Our work with permeance and hydraulic permeability tests on the SiN-NP seemed to show that the porosity and pore sizes I had calculated from the STEM images were too high. I used URnano’s TEM to get better quality images and, as suspected, the pore sizes need to be revised smaller. Wafer # 1030 (40 s…
I found another old wafer # 760 and asked Josh Miller to deposit a 25-50-25 OSO stack. He did a standard RTP of 1050 C, 60 s, 100 C/s. (and Josh Miller did the EDP etch, so this is really all his work) I measured a porosity ~4.5 %, and avg. dia. ~40 nm. For…
In determining an appropriate animal model for hemodialysis efficacy, several metrics need to be compared to the human vasculature. Blood volume, blood pressure, and heart rate could effect the suitability of these animals to model clinical hemodialysis. Blood volume can be estimated as follows. Blood weight is ~ 7% of body weight, the density of…
Since the basic protein diffusion experiments went well, I’m moving up to something that more closely resembles an actual assay application. The basic idea is this: Biotin-conjugate FLAG antibody will be bound to Avidin acrylic beads in order to make them far too large to pass through the MP8NP50 membrane. Then, Bacterial Alkaline Phosphatase (bAP)…
Ultimately we want to use SiN-NP filters to separate viruses or some other biological species, but repeated attempts to pass 20 nm fluorospheres in water or PBS have failed. Au particles, however, have passed through the filters. This post reports the results of Sarah and I attempting to pass Au particles from 20 to 100…
Following up on our previous work with SiN-NP with varied RIE times, Sarah and I measured permeability and permeance using a new measuring system better suited to the higher permeance and permeability we expect with the larger pores and higher porosity. Using the pressure regulator pictured above, we can set pressures of 3 psi and above…
JP and Josh Miller used the Xactic Si etcher to remove the pnc-Si from SiN-NP samples. I believe they ran cycles until the samples looked visibly like SiN only. Below are some SEM cross-sections showing before and after images of the samples. Sample 1028 with no RIE etch: Sample 1036 with 20 s RIE…
The following is a public service announcement: I’ve just aliquoted about 40mL of fluorescent BSA and placed it in the freezer. Each aliquot contains roughly 1mL of 6mg/mL TRITC-conjugate BSA, so there’s plenty of them. If anyone needs fluorescent BSA for anything, feel free to take as much as you need from the box labeled “TRITC-conjugate BSA”…
As I mentioned in my last post, I will be performing protein diffusion tests through CytoVu assemblies (from one well to the other) and measuring the amount of protein that is still in solution when the system reaches equilibrium in order to determine the amount of protein that is adsorbed to the assembly and thus…
This is a follow up to Mohammad’s previous posts: “Burst Pressure”, and “Burst Pressure Probability”. Josh and I had Mohammad’s wafer remade, and burst several 30nm thick pnc-Si TEM chips to add to Mohammad’s earlier data. Pore size still needs to be verified using the TEM. Burst pressure data was gathered for chips with constant perimeter,…