Microseparations and Microfluidic Studies

Microscale integrated chemical analysis systems have been fabricated which employ electrokinetic chromatography with laser-induced fluorescence detection. The microoptical systems utilize vertical cavity surface emitting diode lasers (VCSELs), diffractive lenses, microreflectors and diode detectors. The flow channels and diffractive optics have been fabricated in fused silica and the VCSELs are attached to the substrates using flip-chip bonding. The electrokinetic separations make use of micellar separations in open channels and reverse phase separations that use both bead-packed microchannels and lithographically-patterned stationary phase supports. The detailed flow characteristics of these systems is visualized using novel imaging methods.