As previously stated in my initial post (found here https://trace-bmps.org/nanomembranes-in-potassium-ion-selective-electrodes), I am in the process of developing a potassium Ion Selective Electrode (ISE) Sensor using our chips. Along the way I have gathered all sorts of curious but interesting data, with observations bringing both old discoveries and new oddities to light. Outlined below are some…
Overview Analysis of blood has long proven to provide insight into the health of the respective patient. Arduously researched, many components of blood have arisen as markers of health. These include various biomarkers such as proteins, antibodies, and cell derived vesicles, but also include ion concentrations. While the library of markers is vast and continuously…
[latexpage] The relationship between the inlet and exit concentrations in a single pass over a membranes can be derived assuming first order loss to the membrane … \begin{equation} \frac{dC(x)}{dt} = -\kappa C(x) \end{equation} where is the local bulk concentration above the membrane and is the ‘elimination rate constant,’ a concept also used in drug delivery….
[latexpage] The solution to the problem of diffusion from a semi-infinite solution to a perfectly absorbing surface is found on page 32 of Crank’s classic text (The Mathematics of Diffusion): \begin{equation} \frac{C(y,t)}{C_o} = erf(\frac{y}{2\sqrt{Dt}}) \end{equation} Where D is the diffusion coefficient is the initial concentration everywhere in the bulk and erf is the error function….
We’ve calculated our instantaneous clearance numbers for the benchtop studies that use sepcon chips. Even calculating per unit area, our chips are not clearing much volume in these experiments. I believe this is due to the very low flow rate (1 µL/min). Kayli is starting experiments to use higher flow rates with the same chips…
[latexpage] This will be at least a three part series. Here in Part I, we will establish why adding flow to electrophoretic sensor (ssNP) is a bad idea. In Part II we will show why microfluidics is a benefit to adhesion-based sensors. In Part III we will explore the ability of a NPN/ssNP dual membrane…
Some of the animation work that I have done (example as above) using Blender has been useful to communicate ideas and generate high quality images for papers. However, it is often time consuming to run them on our own personal laptops. The figures I generated for Kyle’s nanoporous tenting paper could take a day…
We have been in discussions with a large membrane company (lets call them Big Filter Inc.) on the topic of using our membrane for virus applications. Josh Miller did a rather remarkable thing and affixed 5.4 mm NPN chips into their standard housings so they could test them directly. Using these devices BF Inc. tested…
3DChipModel.mph I’ve created a 3D model for our flow chips. It should work between classroom licenses, but in the event it does not I will post a set of step by step instructions to create this model. The model is currently set to do 2 micron slits, with 12 micron lengths (10micron + two caps)….
I created a COMSOL model (zip) model with geometry based on the CAD drawing of the sepcon fixture Jared provided. I’ve included Velocity results (then Concentration, Pressure, Vorticity, and Shear rate). Also included is the Parameter table which has the Diffusion Coefficient for Urea taking into account the drawn thickness of the membrane (100 µm) vs…