title: Infinite lifetime of underwater superhydrophobic states.
abstract: Submerged superhydrophobic (SHPo) surfaces are well known to transition from the dewetted to wetted state over time. Here, a theoretical model is applied to describe the depletion of trapped air in a simple trench and rearranged to prescribe the conditions for infinite lifetime. By fabricating a microscale trench in a transparent hydrophobic material, we directly observe the air depletion process and verify the model. The study leads to the demonstration of infinite lifetime (>50 days) of air pockets on engineered microstructured surfaces under water for the first time. Environmental fluctuations are identified as the main factor behind the lack of a long-term underwater SHPo state to date.
authors.affiliation: Mechanical and Aerospace Engineering Department, University of California at Los Angeles (UCLA), Los Angeles, California 90095, USA.
authors.forename: Muchen
authors.initials: M
authors.lastname: Xu
authors.affiliation: Mechanical and Aerospace Engineering Department, University of California at Los Angeles (UCLA), Los Angeles, California 90095, USA.
authors.forename: Guangyi
authors.initials: G
authors.lastname: Sun
authors.affiliation: Mechanical and Aerospace Engineering Department, University of California at Los Angeles (UCLA), Los Angeles, California 90095, USA.
authors.forename: Chang-Jin
authors.initials: CJ
authors.lastname: Kim