Felix Sunjoo Kim is a Professor in the Department of Chemical Engineering at Chung-Ang University (Seoul, Korea), where he has been a faculty member since 2013. He received his B.S. degree in Chemical Engineering from Seoul National University (Korea) in 2003, and his Ph.D. from the University of Washington (USA) in 2012. His research focuses on the charge- and ion-transport properties of polymers and metal oxides, as well as their applications in unconventional electronics.

Organic electrochemical transistors (OECTs) are a class of electronic devices that rely on ion dynamics for their operation, and they have attracted interest as a novel platform for memristive functionality in neuromorphic computing for flexible systems. However, the field still lacks an in-depth understanding of the underlying device mechanisms, as the ionic and electronic signals are often strongly coupled in these materials. In this talk, we present our recent studies on controlling ion distribution, conduction, and interactions in solid-state OECTs based on polymer blends, aiming to finely tune their electrical performance toward realizing spiking neural networks. Both electron- and ion-transport properties of the constituent layers are important factors that determine these device characteristics. A set of complementary electrochemical approaches elucidates the working mechanisms and fundamental principles underlying the memory behaviors of these devices. We conclude that both electrolyte and channel materials in OECTs can be engineered to directly tune the electrochemical processes, including ion transport, accumulation/depletion, and charge transfer, and that this strategy provides a promising route toward the system-level integration of OECTs.

1. D. Kim, F. S. Kim, Chem. Mater. 33, 7572 (2021) DOI: 10.1021/acs.chemmater.1c00912
2. D. Kim, W. J. Pyo, S. Youn, J. So, Y. Kim, H. Kim, F. S. Kim, Device 3, 100940 (2025) DOI: 10.1016/j.device.2025.100940
3. Y. Hwang, J. H. Jeon, J. Lee, J. Yoon, F. S. Kim, H. Kim, J. Nanosci. Nanotech. 21, 4303 (2021) DOI: 10.1166/jnn.2021.19393
4. J. So, T. Kim, J. Shin, D. Kim, F. S. Kim, Macromol. Res. 31, 1095 (2023) DOI: 10.1007/s13233-023-00188-9