I constructed a plot of hydraulic permeability based on the flow rates that Sterlitech has predicted for their membranes. Looking at the permeability values that I posted last week, outside the tested that appeared to leak, there was a 0.01um membrane with a permeability of 33.4, two 0.05um membranes with permeabilities of 59.9 and 71.1,…

I ran some tests today using the 0.01um, 0.05um, and 0.10um pore diameter track-etched membranes from sterilitech. The tool the paul built to cut the membranes works very well, and assembly into the microcon systems it simple. I used the standard vertical-wall o-rings that come in the microcon systems because based on yesterdays test results…

From this updated post its evident that the O2 RTP treated samples start discoloring after ~10 days. Also, the O3 + O2 RTP treatment is probably better in preventing dicoloration than just O2 RTP. So amongst all the samples, the O3 + O2 RTP treated one starts discoloring at the last.

This morning I did a little work with the track etched membranes (0.05um 13mm). I talked with Paul over in Hopeman and he is currently working on making a small coring tool to cut out the membranes (it should be done by the end of the day). In the mean time I figured out that…

The graph below is air permeabilities for four samples from wafers 344,338,342,345 without and with 15 nm thick deposited oxide on the front side. All of this samples don’t have pinholes.Look at the data for samples 2 and 4 on the graph. The approximate porosities of these samples are 2.7 and 4.6% which is the…

The SiO2 coated samples (from W335 & W341) were found completely discolored after 5 days in DMEM (benchtop). Thus, silicon dioxide coating didn’t prevent discoloration as much as the RTP treatment. There’s a need to check the discoloration profile of the SiO2 coated samples within 5 days. Till 24 hrs. there was no discoloration observed….

In continuation of the previous post, its been further observed that O2 RTP treated samples remain unchanged whereas the Ar RTP treated samples started to discolor after a week, as shown in the following images: In order (left to right)1. Ozone+Ar RTP2. Ozone+O2 RTP3. Control (Untreated)4. Ar RTP5. O2 RTP

I briefly experimented with the track-etched membranes this morning and found that they are extremely fragile and near impossible to cut. I disassembled a few of the microcons and found that a circular piece of paper the size of a hole punch (like the one on the bench by the mac) fits perfectly into the…

I retested the 100K Microcon, 100K Nanosep, and 300K Nanosep membranes at 1000RPM, which in the clinical centrifuge is 4.33psi by my calculations. I retested the 100K Nanosep just to make sure that we had some solid permeability values. I retested the 300K Nanosep because of the extremely low permeability I calculated for the first…

I tested those membranes from w335 and w341 with approximately 40 nm of deposited oxide on both sides for air permeability and burst pressures. There was tiny amount of air flow (I checked for leak) from few of them which I didn’t expect with such thick oxide. The burst pressures are higher then without the…