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…
Category: NRG
Small Animal Model Dialysis: Nonporous and Microporous Membranes
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…
Posted in NRG
Pressure Distribution and Membrane Deflection During EO
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…
Posted in NRG
Hydraulic Permeability
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…
Posted in NRG
Continued Reverse centrifuge tests
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…
Posted in NRG
Gate-Voltage-Dependent EO Pumping: -6 V on the Gate Changes the Pumping Rate by an Order of Magnitude
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…
Posted in NRG
A First Attempt to Generate Ultrasound with pnc-Si EO Pumps (with Stephen McAleavey) was Inconclusive.
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:…
Posted in NRG
Bonding silicone gaskets with nanoporous nitride (Solved ?!?)
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…
Posted in NRG
Introduction to the Membrane Flow Analysis Device for Gas (MFAD-G), QC Model
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…
Posted in NRG
“Reverse” centrifuge seperations
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…
Posted in NRG
