Nanoengineered Surfaces for Robust Droplet TENGs: Mitigating Contamination and Improving Longevity

Abstract

The droplet triboelectric nanogenerator (D-TENG) harnesses energy from natural water droplets, though its performance and lifespan can be compromised by contamination on the functional layer. Water molecules have a strong affinity for polymer surfaces, which increases surface tension and the sliding-off angle, leading to greater droplet adhesion. As these droplets evaporate, they leave behind residues, such as calcium (Ca) and magnesium (Mg) salts, that obscure the polymer surface, thereby diminishing the electrification area and altering droplet dynamics—resulting in decreased electrical output. This study presents a micro-nanostructured D-TENG with advanced anti-fouling capabilities. By adding a layer of metal nanoparticles to the polymer surface, followed by ion etching and fluorination grafting, water retention and ion accumulation are effectively minimized. The anti-fouling D-TENG demonstrates a fourfold increase in electrical output compared to its predecessor. Following 10 000 droplet interactions, the output of the original D-TENG drops by 53%, whereas the anti-fouling variant only experiences a 7% reduction. These enhancements provide significant insights for D-TENG applications and contribute to the development of anti-fouling strategies.