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…
From the past experiments we know that it is not easy to form pores in thicker silicon layer. It is mainly because that higher energy is required to form open holes in a thicker silicon film. Dave showed us less but bigger pores were formed in a 50nm thick silicon film after annealing. According to…
SU-8 3010 (MicroChem) was chosen for its improved adhesion strength, and reduced stress. MicroChem also provides a datasheet on the usage of this negative resist that was followed as a baseline. For Post Exposure Bake (PEB) two methods were implemented, standard procedure, and part of Li, et al process: 55C for 2 hours to reduce…
The schematic of the slot device is shown below. The main support structure is the pnc-Si membrane with Au or Ag metal on both sides. There is a conformal covering of Alumina shown in blue in the figure which actually makes the slot. This type of structure helps in squeezing the light in the nanoholes….
Because the Barcikowski lab intends to use the nanoparticles they sent us, relatively high yields are necessary for any step that cleans them up. This is unfortunate, because in every single separation that we’ve done (with one exception mentioned further on) we never see yields higher than about 5%. We’d thought that the problem was…