Plasma Cleaning

This procedure is used to clean surfaces and enhance attachment of PDMS to glass or PDMS to PDMS.

1. Clean all substrate surfaces with Scotch tape.

2. Place PDMS mold (feature side facing up) on a microscope slide. Transfer PDMS on slide into the plasma cleaner.

3. Put another microscope slide (to be attached to the feature face of PDMS mold) in the plasma cleaner.

4. Close the door to plasma cleaner, and close the valve (turn knob inward) on door to isolate inside from outside air. Set power level to medium.

5. Create vacuum by turning on pump. Watch needle on vacuum gage moving counterclockwise past the 200 mark.

6. Turn on power, slowly open valve (turn knob outward) until a purplish glow is observed.

7. Let the purplish glow persist for 25 seconds, then turn power off.

8. Open valve completely to let air in. Close valve to reestablish vacuum. Turn off pump when the needle on vacuum gage returns to its position around the 200 mark (this step is important in removing toxic gas generated in the plasma cleaner).

9. Open valve to let air in. Open door when atmospheric pressure is reached.

10. Remove PDMS mold on microscope slide and the other microscope slide.

11. Attach the empty microscope slide (the side facing up when placed in plasma cleaner) to the PDMS mold (feature, the side facing up) and squeeze for 30 seconds.

12. Remove the microscope slide lying underneath the PDMS mold (contacting the non-feature side). The PDMS mold should now be only attached to the originally empty microscope slide, with feature facing down to the slide.