1. Mask Design for Molds

2. Mask Design for Molds Spin SU8(negative resist) on Si wafers
Expose using mask (channel mask and interconnect mask)
Develop both molds

3. Mask Design for Molds
From molds: spin on PDMS less than the vertical dimension
From channel mold: make two layers
From interconnect mold: make one layer
Stack three layers in channel, interconnect, channel (90o rotation from first channel layer) order
I/O
Bottom layer
I/O
Middle layer
Top layer

4. Mask Dimensions
For initial preliminary fabrication larger dimensions are better
Approximate channel and interconnect width 150 mm
Channel length 45mm
Reservoirs 300mm diameter (total length channel and reservoir 45.6mm
Distance between channels 300mm
Mold feature height 300mm

6. Modified Mask Design for Molds
Spin SU8(negative resist) on Si wafers
Expose using mask (channel mask, interconnect mask, and top mask)
Develop all three molds

7. Modified Mask Design for Molds
From molds: spin on PDMS less than the vertical dimension for all four layers
From channel mold: make two layers
From interconnect mold: make one layer
From top mold: make one layer
Stack all four layers in channel, interconnect, channel (90o rotation from first channel layer), and top order

8. Modified Mask Dimensions
Coordinate of the reservoirs (mm):
(20.0,20.9), (5.6,12.8), (12.8,5.6) in all four quadrants
Coordinates of the channel intersections (mm):
(0,0),(0,7.2),(7.2,0),(3.6,3.6) in all four quadrants
Channel Width: 150 mm
Reservoir Diameter: ?

9. Modified Mask Considerations
How many of the nine channel intersections should be used as interconnects between layers (3 or 9)
Should the first channel layer be open or closed on the bottom surface (PDMS or Pyrex bottom)
Should a top layer channel be used or should the top remain open
Should the size of the reservoir throughputs be the same size or smaller then the reservoirs