Abstract
We studied formation process of gas-liquid interface in a microchannel having hydrophobic cavity-shaped microstructures. The microstructures were fabricated on a test wall by wire electric discharge machining, and the test wall was coated with triazine thiol to induce hydrophobicity. Width and height of the microstructures are 1 mm and 100 μm, respectively, and the microcavities (100 × 100 × 100 μm^3) are aligned on side walls with 100 μm spacings. We experimented with 6 different concentrations of aqueous ethanol solutions in order to investigate the effect of the surface tension. As a result, it was found that formation process of gas-liquid interface can be categorized into 3 types of processes by the difference of the surface tension.
