Out‐Of‐Plane Electrokinetics via Pumping Potential Achieved by 100 nm‐Thin Polyethylene Nanomembranes

Abstract Droplet‐induced electricity generation, as one of the most emerging environmental energy harvesting technologies, is extensively investigated for nearly a decade. Its interaction between ions (in droplets), electrons (in conductors, e.g., graphene), and charges (on the substrate surface) is the key to electricity generation. However, the indirect interaction between ions and charges due to the shielding effect from conductors, inevitably suppresses device performance and limits conductor selection. Herein, the above issues are addressed by proposing an out‐of‐plane electrokinetic effect based on a 100 nm‐thick negatively charged polyethylene nanomembrane, providing direct interactions between ions and charges, with the shielding effect of conductors eliminated. This new form of electrokinetics can induce a persistent potential for 6 h and a specific power of 177.2 nW µL⁻¹ (highest droplet‐induced electrokinetics). With new device topologies and extensive conductor materials unlocked, this work provides a new concept and expanded scope for electrokinetic applications.