Hybrid Nanogenerator Research Articles

A hybrid nanogenerator for collecting both water wave and steam evaporation energy

Water is an important resource for building different energy systems towards diversified applications. In this paper, a novel hybrid nanogenerator is proposed based on a water-wave triboelectric nanogenerator (TENG) and evaporation generator, which opens up a more effective approach to fully utilize the energy from water. This hybrid nanogenerator can solve the problem of insufficient output of water wave TENGs in calm water. The optimized peak power of water-wave TENG can reach 0.62 mW under simulated waves frequency of 2.5 Hz, while a capacitor of 0.33 µF can be charged to 15 V by TENG within 80 s in actual water waves. The evaporation generator based on wood block can continuously generate direct currents during the spontaneous evaporation of water. The solar-vapor conversion efficiency of evaporation generator can reach 84.2%, while the evaporation generator can provide a maximum current density of 3.2 μA·cm−2 and a maximum output power density of 1.4 mW·m−2 with a matching load of 10 kΩ (23 ℃, 30% RH). To demonstrate the application capability of the evaporation generator, we design a multi-stage boost circuit coupled with the pulse charging method, which can increase the voltage output and effectively reduce the charging time. The proposed hybrid nanogenerator provides a promising way for collecting both water wave and steam evaporation energy, effectively broadening methods for energy harvesting by TENGs.

Improving the performance of nanogenerators via micro-capacitors and enhanced dipoles

Nanogenerator has developed rapidly in recent years due to new demands for portable power and smart living. However, its applications are greatly limited due to its low output performance and complex structure. Here, we have prepared a hybrid nanogenerator (HNG) with excellent performance and simple structure by electrospinning through mixing barium titanate and carbon nanotubes into PVDF and PDMS. The micro-capacitors inside the film and the charge generated by friction promoting the dipole polarization together improve the performance of HNG. The optimized HNG shows the highest open-circuit voltage and short-circuit current of 117 V and 4.7 μA, respectively. And the maximum output power density is 223.7 mW/m2 when the load is 100 MΩ. At last, we designed an intelligent monitoring system for security protection. The integrated HNGs can accurately and reliably collect abnormal signals and alarm to achieve monitoring functions, which shows great potential for application in the future.

Strategic Development of Piezoelectric Nanogenerator and Biomedical Applications

Nanogenerators are the backbone of self-powered systems and they have been explored for application in miniaturized biomedical devices, such as pacemakers. Piezoelectric nanogenerators (PENGs) have several advantages, including their high efficiency, low cost, and facile fabrication processes, which have made them one of the most promising nano power sources for converting mechanical energy into electrical energy. In this study, we review the recent major progress in the field of PENGs. Various approaches, such as morphology tuning, doping, and compositing active materials, which have been explored to improve the efficiency of PENGs, are discussed in depth. Major emphasis is given to material tailoring strategies and PENG fabrication approaches, such as 3D printing, and their applications in the biomedical field. Moreover, hybrid nanogenerators (HNG), which have evolved over the last few years, are discussed. Finally, the current key challenges and future directions in this field are presented.

Impact of PVDF and its copolymer-based nanocomposites for flexible and wearable energy harvesters

Encountering the consumption of fossil fuels on a large scale and contamination of the environment due to chemical batteries, along with the rapid growth of various wearable devices and IoT-enabled devices, researchers are urged to discover lightweight, flexible, biocompatible wearables which can be self-powered. Currently, flexible piezoelectric, triboelectric and hybrid nanogenerators are good power sources to integrate into self-powered wearable devices that can even monitor human health conditions. PVDF and its copolymers are widely used materials in self-powering wearable technology, as it is flexible, biocompatible, easily processable and is of low cost. PVDF has five crystalline phases, among them the β phase has strong electroactive and piezoelectric properties. Several attempts have been made to enhance the β phase of PVDF by incorporating different nanofillers for implementation in energy harvesting applications. This review focuses on the recent advancements in energy harvesting by using various additives like Mxene, ZnO, hBN, TMDCs and QDs. Mxene has superb mechanical properties that include good bending stiffness, good Young’s modulus, high thermal conductivity, absorptivity, intrinsic hydrophilicity etc. ZnO is a piezoelectric material with good electrical, chemical, thermal stabilities and optical as well as photocatalytic properties. It is a less toxic material with good resistance against microbes. hBN is an electrical insulator which possess good thermal conductivity, is transparent to visible light and exhibits a high Young’s modulus of ∼1TPa. TMDCs are non-toxic materials with an ultrathin structure and good surface area to mass ratio, exhibiting good mechanical, optical and electronic properties. The current review briefly discusses the deformation sensing mechanism, various methods of β phase enhancement in PVDF, fabrication of PVDF based energy harvesting devices and material selection criteria of nanofillers. A dedicated section is presented for humidity sensors as wearable devices are prone to sweating conditions. The authors hope this review brings a general understanding of PVDF and its copolymer-based nanocomposites for flexible and wearable energy harvesters.

Dynamic Pluronic F127 Crosslinking Enhancement of Biopolymeric Nanocomposites for Piezo-Triboelectric Single-Hybrid Nanogenerators and Self-Powered Sensors.

Biomechanical and nanomechanical energy harvesting systems have gained a wealth of interest, resulting in a plethora of research into the development of biopolymeric-based devices as sustainable alternatives. Piezoelectric, triboelectric, and hybrid nanogenerator devices for electrical applications are engineered and fabricated using innovative, sustainable, facile-approach flexible composite films with high performance based on bacterial cellulose and BaTiO3 , intrinsically and structurally enhanced by Pluronic F127, a micellar cross-linker. The voltage and current outputs of the modified versions with multiwalled carbon nanotube as a conductivity enhancer and post-poling effect are 38V and 2.8µA cm-2 , respectively. The multiconnective devices' power density can approach 10 µW cm-2 . The rectified output power is capable of charging capacitors, driving light-emitting diode lights, powering a digital watch and interfacing with a commercial microcontroller board to operate as a piezoresistive force sensor switch as a proof of concept. Magnetoelectric studies show that the composites have the potential to be incorporated into magnetoelectric systems. The biopolymeric composites prove to be desirable candidates for multifunctional energy harvesters and electronic devices.

Piezo/Triboelectric Nanogenerator from Lithium-Modified Zinc Titanium Oxide Nanofibers to Monitor Contact in Sports

The need for technological innovation in competitive sports is crucial for self-monitoring and smart decision making. In this work, we demonstrate how intelligent sports and smart decision making can be achieved in cricket and boxing using lithium-modified zinc titanium oxide (LZTO) nanofibers based on piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators (TENGs). Zinc titanium oxide (ZTO) nanofibers synthesized using electrospinning followed by a calcination technique are modified with lithium to increase the output of the nanogenerator. An optimized PENG is fabricated using 25 wt % loading of LZTO (d33 = 214 pm/V) in a poly(vinylidene fluoride) (PVDF) matrix as a double-layered structure and yields an open-circuit voltage (Voc) of 35 V and a short-circuit current (Isc) of 1.6 μA by manual tapping. To fabricate the TENG, Kapton and LZTO are used as negative and positive tribolayers, while Cu and adhesive polymer tape are used as the electrode and spacer, respectively. Furthermore, a hybrid nanogenerator (HNG) is fabricated by combining the PENG and TENG to produce a rectified voltage, current, and power density of up to 75 V, 3.2 μA, and 240 μW/cm2, respectively. These HNGs are integrated with a punching bag and demonstrated to differentiate among the six types of punches in boxing. Furthermore, PENGs are used in cricket to monitor the number of balls middled on the bat during practice and the contact of the ball with the bat and stumps for smart decision making. All kinds of lab-scale testing are done for these applications, which pave a way for exploring the frontiers in nanogenerator applications in sports as maintenance-free and self-powered sensing technology.

Brachistochrone Bowl‐Inspired Hybrid Nanogenerator Integrated with Physio‐Electrochemical Multisensors for Self‐Sustainable Smart Pool Monitoring Systems

AbstractMaintaining clean and fresh pool water requires regular monitoring and treatment. However, the employed methods are manual, complex, and time‐consuming. Herein, a self‐sustainable autonomous smart pool monitoring system (SPMS) that can monitor various physio‐electrochemical properties of the pool water in real‐time without requiring external power is proposed. SPMS includes an electromagnetic generator inspired by the novel brachistochrone bowl which harvests energy from random motion (peak power 72 mW at 4 Hz and 0.5 g) and supplies the wireless transmission unit and the highly sensitive multifunctional sensor unit (MSU) including pH (−60.71 mV pH−1), temperature (2.5 Ω °C−1), chloride (0.355 mV ppm−1; <250 ppm), conductivity (3.25 × 10−5 µS ppm−1), and wave motion (1.27 V Hz−1). The fabricated MSU has adequate sensitivity and accuracy to detect minor variations in the water quality for indoor and outdoor environments. Finally, the smart pool monitoring application of the SPMS is demonstrated in real‐time by acquiring the sensor data and wirelessly transmitting it to the custom‐developed mobile application utilizing harvested energy. Combining energy harvesting and water quality sensing, the free‐floating completely isolated SPMS device demonstrates a portable, freestanding, wireless, autonomous, and self‐powered pool monitoring system for maintaining a hygienic and safe swimming environment.

Soft Ball‐Based Triboelectric–Electromagnetic Hybrid Nanogenerators for Wave Energy Harvesting

AbstractTriboelectric nanogenerator (TENG) provides a new cost‐effective strategy to harvest water wave energy due to the broad options of triboelectric materials and the high efficiency in low‐frequency energy harvesting. Here, a new triboelectric–electromagnetic hybrid nanogenerator (TEHG) consisting of a soft ball‐based triboelectric nanogenerator (SB‐TENG) and an electromagnetic generator (EMG) is reported for harvesting wave energy. The soft balls are utilized as one triboelectric layer to increase the contact area with the copper electrodes. The critical parameters that may affect the energy harvesting performance of the SB‐TENG are investigated, including the type of the filled liquids, the thickness of the silicone shell, the number of layers, and the added soft balls. Under an operating frequency of 1 Hz, the SB‐TENG and the EMG can reach a maximum output peak power of 0.5 and 8.5 mW, respectively. The TEHG has been demonstrated to power dozens of light‐emitting diodes and drives a digital temperature sensor to monitor the water temperature for an extended period. This study provides a new design and approach to improve the output performance of TENGs and presents an excellent prospect for building a self‐powered water‐sensing system driven by low‐frequency water waves.

MoS2-PVDF/PDMS based flexible hybrid piezo-triboelectric nanogenerator for harvesting mechanical energy

A green energy generating device, which can harvest the energy from ambient sources present in our surroundings to fulfill the energy needs of future technologies without polluting our surrounding are becoming more in demand. To extract electrical energy from mechanical vibrations, nanogenerators based on piezoelectric and triboelectric phenomena are being explored recently. When a piezoelectric material is used as one of the two components in the triboelectric nanogenerator, these two effects can be coupled. It is possible to further improve the output efficiency of the nanogenerator by integrating these two effects to form a hybrid nanogenerator. In this work, we have fabricated the different piezoelectric energy harvesters based on MoS2-PVDF materials by varying the weight percentage (0%, 2%, 5% and 7 wt%) of MoS2. The piezoelectric output of the PVDF was found to be increased due to the incorporation of MoS2. In comparison to bare PVDF film, the piezoelectric nanogenerator based on 7 wt% of MoS2 as filler in PVDF shows nearly 2-fold increase in output voltage from 9.4 V to 18.0 V. Further, a piezo-tribo based hybrid nanogenerator (HNG) is fabricated by integrating the MoS2-PVDF film having highest piezoelectric output with PDMS thin film as two layers required for the HNG device. It may be highlighted that the introduction of MoS2 in PVDF matrix not only enhanced the piezoelectric output which may be attributed to the intrinsic piezoelectric nature of MoS2 and enhanced β-phase crystallization, the triboelectric charge generation also gets enhanced. The enhanced hybrid output performance may be attributed to its increased dielectric property and surface roughness. The MoS2-PVDF/PDMS based HNG provides an output voltage of 35.3 V, which is 1.6 times greater than the HNG based on bare PVDF/PDMS layers. The generated output power successfully lit up 21 LED bulbs by the application of a small mechanical force generated by finger tapping and could charge a 10 μF capacitor to ∼9 V in ∼400 s. The present findings suggest that by hybridizing different device mechanism in a single device the energy harvesting performance of resulting HNG can be enhanced, making it possible to drive smart wearable electronic devices.

Stackable Direct Current Triboelectric‐Electromagnetic Hybrid Nanogenerator for Self‐Powered Air Purification and Quality Monitoring

AbstractTriboelectric nanogenerators (TENGs) and electromagnetic generators (EMGs) show their strengths in harvesting mechanical energy from ambient environment, while the output characteristics of the hybrid generators are not optimally utilized. Here, a stackable triboelectric‐electromagnetic hybrid nanogenerator is designed to construct a self‐powered environmental governance system that fully harnesses the high‐voltage output of TENG and high‐current output of EMG, respectively. Based on the corona discharge, a cylindrical direct‐current TENG is obtained by a flexible contact between flourinated ethylene propylene and Ag fiber cloth. Systematic studies of the parameters that affect TENG outputs are also performed. The results show that the two stacked direct‐current TENG generates a −8.76 µC s−1 discharge rate and −21.61 kV voltage at 1400 rpm. For the EMG component, the rectified average power is 2.51 W, which can charge a capacitor of 1 F to 3 V in 38.9 s. Finally, driven by airflow, the designed hybrid nanogenerator is applied to release negative air ions and continuously power an air quality detector. The self‐powered air purification and quality monitoring system via hybrid nanogenerator established in this work may provide an alternative avenue for sustainable societies.

Comment on “Enhancing the output performance of hybrid nanogenerators based on Al-doped BaTiO3 composite films: a self-powered utility system for portable electronics”, by B. Dudem, L. K. Bharat, H. Patnam, A. R. Mule and J. S. Yu, J. Mater. Chem. A, 2018, 6, 16101

This Comment discusses a lack of proof for the relationship of the nanogenerator performance reported in J. Mater. Chem. A, 2018, 6, 16101 to the enhanced piezoelectricity and to the Al-doping of BaTiO3 particles used as the nanogenerator core.

Reply to the ‘Comment on “Enhancing the output performance of hybrid nanogenerators based on Al-doped BaTiO3 composite films: a self-powered utility system for portable electronics”’, by A. Tkach and O. Okhay, J. Mater. Chem. A, 2023, 11, D3TA01041D

With this contribution, we reply to the Comment by Tkach et al. on our publication in J. Mater. Chem. A, 2018, 6, 16101. For that, we provide additional experimental evidence including the structural and material characteristics of ABTO.

Recent Advances in Self-Powered Wearable Sensors Based on Piezoelectric and Triboelectric Nanogenerators.

Early clinical diagnosis and treatment of disease rely heavily on measuring the many various types of medical information that are scattered throughout the body. Continuous and accurate monitoring of the human body is required in order to identify abnormal medical signals and to locate the factors that contribute to their occurrence in a timely manner. In order to fulfill this requirement, a variety of battery-free and self-powered methods of information collecting have been developed. For the purpose of a health monitoring system, this paper presents smart wearable sensors that are based on triboelectric nanogenerators (TENG) and piezoelectric nanogenerators (PENG), as well as hybrid nanogenerators that combine piezoelectric and triboelectric nanogenerators (PTNG). Following the presentation of the PENG and TENG principles, a summary and discussion of the most current developments in self-powered medical information sensors with a variety of purposes, structural designs, and electric performances follows. Wearable sensors that generate their own electricity are crucial not only for the proper development of children and patients with unique conditions, but for the purpose of maintaining checks on the wellbeing of the elderly and those who have recently recovered from illness, and for administering any necessary medical care. This work sought to do two things at once: provide perspectives for health monitoring, and open up new avenues for the analysis of long-distance biological movement status.

High‐Performance Flexible Piezo–Tribo Hybrid Nanogenerator Based on MoS2@ZnO‐Assisted β‐Phase‐Stabilized Poly(Vinylidene Fluoride) Nanocomposite

The fabrication of nanogenerators is most promising for the worldwide energy crisis situation. Nowadays, piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators are getting immense recognition in the energy field. Herein, piezoelectric and triboelectric effects are combined in a fabricated piezo–tribo hybrid nanogenerator (HNG) for better output performance. A few layered MoS2 on Cu foil via electrodeposition process is deposited and then ZnO is incorporated through electrodeposition, followed by spin coating of poly(vinylidene fluoride) (PVDF) as piezoelectric material. Incorporation of ZnO increases both the piezoelectric property of the PENG and the triboelectric performance. The PVDF/MoS2@ZnO‐based HNG shows astonishing results of open‐circuit voltage (≈140 V) and short‐circuit current (≈4.6 μA) with 256 μW cm−2 power density under piezo‐tribo imparting, which is even better than most ultramodern and complex cleanroom processed nanogenerators. With excellent output performance, this HNG is also capable of harvesting energy from various mechanical and biological movements like walking, heel pressing, elbow bending, and machine vibration. It can lighten up 33 LEDs connected in series and can power up electronic devices like a calculator and wristwatch. The PENG is also biocompatible and sensitive toward physiological signal monitoring, which can be useful for potential biomedical applications.

An eccentric-structured hybrid triboelectric-electromagnetic nanogenerator for low-frequency mechanical energy harvesting

With the increasing aggravation of the environmental pollution and energy crisis, exploiting clean and renewable energy becomes imperative for human existence and development. In this paper, an eccentric-structured hybrid triboelectric-electromagnetic nanogenerator (EHNG) is proposed to harvest low-frequency mechanical energy. It mainly contains two parts, – a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG). Exploiting the unique eccentric structure, the EHNG can effectively transfer one-dimensional mechanical motion of an object to the rotation of the eccentric rotor, resulting in electricity generation. In comparison to a separate energy harvesting unit, the hybrid nanogenerator operates beyond the single energy harvesting mode, showing preferable electrical output performances including a broader output range and shorter time of voltage boosting. In terms of energy storage, the EHNG provides not only a higher saturation charging voltage and continuous charging from the TENG part, but also a rapid charging speed in the early charging phase from the EMG part. As a practical power source, the EHNG is shown to be capable of directly powering LEDs. The present work develops an effective and sustainable technique to maximally harvest mechanical energy from the environment.

Highly Adaptive Triboelectric‐Electromagnetic Hybrid Nanogenerator for Scavenging Flow Energy and Self‐Powered Marine Wireless Sensing

AbstractWith the development of the smart ocean which contains a large number of wireless sensor nodes, it is a great demand to develop high‐performance marine energy harvesters for powering those sensors. In this work, a highly adaptive hybrid nanogenerator based on triboelectric nanogenerator and electromagnetic generator is proposed. The hybrid nanogenerator can be used for scavenging both wind energy and ocean current energy. The peak power of the hybrid nanogenerator can reach 449.74 mW, which can recharge a 50 mAh‐3.7 V Lithium battery. In addition, it is found that there is a linear relationship between the voltage frequency of the triboelectric nanogenerator and the rotation speed, indicating the hybrid nanogenerator can serve as a flow velocity sensor. A fully self‐powered marine wireless sensor node is fabricated based on the hybrid nanogenerator and management circuit. The demonstrations show that the present hybrid nanogenerator has great potential applications for marine wireless sensing in the scenarios of nearshore, offshore, and underwater.

Hybrid nanogenerator driven self-powered SO2F2 sensing system based on TiO2/Ni/C composites at room temperature

The application of conventional sensors is limited due to energy supply issues and environmental problems, and current triboelectric nanogenerator (TENG) based self-powered sensing systems is hard to meet the specific requirement. In this paper, TiO2/Ni/C composites were prepared using MOF-derived Ni/C materials for SO2F2 detection at room temperature. The excellent pore structure and high electrical conductivity of Ni/C material greatly improve the sensitivity properties of TiO2. The TiO2/Ni/C composites-based SO2F2 sensor exhibits a wide detection range of 5–200 ppm concentration and a fast response/recovery time of 26 s/9 s, while its response value for 200 ppm SO2F2 is 18.34 times higher than that of the pure TiO2-based sensor. Furthermore, by modifying the PVDF film with TiO2, the permittivity of PVDF is greatly improved, and the surface potential is 2.6 times higher than that of pure PVDF film. Eventually, a dual-layer hybrid TENG based on TiO2/PVDF composite film was constructed. Its upper TENG powers the TiO2/Ni/C composite sensor, and the lower hybrid TENG drives the thermohygrometer to realize a self-powered temperature and humidity-corrected SO2F2 sensing system, which can accurately implement SO2F2 gas concentration alarms at 10 ppm, 50 ppm, and 100 ppm at different humidity levels. This work broadens the application of TENG in the field of self-powered gas sensing while providing a new idea to achieve the trace detection of SO2F2 at room temperature.

A Wind-Driven Rotating Micro-Hybrid Nanogenerator for Powering Environmental Monitoring Devices.

In recent years, environmental problems caused by natural disasters due to global warming have seriously affected human production and life. Fortunately, with the rapid rise of the Internet of Things (IoT) technology and the decreasing power consumption of microelectronic devices, it is possible to set up a multi-node environmental monitoring system. However, regular replacement of conventional chemical batteries for the huge number of microelectronic devices still faces great challenges, especially in remote areas. In this study, we developed a rotating hybrid nanogenerator for wind energy harvesting. Using the output characteristics of triboelectric nanogenerator (TENG) with low frequency and high voltage and electromagnetic generator (EMG) with high frequency and high current, we are able to effectively broaden the output voltage range while shortening the capacitor voltage rising time, thus obtaining energy harvesting at wide frequency wind speed. The TENG adopts the flexible contact method of arch-shaped film to solve the problem of insufficient flexible contact and the short service life of the rotating triboelectric generator. After 80,000 cycles of TENG operation, the maximum output voltage drops by 7.9%, which can maintain a good and stable output. Through experimental tests, the maximum output power of this triboelectric nanogenerator is 0.55 mW at 400 rpm (wind speed of about 8.3 m/s) and TENG part at an external load of 5 MΩ. The maximum output power of the EMG part is 15.5 mW at an external load of 360 Ω. The hybrid nanogenerator can continuously supply power to the anemometer after running for 9 s and 35 s under the simulated wind speed of 8.3 m/s and natural wind speed of 5.6 m/s, respectively. It provides a reference value for solving the power supply problem of low-power environmental monitoring equipment.

Whirligig-Inspired Hybrid Nanogenerator for Multi-strategy Energy Harvesting

Whirligig-Inspired Hybrid Nanogenerator for Multi-strategy Energy Harvesting

ZnFe2O4 nanocomposite films for electromagnetic-triboelectric-piezoelectric effect-based hybrid multimodal nanogenerator

Hybridizing the pre-existing energy harvesting techniques in a single device is in focus nowadays to improve the electrical output of energy harvesting device. This work uses a versatile nanocomposite films comprises cuboctahedron zinc ferrite nanoparticles (CZF NPs) and polymer matrix as energy harvesting layers to implement a hybrid multimodal nanogenerator (HNG) of a triboelectric nanogenerator (TENG), a piezoelectric nanogenerator (PENG), and an electromagnetic nanogenerator (EMG). Polydimethylsiloxane (PDMS) and polyvinylidene fluoride (PVDF) were used as polymer matrix materials of two different nanocomposite films. With embedded multi-spiral coil structuring, CZF NPs @PDMS composite film works for the EMG and the TENG. Furthermore, ferroelectric CZF NPs @PVDF composite film produces piezoelectric output by pushing force, serving as the PENG. Our HNG provides an efficient multimodal energy harvesting as the integrated nanogenerators generate high output power with not only high output voltage, but also low internal electrical impedance with three different working modes including non-contact mode, contact-separation mode, and non-separation mode in response to the external mechanical pushing force and its release. We believe that these techniques can realize the commercial application of flexible hybrid nanogenerators.