Stretchable and Stable Electrolyte‐Gated Organic Electrochemical Transistor Synapse with a Nafion Membrane for Enhanced Synaptic Properties

• Published in: Advanced engineering materials Vol. 24; no. 4
• Main Authors: Nguyen, Trong Danh, Trung, Tran Quang, Lee, Yurim, Lee, Nae-Eung
• Format: Journal Article
• Language: English
• Published: 01.04.2022
• Subjects: long-term plasticity; Nafion membranes; organic electrochemical transistors-based synaptic devices; PEDOT:PSS; stretchable organic electrochemical transistors
• ISSN: 1438-1656; 1527-2648
• DOI: 10.1002/adem.202100918

Stretchable artificial synaptic devices are promising for integration into soft neuromorphic systems. However, the organic electrochemical transistor (OECT)‐based synaptic device is challenging due to the difficulty of obtaining high mechanical deformability and durability as well as high long‐term plasticity (LTP) and retention time. Herein, a highly stable and stretchable synaptic OECT fabricated on a 3D mogul‐patterned substrate with stress absorption capability with improved synaptic properties is reported. The mechanical stability of a poly(3,4‐ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) channel and, in turn, the OECT is improved by adding additives in the channel. Synaptic properties including synaptic weight (SW), LTP, and retention time could be tuned and improved by adopting a Nafion membrane between the channel and the gate electrode, which modifies the transport dynamics of ions in the electrolyte across the membrane. This approach paves a way for improving and tuning the synaptic properties of stretchable biomimetic OECT synapses. A highly stable and stretchable synaptic organic electrochemical transistor is demonstrated by improving the mechanical and electrical stability of device through modification of the poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) channel. By controlling the ion transport dynamics in the electrolyte using a cation exchange membrane, Nafion, we improve the synaptic plasticity. This approach provides an approach for soft artificial synaptic devices.