Stage 2 - 1st Trial

Problems• Thickness of PDMS

layers• Interconnects • Delamination• Air bubbles

Stage 2 - 2nd 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

Phase 2 - 2nd TrialSuccesses & 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

Phase 2 – Experimental Procedure

Phase 2 – Channel Layout

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

Processing Problems Continued

• Feature alignment– Extremely difficult– Inaccurate

• Interconnect layer– No connection provided– Problem with layer thickness