Integration of micro-optical systems for fluorescence detection in μTAS applications

Microfabrication technology has become a widely used approach in the development of miniaturized systems for chemical analysis in microfluidic channels. Moreover. microfabrication technology can be used to integrate microlens and aperture arrays directly onto microchemical chips. Such optical elements enable the: realization of optical functions for illumination. collection and signal filtering, necessary for fluorescence detection. A new completely integrated microfluidic/micro-optic device is presented: in which refractive microlens arrays (with a diameter of a couple of hundred mum) and aluminum aperture arrays are integrated on both sides of a chemical chip. The chip is composed of two 4" thermally bonded pyrex glass wafers in which microfluidic networks are etched. The microchannels are 25 mum deep and 50 mum wide. The overall thickness of the chip with the detection system is less than 2 mm.