In order to include pumps on the prototype blood analyzer cartridges, it was necessary to implement a small pump using the existing knife-cut PDMS layer layup technique. The diaphragm architecture was selected due to ease of operation and minimal additional part requirements. CAD model of pump in Autodesk Inventor Bottom view of fabricated pump. The…
INT received the first samples of their new cartridge design. The following slides were given to us by INT to provide some detail. The shorter cylinder on the left that is called the “glass bead pod” needs on filter fixed to the bottom. The taller cylinder is the “desalting chamber” and will require a filter…
Because of the failure of bonding the electrode to the top gasket in my last design, I have been trying to make improvements to my fabrication to make the electrode/gasket surface more planar. Things I have tried: 1. Pressure during curing. I placed a 500g weight on top of a microscope slide on top of…
Using the same successful procedure as the last lift-off attempt, another large piece of membrane lifted off. This came from the same wafer, but confirms that 30 minutes in BOE is sufficient to etch 25 nm of thermal oxide under the SU8 structure. Ideally this time can be reduced by means of a different sacrificial…
With Joe’s help, I was able to take some SEM images of the samples that I performed my previous set of separation experiments on. Sample 1: The obvious aggregation in this sample (exemplified by the ‘victory eagle’ blot in the second image) is observed in all five of the samples. What we can’t know is…
Karl and I went to INT to meet with Mike Connolly and Rick Murante for preliminary discussions on the PFI project. Our role as proposed in the grant is to provide membranes capable of eliminating false positives by using ~20nm pnc-Si to reduce contamination. Here’s a link to an INT video showing their process and prototype. (4…
While my focus will be on packaging a single multi-channel chip device, I have captured here an initial concept for packaging multiple channels. The technique required is the application of verticle PDMS structures to direct blood and dialysate to and from the stacked levels of chips.
After integrating my thin film electrodes into the layer stack of the BBB device, I want to make some TEER measurements. I stripped off the well-plate attachment off of the TEER tool, exposing the individual leads. To test that the circuit functioned properly, I placed the leads in DI water and then…
Using a wafer with a stack of Si-25nm(thermOx)-40nm(SiN)-50nm(PNCSi), lift-off was achieved on a small scale. First the SiN was etched using the standard process Simpore has developed, this also removed most/all of the PNCSi. The standard uChem process was then followed for SU8 application. A negative mask with 10um lines and 50um spaces was chosen…