2008 年 59 巻 1 号 p. 57
In this research, it is aimed to control the flow velocities of some liquids by surface energy control on the channel of a chemical chip substrate.
Chemically adsorbed monolayers were used to control the flow velocities on a Y shaped channel of a chemical chip substrate. Five kinds of glass substrates covered with chemically adsorbed monolayers of a fluorocarbon compound, two hydrocarbon compounds, and two mixture compounds of those were made. With the use of Zisman's plot, the surface energies were determined on these glass substrates.
In measurement of the flow velocity, three chemically adsorbed monolayers having different surface energies were chosen. Each of the chemically adsorbed monolayers was selectivity formed on one side of the branching channels to control the flow velocity, and not on the other side. Xylene, methyl benzene, and tetrabromoethane were respectively injected into the channel of the chemical chip substrate, and relationships between the surface energy and the flow velocity of the liquids were measured. The flow velocity increased with increasing the surface energy of the channels. It was shown to be possible to control the surface energy of the channel without spoiling the channel function by the chemically adsorbed monolayers, and to be possible to control the flow velocities of the liquids on the channel of the chemical chip substrate by surface energy control. It was confirmed that the effect of the surface energy became stronger with decreasing the liquid viscosity.