Taking charge off droplets: Introducing the multi-point electrode TENG

Droplet triboelectric nanogenerators (D-TENGs) offer a promising route for ambient energy harvesting, yet their efficiency remains limited by poorly understood and suboptimal charge transfer mechanisms. Here, we introduce a novel point electrode design (P-TENG) that decouples the surface electrode from the dielectric, enabling systematic investigation and optimisation of charge dynamics. Compared to conventional droplet electrode generators (DEGs), the P-TENG exhibits a 315 % increase in peak power and a 519 % increase in energy output. Through extensive experimentation combined with analytical modelling, we demonstrate that electrode placement, droplet dynamics, and surface charge gradients significantly influence charge transfer efficiency. Extending this architecture to a two-electrode configuration (2P-TENG), we show that introducing a heterogeneous dielectric interface, combining PDMS and PLA, amplifies spatial charge variation and enhances charge transfer. This increases the charge recovery by 81.6 % compared to its single electrode equivalent. Our results reveal that engineered dielectric ‘imperfections’ can outperform uniform surfaces, offering a new strategy for scalable, high-efficiency TENG designs. These insights lay the foundation for future multi-material, multi-electrode droplet-based TENGs tailored for practical energy harvesting applications. • New point-electrode design delivers 315 % more power than droplet energy generators. • Multi-electrode layout enables charge recycling and boosts efficiency. • Heterogeneous dielectric improves inter-electrode charge recovery. • Demonstrates route to high-efficiency droplet triboelectric nanogenerators. • Advances energy harvesting solutions for the Internet of Things.