I recently tested the burst pressures of samples from W510, 511, and 513. None of the membranes are pinhole free. Silicon thickness varies (15 nm, 10 nm, 20 nm). See Dave’s post for complete fabrication information. W513 has noticeably higher burst pressures compared to W510 and 511. Overall W510 is in the worse shape overall,…
I recently attempted a fibroblast (L1 3T3 cell line) growth test. The cells were seeded at too high of a density, so growth curves can’t be produced. However I checked cell viability and pnc-Si discoloration. As expected RTP treated samples discolored later than treated samples. Samples with cells seemed to discolor sooner than samples without…
To improve our knowledge of pinhole formation I have started counting pinholes on W510, W512, and W513. I also am playing close attention to areas surrounding the samples that have been completely etched, to see if this correlates to pinhole number. A schematic of W510 with number of pinholes is shown below. I would like…
Last week I attempted another HUVEC growth study on Si, coverslips (glass), and culture wells (plastic). The cells were seeded at too low of a density on the membrane so I adjusted my protocol and started a third growth test. The results of the third growth experiment is shown below. After 86 hours the cells…
(Transferred from old blog) From the above discoloration array it can be inferred that the RTP treated samples in the incubator are discoloring in much slower rate than the ones on the benchtop. Thus, incubator conditions prevent the chips from discoloring. The reason behind this could be the carbon dioxide present in th incubator which…
(Transferred from old blog) The above TEM images show that RTP (800C, 5 min) treated samples (from W334) have their pores intact in salt over a period of time! 1M and 2M NaCl solutions were used and TEM samples were taken at different time points. There is some deformation observed near the edges of the…
(Transferred from old blog) Wafer 303 samples, both non-RTP and RTP (800C for 5 minutes), were tested in cell media (DMEM supplemented with 10% FBS) or deionized water, and placed in the incubator (37C 5% CO2) or oven (approximately 37C). Discoloration, pH, and the bead assay were measured initially and every 24 hours. Deionized water…
(Transferred from old blog) Aim: Determine how quickly DMEM pH changes once removed from the incubator Methods and Materials: • non-sterile complete Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% FBS • 6 and 24 well cell culture plates • 37 ºC 5% CO2 incubator 2 mL and 5 mL DMEM were placed in a…
Here are the results for air permeability testing of W501. The sample closest to the origin had one very small (very difficult to see on Brian’s scope unless viewing at 100x) pinhole, the middle sample had 3 very small pinholes. The completely intact sample had a permeability of .773 cc/(cm^2*atm*s). It seems that the pinholes…
Over the past five days Anant and I monitored human umbilical vein endothelial cell (HUVEC) proliferation on three substrates: RTP-treated Si samples (both with and without membranes), glass (microscope coverslips), and plastic (6-well tissue culture plates). After the first two time points very few cells were observed on the silicon samples, so we added more…