card-TENGs can be combined to form single and multilayer structures, which will enhance their electrical output. Furthermore, the as-fabricated Card-TENGs can be easily integrated into packs to increase the total output for lighting LEDs arrays and powering calculators.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Card-type triboelectric nanogenerators (Card-TENGs) as portable power sources are demonstrated. </LI> <LI> Card-TENGs are assembled by using less problematic, readily available materials. </LI> <LI> Card-TENGs with multilayer structures are demonstrated. </LI> <LI> Card-TENGs can be easily integrated into a pack to increase the total output. </LI> <LI> Card-TENGs have low fabrication cost and are environment friendly. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>