Hi all, After a brief hiatus from winter break and my paper writing Mike and i have resumed our work on fabricating the counetrflow system, and we do have a success. Fabrication: The counterflow system is constructed based on oxide-layer protected pnc-Si, hosted within the V-notched Si-wafer that Dave specially produced for us. The membrane…
In an attempt to push the cutoff higher, we annealed two wafers outside the susceptor at 1000 C (SC 066) and 1100 C (SC 067) with a ramp rate of 100 C/s. The 1100 C does give a cutoff slightly higher ~5 nm, but I’m not sure if this is within the variability in different…
Below are a series of TEM micrographs showing a set of membranes produced last week. We RTPed these wafers at 700 (SC 062), 800 (SC 064) and 850 C (SC065) without the susceptor at a ramp rate of 100 C/s. The trend is increased pore size and porosity with increasing temperature which follows our intuition…
This is kind of a shot in the dark, but I wanted to see if I could get a zeta potential for pnc-Si that was as high as predicted by the electroosmosis results. First I tried to get the membranes to break in 1mL of PBS so that the windows were floating on top of…
As I told at the meeting, I tried spincoating PDMS on the membrane and it worked without breaking membrane. To make an ultrathin polymer film by spincoating the polymer has to be diluted in the particular solvent first. I used PDMS with elastomer to curing agent ratio (10:1) diluted in hexane (and xylene) by weight…
Since HUVEC morphology hasn’t looked good in short-term adhesion assays recently, I analyzed HUVEC on the 2nd day after cell seeding. Normally, CMFDA staining is done for 30-45 minutes in serum-free media. I wondered if the serum-free environment during staining was affecting the HUVEC. So, I stained one sample with 5uM CMFDA in serum free…
After four days of this ongoing HUVEC culture in pncSi transwell, HUVECs look much better than before. Here I have freshly stained them with Calcein AM and we can see how bright it is in comparison to CMFDA stained cells (or may be there’s some flaw in my CMFDA staining procedure). Till now its been…
There’s been a lot of production in the last month and we’re still sorting through the data, but here is a synopsis of some key findings. All films were deposited with the AJA tool. Film reproducibility Week-to-week variation in pore morphology has never been noted explicitly due to the rapidly changing conditions we place on…
On Day 2 of cell growth from trial 3 of adhesion study, cells looked much more spread out but less in density. Most of the cells were observed to have concentrated near the edge of the pnc-Si chip near the Sepcon as seen in the figure below (first image in the bottom row). This could…
Samples (no RTP) from W673 and W684 were taken (four from each wafer; with atleast one blank chip) in Sepcons and HUVECs were plated @ ~19,000 cells/sq. cm. density. Cells were allowed to adhere for over 4 hours and this time stained with CMFDA (instead of Calcein). Cell types loaded with the CellTracker probes are…