Achieving a High-Output Direct-Current Droplet Triboelectric Generator via Synergistic Effects of a Dual Switch and Electric Double Layer.

Droplet triboelectric generators (D-TENGs) have garnered significant attention for harvesting raindrop energy but face challenges such as low output performance and alternating current (AC) output. This study proposes a high-performance direct current (DC) D-TENG with a dual-switch (DS) structure (DS-DC-D-TENG) that synergizes dual-switch effects and electric double layers (EDL) to generate DC pulses. Remarkably, using 0.1 mM NaCl droplets, the DS-DC-D-TENG achieves a record-breaking DC short-circuit current of 75 μA for polymer-based DC-D-TENGs. The physical mechanism is elucidated through an equivalent circuit model and a finite element method (FEM) simulation. Unlike conventional designs, it directly charges capacitors without a rectifier, powers integrated systems for temperature and humidity sensing display, and can be used as a self-powered droplet counter to measure droplet number and frequency, showcasing its application potential. This work provides novel insights into the design and future applications of high-performance DC-D-TENGs.