I submitted a proposal last week with Tom & I as co-PI’s to NSF’s Process Reaction Engineering division in CBET. Novel Catalytic Membrane Reactor Based on Ultra-thin Palladium Film Supported on Nano-structured Inorganic Membrane I’m attaching the intro. paragraph and a couple of the figures to give a general idea of what the proposal is…
Kelly & I finally succeeded in getting a measurement of the SU-8 scaffold change in size upon liftoff. Kelly, lifted off a sample (~0.5 x 2 cm) using the XeF2 dry etch and transferred the sample to a glass slide with pdms bonded to it. The slide was then placed on top of the printed…
I’ve been trying to do separations with the NPN 5-slot filters by driving the solution with a syringe pump. This type of separation is required by INT for use in their cartridge. Unfortunately, at most concentrations, solutions with fluorospheres tend to stop flowing after 20-30 µL of filtrate is collected. We believe their is a…
On Wednesday Feb. 12 and Wednesday Feb. 19, limited exposure dialysis was performed on rats. In the first experiment, blood was pumped with the peristaltic blood pump through a two-chip dialysis device in an acrylic fixture. The membranes were non-porous silicon nitride so no dialysate was included in the experiment. Blood was successfully pumped through…
The pressure distribution during EO is a little counter-intuitive. Assuming no back pressure, and neglecting the effects of the meniscus on either end of an EO channel, the pressure distribution relative to the (left-to-right) direction of flow must look something like … The counter-intuitive part is that the pressure drop across the membrane opposes the…
The hydraulic permeability of a membrane is the inverse of the fluid resistance normalized to the membrane area. Experimentally it is found with Where Q is the measured flow rate, is the pressure drop across the membrane and is the membrane area. It can be calculated from membrane properties with Where is the fluid resistance…
Our first attempt to “reverse” centrifuge materials using our standard 5-slot filters made of NPN from wafer 1070 are detailed in a previous post using GEN2 SEPCON assemblies. In this post we modify our method to more closely match the Sartorius Centrisart approach. To that end, we switch to using GEN3 SEPCONs because they are easier…
In my previous post on applying voltage to a silver-coated NPN chip, I put up a video which, if you squinted and were willing to be charitable, showed that I could modify the EO pumping behavior of the chip by applying 2 V to the membrane. I repeated the experiment, and I think I can…
After seeing my previous post on modulating EO pumping behavior with an applied voltage, Jim asked if we could use pnc-Si as an Ultrasound generator. In the following video, I gave it a shot: MVI_2604 (relevant points from the video: a square wave of +/- 10V applied across a pnc-Si membrane results in apparently instantaneous…
In order to resolve the silicon nitride- silicone gasket bonding issue, I, Josh, Tucker and Greg used different approaches to functionalize the nanoporous nitride (NPN) surface. Both surfaces of NPN, although have same material (silicon nitride), behave differently. The flat side is etched using xenon fluoride to remove pncSi layer on top. Different tools at…