Patent ID: 8858682

Claim:
A pressure-difference bubble transfer control method comprising: disposing a first flow channel for flowing a first fluid of liquid and a second flow channel for flowing a second fluid of liquid with a gas exchange unit, through which a liquid cannot pass but a gas component(s) can pass, being interposed therebetween; transferring a dissolved gas component due to concentration gradient from the first fluid into the second fluid through the gas exchange unit, the dissolved gas component being initially contained in the first fluid; and transferring bubbles from the second fluid into the first fluid due to a pressure difference between the first and second flow channels with the gas exchange unit interposed therebetween by making a pressure in the second flow channel higher than a pressure in the first flow channel, wherein the gas exchange unit comprises one element, and the element being selected from the group consisting of: (a) a porous gas permeable membrane, (b) a membrane filter having a plurality of pores penetrating therethrough, (c) a membrane filter having a plurality of pores penetrating therethrough and a gas permeable layer formed of a hydrophobic material on the membrane filter to prevent the transfer of a liquid through the pores of the membrane filter and to form gaps through which only a gas component(s) contained in the liquid can pass, and (d) a plurality of grooves connecting the first and second flow channels to each other, at least a part of the inner surface of each of the grooves being hydrophobized and the cross-sectional area of each of the grooves being determined so that a liquid cannot be transferred through the grooves but only a gas component(s) contained in the liquid can be transferred through the grooves.