This experiment compares the metal developer used in Integrated Nano Technologies’ device to to the flow properties of water. Using the pressure cell at 3 psi, with no allyl treatment, for 10 minutes, and 200 microliters of liquid, I pushed water and developer through our membranes and examined the difference in flow rates. All of…
This is a continuation of the initial experiments testing the possibility of creating porous Si membranes with thicknesses ranging from 50 to several hundred nm, and mean pore diameters from ~50-200 nm. As suggested, we’ve started using 200 µm thick wafers and we’ve patterned with the Cell Culture mask as well as the Deflection Mask….
EO permeability: We often refer to the ‘efficiency’ of EO with pnc-Si as being very high, but this may not be the case. What is actually high, as in the case of the other modes of transport, is the ‘permeability’ in EO. Dimensionally, the quantity we’ve referred to (in various places) as the ‘efficiency, the…
This post relates to the ongoing project and potential grant between Integrated Nano-Technologies, Simpore, and NRG. The goal of my research is to show that our membranes can be integrated into Nano-Technologies’ device. Our membranes must be able to filter out or hold back large debris that can cause false positives in their device, while…
We are proposing a novel method for the fabrication of porous thin-film silicon membranes. It has been shown that metallic nanoparticles on the surface of silicon submerged in a solution of hydrofluoric acid and hydrogen peroxide will bore holes into the silicon. This selective etching occurs because the metal acts as a catalyst in the…
Continuation of the work with the Borkholder group (see this post). We put together a couple of videos of EO flow in the streaming potential cell today. Runs were performed using Ag/AgCl painted wires at ~2.5 V. Lower voltages weren’t producing very convincing flow rates. Here’s the best video of pumping we obtained: Rec0003_comp The…
Last week, I did another two wafers with different top oxide thicknesses to verify my hypothesis about the top oxide thickness effect on pores. The wafers were 20/15/03(bottom/middle/top) and 20/15/40. According to the hypothesis, the porosity of 20/15/03 would continue decreasing, where for the 20/15/40 structure, the porosity might drop. Same tip I used before,…
A long time ago, Charles did Asymmetrical Oxide Experiment to test how the asymmetrical oxide affects the pores, see Asymmetrical Oxide Experiment. He deposited three structures, which were 40/15/40, 40/15/20 and 20/15/20. It showed that when the thickness of top oxide decreased from 40nm to 20nm while kept the bottom oxide at 40nm, the porosity…
This is my attempt to summarize where we are with our investigation into the use of membrane arrays in high throughput screening. The effort is known colloquially as the ‘Harold Smith Project’ because the model protein system comes from Harold and is inspired by work in his laboratory on HIV. The principle being tested is…
Today I brought membranes and the streaming potential device to David Borkholder’s lab at RIT. His students and I set up an initial low voltage experiment. They will continue to test the device for flow rates and back pressures. Here is a list of methods and results from today: SC 214, RTPed but not oxidized,…