Water Droplet‐Based Nanogenerators

Abstract

Water is one of the most sustainable resources in the world, offering an abundance of hydro energy. Getting a large amount of electricity through conventional water energy harvesting is expensive, with complex mechanisms and bulky installation systems. In the case of the small amount of energy for some portable electronic devices and sensor systems, water droplet harvesting as a sustainable energy resource has become a forward‐looking step to meet the future demand for green energy. The ultimate demand for green energy in the future requires all the possible sustainable energy sources surrounding human society. The emerging potential of water droplet‐driven energy‐harvesting nanogenerators can meet a significant portion of the green energy demand. In this review, the recent developments in droplets‐driven nanogenerators for effective energy scavenging is summarized. It also includes an extensive discussion about the device structures from the material selection and output performance aspects. This review also gives a brief discussion on the applications of droplet‐based nanogenerators and outlines the future possibilities via the current improvement in designs and fabrication strategies that have been introduced by the field.

Fibers/Textiles-Based Flexible Sweat Sensors: A Review

“…In addition to the small number of ingredients in sweat, recent research suggests that droplets may also be used to generate electricity. 160 Therefore, water, which is the most abundant component of sweat, can also be used for power supply. In 2022, Xingcan Huang et al 161 used the redox reaction of sweat with magnesium and combined near-field communication (NFC) technology to prepare sweat-activated batteries embedded in textiles, as shown in Figure 11d.…”

“…Because of the lower content of reactants in sweat, the resulting energy density and open-circuit voltage are 0.26–252 μW cm –2 and 0.31–1.08 V, respectively. In addition to the small number of ingredients in sweat, recent research suggests that droplets may also be used to generate electricity . Therefore, water, which is the most abundant component of sweat, can also be used for power supply.…”

Robust Solid‐Liquid Triboelectric Nanogenerators: Mechanisms, Strategies and Applications

“…[20] Subsequently, this environmentally friendly, efficient and easy-to-operate method quickly attracted the attention of scholars worldwide, opening a new chapter in the research of collecting renewable clean energy from water. [21][22][23][24][25][26] The SL-TENGs cleverly combine solid-liquid interface CE and electrostatic induction, and as micro-nano energy harvesters, show significant advantages and prospects in energy harvesting and utilization from water in the forms of water resources such as droplets, waves, and flows, and others. So far, research on SL-TENGs has been developed for nearly a decade (Figure 1), and their applications involve blue energy harvesting, [27] physical sensors, [28] chemical sensors, [29] biomedicine, [30] underwater wireless communication, [31] and many other fields.…”

An Electrode‐Grounded Droplet‐Based Electricity Generator (EG‐DEG) for Liquid Motion Monitoring

“…[4][5][6] TENG can be as self-powered sensors to output electric signals according to external stimulus with advantages of simple structure and low cost. [7][8][9] So far, TENG has been employed in different contacting interfaces, such as solid-solid interface, liquid-solid interface, liquid-liquid interface and etc. [10][11][12] For liquid-solid TENG DOI: 10.1002/adfm.202302147 (LS-TENG), recent studies have demonstrated that LS-TENG was used as selfpowered sensors in the field of droplet motion monitoring, [13] lubricating oil condition monitoring [14] and ship draft detecting.…”