On Monday I presented our progress on the hemodialysis project for the Coulter Foundation. They seemed very pleased with our progress and impressed with our team. Its a tough crowd and for the first time, I sensed they had confidence in us. I’ve uploaded my presentation to the blog (PDF; ppt). Their primary points of…
This is the third set of studies to assess the hemocompatibility of pncSi. It aims towards a quantitative analysis of the formation of the complement protein C3a in the blood upon interaction with pncSi surfaces. Biological Motivation: Complement proteins help the functioning of the innate immune systems in clearing away the pathogens from the organism,…
Instantaneous Clearance: Kd CBi, and CBo are the concentration of solute in the blood at the input and output of the dialyser. CDi and CDo are the concentration of solute in the dialysate at the input and output. QBi, QBo, QDi, and QDo are the flow rates at the inputs and outputs. The volume of…
See Microfluidic Mold Making for instructions. I have assembled 3 more Barrett Chamber/ SC114 pnc-Si microfluidic devices this week. Currently, there are 2 Barrett chambers remaining and the mold is missing. The mask to make the mold still exists, however, there was a lack of N2 gas for processing (spin-coater requisite), so Henry and I…
Barrett Chamber Flow Visualization For my lab rotation here, I was tasked with visualizing the flow of blood/blood-like objects across the 1st generation Barrett chambers. The design of the chamber is seen below. Some key characteristics are that the chamber is suspended from resting flat on a surface to allow liquids to diffuse through the…
The purpose of the fluidics in our hemodialysis system is to move the sample to and the retentate away from the membranes. The dialysate (permeate, filtrate) will be handled passively in the initial designs and therefore do not require fluidic manipulation. The parameters influencing the movement of the sample past the membranes include channel geometry…
In the last post, we have discussed the intermediate state of the membranes which shows the irregular shape pores and silicon nanocrystals after annealed at 700C. Last week I did a quick test on the same nitride membrane with a different annealing process to verify this intermediate state. I run two different heat treatments. The…
This is the first set of studies to assess the hemocompatibility of pncSi surfaces based on the paper by Fissell and Roy. It looks for the behavior of platelets in the plasma upon interaction with pncSi surfaces. Biological Motivation: Platelets are one of the most important components of the human immune system and also one…
The minimum essential medium elution assay with neutral red is a commonly used method for determining the cytotoxicity of a material, typically polymers1-4. The neutral red dye is only endocytosed by viable cells; relative viability can be determined by absorbance measurements from solutions of the extracted dye. After several weeks in the lab stabilizing the…
In this post, I would like to sum up all different annealing scenarios, which corresponding to different morphologies of the pnc-Si membrane so far we have observed. It should be very helpful to understand the evolution of the pore formation during the annealing. This whole evolution I believe, not only applies to the oxide/silicon/oxide stack,…