| 초록 |
Microfluidic devices are finding increasing application in bio/chemical analysis. Conventionally, such devices are fabricated by etching glass or silicon. Soft-lithographic methods of fabricating the microchips in poly(dimethylsiloxane) (PDMS) provide rapid prototyping and replica molding, which enable the devices to be fabricated under benchtop conditions and have greater accessibility to analytical chemists. Recently we have developed techniques that enhance the applicability of PDMS to microfluidic devices: (1) Squeezing pumping, which is based on squeezing out a fluid in a PDMS microchannel by using an external mechanical roller. This pumping system is free of integrated mechanical and control parts, and avoids leak-free connections often associated with other pumping schemes. We have demonstrated unprecedented picoliter-volume pumping and segmentations. (2) Adhesive and dead volume free PDMS microchannel interfacing technique through capillary tubings. The technique employs intrinsic swelling behavior of PDMS in organic solvents. (3) Monolithic integration of optical components in a microfluidic device. We have realized a light collimation system in a PDMS capillary electrophoresis microchip through monolithic integration, in order to minimize stray light due to the divergence of light from an optical fiber, and achieve high-performance absorbance detection with an extended optical path length. |
