Goal: Measure SU-8 shrinkage that have gone through various soft and hard bake conditions To measure the shrinkage, the SU-8 scaffolds needed to be lifted off, but there was some issues. Originally, the SU-8 was spincoated onto an oxide layer, which would be etched away using BOE. The SU-8 had appeared to be disintegrating due…

I tested all the microbeads that the Gaborski and Lapizco-Encinas labs own.  The results are summarized below.  The sizes ranged from 50 nm to 2 µm.  I mixed them to concentrations of 0.2 g/L for all bead less than 1 µm and 1.0 g/L for all 1 µm or greater.  Interestingly, the scans look rather…

From last few months, I am working on the development of a co-culturing system that can work as an in vitro mimetic of the human vasculature. The idea is to make a device capable of co-culturing, real time imaging, equipped with fluidics for testing different assays as well as to grow cells under shear. TEER measurement…

Here’s a few sketchup animations I made for Dean’s device, based on his PPG presentation last week:      

Poor English Paper used as a starting point: Silicon Nitride Etch Rate paper This is a continuation of the work I’ve done, attempting to make freestanding MgF2 nanomembranes (theory and deposition) using a Silicon Nitride nanoporous substrate. I originally  wanted to use hot phosphoric acid to remove the Si3N4, but since we do not have that…

In this experiment, I soaked membranes (from either wafer 1064 [150W deposition power] or wafer 1065 [100W deposition power]) in different fluids that are standard use in cell culture applications, or which provide a similar situation as could be found in such (cause of pH change, salts, etc.). Each membrane is made into a single-well…

EDIT – 2/10/14 – Adding 1 mM phosphate buffer fixes the problems outlined in this post. I’ve been having some trouble taking consistent pH measurements with the new pH probe. Prior to Thanksgiving I made a spectrum of 10 mM KCl buffers (at 4, 6, 7, 8, and 10 pH units) for use in my…

In evaluating the usefulness of our membranes for cell culture, it is important to understand if and how cell growth is affected by the surface.  The desire is that they be consistent with standard culture substrates (i.e. Tissue Culture Plastic (TC)). I performed two growth trials using HUVECs (Human Umbilical Vein Endothelial Cells), one focusing…

I am attempting to fabricate a free standing, porous, MgF2 nanomembrane for Raman spectroscopy applications (see my previous post for background). To that end, I’ve used the Lesker p75 evaporator in the basement to deposit ~100nm of MgF2 on one of our nanonitride Sepcon chips (Wafer 1055, 50 nm SiN, 2% porosity, 20-40 nm pores)….

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)…