Flexible and highly stable organic electrochemical transistors for bioelectronics applications

In recent years, research on organic electrochemical transistors (OECTs) is rapidly increasing due to its potential applications in bioelectronics. Although flexible substrates are critically required to produce devices that conform to any deformable surface of the targets, fundamental physics of flexible OECTs are remain largely unexplored. In this research project, we developed low cost, transparent, and micro-scale OECTs arrays based on conducting polymer, poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS), on a flexible poly(ethylene terephthalate) (PET) substrate. Significantly, the PEDOT:PSS film (spin-coated from CleviosTM PH1000 PEDOT:PSS dispersion mixed with 5% glycerol), without the addition of any cross-linking agent, shows robust adhesion on the substrate even after 3-month water immersion tests. Accordingly, a widespread fabrication procedure has nto only been simplified but rendered completely biocompatible. Transistor channel lengths as short as 5 um are achieved by patterning with a biocompatible fluorinated photoresist. Bending tests show that the film conductivity is stable at different bending angles. This work significantly contributes to the organic bioelectronics research aiming at practical applications such as brain activity monitoring – thanks to the biocompatible fabrication process chosen for device realization.

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Mots clés

• Polymers and Plastics
• Conducting polymers and applications