Surface Modification Method of Microchannels for Gas-Liquid Two-Phase Flow in Microchips

详细信息    查看全文

• 作者：Akihide Hibara ; Shinobu Iwayama ; Shinya Matsuoka ; Masaharu Ueno ; Yoshikuni Kikutani ; Manabu Tokeshi ; and Takehiko Kitamori
• 刊名：Analytical Chemistry
• 出版年：2005
• 出版时间：February 1, 2005
• 年：2005
• 卷：77
• 期：3
• 页码：943 - 947
• 全文大小：311K
• 年卷期：v.77,no.3(February 1, 2005)
• ISSN：1520-6882

文摘

A capillarity restricted modification method for microchannel surfaces was developed for gas-liquid microchemical operations in microchips. In this method, amicrostructure combining shallow and deep microchannels and the principle of capillarity were utilized forchemical modification of a restricted area of a microchannel. A hydrophobic-hydrophilic patterning in microchannels was prepared as an example for guiding gas andliquid flows along the respective microchannels. Validityof the patterning was confirmed by measuring aqueousflow leak pressure from the hydrophilic microchannel tothe hydrophobic one. The leak pressure of 7.7-1.1 kPaagreed well with that predicted theoretically from theYoung-Laplace equation for the microchannel depth of8.6-39 m. In an experiment to demonstrate usefulnessand effectiveness of the method, an air bubble was firstintroduced into the hydrophilic microchannel and purgedfrom the hydrophobic-hydrophilic patterned microchannels. Next, the patterning structure was applied to removedissolved oxygen by contacting the aqueous flow with anitrogen flow. The concentration of dissolved oxygendecreased with contact time, and its time course agreedwell with numerical simulation. These demonstrationsshowed that the proposed patterning method can be usedin general microfluidic gas-liquid operations.