Hydraulic permeability of SiN-NP wafer #'s 1029 and 1030 with "clean" water
Sarah, Tejas, and I bought some “Invitrogen Ultrapure DI water” from the medical center to see if we would find a different permeability using the clean water vs the water from the Barnstead.
Sarah and I repeated our permeability tests but made sure to measure the flow rate for the first 100 uL. We got the following plots for wafers 1019, 1029 and 1030. The measured permeabilities for the first 100 uL were:
1019 F – 0.626 cc/cm2/s/bar
1019 G – 0.234 cc/cm2/s/bar
1019 I – 0.789 cc/cm2/s/bar
1029 clean A – 2.415 cc/cm2/s/bar
1030 clean A – 5.368 cc/cm2/s/bar
Even with the “ultrapure” water, we are seeing the permeability decrease with time. We are also seeing inconsistent permeability as more water is passed. I don’t have a great idea on quantifying this behavior other than showing the plots below, but I would warn anyone trying to measure changes is flow rate to keep in mind that total volume passed may also alter the flow rate on top of any other parameters.
