Crystalline PEDOT:PSS-based mixed conductors for bioelectronic applications
Myung-Han Yoon, Ph.D., Professor
School of Materials Science and Engineering
Materials Science and Engineering
Gwangju Institute of Science and Technology
Abstract: In this research, we investigated the crystalline poly(3,4- ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS)-based on mixed conductors for bioelectronic applications. In particular, we studied the correlation among polymer film microstructure/composition, electrochemical performance, and underwater stability. Various film characterizations confirmed that crystallized PEDOT:PSS (Crys-P) films have the highly-crystallized anisotropic microstructure with vertically edge-on and horizontally π-π orderings, while unbound styrene sulfonate residues were minimized. Compared with the conventional PEDOT:PSS film, the highly-organized film microstructure in Crys-P lead to remarkable organic electrochemical transistor (OECT) characteristics such as large transconductance (>20 mS), low contact resistance (20-day water immersion, >2000-time repeated on-off switching, or high-temperature/pressure sterilization. We expect that the present study will contribute to the in-depth understanding of the material microstructure/composition effect on channel-electrolyte interfaces and mixed ion-hole/electron transport, and the future development of implantable bioelectronics targeting at prolonged neural recording/stimulation. Furthermore, we implemented crystalline PEDOT:PSS-based bioelectronics interfaces such as multi-electrode arrays (MEAs) for cardiac/retinae recording and stimulation and single-strand microfiber OECTs for ion sensing in human sweat.
- Seong-Min Kim, Chang-Hyun Kim, Youngseok Kim, Nara Kim, Won-June Lee, Eun-Hak Lee, Dokyun Kim, Sungjun Park, Kwanghee Lee, Jonathan Rivnay, and Myung-Han Yoon* Nature Comm. 9, 3858 (2018) “Influence of PEDOT:PSS Film Microstructural Crystallinity/Composition on Electrochemical Transistor Performance and Long-Term Stability”
- Seong-Min Kim, Nara Kim, Youngseok Kim, Min-Seo Baik, Minsu Yoo, Dongyoon Kim, Won-June Lee, Dong-Hee Kang, Sohee Kim, Kwanghee Lee* and Myung-Han Yoon* NPG Asia Mater. 10, 255 (2018) “Solution-Processed Conductive Polymer Cellular Interfaces for Direct Electrical Stimulation and Recording”
Bio: Myung-Han Yoon received his B.S. (1999) in Chemistry and M.S. (2001) in Physical Chemistry at Seoul National University, South Korea. He studied “Organic Semiconductors and Dielectrics Based Thin Films Transistors” for his Ph.D. (2006) in Materials Chemistry with the guidance of Prof. Tobin J Marks at Northwestern University in US. In 2006, he moved to Department of Chemistry and Chemical Biology at Harvard University (Prof. Hongkun Park group) as a postdoctoral fellow and focused on neuronal electronic/fluidic interfaces. He joined School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST) as a junior faculty member in 2010, and became promoted to an associate professor in 2015 and a full professor in 2018. He has been an advisory professor at LG Electronics since 2016. His research interest is “Developing Solution-Processable Functional Materials Based on Conducting Polymers, Sol-Gel Metal Oxides, Fibrillar Hydrogel for Printable Flexible Electronics and Bio-Electronic Interfaces”.
For more information about Prof. Yoon's research, you can consult his group web page.