Broadband Vibrational Energy Harvesting Based on a Triboelectric Nanogenerator

Abstract

. IntroductionOver the past decades, harvesting ambient environmental energy has attracted increasing interest for realizing self-powered systems and for meeting large-scale energy demands. Searching for clean and renewable energy with reduced carbon emissions is urgent to the sustainable development of human civilization. [ 1 ] To date, various energy harvesters for scavenging ambient environmental vibrational energy have been developed that rely on piezoelectric, [2][3][4][5][6] electromagnetic, [ 7,8 ] and electrostatic [ 9,10 ] transduction mechanisms. Considerable research effort has been devoted to improve the effi ciency of vibrational energy harvesters. [11][12][13][14][15][16][17][18] However, regardless of the transduction mechanisms and novel structures, the vibration-to-electric conversion effi ciency is still quite low in the existing harvesters because: 1) most of them are designed as linear resonant structures in order to achieve maximum power generation, which limits their application in realworld environments with stochastic or varying vibration spectra; [ 14 ] and 2) most devices can only effectively harvest vibrational energy from a single motion direction and/or within a small bandwidth. In this case, the harvesters are not effective at scavenging energy from a vibration with multiple or time-variant motion directions. [ 11,12,14 ] Recently, the innovative triboelectric nanogenerator (TENG) has offered a costeffective, simple, and robust approach to convert mechanical energy into electricity based on the coupling between triboelectrifi cation and electrostatic induction. [19][20][21][22][23][24][25][26][27] The triboelectrically charged planes of TENGs change the electric polarization and fi eld across two electrodes by either periodic vertical contact separation [19][20][21] or in-plane sliding, [ 22,23 ] leading to an alternating fl ow of electrons through the external load. The developed TENGs have been successfully applied as sustainable power sources for portable electronics, [ 21 ] magnetic sensors, [ 24 ] environmental monitors, [ 25 ] and other self-powered systems. [ 26,27 ] Here, we demonstrated a newly designed 3D-TENG that is able to scavenge vibrational energy in the out-of-plane direction and arbitrary in-plane directions with considerable wide bandwidth. It works in a hybridized mode of both vertical contact separation and in-plane sliding. Under out-of-plane motion excitation, the 3D-TENG produces an open-circuit voltage up to 123 V, a peak short-circuit current density of 30 mA m −2 , and a peak power density of 1.35 W m −2 . The corresponding electrical outputs are 143 V, 32 mA m −2 , and 1.45 W m −2 , respectively, when the 3D-TENG works under in-plane motion excitation. The remarkable performance enables the 3D-TENG to have tremendous practical applications including harvesting windor rain-droplet-induced vibrational energy from the national grid transmission lines, natural vibration energy from human walking, and rotation energy from vehicles with wheels.

Self-cleaning hybrid energy harvester to generate power from raindrop and sunlight

“…This type of iterative contact and separation process generates output with AC behavior. Based on this mechanism, most research on TENGs has focused on harvesting ambient mechanical energy types such as vibrations [21][22][23], air flows [24,25] and the mechanical energy of water [26,27]. On the other hand, water-solid interaction also causes triboelectricity with the formation of an electrical double layer (EDL) [28][29][30][31][32].…”

Multifunctional triboelectric nanogenerator based on porous micro-nickel foam to harvest mechanical energy

“…However, triboelectric nanogenerators [26][27][28][29][30][31][32][33][34][35][36] (TENGs), on this basis, has been hatched up to harvest mechanical energy as an efficient means. In virtue of coupling effect of contact electrification and electrostatic induction, the periodic contact and separation between two materials with triboelectric polarities could drive the charges between electrodes to produce an alternating current.…”

3-Dimensional broadband energy harvester based on internal hydrodynamic oscillation with a package structure

“…As a result, electron flows through the electrodes to attain a state of equilibrium by valancing this electrical potential difference. Based on this approach, various novel and efficient TENGs [17,18] have been used in conjunction with diverse energy sources, such as mechanical vibration, [19,20] human motion, [21,22] the impact of water [20,23] and air flows [24][25][26]. Apart from scavenging diverse energy sources, various power management techniques have been also well developed utilizing novel device configurations [27][28][29].…”