Multilayer biochips with integrated optics replicated in PMMA and PDMS

Abstract

This paper describes the development of multi-level lab-on-a-chip devices that use integrated optics to reduce the size and cost of portable dual-function analysis systems. Silicon/polymer and all-polymer devices were fabricated that have separate optics and fluidics layers that are bonded together. The optical layer has hollow v-groove waveguides in anisotropically etched silicon or in polymethylmethacrylate (PMMA) that is replicated from the silicon in a two-step replication procedure using polyvinyl alcohol (PVA) as an intermediate negative replica. Light from hollow v-groove waveguides in the optical layer is coupled to the fluidic layer by reflection from metallized reflective planes. The fluidic layer is constructed of polydimethylsiloxane (PDMS) in a two-step positive replication procedure from a micromachined glass master. A thin intermediate PMMA layer with reflective metal strips seals both the hollow optical waveguides and the PDMS microchannels.