Biomimetic Superhydrophobic Surfaces Efficiently Harvest Fog by Leveraging the Triboelectric Phenomenon

Fog harvesting presents a promising solution to water scarcity, yet its efficiency on passive surfaces is inherently constrained by the trade-off between droplet capture and removal. Herein, we report an active strategy that synergistically integrates a biomimetic superhydrophobic surface (MMC-T) with a triboelectric effect for on-demand droplet shedding. Inspired by the desert beetle and lotus leaf, our surface incorporates nanoscale hydrophilic domains to promote condensation. Crucially, a subsurface triboelectric layer, activated by mechanical motion, generates an asymmetric electric field to drive droplet removal. This active control enables a remarkable fog harvesting rate of 10.74 ± 0.35 kg·m^-2 ·h^-1, which represents a 44.16% increase compared to the passive mode. Moreover, we demonstrate a portable device powered by biomechanical energy (e.g., walking), highlighting its potential for practical decentralized water collection. This work represents a paradigm shift from passive to active water harvesting and paves the way for next-generation fog harvesters.