Achieving the directional and long-range droplet transport on solid surfaces is widely preferred for many practical applications but has proven to be challenging.Particularly,directionality and transport distance of d...Achieving the directional and long-range droplet transport on solid surfaces is widely preferred for many practical applications but has proven to be challenging.Particularly,directionality and transport distance of droplets on hydrophobic surfaces are mutually exclusive.Here,we report that drain fly,a ubiquitous insect maintaining nonwetting property even in very high humidity,develops a unique ballistic droplet transport mechanism to meet these demanding challenges.The drain fly serves as a flexible rectifier to allow for a directional and long-range propagation as well as self-removal of a droplet,thus suppressing unwanted liquid flooding.Further investigation reveals that this phenomenon is owing to the synergistic conjunction of multiscale roughness,structural periodicity,and flexibility,which rectifies the random and localized droplet nucleation(nanoscale and microscale)into a directed and global migration(millimeter-scale).The mechanism we have identified opens up a new approach toward the design of artificial rectifiers for broad applications.展开更多
基金This work is partially supported by the Research Grants Council of the Hong Kong Special Administrative Region(Nos.11213915 and 11218417)the Innovation and Technology Fund(No.9440248)+1 种基金the National Natural Science Foundation of China(No.21805294)the Shenzhen Science and Technology Innovation Council(Nos.JCYJ20170413141208098 and JCYJ20170818103206501).
文摘Achieving the directional and long-range droplet transport on solid surfaces is widely preferred for many practical applications but has proven to be challenging.Particularly,directionality and transport distance of droplets on hydrophobic surfaces are mutually exclusive.Here,we report that drain fly,a ubiquitous insect maintaining nonwetting property even in very high humidity,develops a unique ballistic droplet transport mechanism to meet these demanding challenges.The drain fly serves as a flexible rectifier to allow for a directional and long-range propagation as well as self-removal of a droplet,thus suppressing unwanted liquid flooding.Further investigation reveals that this phenomenon is owing to the synergistic conjunction of multiscale roughness,structural periodicity,and flexibility,which rectifies the random and localized droplet nucleation(nanoscale and microscale)into a directed and global migration(millimeter-scale).The mechanism we have identified opens up a new approach toward the design of artificial rectifiers for broad applications.
