Chris and I visited the AJA sputter company in Boston last week. The tool was fully functional and we were able to deposit several test wafers. Overall, we were impressed with the performance. The uniformity across a 6″ substrate was sub-1 %. This is certainly a huge improvement over the 3-5% uniformity we currently achieve…
This week I went back and took a look at this figure. In the previous incarnation, when prewetted, PES dropped down in adsorption much less than cellulose. I decided to retry this sample and keep in mind some of the things we have learned since then. I was careful to expose both sides of the…
I recently received wafer 567 from Dave for cell culture work. It has many intact membranes but is riddled with pinholes, having only 3 pinhole-free samples. I decided to test them for air permeability and burst pressure, shown below. I also noticed some odd features on the membrane and surrounding Si. They are circular but…
Lingyun and I used the stir cell and spectrometer to measure the diffusion of rhodamine across the membrane. This was the first time I was able to construct an experiment in the stir cell while keeping both membranes intact. In the past one membrane would rupture or the cell would leak too much. For this…
Couple of HUVEC adhesion trials were carried out and the results were found satisfactory as seen in the charts below.
I recently tested W510X and W600 described by Dave here for air permeability, rhodamine diffusion, and burst pressure. No air permeability was observed; even a sample with one very small pinhole (W600 800C anneal) only had a permeability of 11 cc/atm*cm2*s. To verify the lack of pores I performed rhodamine diffusion on the W600 700C…
HUVEC growth was monitored for 4 days on different substrates (glass, plastic and pncSi), this time in media (EGM) with and without serum. Growth in media w/o serum was observed to be much slower than the growth in media with FBS. Hence, media w/o serum can be used as a possible control for the growth…
This is just an update on the progress being made towards creating a closed flow cell by bonding PDMS to our membrane chips. For those who were not at the meeting on Tuesday we have successfully bonded PDMS to both glass cover slips as well as out membrane chips using the UV Ozone cleaner. Yesterday…
I hope to bring this question to our group meeting. As we discussed before, we know that Cl- can be absorbed at the gold surface to screen the applied positive charge. We are using R6G as the filtration species, which is positively charged. So we must either use DI water as the buffer solution (we…
Desalting of 4M NaCl in deionized water was performed using our membranes in the SepCon format. I ran the SepCons in the same as way as the previous study, using a low stir rate and floating the SepCons. Once again, a conductivity probe was used to measure the amount of salt in the dialysate. Transport…