I recently popped out membranes from wafers 1064 and 1065 for our lab. I only started with about half a wafer, but these are the numbers from the extraction: Wafer ID # of In-Tact Extracted Membranes : High/Low Porosity # I broke during extraction # already broken before extraction # apparently under etched 1065 (100W)…
I’ve redesigned the co-culture devices described in an earlier post to allow for media isolation as well as to alleviate concerns regarding bubble trapping. The new design is pictured below: The large cube of silgard builds a cylindrical reservoir for media and can support upwards of 100 uL of fluid (equivalent to other co-culture devices…
Over the past week Andrea and I designed a new co-culture support structure for use with SiMPore’s 5.5 mm square membranes. The devices are built for use in standard 24-well plates and should prove useful to anyone wanting to do basic co-culture with these membranes going forward. The device is constructed of PDMS rings as…
EO tests were continued using 2 micron carboxylated PS Latex beads in a 0.2 mM K2HPO4 solution containing 0.1% tween. The solution had a pH of 7.54 and a conductivity of 67.0 uS/cm. The beads were negatively charged, and so would move towards the positive electrode absent electroosmotic flow. It was suggested that the pump…
Silver chloride electrodes are useful for microfluidic devices since they can generate current below one volt. This allows them to function without fear of electrolysis confounding experimental results by way of gaseous clogging. Several different methods for coating silver mesh were tested to determine which would be ideal for future experimentation. These methods were as…
Fluorescent beads were employed to assess electroosmotic flow in various devices. The beads were 200 nm in size and were negatively charged (on account of being carboxylated polystyrene). These beads were suspended in a 0.2 mM K2HPO4 buffer. They were also incubated in 1% BSA solution in an attempt to reduce their surface charge, though…
Summary of Results Membrane Pore Diameter Thickness Porosity Permeability (cc/cm^2*min*bar) SiN 3.2-4.0 um 0.12 um 22.1%-35.3% 30000 PCTE 2.4-3.0 um 9 um 11.9%-16.1% 1652 SiN Experimental Design Permeability of the 3 um pore Si Nitride membranes was assessed using the pictured apparatus: Fluid (ultrapure water) was pumped at a constant rate into a pipet whereupon…