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In the new energy era, ocean wave energy is recognized as one of the most important clean and renewable energy sources. As an advanced energy technology, developing triboelectric nanogenerators (TENGs) to harvest ocean wave energy has become a promising research direction. However, for most of the current fully enclosed TENGs or liquid–solid TENGs, the industrialization is limited. In this work, a TENG with a new working scheme is proposed for water wave energy harvesting. Through designing the opposite dynamic electric‐double‐layers, the efficient conversion of water kinetic energy into electrical energy is achieved. Moreover, the TENG structure is extended to an array. Under irregular water waves, the TENG array exhibits desired output performance, with the stable output current of 60.0 µA, output voltage of 60.0 V, and average power density of 5.38 W m−3. Finally, the TENG array is demonstrated to successfully power signal spotlights, the digital thermometer and the water quality detector. This study not only broadens the research ideas for TENGs, but also provides a new mechanism for the ocean wave energy exploitation, which is of great significance to the industrialization of TENGs and blue energy. [ABSTRACT FROM AUTHOR]

As an important part of natural resources, islands support the marine economy and build a blue barrier for marine ecological civilization. However, the power supply on these islands is difficult, limiting the development of marine internet of things (IoTs). In order to break the status quo, this work applies triboelectric nanogenerators (TENGs) to island power supply and ecological monitoring. A spherical TENG with two multilayered helical units is designed to harvest water wave energy, in which the space utilization rate reaches 92.5%. Then a charge shuttling mechanism is developed to improve the electrical output. The output current and power of a single TENG without power management reach 200.3 µA and 16.2 mW respectively, corresponding to a peak power density of 23.2 W m−3. Moreover, a scheme of the power managed TENG is proposed for realizing large‐scale wave energy harvesting. The TENG is demonstrated to successfully power a water quality detector, a Bluetooth thermo‐hygrometer, and an intelligent wireless alarm system for remote environmental monitoring. This work not only proposes a new type of TENG for water wave energy harvesting with improved performance, but also provides a new strategy for intelligent ocean IoTs, which even contributes to the carbon neutralization. [ABSTRACT FROM AUTHOR]

With increasing global warming, catastrophic floods have threatened people's lives seriously and caused huge economic losses. However, present water hazard alarming systems generally rely on commercial batteries, limiting the intelligent development of disaster prevention planning and maintenance costs. In order to break the limitation, this work applies triboelectric nanogenerators (TENGs) to water hazard alarming. A spherical TENG device with four spiral units is designed to harvest water wave energy, and charge excitation modules (CEMs) are created and integrated with the TENG to improve its electric output. The output current and output power of the spherical TENG with CEMs can reach 15.09 mA and 24.48 mW, which are increased by 250.5 and 4.0 times, compared to the TENG without CEMs. Based on the charge excitation TENG, a self‐powered intelligent buoy is constructed. Utilizing the buoy to transmit 433 MHz radio frequency signals to 25 meters away, a water level alarm system and a water level information exchange system with a mobile phone are successfully realized. This work extends applications of TENGs toward water wave energy harvesting and provides a new strategy for water hazard alarming, which is conducive to the fields of carbon neutralization, Internet of Things, and disaster prevention. [ABSTRACT FROM AUTHOR]

Utilizing hydrogen energy produced by water electrolysis is conducive to carbon neutrality from a technological point of view. However, this perspective is restrained by the high electricity cost in commercial development. Powering electrochemical reactions by renewable electricity converted from distributed mechanical energy can lead to commercial electric energy saving and cost reduction. In this work, a self‐powered electrochemical system (SPECS) is proposed for the conversion from blue energy of ocean waves to green energy via hydrogen fuel. This system consists of triboelectric nanogenerator (TENG) devices and an electrolyzer, where the TENG devices serve as ocean wave energy harvesters for electricity generation, while the seawater‐containing electrolyzer is employed for hydrogen generation. After power management on the output of the TENGs and electrochemical reaction optimization, the system can generate hydrogen at a rate of 814.8 µL m‐2 d‐1 and a Faraday efficiency of 69.1% under ideal operation conditions, demonstrating the practical potential of the constructed system toward carbon neutralization. [ABSTRACT FROM AUTHOR]

The internet of things in the context of the ocean is vitally important. For ships sailing on the wide ocean in adverse weather conditions, evasion of marine islands and reefs is crucial to ensure safe navigation. Here, a hybrid wave energy harvesting nanogenerator is proposed (HW‐NG) as a power source for long‐distance wireless transmission, and demonstrated a self‐powered route avoidance warning system for ocean navigation. The HW‐NG is developed based on a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG), integrated by a pendulum structure. The TENG based on a contact‐separation mode is designed into a spring‐assisted multilayered structure, in which the EMG unit is well hybridized. Simply relying on the energy extracted from water waves, the HW‐NG can establish long‐distance (1.5 km) communication nodes on the sea. In application, a large HW‐NG network could be developed in the adjacent water areas of islands or reefs. With a network formed by hundreds of thousands of HW‐NGs, the forewarning signal transmission could be realized per second on the sea. More importantly, the wireless emitting is spontaneous through the designed automatic switch module. This work demonstrates a practicable strategy for ensuring safety of sea transportation based on wave energy collection. [ABSTRACT FROM AUTHOR]

Ocean waves are considered to be one of the most promising renewable energy sources, and harvesting such energy via triboelectric nanogenerators (TENGs) is an effective strategy toward large‐scale blue energy. However, most previous optimization schemes of TENG cannot meet the demands of practical applications. In this work, a new charge excitation circuit (CEC) with advantages of integration, high efficiency, and minimum impedance is developed specially for TENGs to harvest water wave energy. The TENG with the CEC exhibits significantly improved output performance, with a maximum power of 25.8 mW and power density of 49.3 W m−3, and a 208 times enhanced current of 25.1 mA is achieved. Furthermore, a scheme of integrating TENG network and CECs is proposed for realizing large‐scale wave energy harvesting. The charge excitation TENG network is demonstrated to successfully power a digital thermometer and a wireless communication system with mobile phone through transmitting radio frequency (RF) signals for remote environmental monitoring. This study not only offers a strategy to greatly enhance the output performance of TENG networks in water wave energy harvesting, but also provides useful guidance for constructing maritime communication platform based on blue energy toward a maritime internet of things system. [ABSTRACT FROM AUTHOR]

Ocean wave energy is a promising renewable energy source, but harvesting such irregular, "random," and mostly ultra‐low frequency energies is rather challenging due to technological limitations. Triboelectric nanogenerators (TENGs) provide a potential efficient technology for scavenging ocean wave energy. Here, a robust swing‐structured triboelectric nanogenerator (SS‐TENG) with high energy conversion efficiency for ultra‐low frequency water wave energy harvesting is reported. The swing structure inside the cylindrical TENG greatly elongates its operation time, accompanied with multiplied output frequency. The design of the air gap and flexible dielectric brushes enable mininized frictional resistance and sustainable triboelectric charges, leading to enhanced robustness and durability. The TENG performance is controlled by external triggering conditions, with a long swing time of 88 s and a high energy conversion efficiency, as well as undiminished performance after continuous triggering for 4 00 000 cycles. Furthermore, the SS‐TENG is demonstrated to effectively harvest water wave energy. Portable electronic devices are successfully powered for self‐powered sensing and environment monitoring. Due to the excellent performance of the distinctive mechanism and structure, the SS‐TENG in this work provides a good candidate for harvesting blue energy on a large scale. [ABSTRACT FROM AUTHOR]

Ocean wave energy is a promising energy source for large-scale exploitation owing to its abundant reserve and renewability. An effort is underway to develop a generator that can adapt to the ultra-low frequency of ocean wave vibration. Here, we designed a cylindrical triboelectric nanogenerator with an internal swing structure for effective water wave energy harvesting. Based on the supporting effect of the bearing component, the rotary dielectric films can be suspended over the stator electrodes, rather than coming into direct contact with them. Benefiting from the largely reduced resistance and continuous swing of an internal rotary component, the fabricated triboelectric nanogenerator can operate for about 85 s and produce over one thousand current pulses after one water wave excitation. Being agitated by a 0.033 Hz water wave (during a period of 30 s), the optimized cylindrical triboelectric nanogenerator can produce a peak power density of 231.6 mW·m−3 and an average one of 39.8 mW·m−3. Successful demonstrations of powering portable electronic devices and iron material corrosion inhibition under such simulated excitation indicate the robust capability for ultra-low-frequency water wave energy conversion. This triboelectric nanogenerator offers a new vision for efficient ultra-low-frequency wave energy harvesting with the possibility of large-scale blue energy. [ABSTRACT FROM AUTHOR]

Abstract: Making use of water wave energy at large is one of the most attractive, low‐carbon, and renewable ways to generate electric power. The emergence of triboelectric nanogenerator (TENG) provides a new approach for effectively harvesting such low‐frequency, irregular, and “random” energy. In this work, a TENG array consisting of spherical TENG units based on spring‐assisted multilayered structure is devised to scavenge water wave energy. The introduction of spring structure enhances the output performance of the spherical TENG by transforming low‐frequency water wave motions into high‐frequency vibrations, while the multilayered structure increases the space utilization, leading to a higher output of a spherical unit. Owing to its unique structure, the output current of one spherical TENG unit could reach 120 µA, which is two orders of magnitude larger than that of previous rolling spherical TENG, and a maximum output power up to 7.96 mW is realized as triggered by the water waves. The TENG array fabricated by integrating four units is demonstrated to successfully drive dozens of light‐emitting diodes and power an electronic thermometer. This study provides a new type of TENG device with improved performance toward large‐scale blue energy harvesting from the water waves. [ABSTRACT FROM AUTHOR]

Ocean waves are one of the most promising renewable energy sources for large‐scope applications. Recently, triboelectric nanogenerator (TENG) network has been demonstrated to effectively harvest water wave energy possibly toward large‐scale blue energy. However, the absence of effective power management severely restricts the practicability of TENGs. In this work, a hexagonal TENG network consisting of spherical TENG units based on spring‐assisted multilayered structure, integrated with a power management module (PMM), is constructed for harvesting water wave energy. The output performance of the TENG network is found to be determined by water wave frequencies and amplitudes, as well as the wave type. Moreover, with the implemented PMM, the TENG network could output a steady and continuous direct current (DC) voltage on the load resistance, and the stored energy is dramatically improved by up to 96 times for charging a capacitor. The TENG network integrated with the PMM is also applied to effectively power a digital thermometer and a wireless transmitter. The thermometer can constantly measure the water temperature with the water wave motions, and the transmitter can send signals that enable an alarm to go off once every 10 s. This study extends the application of the power management module in the water wave energy harvesting. [ABSTRACT FROM AUTHOR]

Ocean wave energy, as one of the most abundant resources on the earth, is a promising energy source for large‐scale applications. Triboelectric nanogenerators (TENGs) provide a new strategy for water wave energy harvesting; however, its average performance in realistic water wave conditions is still not high. In this work, a whirling‐folded TENG (WF‐TENG) with maximized space utilization and minimized electrostatic shielding is constructed by 3D printing and printed circuit board technologies. The flexible vortex structure responds easily to multiform wave excitation with improved oscillation frequency. A standard water wave tank is established to generate controllable water waves to characterize the device performance. It is found to be determined by wave conditions and internal structure, which is also revealed by a theoretical dynamical analysis. The WF‐TENG can produce a maximum peak power of 6.5 mW and average power of 0.28 mW, which can power a digital thermometer to operate constantly and realize self‐powered monitoring on the TENG network to prevent possible damage in severe environments. Moreover, a self‐charge‐supplement WF‐TENG network is proposed to improve the output performance and stability. This study provides an effective strategy for improving the average power and characterizing the performance of spherical TENG towards large‐scale blue energy. [ABSTRACT FROM AUTHOR]

The exploration of water wave energy to generate electric power is a promising and valuable way to solve global energy crisis. Triboelectric nanogenerators (TENGs) are considered as one of the most promising approaches for harvesting water wave energy. Here, a butterfly‐inspired triboelectric nanogenerator (B‐TENG) with spring‐assisted four‐bar linkage is fabricated to acquire multidirectional water wave energy from different types of movements generated by the device. The arc‐shaped outer shell can efficiently absorb the impact force of water wave and inner spring‐assisted four‐bar linkage can induce multiple contact–separation motion of TENG module, both of which allow the B‐TENG to harvest energy from different types of low‐frequency waves. The short‐circuit current and open‐circuit voltage of this B‐TENG device can reach 75.35 µA and 707.01 V, while a maximum output power density of 9.559 W m−3 can be achieved and 180 light‐emitting diodes can be directly lightened up by this B‐TENG. The energy generated from this B‐TENG can also be stored in a capacitor and to drive some marine sensor devices, such as an electronic thermometer. This proposed B‐TENG device is specially designed for multidirectional water energy harvesting and it may have good application prospects for ocean information monitoring and power supply to oceanic islands. A butterfly‐inspired triboelectric nanogenerator with spring‐assisted four‐bar linkage is fabricated to harvest energy from different types of low‐frequency waves. [ABSTRACT FROM AUTHOR]