PDMS biochips with integrated waveguides

A general method is described for the fabrication of polydimethylsiloxane (PDMS) lab-on-a-chip (LOC) devices with integrated optic and fluidic elements. The PDMS core layer containing the optic and fluidic components is cast and cured under pressure on a silicon master. Subsequently, outer layers of lower-index PDMS are bonded to the core layer to provide optical and fluidic confinement. The functionality of the waveguides and microchannels is demonstrated by the detection and identification of two different types of fluorescent polystyrene beads in a pressure-driven flow inside a microfluidic channel in a device fabricated by this process. (technical note)