title: Chemosensitive running droplet.
abstract: Chemical control of the spontaneous motion of a reactive oil droplet moving on a glass substrate under an aqueous phase is reported. Experimental results show that the self-motion of an oil droplet is confined on an acid-treated glass surface. The transient behavior of oil-droplet motion is also observed with a high-speed video camera. A mathematical model that incorporates the effect of the glass surface charge is built based on the experimental observation of oil-droplet motion. A numerical simulation of this mathematical model reproduced the essential features concerning confinement of oil droplet motion within a certain chemical territory and also its transient behavior. Our results may shed light on physical aspects of reactive spreading and a chemotaxis in living things.
authors.affiliation: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Sumino
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kitahata
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nagayama
authors.forename: Shin-ichiro M
authors.initials: SM
authors.lastname: Nomura
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Magome
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Mori