title: Cutting a drop of water pinned by wire loops using a superhydrophobic surface and knife.
abstract: A water drop on a superhydrophobic surface that is pinned by wire loops can be reproducibly cut without formation of satellite droplets. Drops placed on low-density polyethylene surfaces and Teflon-coated glass slides were cut with superhydrophobic knives of low-density polyethylene and treated copper or zinc sheets, respectively. Distortion of drop shape by the superhydrophobic knife enables a clean break. The driving force for droplet formation arises from the lower surface free energy for two separate drops, and it is modeled as a 2-D system. An estimate of the free energy change serves to guide when droplets will form based on the variation of drop volume, loop spacing and knife depth. Combining the cutting process with an electrofocusing driving force could enable a reproducible biomolecular separation without troubling satellite drop formation.
authors.affiliation: Department of Chemistry & Biochemistry, Arizona State University, Tempe, AZ, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Yanashima
authors.forename: Antonio A
authors.initials: AA
authors.lastname: García
authors.forename: James
authors.initials: J
authors.lastname: Aldridge
authors.forename: Noah
authors.initials: N
authors.lastname: Weiss
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hayes
authors.forename: James H
authors.initials: JH
authors.lastname: Andrews
mesh_terms: D000465:Algorithms; D057927:Hydrophobic and Hydrophilic Interactions; D008962:Models, Theoretical; D020959:Polyethylene / Q000737:chemistry*; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D014867:Water; D020959:Polyethylene