We’ve made a few academic inquiries so far into the theory which governs our nanoporous membrane transfer, but engineers as we are, the pace of our practical knowledge has outstripped that of our theoretical understanding. Here, I want to share a summary of what we know about these transferred membranes from a practical perspective, oriented…

Background: Similar to the Gaborski lab, the authors of the publication “Microfabrication of high-resolution porous membranes for cell culture” fabricated and characterized ultra-thin polymeric membranes for use as cell culture substrates. Upon reviewing their publication, Tom and I discussed some of the experiments that we’d like to replicate to further characterize the SiO2 membrane for our…

This post is a followup to my previous post, which can be found here. When last I posted, I shared a handful of videos showing membranes transferred onto glass with water vapor being wetted in shear, and noted how the wet-dry interface tended to rend them apart and/or drag them along them surface. I provided…

Jirachi has been working to make thin nafion films using our membranes as a support structure. Nafion is polymer that contains a sulfonate group, and as a result acts as a proton wire, allowing for cations (+) to be transported across a membrane, but not anions or electrons. Such a membrane can be used for filtering a…

Hi all, a quick update in case you want to know what we are up too.   This summer it will be just me at the McGrath lab; the main goal is to produce some preliminary data with an eye on submitting an NSF grant in the fall.  The topic is nano-biosensing, using Henry’s shear-free…

Attached is a paper I’d like to review on Thursday (June 11, 2015). This group is using two planar surfaces in an attempt to mimic a 3D cell culture environment. This is similar to our claims that cells growing on a permeable membrane can be akin to a slice of a 3D matrix. I met…

Pertaining to the tenting work that Greg and I have been doing, some of the experiments discussed on my last post have given us reason to believe that the transferred membranes may not adhere well to silicon oxide, floating just above it rather than sticking to it. As a test for the stability of the…

I spent some time testing the various steps of the transfer and wetting process to see if I could find the cause of membrane delamination that I saw earlier. The result seems to be that time is the main culprit. Here is the membrane just after transfer (dry between the membranes initially, steam after transfer…

My original post reported burst pressures on rectangular windows with the chips trench side down in the fixture (pressure from below). These values are low compared to square window pressures. My pressures ranged from 2 psi to 12 psi while square windows achieved 10 psi to 50 psi (Sarah Wayson’s post on square windows). So I did a limited set…

My first attempt at a nanopore fabrication/DNA experiment in NPN assemblies was interesting but ultimately unsuccessful. As I said in our last meeting, I have been able to reproduce the membrane transfer process (using some steam between the two membranes to make good contact) and the wetting behavior using a freezer to condense vapour on…