文摘
A novel concept for assembling various chemical functionsonto a single microfluidic device is proposed. The concept, called a capillary-assembled microchip, involvesembedding chemically functionalized capillaries into alattice microchannel network fabricated on poly(dimethylsiloxane) (PDMS). The network has the same channeldimensions as the outer dimensions of the capillaries. Inthis paper, we focus on square capillaries to be embeddedinto a PDMS microchannel network having a square crosssection. The combination of hard glass square capillaryand soft square PDMS channel allows successful fabrication of a microfluidic device without any solution leakage,and which can use diffusion-based two-solution mixing.Two different types of chemically modified capillaries, anion-sensing capillary and a pH-sensing capillary, areprepared by coating a hydrophobic plasticized poly(vinylchloride) membrane and a hydrophilic poly(ethyleneglycol) membrane containing functional molecules onto theinner surface of capillaries. Then, they are cut intoappropriate lengths and arranged on a single microchipto prepare a dual-analyte sensing system. The conceptproposed here offers advantages inherent to using aplanar microfluidic device and of chemical functionalityof immobilized molecules. Therefore, we expect to fabricate various types of chemically functionalized microfluidic devices soon.