A membrane raindrop generator and its application as a self‐powered pH sensor

Abstract

Abstract Raindrop contains a large amount of renewable mechanical energy. Acid rain has adverse impact on the plants, aquatic animals and infrastructure. In this work, a triboelectric raindrop generator (TRG) was developed to harvest raindrop energy on a large scale. The TRG consists of electrification layer, electrodes and substrate. At the rainfall rate of 53 mL/s, the open‐circuit voltage and short‐circuit currents of the device reaches 27 V and 4.6 μA, respectively, which can simultaneously drive 60 LED light‐emitting diodes or charge a 5 μF capacitor. In addition, relied on the electrostatic shielding effect of the solid–liquid interface, the pH value of ambient solution drops can be spontaneously detected to reveal the potential in real‐time monitoring of environmental quality. By integrating with a signal processing circuit, a self‐powered acid rain alert system was formed for real‐time monitoring the acidity of the falling raindrops. This work proposes a feasible and innovative approach for active environmental monitoring.