Production was scarce last week because we ran into some problems with our patterning/etch process. The first two wafers I attempted to etch did not react with the EDP because there was a thicker than normal layer of oxide remaining after our lithography step which prevented the EDP from attacking the underlying bulk silicon. We’ve…
I measured burst pressures on two non-unifrom wafers w391, w393. They have lots of pinholes (especially w391) but the pressure they withstand is pretty high. I expected it to be much lower after looking at the membranes in the microscope.
Attached is a series of images we took of two populations of neutrophils above and below the membrane.I’m including by methodology for those who are interested:One population was pre-labeled with AF488 (green) antibody against L-selectin, the other with AF546 (red). The green population was suspended in a low protein buffer (~1% serum) and a 20…
A couple of summers ago a Penn State summer student named Joe Fantuzo was working in the lab measuring cell growth rates and cell spreading on pnc-Si membranes and comparing the results to glass coverslips and tissue culture grade plastic. At least that is what we hired him to do. Joe spent much of that…
20nm polystrene beads in 1x PBS passed through w218. This wafer looks a little strange, like it was not fully etched (Dave do you know what happened to this one?). This was just a first stab at the benchtop diffusion with PS, so I didn’t use a “good” membrane. At any rate, the PS went…
Earlier in the week I retested the 100K microcons in our wet-wet EQ format. When I last ran them this way I calculated very little flow and very small permeability values. I noted that there was a rather large air pocket collecting on the underside of the membrane in the plastic support structure; most likely…
Today I looked at a wafer (391) that had been annealed in the RTP on top of a 6″ wafer substrate. The idea is that the six inch substrate would create a “shadow” around the 4″ wafer which would improve thermal uniformity by blocking the multiple reflections from the lamps inside the chamber. Here is…
We’ve got pores! Unfortunately, we are still being plagued by an unknown contamination that seems to be “eating” away at our membranes. This would explain why we’ve been having a hard time separating. We also observe a strong radial dependence in porosity AND size with these RT deposited films. In the past it was limited…
Our two O2 regulators arrived this week (it figures we would have two to arrive within a day of each other after waiting for weeks to have one). Tom and Lingyun got to work right away. The image below shows that the UV/Ozone system does reduce the contact angle dramatically when used with oxygen (recall…
Coming to a basement near you by the end of 2008 (assuming no delays that is). Pretty exciting in my opinion.