Over the past few days Josh and I installed windows 7, windows office suite, Malvern’s Zetasizer software (available online), Tecan’s I-control software (available in the 3-ring binder in the glass cabinet above the machines), and chrome onto the new(er) laptop in the basement. I copied the files on the old computer that seemed relevant –…
Last week I conducted a variety of experiments to try to make a nanofluidic transistor (a device described in detail in this previous journal club post). I did some light optimization of the E-beam deposition of Ag films over a 3nm Ti adhesion layer in the PVD lesker machine and found that 12nm of Ag gives…
On June 10th, 11th, and 12th I was in Boise, ID for the North American Membrane Society (NAMS) annual meeting. While there, I presented Jess’s work on the EO pump in a poster session. I got the chance to meet Andrew Zydney of Penn State, Peter Pintauro of Vanderbilt, and hang out with our Clarkson collaborators Ruth Baltus and…
The Cambridge Microsystems Savannah 200 atomic layer deposition (ALD) system uses a two-step chemical process that alternates pulses of water vapor and trimethylaluminum (TMA) to build a layer of Al2O3 on a silicon substate. Because of the two-step nature of the process, the film is forced to grow by successive monolayers, each with a thickness…
This lovely paper: 121025 – ACSnano fluidic transistor pore details the creation of a “nanofluidic transistor”. In essence, by changing the charge on the (metallized) membrane from 0V to 500V, the group can completely stop the transport of DNA molecules (which are driven across the membrane via electrophoresis) or allow them to pass. The membrane is an…
I couldn’t really make sense of what was happening in this post, and in particular this figure threw me for a loop: So to help myself understand the relationship I whipped up a little matlab app to show the relationship a little clearer: Moving the sliding bar on the bottom changes the y-position…
I brought some 20nm and 40nm Sepcons to Integrated NanoTechnologies last Wednesday. First, we passed some short radio-labeled DNA strands through a 40 nm Sepcon, and then some longer strands. Both were able to pass through the membrane with a transmission rate of ~70% (as measured by scintillation), and the length of the strand did…
In Tuesday’s NRG, we wondered if the fact that some of Josh’s pores overlap could throw the PoreImageProcessor off enough to explain a 2x discrepancy between our theoretical hydraulic permeability and our experimental permeability (the experimental was lower). From this picture: I took the following close up: If we assumer that each of the sub-pores has a radius of…
Hey folks, Science Saturday is this Saturday and Sunday at the Rochester Science Center. We need volunteers to man our tables from 12-4pm on both Saturday and Sunday. Please indicate in the comments of this post if you can volunteer, and when you can volunteer. The tentative schedule is as follows: 12-1 Saturday – Greg,…
Previously, I had gotten some inexplicable results showing that increasing salt concentration decreases the flow through a membrane. This makes no sense (and goes against our previous data) because we would expect electrostatic forces to counteract the flow, an effect called counterelectroosmosis by Zydney: “The situation in the presence of a net fluid flow through…