Author: Greg Madejski

Over the last few months, I have been trying to reestablish my SERS measurements, and generate a paper based on SERS sensing with our nanomembranes. Previously, I have created magnesium fluoride coated substrates that seem to have better SERS performance than just NPN alone. Combining our TEM imaging with SERS data would be a powerful…

Thanks to Dan Ahmad for performing the filtrations. Introduction I want to see if we can improve the sample preparation method for the recovery of SARS-COV-2 from wastewater filtration using our nanomembrane technology. Currently, raw samples are ultracentrifuged against a sucrose cushion to create a pellet that can be used with a RNA extraction kit,…

This post is a continuation of the project found here:  Fabricating 500 nm Channels in Silicon Wafers. The chief limitation of the previous device design was that the long narrow nanochannels were not effectively wetted. To combat this problem, we would like to fabricate the channels in situ on top of NPN. This could be…

Summary There’s a lot to be desired in counting pores in grayscale images, especially when the contrast differences are low. A human eye is usually much better at picking out slight differences in contrast, and this can mean the difference between an open and closed pore. Differences of 5 nm can be significant in certain…

Summary This post complements Fabricating 0.5 um Channels in Microscope Slides for Staph Invasion Assays. Challenges in the etch transfer process necessitated switching to a different substrate that had stronger selectivity. With that in mind, we set out to create 500×500 nm channels in silicon wafers for the bone invasion study. We had partial success (micron-sized…

Summary: The fabrication of NPN relies on the formation of pnc-Si over a non-porous SiN film, then etching the pattern of the pnc-Si into the SiN. I used the same concept to replicate the dual-scale nanomembrane style (microporous+nanoporous) featured in Alec’s work, as well as create a porous/nonporous nanomembrane substrate, by using existing SiN or…

Summary: Dan and I went to Woods Hole Oceanographic Institute to learn about the current state of microplastics research. There were a number of things that we learned that we did not know. The common sentiment among researchers agreed climate change was a much bigger threat to humans than microplastics, but the reality and immediacy…

Thanks to Ian Krout for the data. As covered in our last post, we hope to distinguish between different kinds of microdebris caught on silicon nanomembranes through the material’s different melting points. Plastics can have a wide range of melting points, depending on the ratio of plasticizers and backbone that compose the material. The additional…

Document: Ian’s Presentation Thanks to Ian Krout for the experiment and the writeup, which I have organized here. The purpose of this set-up was to develop a tool to melt plastic particles collected on the silicon nanomembranes membranes. Due to the different melting temperatures of plastic polymers this tool allows users the ability to rapidly…