Category: SCIENCE

I’ve realized that Fick’s Laws for diffusion are very important for a lot of different fields, but aren’t very easily searchable. Below is a short compilation of my *favorite* problems and their solutions. Just for fun!   Steady State Diffusion through the Walls of a Cylindrical Pipe (From Jeff Hoyt’s MSE 103 Course at UC Berkeley) Consider hydrogen diffusing through an… Read more →

Here’s a partial list of materials and their etch rates!     Isotropic Etch Mode Rate (Å/Min) Selectivity (:1) Anisotropic Etch Mode Rate (Å/Min) Selectivity (:1) Silicon Nitrate (Si3N4) SF6/O2 RIE/PE >1000 2-3, Resist CHF2/O2 DRIE 400+ 2-3, Resist >7, SiO2 >10, GaAs >20, GaAs, Al >10, Ti, W, Al 1, Si Silicon Dioxide (SiO2) BHF 100 CHF2/O2 DRIE 300-400 2-3,… Read more →

This is the second part to my first post about Hard Lithography (Wafer Fabrication). I’m going to just briefly cover soft lithography techniques.   Polymer Materials vs. Glass for BioMEMs Glass has well known surface and electro-osmotic properties for microfluidic applications. Polymers also have some similar properties, such as optical transparency and biocompatibility, but also have a few advantages and disadvantages.… Read more →

Smart Polymers are polymers that respond to characteristics of their environment such as pH, temperature, calcium, magnesium, organic solvents, magnetic field, electrical potential, IR radiation and UV radiation. Polymer responses can include altering color or transparency, becoming conductive or permeable to water or changing shape (shape memory polymers).   Below is a table I made of common polymers and their stimuli, based… Read more →

Here’s a brief introduction to Silicon Wafer Processing I wrote (based on Chapter 2 of Fundamentals of BioMEMS and Medical Microdevices by Steven S. Saliterman). Silicon dioxide Film Growth on Silicon Wafers Silicon dioxide film can be produced through thermal oxidation. This can include dry, wet or pyrogenic oxidation. Dry oxidation uses rapid thermal annealing to react pure silicon with oxygen gas… Read more →

I’ve realized I’m incredibly passionate about injecting the beautiful, vibrant startup industry into Medicine on a fundamental level. Technology in the Medical Industry tends to be an sluggish 5 year turn around for approved projects. The majority of the startup industry strives to work a little bit faster, with year long turn around. My philosophy is to attempt to mimic this… Read more →

This carbon holey film was made from a silicon wafer template I fabricated. I made the wafer template and the imaged sample is carbon film Dr. Kenneth Downing made using the template. Credit to the UCB Nanolab, for tools and guidance. This was my first experience with wafer fabrication, but definitely not the last. This technique is not fully perfected… Read more →

A lot of my research has to do with TEM grids, which is basically a sample holder. Recently I did SEM analysis in order to characterize the purity of the grids. It’s important to know the qualities of the materials I am working with to avoid interactions with any reactive samples I may have. I’ve always loved photography, so these… Read more →

The other day I had a dream about a housewarming present for a friend. Cookie Cutters. 3D printing has opened a world of possibilities for me. Now, if I want to make a custom project, I’m no longer limited to normal materials. If I need to make a stencil, I can 3D print a stencil. If I need a part… Read more →