Update: After doing several measurements again, it appears that the data shown below were not repeatable. It is believed that these data were just the artifact. Please see my new blog post “Flow Sensing and Energy Harvesting Capabilities of NPN Membrane” for a new data set. Here are the streaming potential measurement data for NPN membrane…
The below figure has three different sieving curves. Solid lines are model calculations assuming a SiN membrane with 37 nm pores, and either 0.4, 1.3, or 5 PSI applied to drive the separation. Markers are real data. Note that the experimental data reflects the pressure-dependence of the curve, but is slightly different in concavity from…
A little while back I posted a design for a capture device that would (nominally) work for dialysis on real patients. Due to strict requirements to avoid clotting, the design included a lot of curves and nuanced structures that would be no problem for a lithographical or molding method, but which are a step too…
Introduction PncSi membranes are used in the development of wearable hemodialysis (HD) device that provides with high toxin clearance rate for end-stage renal disease patients. Chips with 11 channels and a flow rate at 45 uL/min per channel were used in rat HD tests; these membranes, however, broke were not strong enough to sustain long…
Xunzhi from the Shestopalov lab gave us a brief presentation on how XPS is used to assess surface modification of the nanoporous nitiride silicon (NPN) membrane chip. Power Point Presentation: surface assessment via XPS
The presented post is somewhat of a follow-up of this previous post, in which we studied the adsorption of proteins on silanized NPN chips. In the presented work, we study the adsorption of fluorescent proteins (BSA and IgG) on both the untreated and the PEGylated nanoporous nitride membrane (NPN) chips using epifluorescence as the imaging…
NRG this coming Tuesday, October 20th, will be dedicated to reviewing progress to-date on our joint NSF-sponsored Phase 1 STTR project. Here is the agenda. • Jamie: Project overview and commercialization aspects • Josh, Bob and Elizabeth: Lift-off of nanoporous silicon nitride • JP: Development of thicker NPN • Tucker: Fluidics and dialyzer devices…
Down the road, we’re going to move towards large-animal studies to test our hemodialyzers, since a large animal model (either a sheep or a pig, preferably the former) allows us to model the effects of complete kidney failure (as opposed to just uremia in rats) and work on a scale that would be comparable to…
Sabrina’s post showed that on a bench top, with ‘blood’ source and return at ATM, the transmembrane burst pressure was between 0.5 psi and 1.5 psi, (initial and after DI or PBS flow for four hours). Extrapolating from Burst pressure chip tests for the 10 mm long HD chips, we can expect the burst pressure to be somewhere between…
This post is from Xuan ‘Sabrina’ Pan Purpose The nanomembrane used in my experiments is expected to promote efficiency of hemodialysis (HD) for end-stage renal disease patients. The membranes, however, broke during HD for rats, and breaking membranes can lead to unwanted consequences. My task is to figure out the transmembrane pressure during dialysis under…