title: Enhanced load-carrying capacity of hairy surfaces floating on water.
abstract: Water repellency of hairy surfaces depends on the geometric arrangement of these hairs and enables different applications in both nature and engineering. We investigate the mechanism and optimization of a hairy surface floating on water to obtain its maximum load-carrying capacity by the free energy and force analyses. It is demonstrated that there is an optimum cylinder spacing, as a result of the compromise between the vertical capillary force and the gravity, so that the hairy surface has both high load-carrying capacity and mechanical stability. Our analysis makes it clear that the setae on water striders' legs or some insects' wings are in such an optimized geometry. Moreover, it is shown that surface hydrophobicity can further increase the capacity of a hairy surface with thick cylinders, while the influence is negligible when the cylinders are thin.
authors.affiliation: State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, College of Engineering , Peking University , Beijing 100871, People's Republic of China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Xue
authors.affiliation: State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, College of Engineering , Peking University , Beijing 100871, People's Republic of China.
authors.forename: Huijing
authors.initials: H
authors.lastname: Yuan
authors.affiliation: State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, College of Engineering , Peking University , Beijing 100871, People's Republic of China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Su
authors.affiliation: State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, College of Engineering , Peking University , Beijing 100871, People's Republic of China.
authors.forename: Yipeng
authors.initials: Y
authors.lastname: Shi
authors.affiliation: State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, College of Engineering , Peking University , Beijing 100871, People's Republic of China ; Key Laboratory of High Energy Density Physics Simulation (HEDPS), CAPT , Peking University , Beijing 100871, People's Republic of China.
authors.forename: Huiling
authors.initials: H
authors.lastname: Duan
keywords: free energy analysis; hairy surfaces; load-carrying capacity; superhydrophobicity