I have done some furnace annealing (FA) on free-standing NSN and OSO stacks in last two weeks after the RTP was down. I’ll show the results in the following two posts. In order to compare the annealing result, I chose both NSN and OSO stacks with the same structure of 30-25-30, which corresponding to 25nm…
What we’d like to have accompany the Sepcon filters is a general way to tune the pore sizes for any given separation. If, for instance, someone wanted to have a filter cutoff of 12nm, we could create a custom wafer with a mean pore size of roughly 17nm. But it would be much easier (and…
Purpose: The purpose of this investigation was to study the diffusion of Rhodamine, a florescent dye, in crosslinked Poly ethylene glycol (peg) using a Leica DMI 6000. Knowing the permeability of crosslinked peg is valuable as peg is a potential material for the hemodialysis project particularly the lift off component, and knowing about Rhodamine’s (MW…
SET-UP Syringe pump: 5 mL of 7.6-nmol/100µL, 5.6 µL/min pump rate. Single Channel dialyser, 10 mm long, 0.5 mm wide, 0.3 mm high in stirred beaker of DI water Fraction Collector programed to rotate every 30 min. Set up in refrigerator, 40˚C. Figure 1: Long term dialysis clearance set up in refrigerator. Syringe pump, stirred…
It is the goal of the Leukocyte counter to have the cells align to a membrane with a one cell to one pore ratio. Ideally the cells would be able to take up pores without using all the pores on the membrane. A possible way to do this would be to dilute the cells enough…
As I am hoping to promote tighter junctions between endothelial cells in my device, I am trying to create an environment that produces shear stress on the endothelial cells. Shear stress up-regulates the pathways that promote tight junctions (Tzima et al 2005, Dejanna et al 2004). The value of the quantity is somewhere around 6…
Oxygen plasma cleaners are a very commonly used tool when bonding PDMS sheets to materials such as PDMS, glass, Si, and SiN. Even though plasma cleaners have proven to be highly effective and reliable tools in this application, they continue to be relatively costly pieces of laboratory equipment. It has been realized that corona discharge…
In my last post we determined that there is an inverse relationship between porosity and burst pressure. I continued to dig further into other factors that affect the burst pressure of the membrane. Pure silicon was used in all the measurements. I measured the burst pressure of many samples that differed in properties that includes…
The goal of this project is to determine the viability of PEG as a structural support for large area nano porous membranes. This would enable lift-off vs. the current method of etching through the wafer. The ideal properties are that the structure can withstand an aqueous solution for many days without peeling off or dissolving,…
BBB Device Update We’ve identified a few areas in which we can improve upon the initial device seen in Booth et al (2012). Mainly: Endothelial TEER increases to an in vivo value, hopefully from increased astrocytic (pericytic?) support from the abluminal chamber due to better membrane characteristics. Real-time microscopy of endothelial cell tight-junctions under the…