Friday, August 7, 2015
URSP Student Thao Tran Determines the Stability of Novel Implantable Microelectrode Arrays with Electrochemical Impedance Measurements
My
major is bioengineering. I am interested in learning how to use available
medical devices and build new devices to make bio-measurements. Besides, I want
to learn more about how to process and analyze data in order to solve health
related problems. This project gives me the opportunity in doing what I always
want to do. During this summer, I am be
able to gain hands on experience from recording impedance of microelectrode
arrays (MEAs), to work on my data analysis skills and to gain understanding
about electrochemical impedance measurements. My plan is going to graduate
school, so I believe that having an opportunity to conduct research with my
mentor Hamid will be a good preparation for my future years in graduate school.
When I first started, my proposal was about characterizing the impedance
profile of shape memory polymers; however, I was not able to do it due to a
connection problem of the board. As the probe was put in the bath at 60˚C, the
water vaporized and got into the board of the probe which then made a
connection problem and the measurement could not be obtained. I tried to seal
the board with silicon, but it did not solve the problem. My mentor then helped
me change the direction of my project, so right now what I am working on
determining the stability of novel low-cost MEAs. This new MEAs are from
University of Texas (UTD), and I want to know if this new UTD arrays can be
used for monitoring cultured neuronal network recording in the lab. On weekly
basis, I monitor the impedance profile of three UTD arrays at different
electrode sites and develop the Matlab code to plot them. When I am not doing
the measurement, I put them in the incubator at 37˚C. Last week, the impedance
went bad for two UTD arrays, and I was not sure what caused it. I later
discovered that there was some water leaking out of the ring, which affected
the measurement. I realized that the glue on the UTD arrays were not good
enough for a long time use. This might happen because when the ring was first
glued; the contact surface was not clean which then made the ring easy to fall
off. I tried to detach the ring completely, washed the surface with deionized
water and let it dry overnight. The next day when I came in, I tried to re-glue
the ring carefully and let it air dry overnight. On the following day, the
impedance went back to normal range again. As the impedance went back to normal
range again, I was very happy. I felt great as I was able to solve a problem
myself.