I tested five types of track-etched membranes (with pore diameters 0.1, 0.08, 0.05, 0.03 and 0.01micron). All of them are 6micron thick and usually have 14-16% porosity. First experiment was to confirm the official air flow rates data with our…

These are low burst results but samples have lots of pinholes on them many of which are on the edges. I also checked porosity of the wafers 338 and 340. They indeed have porosities close to 7%. Wafer 340 (0,5)…

w312 Number of Pores HistogramContributed Area Histogram 5nm BSA-Au is detected in the filtrate after 24 hours. 10nm BSA-Au is not. The 5nm registers around 10nm after conjugation and the 10nm is closer to 15nm. This selected membrane is not…

Wafer 403 was processed last week using the new thermal oxide/TEOS steps outlined in the previous posts. I took images from six positions at different radial positions on different axis. All six samples looked relatively uniform! (1,0) – 35kx (0,-2)…

Directory containing article and presentation Nature Article about Willem Kolff

Theoretical molar flow is calculated for membranes with different porosities and is based on data extracted from TEM images using Mike’s program. Experimental data is calculated using air permeability test results. It is associated with porosity only through TEM data.…

I figured I’d throw this up in case anyone needed to know how to order anything… enjoy. http://docs.google.com/Presentation?id=ddfnw7hd_235d2f4v4f5

I have uploaded the TEOS process outline: TEOS is tetra-ethyl-ortho-silicate, or equivalently tetra-ethoxy-silane. TEOS slowly hydrolyzes into silicon dioxide and ethanol when in contact with ambient moisture. IMPROVEMENTS: -This process prevents us from having to expose the front-side of the…

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…

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.