Introduction The Membrane Flow Analysis Device for Gas (MFAD-G), Quality Control Model, is the first* of a 3-version series of devices that, altogether, will allow use-specified measurement of flow rate and flow pressure of gas and liquid media through chip-mounted membranes. The QC Model has a rudimentary form of the general system and acts as…
Back in November we were visited by Tom Berkelman of BioRad to see if he could use our NPN membranes to successfully separate some proprietary nanoparticles from IgG in a solvent with secret ingredients. These particles have an interesting absorbance spectrum as well as strong fluorescence. During that visit and in subsequent separations in the…
Because I’ve been having such a difficult time measuring consistent zetapotentials (a big and heartbreakingly inconclusive post on those efforts is forthcoming) I decided to use one of my silver-coated SNMs as an EO pump and see if changing the voltage applied to the membrane changed the rate of EO. And I’m very happy to…
Please plan accordingly and be sure all moveable items are off the floor the night before.
Cindy Hartnett – professor of mechanical engineering at Louisville requested some pnc-Si chips after reading our PNAS paper. In requesting the material she mentioned … I’ve long been searching for a low-voltage way to drive some micro-actuators. Electrokinetic pumps looked good but until now the necessary voltage was far too high. About a month after…
SU-8 3010 has been used to create a scaffold in the fabrication of the liftoff membranes. The supplier of the negative resist, MicroChem, rates it for a 13 moth shelf life. We were having difficulty achieving good liftoff with membranes in the second half of last year. The SU-8 had expired by several months, so…
In April of last year, I spent a considerable amount of time trying to visualize protein separations using SDS-PAGE (Sodium Dodecyl Sulfate-PolyAcrylamide Gel Electrophoresis) gels, and ultimately was able to get some data: I was trying to show that 15 nm pnc-Si could be used to separate BSA from cytochrome c, and while at first…
Previous posts: Theory Deposition Etching Imaging First Freestanding Membranes I had previously made free-standing nanomembranes that were mostly MgF2 according to the EDAX scan of the freestanding region: I hoped to duplicate my results and send over a few more samples to Nottingham. With that in mind, I ran an evaporation to produce a 50nm MgF2 nanomembrane (250C, 1-2…
(Meghan Kazanski actually did all the work, but she didn’t have a login when this post was started.) The calculated porosity is 16.4 % with an average pore diameter of 417 nm. SepCon assembly was performed with chips from wafer 4409. Assembly was performed systematically – SepCons were boxed following assembly for later control…
The following data is from analysis of Wafer #1059, consisting of 30nm pnc-Si with 7% porosity and an average pore diameter of 28nm. Square window sizes with sides lengths of 0.1mm, 0.3mm, 0.5mm, 0.7mm, and 0.9mm were tested. For 1.1mm x 1.1mm windows, burst pressures could not be determined, as these windows did not etch…