Sarah recently attempted to build a prototype voltage-gated drug release mechanism using one of my standard nanofluidic transistors. When she turned on her circuit (pictured below), instead of getting voltage-dependent diffusion behavior, she instead saw electro-osmosis. We’ve been debating what this means, but I contend that this means the insulating alumina film coating the silver…
Overview I burst pressure tested TEM chips with 1×1 mm windows of 100 nm SiO2 that were both annealed and unannealed (provided by JP and Josh Miller). In our experience it seems that the forming gas (H2/N2) annealed chips are stronger and never wrinkle. These burst pressure tests were performed in an attempt to…
We used chips from the latest 5 slot SepCon NPN wafer 1142 (14%, 36nm) to test our ability to separate 20 nm “blue fluorescent” polystyrene NPs from Invitrogen from IgG. We used a concentration of 10^14 particles/ml NPs and 1 mg/ml IgG. (This is a mixture of fluorescent and unlabeled IgG) We compared forward vs…
In this post we look at the effect of altering the area available for filtration on a standard 5 slot SepCon. Karl and I did this by simply cutting gaskets such that they covered different regions of the surface of a chip. We have three configurations, 1, 3 and 5 slots. Here’s a picture of…
BOTTOM LINE: We had great results from the small number of nanoporous membranes used to clear urea from Sprague-Dawley rats. We are clearing Urea better than commercial materials. (see fig) Recap of previous work: First we leaned how to set up the dialysis experiments using Sprague-Dawley rats. We made some rats uremic to elevate the…
I have been developing a microsystem for Paul Dunman’s group that will allow them to flow in bacteria, immobilize them on antibodies, and then subject them to varying concentrations of antibiotics. The full system will incorporate a fluidic mixer and a NPN membrane as a way to introduce the antibiotic I have been working with…
Here’s the paper we’re discussing this week: Wu(Moulin)JMS14 The authors motivate their work by claiming that ultrafiltration membranes can be used to keep “engineered nanomaterials” (ENM) out of our waters. They use confocal laser scanning microscopy to locate the position of fluorescent CdTe quantum dots (QD) on/inside an Ultracel membrane. (Made by Millipore using regenerated…
In this post I’m trying to give a better comparison among filtrations using chips from wafer 1085 using 20 and 100 nm fluorospheres, IgG, and 5 and 20 nm Au NPs. In each slide I try to indicate the flow direction with respect to the membrane. Unless I’ve written “Pressure” near the direction the separations…
Hello everyone! I’d like to show you some recent result about pnc-Ge membrane. We have been thinking to replace Si with Ge for a long time to see whether we can transfer pore formation to another materials other than silicon. In this post, I’m gonna show you some exciting pnc-Ge membrane images! The fabrication process…
Update 8/15/14: Replaced the plots with updated versions including more data for NPN (now n = 3) and cellulose (n = 4,) as well as new high-flux polyethersulfone membrane data (n = 3.) I also dropped one clearly erroneous datapoint from the NPN dataset to dramatically cut down the standard deviation. — This is a followup…