Abstract
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 anti-reflection coating on the bottom surface to eliminate the reflection light induced exposure. Testing result shows the top wall thickness of embedded channels can be well controlled in a resolution of 2 μm for the UV dose 120-190 mJ/cm 2 . Stacked channels have also been successfully fabricated and showed 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, as shown in Fig. 1, for the applications of μTAS, inkjet printhead, capillary electrophoresis, and micro PCR, etc.