Breathable Window Screen Against High-velocity Droplet Penetration.

Abstract

Window screens serve the multiple purposes of enabling ventilation while preventing the ingress of solid objects and insects. However, their intrinsic porosity makes them susceptible to fluid intrusion while maintaining ventilation, notably evident in the infiltration of high-velocity raindrops during inclement weather, flooding the room. Addressing this challenge, bilayer synergistic mesh featuring an upper superhydrophilic (SHPi) surface and a bottom Janus wettability designed is presented to withstand puncture from continuous high-speed droplets. This innovative design incorporates a dual waterproof mechanism, providing instantaneous penetration resistance through energy dissipation and long-term infiltration resistance by a stable liquid film against high-speed droplets. The SHPi-Janus bilayer synergistic mesh demonstrates exceptional capability in repelling droplet penetration at a vertical high velocity of 4.5 m s^-1, significantly mitigating droplet infiltration under most rainfall conditions in the real world. Experimental findings reveal that the droplet penetration ratio of SHPi-Janus mesh is a mere 3.6% under sustained high-velocity droplet impact, a substantial leap forward compared to the 61.1% observed with commercial screen.