My Very Own Electrode: from Plasma Etching to Experimentation!

Today I began my internship by learning about the plasma etching process which is used to clean electrode arrays. The arrays are placed on a tray that is then put into a low-pressure chamber where the plasma etching will take place. Plasma is known as the fourth state of matter, because it is not a solid, liquid or gas. It is instead a mixture of atoms, ions, and free radicals. Plasma naturally occurs only in lighting and the aurora borealis. We created plasma by creating a vacuum, and then pumping oxygen into the chamber. After about a half-hour of this gas treatment, we sent an electrical charge through the chamber, thus creating plasma. The plasma ions become activated by this electrical field, and begin to vibrate and glow a bluish-purple color. (Seeing the glowing plasma was definitely the coolest part of this process!) The vibrating ions essentially “scrub” the arrays in the chamber, leaving them perfectly sterile. A vacuum pump then takes the contaminants that might have been on the arrays and removes them from the chamber. Plasma etching is incredibly important to the entire process of making an electrode array, because any type of contamination can interferer with the electrode's impedance or resistance, thus creating inaccurate data. 

I also passaged the BSC-1 cells I created last time (which, thankfully, turned out to be healthy!) to create new cells for next week, and also to use in my own ECIS experiment. I was on my own today to replicate the process of inserting cells into an electrode array. I then took my electrode that was filled with BSC-1 cells and plugged it into the ECIS-Z instrument, essentially the simplest version of the ECIS instruments to use. 

It was really interesting to see my electrode go through so many steps: from manufacturing, to etching, to its use in the lab, and finally into the ECIS instrument to conduct and experiment.