In this paper, I sought to identify and develop a protocol on electrode arrays as a result of rapid aging by applying rapid current over time. We, however, apply a different approach by using phosphate buffer solution (PBS) to mimic the conditions of the body. Here we have established an in vitro protocol for accelerated aging, a process that involves testing in extreme conditions such as oxygen, heat, sunlight, humidity, and vibration aimed at speeding the normal aging process of items; on commercially available shape memory polymer electrode arrays from Qualia over a period of 30 days in PBS. Two electrode arrays were placed in 37°C and 2 were placed in 57°C. Open lead electrochemical impedance spectroscopy (EIS) was conducted on the electrode arrays. Overall, the results showed there were differences in average impedance during this accelerated aging protocol. At 37°C we see that the average impedance values increased as the electrodes were aged at 1kHz from an average of 4.15E6 to 9.14E6 Ohms. At 57°C electrode arrays 4 and 5 showed strong P values well above 0.05, but average impedance increased drastically from 3.27E6 to 9.97E6 and P value of 0.04 from measurement day 24 to day 30. This indicated to us that the electrode could be experiencing some delamination. In addition, this could be because the Qualia nerve cuffs tested were "B" grade, so changes in impedance could be due to the integrity of the device. This would tell us that these electrode arrays would not be capable to withstand long – term recording for up to 240 days. As a result, rejecting the hypothesis that this protocol would show no change in impedance levels for a simulated aging period of 240 days. Although this protocol was not in a perfect setting and the quality of the electrodes were not up to standard, this gave us insight into the electrochemical properties of SMP electrodes which will be useful when we bio-fabricate our own electrodes to study gastrointestinal (GI) disorders.
