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…
Author: Karl Smith
Karl is the 'separations czar' for NRG. As a Biophysics Ph.D. Candidate, Karl has the responsibility of characterizing new membranes, modeling the unique physics of nanomembrane separations, and finding ways to apply pnc-Si technology to protein purification, nanofluidic transistors, and human hemodialysis. Karl graduated from Allegheny College in 2011 with a double major in English and Physics.
Gate-Voltage-Dependent EO Pumping: -6 V on the Gate Changes the Pumping Rate by an Order of Magnitude
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
Applying a Voltage to Silver-Coated SNM Can Change the Rate of EO
Because I’ve been having such a difficult time measuring consistent zetapotentials (a big and heartbreakingly inconclusive post on those efforts is forthcoming) I decided to use one of my silver-coated SNMs as an EO pump and see if changing the…
Posted in NRG
Hand-cast Protein Gels: New Technique and Fresh Chemicals
In April of last year, I spent a considerable amount of time trying to visualize protein separations using SDS-PAGE (Sodium Dodecyl Sulfate-PolyAcrylamide Gel Electrophoresis) gels, and ultimately was able to get some data: I was trying to show that 15…
Posted in NRG
Fun Posters for the Lab
Over winter break I put together some posters to hang up in the lab. I tried to represent in an clever way a few key areas of research that NRG is interested in: If anyone has any ideas for…
Posted in NRG
ALD ladders of SiN chips
In all of the below graphs, the x-axis has the same scale for easy comparison (-10 nm to 80 nm diameter). The Y-axis varies from plot to plot, but since we care more about pore density than actual numbers of…
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Where pnc-Si Separations Fall on the Zydney “Robeson” Plot
In the field of gas permeance there is a plot called the “Robeson Plot” (the paper that debuted it) that is used to compare the separation behavior of various membranes made of different materials and measured in different systems. An…
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Cross-chip resistances for SiN chips coated in Ag and Al2O3
In my continuing efforts (previous post) to create a nanofluidic transistor, I recently repeated some of my earlier attempts to prototype a basic Si-Ag-Al2O3 stack. This time, however, I used SiN chips from wafer #1070 (<40 nm>). As before, I…
Posted in NRG
Mapping Flow Patterns in the ALD
In this post I’ve detailed my attempts and eventual success (with Josh’s help) to get the ALD to coat TEM grids without blowing the delicate chips around. The actual technique is at the end of the post, beginning with the…
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Sepcon Documentation
On Friday, Henry was kind enough to ship 15 tested Sepcons to the Barcikowski group in Essen, Germany. With luck they will arrive in time for Christmas. I wrote up some documentation and an illustration for wetting and using the…
Posted in NRG
