I am in the process of inspecting each membrane in the newly created wafer 612. First of all, some samples (~10% counted so far) have tears on the membrane edges, shown below. Images were taken at 20x microscope magnification (reflection image followed by transmission). I also have been seeing circular defects which do not penetrate…
Last week I ran cell culture growth experiments on RTPed (800C 5 minutes in Ar) samples from W567 (single slit 100um x 1000um). For this study I tracked discoloration w/cells, membrane stability w/cells, and the bead assay w/cells to see if we can predict if a membrane used in cell culture is intact by monitoring…
Time lapse movie of fibroblast spreading on the nanomembrane was captured over a period of ~ 8 hours. I was having some problem uploading the video here, thus have done so in the NRG knowledge page under the cell culture manuscript.
I recently received three pinhole-ridden wafers for cell-related experiments. All three have been RTPed at 800C for 5 minutes in argon, which is the typical procedure we have been using for cell culture. The bursts pressures for each wafer are shown below. W520 is weaker than 558 and 559; I plan on using the stronger…
In continuation of the desalting work, I ran three additional controls: a SepCon with no slits (negative control) and direct addition of 4M NaCl producing final dilutions of 1:400 and 1:600 (these are the experimental final dilutions I have been working with). The results are shown below. I also calculated the flux for each condition….
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…
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…
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…