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 he did different last week, but I think the next step will be trying vacuum grease by itself and try running the system at a very low flow rate.
The NSF STTR phase I project officially ended last week, and we are writing the final report and preparing to submit a Phase II proposal. I will attempt here to summarize the program achievements and list some of the persisting technical issues we are facing. Program Technical Objectives: Optimize nanoporous silicon nitride (NPN) membrane properties…
I obtained gold in 5nm, 20nm, 40nm, and 60nm through Mort/Oberdorster Lab. Separations were performed with fully crystallized samples from SC 073. Here are sizing and absorbance data: In Water I have tried 24 hour separations in diH2O (SC 073) with these particles. Here are the results: No 525nm peak in filtrate for 5nm sample. …
Alright, so this is kind of a big update and I will probably split it into a couple of parts. Basically, in a search for a way of confirming that the particles we are seeing on the membranes, I have tried several techniques with varying degrees of success. The initial experiment involved me conjugating an…
After completing proof of concept testing with polystyrene beads and with the goal of creating a SARS-CoV-2 sensor (Discussed in this post: https://trace-bmps.org/beadazzled-laying-the-foundation-of-the-%ce%bcsim-dx-fouling-based-sensor/), we sought to test the performance of the system with a target more similar to the SARS-CoV-2 virus. We found this target in vaccinia virus. As we did with the polystyrene beads,…
We have previously observed some interesting transfer characteristics of our nanomembranes, using water vapor (breath) to delaminate and adhere them to glass and silicon nitride surfaces. Some membrane transfers do not appear to be stable (fragments or floats away when submerged and exposed to shear stress), while others can withstand shear stress at high rates…
Using Mike B.’s MATLAB script, I was able to generate some histograms and stats for wafer 187, 310, 319 and 320. I excluded the “small pore background”, as I do not believe these features go all the way through the membrane. wafer 187 wafer 310 wafer 319 wafer 320 The reason why I did not…