This week I’ve added male connectors to my device. Originally, I had female-female tubing connections to the device, which were very prone to leaking around the insertion ports. Tejas suggested that I try printing out the male connectors to combat this problem. The tubing I’m using is ID=2 mm, OD= 5mm. It’s compliant enough to…
Sugiura 2010 (Anal. Chem) This paper details a PDMS microfluidic system to perform dose response assays (what I’m hoping to achieve over this summer). They use serial dilutions to get separate trials spanning six orders of magnitude, showing an optimal dosage to kill HeLa cells. Their system is very efficient, using very shallow channels and balancing the…
One neat feature of the Makerware software is to visualize the printed layers before actually printing them. You can catch a lot of errors with this feature; I highly recommend it.
We currently use Adobe Illustrator to design silicone gasket geometries for our microfluidic devices. Here is a quick way to do a similar thing from sketchup. The advantage of this procedure is that you can create a complete 3d model of your device and export different snapshots to the 3d printer for bulk fabrication and a…
Meghan and I continued to experiment with our PLA printed transwells. We came up with a protocol that has some cells growing on pnc-Si (albeit not to confluence yet), and less so on nonporous Silicon nitride. In the gallery below B2, B3, and B4 are 1060 nonporous silicon nitride SEPCONS (cells in trenches) and B5…
Sketchup is a great tool for showing off your microsystem ideas, complete with animation capabilities. However, it cannot intrinsically move objects around, show how water flows in a channel, or insert pieces into a slot, which are useful for understanding how a microsystem can be assembled. Keyframe Animation is a plugin for sketchup that…
In Nottingham this summer, I attempted to use a Makerbot2 printer to create culture devices for SEPCON chips. I had varying degrees of success, but I was not able to get a good seal between the PLA and gaskets using only machined grooves. This would have limited our ability to do TEER and other 2-chamber…
Previous posts: Theory Deposition Etching Imaging First Freestanding Membranes I had previously made free-standing nanomembranes that were mostly MgF2 according to the EDAX scan of the freestanding region: I hoped to duplicate my results and send over a few more samples to Nottingham. With that in mind, I ran an evaporation to produce a 50nm MgF2 nanomembrane (250C, 1-2…
Previous posts: Theory Deposition Etching Imaging I have tinkered with the etch recipe some more, adding Argon to help prevent polymer formation (adding 5% O2 was not enough). The current recipe is 200 mTorr (100 mTorr Ar, 5 mTorr O2, 95 mTorr CHF3) at 120-125 W (6-12 W reflected). The plasma color is initially rosy (Argon), settling into a…
Here are some images of deposited magnesium fluoride films on 50 nanonitride: