Wu Hao, Mendel Niels, van der Ham Stijn, Shui Lingling, Zhou Guofu, Mugele Frieder
Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China.
National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China.
Adv Mater. 2020 Aug;32(33):e2001699. doi: 10.1002/adma.202001699. Epub 2020 Jul 6.
Strategies toward harvesting energy from water movements are proposed in recent years. Reverse electrowetting allows high efficiency energy generation, but requires external electric field. Triboelectric nanogenerators, as passive energy harvesting devices, are limited by the unstable and low density of tribo-charges. Here, a charge trapping-based electricity generator (CTEG) is proposed for passive energy harvesting from water droplets with high efficiency. The hydrophobic fluoropolymer films utilized in CTEG are pre-charged by a homogeneous electrowetting-assisted charge injection (h-EWCI) method, allowing an ultrahigh negative charge density of 1.8 mC m . By utilizing a dedicated designed circuit to connect the bottom electrode and top electrode of a Pt wire, instantaneous currents beyond 2 mA, power density above 160 W m , and energy harvesting efficiency over 11% are achieved from continuously falling water droplets. CTEG devices show excellent robustness for energy harvesting from water drops, without appreciable degradation for intermittent testing during 100 days. These results exceed previously reported values by far. The approach is not only applicable for energy harvesting from water droplets or wave-like oscillatory fluid motion, but also opens up avenues toward other applications requiring passive electric responses, such as diverse sensors and wearable devices.
近年来，人们提出了从水的运动中获取能量的策略。反向电润湿可实现高效发电，但需要外部电场。摩擦纳米发电机作为无源能量收集装置，受到摩擦电荷不稳定和密度低的限制。在此，提出了一种基于电荷俘获的发电机（CTEG），用于从水滴中高效地进行无源能量收集。CTEG中使用的疏水性含氟聚合物薄膜通过均匀电润湿辅助电荷注入（h-EWCI）方法进行预充电，可实现1.8 mC m的超高负电荷密度。通过利用专门设计的电路连接铂丝的底部电极和顶部电极，从连续下落的水滴中可实现超过2 mA的瞬时电流、高于160 W m的功率密度以及超过11%的能量收集效率。CTEG装置在从水滴中收集能量方面表现出出色的稳健性，在100天的间歇测试中没有明显降解。这些结果远远超过了此前报道的值。该方法不仅适用于从水滴或波状振荡流体运动中收集能量，还为其他需要无源电响应的应用开辟了道路，如各种传感器和可穿戴设备。
