title: One-Directional Fluidic Flow Induced by Chemical Wave Propagation in a Microchannel.
abstract: A one-directional flow induced by chemical wave propagation was investigated to understand the origin of its dynamic flow. A cylindrical injection port was connected with a straight propagation channel; the chemical wave was initiated at the injection port. Chemical waves propagated with a constant velocity irrespective of the channel width, indicating that the dynamics of the chemical waves were governed by a geometry-independent interplay between the chemical reaction and diffusion. In contrast, the velocity of the one-directional flow was dependent on the channel width. Furthermore, enlargement of the injection port volume increased the flow velocity and volume flux. These results imply that the one-directional flow in the microchannel is due to a hydrodynamic effect induced in the injection port. Spectroscopic analysis of a pH indicator revealed the simultaneous behavior between the pH increase near the injection port and the one-directional flow. Hence, we can conclude that the one-directional flow in the microchannel with chemical wave propagation was caused by a proton consumption reaction in the injection port, probably through liquid volume expansion by the reaction products and the reaction heat. It is a characteristic feature of the present system that the hydrodynamic flow started from the chemical wave initiation point and not the propagation wavefront, as observed for previous systems.
authors.affiliation: Department of Material and Biological Chemistry, Faculty of Science, Yamagata University , 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Miyu
authors.initials: M
authors.lastname: Arai
authors.affiliation: Department of Material and Biological Chemistry, Faculty of Science, Yamagata University , 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Material and Biological Chemistry, Faculty of Science, Yamagata University , 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Hattori
authors.affiliation: Department of Material and Biological Chemistry, Faculty of Science, Yamagata University , 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Department of Material and Biological Chemistry, Faculty of Science, Yamagata University , 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Sato
authors.affiliation: Department of Material and Biological Chemistry, Faculty of Science, Yamagata University , 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Unoura
authors.affiliation: Department of Material and Biological Chemistry, Faculty of Science, Yamagata University , 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nabika