BME PhD Preliminary Exam Announcement for Elizabeth Olivo (K. Otto, Advisor) Everyone is invited to attend the public presentation beginning at 2:00 PM. Title: Investigating Chronic Performance of Ultramicroelectrode Arrays for Intracortical Microstimulation Date: Dec 9th, 2025 Time: 2:00 PM Location: MJIS 2001 Committee: Kevin Otto (Chair), Mark Orazem (Member), Tamara Kinzer-Ursem (Member), Maria Dadarlat (Member) Abstract: Neural stimulation has shown great promise in treating neurological disorders and in developing advanced neuroprosthetic devices, but challenges with traditional electrode arrays persist. These larger microelectrode arrays (MEAs) can cause significant immune response which results in encapsulation of the device by immune cells. The glial sheath that forms can reduce device stimulation and recording efficacy and ultimately limit their long-term stability. Ultramicroelectrode arrays (UMEAs), with electrodes an order of magnitude smaller and a reduced surgical footprint, offer a potential solution by reducing inflammatory responses which in turn minimizes encapsulation of the device and extends the lifespan of the device. Preliminary studies have demonstrated that UMEAs can achieve effective neural stimulation at chronic timepoints, providing initial validation of their potential utility. However, there is still a lack of understanding about how the miniaturization of these electrodes affects their response to standard stimulation parameters over chronic time periods. The goal of this project is to address a key knowledge gap by investigating the impact of electrode size, spacing, and stimulation pulse frequency on the effectiveness of UMEAs. By addressing these critical gaps in knowledge, this research will not only improve fundamental understanding of UMEA performance but could also lead to better therapeutic outcomes for individuals with neurological disorders such as Parkinson's disease, epilepsy, and spinal cord injuries. By minimizing inflammation and improving the precision of neural activation, UMEAs could offer a significant advantage over traditional MEAs by potentially enhancing both the longevity and effectiveness of long-term neuromodulation therapies. Ultimately, this work will provide critical insights into optimizing neuromodulation for clinical and research applications and contributing to the advancement of neural interfaces for neuroprosthetics and therapeutic interventions. -- Bmeroundtable-list mailing list Bmeroundtable-list@ecn.purdue.edu https://engineering.purdue.edu/ECN/mailman/listinfo/bmeroundtable-list