Yesterday I found a bug in the pore image processor. The “i” hotkey is supposed to save the current image, but it wasn’t working. I contacted Mike Bindschadler and he fixed it. The updated version can be found here. The only change is in the “pore_processing_gui_call” .m file. Happy processing!
I tried to clean samples from W615 using UV/ozone to cleanse the membranes of the organic impurities we have been seeing lately. I followed the UV/ozone protocol, with a stage temp of 25C and treatment time of 5 minutes. No change in the impurities were observed; I plan on trying to run it again for…
Yesterday I started a test to try and reproduce the results Henry was able to obtain with a closed flow system last week. Using four samples (W619) I ran the UV Ozone bonding process and allowed them to sit over night. This morning I found that only one of the four samples was bonded; recently…
I tested W612 for air permeability and burst pressure, shown below. It should be noted that the air permeability and burst pressure values are comparable to W504; looks like a good reproduction! I also tested a sample with the hexane residue and debris, no difference in permeability or burst pressure was seen. Background pores included…
In an attempt to improve membrane life in cell culture, different RTP times were tried on a single wafer. Samples from W514 were RTPed in Ar at 800C for 1, 5, and 10 minutes, respectively. Cells were then seeded at confluence on membranes, with membrane stability monitored for breakage. Discoloration was monitored on samples without…
Just an update on the closed flow systems I put together yesterday using vacuum grease. Even with the vacuum grease at the point of entrance of the capillary tube to the PDMS-pncSi system the PDMS was able to get into the trough of the membrane chip. I will talk with Henry today to see what…
I ran another diffusion cell last week using Human Albumin and Cytochrome C. I increased the volume of PBS because the last time I ran the gel for this mixture, the band for cytochrome c was very prominent. Out of the three chambers of the diffusion cell that I ran, only one of them actually…
While Chris and I were in Boston we deposited our membrane stack on a patterned wafer. It was annealed at 1000 C and then etched. Because we didn’t have an accurate deposition rate for Silicon, we overestimated and put down 30 nm (instead of 15 nm). Still, we can see in the TEM that pores…
Wafer 612 was made to mimic wafer 504: 850 C RTP, cool down, 1000 C RTP. Wafer 615 was annealed in two steps: first to 400 C and then to 1000 C (without inbetween cool down). Both wafers showed a lower pinhole density. Wafer 615 had a few “traditional” round pinholes. Wafer 612 had some…
Introduction One area of use to explore for the membranes is desalting, the removal of salts from solutions (such as those containing proteins). Ideal membranes have uniform pore distributions, high mechanical strength, tunable, sharp pore cutoffs, and high porosity. In this study intact samples from W565, which showed no air permeability but allowed rhodamine to…