High Hole Mobility Fiber Organic Electrochemical Transistors for next-Generation Adaptive Neuromorphic bio-Hybrid Technologies.

The latest developments in fiber design and materials science are paving the way for fibers to evolve from parts in passive components to functional parts in active fabrics. Designing conformable, organic electrochemical transistor (OECT) structures using poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) fibers has excellent potential for low-cost wearable bioelectronics, bio-hybrid devices and adaptive neuromorphic technologies. However, realizing this potential requires developing approaches to form good electrodes, on small fiber diameters with poor wettability and irregular coatings, to achieve high-performance and good stability devices. Additionally, PEDOT:PSS-fiber fabrication needs to move away from small batch processing to roll-to-roll or continuous processing. Here, we show that synergistic effects from a superior electrode/organic interface, and exceptional fiber alignment from continuous processing, enable PEDOT:PSS fiber-OECTs with stable contacts, high μC* product (1570.5 F/cmVs), and high hole mobility over 45 cm 2 /Vs. We developed fiber-electrochemical neuromorphic organic devices (fiber-ENODes) to demonstrate that the high mobility fibers are promising building blocks for future bio-hybrid technologies. The fiber-ENODes have synaptic weight update in response to dopamine, as well as a form factor closely matching the neuronal axon terminal. This article is protected by copyright. All rights reserved.