Josh has just started teaching us how to play with these; some early findings: – So far, standard centrifugation results mostly on the caking of lipids that clogs the membranes. – Use of the pressure cell has shown some promise, we have passed 120nm lipid-nps through 400nm pores @10PSI. The result? 70nm particles… – Reverse…
As discussed in a previous post, we decided to test chips from wafer #1070 because they have smaller pores than those used in the most recent forward vs. reverse study. In the forward direction, 31 uL of filtrate was passed after 30 minutes at 3 krpm. (after 30 additional minutes at 5 krpm the total…
We still have plenty of things to do, but after five weeks working at the UR, we have come a long way: – Chip production for instructional use: done – Design and production of SU8 mold: done – Protocols for (@Fisher) manufacture of micro and milli (silhouette) fluidic devices: done – Construction and testing of chips…
Last week Sarah and I made several standard nanofluidic transistor (NFT) stacks (3 nm Ti, 12 nm Ag over a 3-slot SiN membrane – wafer # 1024) in the cleanroom. I then measured the zetapotential of these devices at pH 7.43, and we thought that because the outer layer of the chip was Al2O3 that the…
I have a preliminary result from Kevin that there is a layer of fluoropolymer remaining on my MgF2 freestanding nanomembranes (which could explain some of the carbon signal in EDX from my previous posts). This would create another unnecessary signal for the intended Raman spectroscopy application. Remembering an old graph from my schooling, I dropped…
This is the method Brian McIntyre developed for the recent URNano Microfluidics Workshop. Based on a polyaddition-based mechanism based on introducing amine groups onto the surface of one material and epoxy groups on another material and enabling the amine–epoxide polyaddition reaction at their closely contacted solid-to-solid interface to establish a covalent and permanent bonding presented in…
Scott Russell from Mech. E. and Steve Gillmer came over to help Sarah and I try to record the burst of membranes at up to 2000 frames per second. Generally we used 100o frames per second because it was the best compromise between our ability to time the 1 s recording time and the amount…
Overview: The goal of this experiment was to determine which membrane type adipose derived stem cells (ADSCs) would proliferate best on. The ADSCs grew over a four day period and were imaged on days 1, 2, 3, and 4. The cells were counted on each of these days to determine growth rates on each of the…
Our main purpose of this project is to reduce or eliminate the protein non-specific adsorption on the oxidized siliconnitride sample surface. By synthesis the PEG molecular on the surface, we believe we can reach the goal. There are different ways to synthesis the PEG on the surface. First is the silanes, after synthesis the silanes,…
Today, I finally demonstrated liftoff of microporous SiOx from a bare Si wafer. The sample is a 2 x 2 cm section of wafer 209A02, which has a 100 nm layer of TEOS SiOx that stress stabilizing anneal. The film was patterned with close-packed ø3 µm pores (6 µm pitch) using S1813 resist, G-line stepper…