Pontederia crassipes inspired bottom overflow for fast and stable drainage†

Abstract

Fast and stable water drainage is essential for living organisms, drainage plane construction, and protection of infrastructure from damage during rainfall. Unlike traditional anti-overflow drainage methods that rely on hydrophobic or sharped edges, this study demonstrates a bottom overflow-induced drainage model inspired by the water path employed by Pontederia crassipes leaves, leading to fast and stable drainage. A superhydrophilic bottom surface guides water to overflow and pin at the bottom of a thin sheet, resulting in dripping at a higher frequency and reduced water retention. This bottom drainage idea assists large-scale thin sheets to function as efficient and stable drainage surfaces in simulated rain environments. The flexible thin sheet can also be feasibly attached to dusty substrates to effectively remove dusty rainwater with slight dust residue. The bioinspired approach presented herein suggests a promising potential for efficient water drainage on outdoor functional photovoltaic surfaces, such as solar panels and radomes, thus ensuring effective energy conversion and stable signal transmission.