(Invited) Morphological Engineering for Polymer-Based Electrochemical Sensors

Abstract

Bioelectronic devices incorporating polymeric materials into their active region has recently emerged as a driver for the next-generation sensors and healthcare technologies. A rapidly growing interest in this new application of versatile organic semiconductors and conducting polymers has been witnessed during the last few years, shaping a distinct field of ‘organic (or plastic) bioelectronics’. Low-temperature, large-area processability (e.g. printing), excellent biocompatibility, chemical tunability, and mechanical softness are some of the major reasons that organic-based bioelectronics can be a promising option for unconventional wearable and implantable platforms. However, only a small number of materials have shown promising performances up to now, and the systematic understanding has been lacking on the general processing-structure-property relationships of relevant polymers. In this presentation, a facile solution-based post-deposition morphological modification technique is reported, which successfully applied to the model bioelectronic polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. Besides the intended solid-state structural transformation, a multitude of beneficial effects on the performances of electrochemical transistor devices (a fundamental sensing element in bioelectronics) made of the engineered materials were clearly observed and systematically analyzed by a number of experimental tools. Most importantly, the nanoscale chain re-arrangements and induced long-range crystallinity gave rise to the substantial compositional changes that eventually led to the improved anti-swelling property, larger volumetric capacitance, and unprecedentedly high thermal and environmental stability. It is therefore expected that both the scientific understanding and application potentials underlined in this study will serve as a practical guideline for the development of viable organic bioelectronics technologies.