title: The movement of a water droplet on a gradient surface prepared by photodegradation.
abstract: A hydrophobic to hydrophilic gradient surface was prepared using the tuned photodegradation of an alkylsilane self-assembled monolayer (SAM) using irradiation of vacuum ultraviolet light (wavelength=172 nm). The water contact angle on the photodegraded SAM surface was adjusted using the intensity and time photoirradiation parameters. The formation of a gradient was confirmed by fluorescent labeling. The water drop moved from the hydrophobic to hydrophilic surface with a velocity that depended on the gradient. The higher the gradient, the faster the water moved. For the first time, we have prepared a gradient surface using photodegradation where the movement of a water drop was regulated by the degree of gradation. Considering that the photodegradation technique can be applied to various surfaces and to lithography, this technique will be useful for various material surfaces.
authors.affiliation: Regenerative Medical Bioreactor Project, Kanagawa Academy of Science and Technology, KSP East 309, 1-2-3 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012 Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Mojgan
authors.initials: M
authors.lastname: Heydari
authors.forename: Ayako
authors.initials: A
authors.lastname: Hashimoto
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Konno
authors.forename: Ayaka
authors.initials: A
authors.lastname: Hirasawa
authors.forename: Satomi
authors.initials: S
authors.lastname: Hori
authors.forename: Kimio
authors.initials: K
authors.lastname: Kurita
authors.forename: Akira
authors.initials: A
authors.lastname: Nakajima
mesh_terms: D015394:Molecular Structure; D010777:Photochemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water