Triboelectric Nanogenerator (TENG)—Sparking an Energy and Sensor Revolution

Introduction

The triboelectric nanogenerator (TENG) was pioneered by Wang and colleagues to convert low-frequency energy, which is often randomly distributed and irregular, into electric power. TENG operates by harnessing the coupling effect of contact electrification (CE) and electrostatic induction, offering advantages such as low cost, easy fabrication, and a wide range of material options for diverse applications. This field utilizes Maxwell’s displacement current as the driving force to efficiently convert mechanical energy into electric power or signals, irrespective of the use of nanomaterials. Since its initial invention in 2012, TENG has garnered significant attention worldwide, with extensive research efforts focused on demonstrating its applications across various fields. These applications include medical science, environmental science, wearable electronics, textile-based sensors and systems, the Internet of Things (IoT), security, and many others.

Figure-1 Four application fields of TENG and a road map defined for the development of TENG technologies [1]

Micro/nano power sources

TENGs serve as nano power and micropower sources ideal for small, wearable, distributed, and potentially flexible electronics. With the rapid advancement of the IoT and sensor networks, there is a growing demand for powering small electronics. Given their mobility, it’s crucial to harvest energy from the environment to sustain the operation of these distributed electronics. However, due to the high output voltage and low output current of TENGs, a power management circuit is necessary to effectively utilize harvested energy for charging an energy storage unit, commonly known as a self-charging power pack for self-powered systems. Demonstrated energy conversion efficiencies range from 50% to 85%, depending on the operation modes of TENGs.

Self-powered sensing

TENGs serve as self-powered sensors with a wide range of applications in the IoT and sensor networks. In the development of artificial intelligence and big data, sensor networks play a crucial role by providing the vast amount of required data. However, many sensors rely on external power sources to operate, posing limitations. The need for sensors that can respond to environmental changes without external power is essential, particularly for active sensors. TENGs are ideal choices for motion, vibration, and triggering sensors, as they generate output signals that can be wirelessly transmitted without requiring amplification.

Blue energy

TENGs serve as high-voltage sources due to their unique characteristic of generating high output voltage. This feature makes them suitable for various applications that necessitate high voltage, including driving electrostatics and excitation of plasma.

HV power sources

TENGs are particularly valuable for harvesting water wave energy, contributing to the realization of the blue energy vision. Their remarkable output efficiency at low frequencies, compared to electromagnetic generators, makes them uniquely suited for this purpose. Through the integration of multiple TENG units into networks, energy can be efficiently harvested from ocean water, thus contributing to blue energy initiatives. Recently, TENG has achieved an impressive energy harvesting efficiency of 28% when triggered in water.

Reference

[1] Wang, Z.L., 2020. Triboelectric nanogenerator (TENG)—sparking an energy and sensor revolution. Advanced Energy Materials, 10(17), p.2000137.

[2] Yang, Y., Zhang, H., Chen, J., Lee, S., Hou, T.C. and Wang, Z.L., 2013. Simultaneously harvesting mechanical and chemical energies by a hybrid cell for self-powered biosensors and personal electronics. Energy & Environmental Science, 6(6), pp.1744-1749.