A multi-layer biochip with integrated hollow waveguides

The fabrication of multi-layer microfluidic biochips with integrated optical waveguides is described. The optical waveguides are metallized silicon v-grooves formed by anisotropic etching and capped by metal strips formed on pyrex glass. Microchannels are fabricated on the other side of the pyrex layer by isotropic wet etching and capped by a layer of PDMS. Optical coupling between the waveguides and microchannels is achieved by reflection from the end-facets of the waveguides. Numerical simulations and measurements of the waveguide properties are described and the excitation and detection of laser-induced fluorescence from 15 µm microspheres is demonstrated.