Development of Screen-Printed Biodegradable Flexible Organic Electrochemical Transistors Enabled by Poly(3,4-ethylenedioxythiophene) Polystyrene Sulfonate and a Solid-State Chitosan Polymer Electrolyte

• Main Authors: Sun, Bo, Hatta, Sharifah F. Wan Muhamad, Soin, Norhayati, Kadir, Mohd Fakhrul Zamani Abdul, Rezali, Fazliyatul Azwa Md, Aidit, Siti Nabila, Ma, Li Ya, Ma, Quanjin
• Format: Article
• Published: American Chemical Society 2024
• Subjects: Q Science (General); TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.um.edu.my/45406/; https://doi.org/10.1021/acsaelm.3c01823
• Institution: Universiti Malaya

Organic electrochemical transistors (OECTs) are gaining interest for applications in neuromorphic devices and biosensors. Traditional OECTs use aqueous or ionic gel electrolytes, but these materials often limit performance and wider application due to their fluid nature and poor biocompatibility. This study introduces a biodegradable, flexible solid-state OECT using a chitosan biopolymer electrolyte. The electrolyte consists of chitosan, dextran, and lithium perchlorate (LiClO4)-based salt. The chitosan-based OECTs feature an organic poly(3,4-ethylenedioxythiophene) polystyrene sulfonate semiconductor channel and are fabricated using screen printing. They demonstrate impressive performance, including an on-state current of 0.19 +/- 0.03 mA at a low 0.6 V bias voltage, a high on/off current ratio of 0.3 x 10(3), and a large transconductance of 0.416 +/- 0.05 mS. Additionally, these OECTs show remarkable endurance and mechanical robustness, maintaining stability after 300 bending cycles, long-term bending, and under temperatures ranging from 30 to 75 degrees C. Significantly, the chitosan-based OECTs are biodegradable, breaking down without toxic byproducts and reducing environmental impact. This makes them a promising option for future bioelectronics and wearable technology that leverage natural biomaterials.