Below are the results of my recent crosslinking efforts. PEG with 1.5% crosslinker was exposed to UV light at varying times through a bar  printer/transparency mask measuring 100/200. In theory this corresponds to 100 micron PEG bars and 200 micron openings. In practice the results are much less neat. The table shows HUVEC cell attachment…

Scope: Adipose derived stem cells were seeded onto  Corning 3um tracketch membranes, human endothelial derived stem cells were seeded onto the membranes approximately five hours later. Numerous control wells were also seeded with ADSCs both on membranes and on the bottom of the 24 well plate. Three days after being seeded, media in each of…

Over the past week Andrea and I designed a new co-culture support structure for use with SiMPore’s 5.5 mm square membranes. The devices are built for use in standard 24-well plates and should prove useful to anyone wanting to do basic co-culture with these membranes going forward. The device is constructed of PDMS rings as…

Wet Etching of Optical Thin Films   As a result of Christian’s trip and Kevin’s discussions with me, I have been wondering if we could make nanoporous MgF2 membranes for Raman spectroscopy. Part of the appeal in using our Si-based nanomembranes is that the volume they occupy in the observation space is extremely minimal. Even…

Scope: ADSCs were cultured on the bottom of the Corning 0.4um translucent membranes in DMEM+ 10% FBS+ 1% Pen-Strep. After 6 hours, the membranes were flipped over and placed into a 24 well plate. Of the four membranes with ADSCs cultured on them, 2 of them were seeded with HUVECs on the top side of…

I updated the software for the SSI.  The software seems to be working properly.  There are some differences, most of which I haven’t fully explored.  Notably, we can open and view log files easily with 3.8. It seems that we may need to alter all of our current recipes to make them compatible with 3.8….

We have considered SiN membranes in PDMS channels as EOF pumps and as constrictions for insulator-based dielectrophoresis (iDEP). For EOF, thicker membranes may yield greater flow rates. For iDEP, a smaller membrane porosity, meaning fewer, smaller holes on a given membrane area, are likely to result in more effective iDEP trapping of particles. I built…

This is in continuation to the studies that I published here. I used two types of membrane surfaces: nano nitride trenches (the back side of membranes) with pure nitride on the surface, and zero-second-etch nano nitride with a completely intact pncSi cap on the top. These two surfaces basically act as materials with two extreme…

Hopefully many more details to follow, but JP, Josh M. and I doped some Si substrates with boron using a spin-on-glass.  It seems well known that heavily boron doped Si is more resistant to EDP etch than intrinsic or n-type material.  We went big and used the 3-slot SEPCON mask.       So at…

Back when I first joined the lab I did some experiments where I varied the pressure driving a gold filtration experiment. The critical plot was this:   It seems unlikely that the sieving coefficient could change so dramatically with applied pressure, so I would like to repeat the experiments. Because the larger gold particles on…