An Easily Assembled Electromagnetic‐Triboelectric Hybrid Nanogenerator Driven by Magnetic Coupling for Fluid Energy Harvesting and Self‐Powered Flow Monitoring in a Smart Home/City

Abstract

with smart devices, is driven by reliable power. With the continuous development of microelectromechanical systems and the Internet of Things (IoT), many small electronic devices, which require a sustainable, portable, distributed, wireless, and even implantable power source, are increasingly widely used in daily life and industrial monitoring environments. [1] However, traditional power supply solutions, which include electric cables and batteries, cannot fully satisfy their special demands. [2] Fortunately, mechanical energy, which is widely present in the environment, such as via wind and water flow, contains a large amount of easily accessible energy. [3] Regarding mechanical energy harvesting techniques, until now, four main energy conversion mechanisms are used: electromagnetic, [4] piezoelectric, [5] electrostatic, [6] and triboelectric. [7] In particular, triboelectric nanogenerators (TENGs), which were first described by Wang and coworkers in 2012 [8] and are based on the triboelectrification effect and electrostatic induction, are becoming the most important devices since they have many advantages, such as simple fabrication, light weight, low cost, high output voltage, and high durability, especially for human-related activities. Recently, Harvesting wind energy and water flow energy from the living environment to efficiently and conveniently power many small electric devices at home is becoming increasingly important for the development of the smart home system. Triboelectric nanogenerators (TENGs) are considered to be one of the most effective devices to harness various types of mechanical energy. Here, an easily assembled electromagnetic-triboelectric hybrid nanogenerator (EANG) driven by magnetic coupling is reported. The introduction of magnetic coupling makes it easy to package, maintain, and assemble a nanogenerator (NG), so its performance is very stable regardless of environmental variations. A sliding freestanding mode TENG and a rotary electromagnetic generator (EMG) are integrated to improve their output and broaden the frequency range of external energy. It is shown that the EANG can be conveniently integrated with a wind cup or water turbine and harvest fluid energy to power small electronic devices, such as a humidity sensor and temperature sensor. Moreover, a NG can be used as a self-powered flow sensor to monitor the flow rate of outdoor wind and tap water. These results can be used to help solve practical problems regarding energy supplying and sensing in a smart home, smart building, and smart city.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.

Progress inTENGtechnology—A journey from energy harvesting to nanoenergy and nanosystem

“…116,[260][261][262] Compared with other kinds of energy generators, EMGs would have an advantage of compensation for the drawback (low power density in high frequency) in TENG, which is the low output current, with their large induction current and high-power generation. [263][264][265] Figure 10 shows several typical examples for the hybridized triboelectric-electromagnetic energy generators. [266][267][268][269][270] The energy generator shown in Figure 10A is aiming at scavenging the ambient energy from airflow, which contains two EMG units and two TENG units.…”

“…Therefore, to increase the output power density and utilize various ambient energy sources more effectively, the integration of other energy scavenging mechanisms with triboelectric has been widely explored in the past few years, including piezoelectric, thermoelectric, solar cell, and EM 116,260‐262 . Compared with other kinds of energy generators, EMGs would have an advantage of compensation for the drawback (low power density in high frequency) in TENG, which is the low output current, with their large induction current and high‐power generation 263‐265 . Figure 10 shows several typical examples for the hybridized triboelectric‐electromagnetic energy generators 266‐270 …”

Self-Powered Sensors and Systems Based on Nanogenerators

“…With the same device area of about 22 mm × 120 mm, the output power delivered by the solar cell and the TENG can reach about 8 mW and 26 mW, respectively. Zhong et al studied methods for harvesting the water flow energy from our living environment to conveniently and efficiently power small household electric devices [203]. A hybrid generator consisting of a rotary EMG and a TENG with the freestanding mode is proposed to be conveniently integrated with a water turbine and a wind cup for harvesting fluid energy.…”

Triboelectric Nanogenerators and Hybridized Systems for Enabling Next-Generation IoT Applications

“…Using the same generator to harvest the outdoor wind energy and the indoor water flow energy simultaneously is also a good strategy to realize sustainable smart home systems. As illustrated in Figure 5(e) [ 151 ], a TENG-EMG hybrid generator was proposed by Zhong et al for collecting energies from multiple sources. The proposed hybrid generator consists of a cylindrical stator with multiple attached electrodes and a cylindrical rotator with several FEP films mounted on the outer surface.…”