Comb-structured triboelectric nanogenerators for multi-directional energy scavenging from human movements

Abstract

A triboelectric nanogenerator (TENG) is an emerging energy harvesting technology utilizing multi-directional, wasted mechanical energies stemming from vibrations, winds, waves, body movements, etc. In this study, we report a comb-structured TENG (CTENG) capable of effectively scavenging multi-directional motions from human movements, which include walking, jumping, and running. By attaching CTENG to a person's calf, we obtain a rootmean-square (RMS) power value of 5.28 μW (i.e. 13.12 V and 0.4 μA) for 1 s during mild running action (~5 m/s), which is sufficient for powering 10 light emitting diodes (LEDs). We integrate a CTENG with a simple hand-held pendulum (HHP) system with a natural frequency of 5.5 Hz. The natural frequency and input energy of our HHP system can be easily controlled by changing the holder mass and initial bending displacement, thus producing different output behaviors for the CTENG. Under the optimal HHP-based CTENG system design, the maximum output reaches 116 V at 6.5 μA under 0.1 kg mass and 4 cm bending displacement conditions. The corresponding output energy is 52.7 μJ for an operation time of 10.8 s. Our HHP-CTENG system can sufficiently power 45 LEDs and shows different output performances by varying the driving velocity of a vehicle, thus demonstrating the possibility for a self-powered velocity monitoring system.

Overview of Human Kinetic Energy Harvesting and Application

“…Wang et al demonstrated a TENG with a linear grating structure, as shown in Figure e, whose electrodes act as a slider, to harvest the swing energy of the arm, which can generate a power of 118.8 μW. Hwang et al . reported a comb-like structure of TENGs integrated with a simple hand-held pendulum (HHP) system with a natural frequency of 5.5 Hz; during light running movements at a speed of 5 m/s on the calf, a power of 5.28 μW was obtained.…”

Research Progress and Prospect of Triboelectric Nanogenerators as Self-Powered Human Body Sensors

“…Many structures such as a zigzag structure, − an x-shaped structure, − and a honeycomb lantern structure are derived. It can be used to collect the energy of human activities such as finger tapping, − walking, and running. − It has been applied in many fields, such as pressure sensors, , vibration sensors, − velocity sensors, and so on.…”

“…It can be used to collect the energy of human activities such as finger tapping, 48−51 walking, and running. 52−55 It has been applied in many fields, such as pressure sensors, 56,57 vibration sensors, 58−69 velocity sensors, 60 and so on.…”

A highly sensitive magnetic configuration‐based triboelectric nanogenerator for multidirectional vibration energy harvesting and self‐powered environmental monitoring

“…Thus, several factors must be considered in developing an effective vibration energy harvester. In particular, given that the most hard‐to‐harvest vibration energies in daily life, such as sea waves and human body movements, exist mainly in various undetermined directions (eg, directions parallel, perpendicular, or oblique to the ground), one of the research directions is to develop a versatile vibration energy harvester for simultaneously scavenging multidirectional vibrations without changing of their orientation 17,22‐28 . In this regard, studies have been conducted to seek a novel mechanism to facilitate the harvesting of such vibration energies.…”

“…In particular, given that the most hard-to-harvest vibration energies in daily life, such as sea waves and human body movements, exist mainly in various undetermined directions (eg, directions parallel, perpendicular, or oblique to the ground), one of the research directions is to develop a versatile vibration energy harvester for simultaneously scavenging multidirectional vibrations without changing of their orientation. 17,[22][23][24][25][26][27][28] In this regard, studies have been conducted to seek a novel mechanism to facilitate the harvesting of such vibration energies. The triboelectric nanogenerator (TENG), which uses the electrification generated through sequential contact and the separation of two different material surfaces, has attracted worldwide attention as a novel vibration energy harvester due to its advantageous characteristics, such as simple configuration, cost-effective fabrication, diverse material selection, and high accessibility.…”