Comsol modeling was done to find the ideal channel height and volumetric flow rate. What is clear from the simulation is that ever increasing flow rates in the model lead to increased clearance and decreasing channel heights give some benefit but not on the order previously expected. In addition, (Depner 2005) shows that increasing the flow…
This study was run to test test the efficacy of PEGylation in blocking BSA adsorption. Three surface types were used, glass, PEGylated glass, and PEGylated pnc-SI. The glass was cleaned in Ethyl Alcohol, dried and UV treated, PEGylated glass was procured from Microsurfaces Inc. who also PEGylated our samples of pnc-Si, which did not have…
SET-UP Syringe pump: 5 mL of 7.6-nmol/100µL, 5.6 µL/min pump rate. Single Channel dialyser, 10 mm long, 0.5 mm wide, 0.3 mm high in stirred beaker of DI water Fraction Collector programed to rotate every 30 min. Set up in refrigerator, 40˚C. Figure 1: Long term dialysis clearance set up in refrigerator. Syringe pump, stirred…
Regarding the single channel dialyzer chip with 20-nm thick nano-porous silicon membrane: 10 mm long, 300 µm deep, 500 µm wide channels. Now that we’ve shown that a measurable quantity of urea is filtered out of DI water in one pass through the single channel dialyzer chip, we turn our attention to “Things Which Must…
The main difficulty with creating a simulation of the single channel dialysis chip is that the membrane is so very thin (20 nm). This is especially true when compared to its length of 10 mm but also when compared to the channel depth and permeate well (which in our case is actually a beaker of…
There is a reliability/handling issue with the single slot chips. 0.5 mm x 10 mm slots, 20 nm thick membranes with 40 nm SiN reinforcement. The membranes are easily packaged in an upper fluidic PDMS layer with inlet/outlets and two PDMS struts (on the membrane side to protect from accidental contact breakage.) The first test…
In order to rapidly test the entire setup for dialysis evaluation, including piezoelectric micro motor and recirculating fluid path, a means of quickly evaluating PDMS designs is needed. A mold was created with a multi-print technique in which printer toner is built up to sufficient height by over printing the same transparency. (see Fig. 1)…
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…