A novel fabrication method of embedded micro channels employing simple UV dosage control and antireflection coating

This paper proposes a novel method to fabricate multi-layers of embedded micro fluidic structures by simply employing time-controlled UV exposure on thick SU-8 resist and an anti-reflection coating on the bottom surface to eliminate the reflection light induced exposure. Test results show that the top wall thickness of embedded channels can be well controlled to a resolution of 2 /spl mu/m for a UV dose of 120-190 mJ/cm/sup 2/. Stacked channels have also been successfully fabricated and show no interference on the bottom structures when exposing the top structures. This simple and inexpensive method can be applied to fabricate multi-layers of complex fluidic systems, for applications such as /spl mu/TAS, inkjet printheads, capillary electrophoresis, and micro PCR.