Arc‐Shaped Triboelectric Nanogenerator Based on Rolling Structure for Harvesting Low‐Frequency Water Wave Energy

Abstract

Ocean occupies about 71% of the global surface area and contains 97% of the total water on the earth. Ocean waves are regarded as one of the most promising renewable energy sources, but it is quite difficult to harvest such low‐quality and low‐frequency energy due to the technology limitations of traditional electromagnetic generators. In this work, a type of arc‐shaped triboelectric nanogenerator (AS‐TENG) with internal rolling structure is designed to harvest low‐frequency water wave energy. The freestanding roller with flexible surfaces can scroll freely with low friction along the arched track under external triggering, generating induced current between the complementary electrodes. The arc‐shaped design facilitates the high‐density integrating of multiple TENG units and effective packaging for potential large‐scope applications. One AS‐TENG can deliver an output power density of 5.47 W m−3 under regular triggering, while a power density of 2.34 W m−3 is achieved for an AS‐TENG array under real water wave triggering of 1.2 Hz. Moreover, through harvesting water wave energy by the AS‐TENG array, self‐powered temperature sensing and wireless transmission systems have been successfully constructed. This work demonstrates huge application prospects of the AS‐TENGs toward large‐scale ocean blue energy harvesting and environmental monitoring.

Highly Stable and Eco-friendly Marine Self-Charging Power Systems Composed of Conductive Polymer Supercapacitors with Seawater as an Electrolyte

“…The input from the TENG to SWSC and the output from the self-charging power system are critical parameters that determine the capacity of the self-charging power system to drive the electronics effectively. Owing to the high performance of the SWSC (Figure i), the as-prepared self-charging power system delivers a higher power output than the reported work that collects water wave energy. − ,− In addition, even when compared with other forms of energy harvestors, the fabricated self-charging power system exhibits a competitive output. ,,− This study shows that the designed marine self-charging power system is a promising candidate for driving the sensors and devices in the smart ocean and marine IoTs. − …”

“…The assembled TENG module can achieve ∼200 W m −3 (98.4 W m −3 for each M-TENG) when driven by a linear motor with the transferred charges, short current, and open voltage of M-TENG at 1.42 μC, 147 μA, and 584 V, respectively. The designed TENG outperforms the marine TENG reported to date, including the spherical TENG, 14,46 arc-shaped TENG, 15 cylindrical TENG-EMG hybrid device, 18 tubular TENG, 2 water balloon TENG, 16 stacked pendulum-structured TENG, 17 and stacked pendulumstructured TENG 35 as shown in Table S2. In addition, when the acceleration is 1, 3, and 5 m s −2 , the M-TENG can take 145, 118, and 88.5 s to raise the voltage of the seawater capacitor to 2 V, respectively (Figure S12g).…”

“…Thus, a TENG-based self-charging power system containing an energy storage device to in situ store the electricity and provide a stable direct current (DC) input is severely required, which would reduce the need for an external power source, enhance the portability, and eliminate the inconveniences of recharging and replacing energy storage devices. 12,13 To sufficiently harvest the water wave energy, a series of selfcharging power systems based on TENG, including the spherical-shaped TENG, 14 arc-shaped TENG, 15 water balloon TENG, 16 stacked pendulum-structured TENG, 17 and even hybrid TENG with EMG devices, 18 is designed to charge the energy storage devices to drive active sensing devices in the fields of chemical and environmental monitoring, smart ocean, and so forth. 7,19−21 However, most of the energy storage devices utilized are supercapacitors (SCs) and batteries with organic mechanicals as electrolytes to enhance the energy density.…”

“…To sufficiently harvest the water wave energy, a series of self-charging power systems based on TENG, including the spherical-shaped TENG, arc-shaped TENG, water balloon TENG, stacked pendulum-structured TENG, and even hybrid TENG with EMG devices, is designed to charge the energy storage devices to drive active sensing devices in the fields of chemical and environmental monitoring, smart ocean, and so forth. ,− However, most of the energy storage devices utilized are supercapacitors (SCs) and batteries with organic mechanicals as electrolytes to enhance the energy density. − Usually, these electrolytes are toxic and unaffordable, which impedes the commercial application of SCs.…”

Chemo‐Mechanical Energy Harvesters with Enhanced Intrinsic Electrochemical Capacitance in Carbon Nanotube Yarns

“…This enables our 8-plied L-coiled yarn harvester could effectively improve the energy transfer efficiency with reduced matching impedance. [20] The frequencydependent volumetric power was also compared with that of other mechanical energy harvesters usable in the ocean including TENGs, [40][41][42][43][44][45][46][47][48][49] PZs, [36,50,51] electrochemical generators (ECGs), [15] and LS-TENGs. [37,52,53] Considering the low frequency environment of the ocean (< 1 Hz), the collected frequency was typically below 100 Hz.…”