1. Stage 2 - 1 st Trial Problems Thickness of PDMS layers Interconnects Delamination Air bubbles

2. Stage 2 - 2 nd Trial Fabrication Successfully made and aligned four layers Layers had very few defects All interconnects joined two different layers Entire wafer looked very good- no rough edges, no air bubbles between layers, no craters

3. Phase 2 - 2 nd Trial Successes & Problems Liquid to flow in all channels –all the way through 2 out of 5 channels Tracked fluid flow using bright food coloring Tested the effects of vertical interconnects No capillary action –had to use pressure from syringe problems Pressure caused delamination Effects of vertical interconnects

4. Phase 2 – Experimental Procedure

5. Phase 2 – Channel Layout

6. Processing Problems Substantial amount of cracks in SU-8 layer Layer alignment problems –Razor blade/ tweezers method –Layer thickness –Wrinkles –Air pockets Cracks in reservoir region of SU-8 mold

7. Processing Problems Continued Feature alignment –Extremely difficult –Inaccurate Interconnect layer –No connection provided –Problem with layer thickness