Study and fabrication of rain triboelectric nanogenerator based on laser-induced graphene interdigital electrode

In this work, a rain triboelectric nanogenerator (R-TENG) based on a laser-induced graphene (LIG) interdigital electrode was developed to harvest rain energy. The R-TENG comprises a LIG interdigital electrode on a polymer substrate with a hydrophobic Polydimethylsiloxane (PDMS) layer as a protective layer. When raindrops fall onto the surface of the PDMS layer and move between two adjacent interdigital electrodes, the accumulated charges move back and forth, resulting in the generation of alternating current. The LIG pattern design and the energy collection efficiency were studied by altering the production parameters of the LIG electrode and measuring the droplet diameter on the PDMS surface. A R-TENG with an electrode width of 3 mm produces a laser power of 2.1 W, and an output voltage of 2.46 V is generated. The R-TENG could be applied as an additional energy source to harvest rain energy for agricultural IoT sensors.