Hybrid Nanogenerators for Ocean Energy Harvesting: Mechanisms, Designs, and Applications

Abstract

power requirements. [1][2][3] The mechanical energy present in the waves and tides of the ocean can be harnessed and utilized by advanced technologies. [4][5][6] Unquestionably, the employment and harvest of ocean energy are increasingly considered a vital solution to the critical energy shortage. [7][8][9] Capturing large-scale wave energy will eventually lead to modifying the world's energy structure to end the energy crisis. [10][11][12] Ocean energy sources are being explored to provide large-scale electricity, typically over a few watts, to meet the energy demands of commercial and residential areas that face power shortages. [13][14][15] In parallel, there is a growing interest in energy harvesting technologies that can generate small amounts of power from nanowatts to milliwatts to replace conventional batteries in portable and wearable electronics. Renewable energy-based self-powered systems have progressed remarkably over the last decade. [16][17][18] The current method of ocean energy harvesting is based on electromagnetic generators (EMGs) or triboelectric nanogenerators (TENGs). [19,20] The TENGs can be an alternative power unit as they can convert various energy vibrations from the ocean into electrical output. [21,22] TENGs often produce a high voltageThe ocean holds vast potential as a renewable energy source, but harnessing its power has been challenging due to low-frequency and high-amplitude stimulation. However, hybrid nanogenerators (HNGs) offer a promising solution to convert ocean energy into usable power efficiently. With their high sensitivity and flexible design, HNGs are ideal for low-frequency environments and remote ocean regions. Combining triboelectric nanogenerators (TENGs) with piezoelectric nanogenerators (PENGs) and electromagnetic nanogenerators (EMGs) creates a unique hybrid system that maximizes energy harvesting. Ultimately, hybrid energy-harvesting systems offer a sustainable and reliable solution for growing energy needs. This study provides an in-depth review of the latest research on ocean energy harvesting by hybrid systems, focusing on self-powered applications. The article also discusses primary hybrid designs for devices, powering self-powered units such as wireless communication systems, climate monitoring systems, and buoys as applications. The potential of HNGs is enormous, and with rapid advancements in research and fabrication, these systems are poised to revolutionize ocean energy harvesting. It outlines the pros and cons of HNGs and highlights the major challenges that must be overcome. Finally, future outlooks for hybrid energy harvesters are also discussed.

Pyroelectric based energy harvesting devices: hybrid structures and applications

“…Combining pyroelectric and triboelectric nanogenerators paves the way for utilizing both mechanical and thermal energies. 83,84 TENGs have drawn much attention owing to their high output, long list of applicable materials, and simple operating scheme. As triboelectric energy generation can occur when two surfaces come into contact, one can easily integrate the pyroelectric function into the existing triboelectric energy harvesting systems.…”

Applications of multifunctional triboelectric nanogenerator (TENG) devices: materials and prospects

“…For effective energy harvesting, variables such as the contact–separation mechanism, separation between triboelectric layers, and overall device structure should be optimized. 88…”

Self-Powered Buoy Triboelectric Nanogenerator with Nanofiber-Enhanced Surface for Efficient Wave Energy Harvesting

“…However, similar to the traditional water wave-based electromagnetic generators, the energy harvesting efficiency heavily depends on the effects of the floater and sinker sizes. An intelligent design of the buoy structure is developed to increase energy harvesting efficiency by investigating the internal triboelectric nanogenerator (TENG) structure. − Wave-triggered and powered buoy TENG has emerged as a promising energy harvesting technology. Wang proposed a self-powered intelligent buoy with a multilayered TENG to harvest blue energy, in which the average output power density reached 13.2 mW/m 2 at a wave frequency of 2 Hz .…”