Laser-fabricated sandwiched fog collector enabling agricultural irrigation and electricity generation

Abstract

Atmospheric fog is an abundant yet underutilized freshwater resource for remote and arid regions, but existing fog harvesters face a fundamental trade-off: impermeable collectors suffer from aerodynamic bypass, whereas porous meshes are prone to pore flooding, clogging, and droplet re-entrainment due to inefficient liquid removal. Here, we report a laser-fabricated sandwiched fog collector that introduces an extreme wettability contrast by stacking superhydrophobic (SHB) and superhydrophilic (SHL) meshes in an SHB–SHL–SHB configuration to enable preferential out-of-plane liquid transport from fog interception sites to drainage pathways. This architecture preserves the high capture capability of porous meshes while continuously renewing open pores, thereby suppressing clogging and re-entrainment under continuous fog-laden airflow. As a result, the collector achieves a high water-collection rate of 1200 mg cm⁻² h⁻¹ with direction-insensitive performance. A large-scale fog collector of 36 cm × 56 cm was fabricated to exhibit scalability and enhanced collection. Beyond water collection, the collected droplets by fog collectors enable accelerated crop cultivation and drive a droplet-based electricity generator delivering electrical outputs of 171 V and 1.75 mJ m⁻². This scalable, low-cost strategy provides a practical route toward simultaneous crop irrigation and electricity generation for remote, off-grid areas.