A Self-powered biomimetic pyramidal-structured droplet generator for cathodic protection against metal corrosion

With the rapid development of renewable energy technologies, droplet electricity generators (DEGs) have emerged as a promising approach to harvest low-frequency and random mechanical energy from falling droplets. However, conventional triboelectric PDMS suffers from a low dielectric constant and charge leakage, limiting charge storage, separation, and output performance. Inspired by the skin structure of planthoppers, we develop a self-powered biomimetic pyramidal-structured DEG based on a fluorinated TiO 2 nanoparticle-decorated pyramid-structured PDMS film (F-TiO 2 @P-PDMS). The resulting micro/nano hierarchical superhydrophobic film exhibits an increased dielectric constant and enhanced electrical output compared with pure PDMS. The device maintains stable performance under both low- and high-frequency droplet impacts. When integrated into a self-powered cathodic protection system, it shifts the corrosion potential of 304 stainless steel from −180 to −390 mV, demonstrating effective corrosion protection. This work offers a strategy for efficient droplet energy harvesting and green anticorrosion applications.