title: Superhydrophobic-like tunable droplet bouncing on slippery liquid interfaces.
abstract: Droplet impacting on solid or liquid interfaces is a ubiquitous phenomenon in nature. Although complete rebound of droplets is widely observed on superhydrophobic surfaces, the bouncing of droplets on liquid is usually vulnerable due to easy collapse of entrapped air pocket underneath the impinging droplet. Here, we report a superhydrophobic-like bouncing regime on thin liquid film, characterized by the contact time, the spreading dynamics, and the restitution coefficient independent of underlying liquid film. Through experimental exploration and theoretical analysis, we demonstrate that the manifestation of such a superhydrophobic-like bouncing necessitates an intricate interplay between the Weber number, the thickness and viscosity of liquid film. Such insights allow us to tune the droplet behaviours in a well-controlled fashion. We anticipate that the combination of superhydrophobic-like bouncing with inherent advantages of emerging slippery liquid interfaces will find a wide range of applications.
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China.
authors.forename: Chonglei
authors.initials: C
authors.lastname: Hao
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Physics, Chinese University of Hong Kong, Hong Kong 999077, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Science and Technology on Microsystem Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China.
authors.forename: Yahua
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.affiliation: Science and Technology on Microsystem Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Lufeng
authors.initials: L
authors.lastname: Che
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China.
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Sun
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Physics, Chinese University of Hong Kong, Hong Kong 999077, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.affiliation: 1] Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong 999077, China [2] Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China.
authors.forename: Zuankai
authors.initials: Z
authors.lastname: Wang