A transparent droplet based triboelectricity generator assisted roadway wireless communication system

In order to achieve the urgent demand for maintenance-free and zero-emission power supply for distributed sensors on smart highways, this work proposes and demonstrates a transparent droplet triboelectric generator (DEG) based on a fluorinated ethylene propylene/indium–tin oxide (FEP/ITO) structure that can directly harvest natural rainfall to power gantry-mounted distance sensors and warning lights. The DEG employs a transparent FEP film as the dielectric layer. With the aid of hydrophobic surface modification and a buck-type power management circuit, a single device can generate 120 V open-circuit voltage, a 25 μA short-circuit current, and a 4.7 W/m2peak power density of under a droplet height of 50 cm and a flow rate of 420 mL/h. After four such DEGs are connected in parallel, they can charge a 220 μF capacitor to 3 V within 5 minutes, successfully driving a millimeter-wave distance sensor and LED indicator, thereby offering a new solution for engineering applications of rain energy in smart transportation.