At MSEG’s Open House on February 12, 2013, Brendan Farrell, a junior BME, was awarded for having one of the two best undergraduate posters. His poster was titled “Chronic Study of the Signal to Noise Ratio of Neural Recording and System Impedance Evolution for In Vivo Polymerization of Poly (3,4-ethylenedioxythiopene) (PEDOT) in Rodent Hippocampus.”
Brendan began working for David Martin in Materials Science & Engineering during the spring of 2012, first being a volunteer and then taking it as a technical elective. He does his research in the lab of Amy Griffin in Psychology who is a collaborator on this project.
A general challenge faced by implanted biomedical devices is that they must be biocompatible, stable and long lasting. Brendan’s project deals with a particular type of implant. When an electrode is inserted into neural tissue to measure the electrical signals, the tissue has a reactive response that leads to glial scarring. This scarring produces an increase in the tissue’s resistance to movement of electrical charge (or impedance) so the electrical recordings are distorted. To decrease this problematic impedance, Brendan plans to test the use of a polymer called PEDOT that is ionically and electrically active. He will train rats to run a figure 8, surgically implant electrodes, and take baseline recordings of tissue impedance in the hippocampus of the awake rats. He will then wait 2-3 weeks for glial scarring to occur (and tissue impedance to increase). After this time, he will deliver PEDOT to the tissue near the electrodes by injecting EDOT and applying current to polymerize it into PEDOT. After polymerization, he will repeat his recordings to see if PEDOT application leads to better electrical signals.
Brendan hopes to finish his project by the end of the spring 2013 semester. “I’ve found that I enjoy doing research work and have found it interesting and challenging,” he said, “I really enjoy my project and the people I work with.” He begins his senior year in the fall and is still considering what he will do after graduation.