The Chemistry and Application of Bioelectronic Polymers

Dr. Bryan W. Boudouris

Professor of Chemical Engineering and Professor of Chemistry, Purdue University

Abstract

Designer macromolecules provide a platform by which to generate structured, multifunctional materials with tailored biochemical, redox, and optoelectronic properties. Furthermore, the solution-processable nature of functional polymers allows for device fabrication procedures that are compatible with high-throughput (e.g., roll-to-roll coating) manufacturing processes. As such, these macromolecules offer the promise of providing made-to-order, low-cost materials solutions to some of the most pressing polymer and soft materials challenges facing the world today. Here, we will describe the synthesis, molecular characterization, and electronic and electrochemical application of an emerging class of transparent conducting macromolecules, radical polymers. Radical polymers are macromolecular materials that have nonconjugated polymeric backbones and pendant groups that bear stable open-shell moieties. In contrast to almost all other optoelectronically-active polymers, radical polymers lack backbone conjugation and are completely amorphous in the solid state. Despite this shift in macromolecular design archetype, we demonstrate that the solid-state electrical conductivity of a designer radical polymer exceeds 20 S m^‑1, and this places this nonconjugated polymer conductor in the same regime as many grades of common commercially-available, chemically-doped conjugated conducting polymers. Additionally, we highlight how controlling the macromolecular physics of the redox-active materials allows for their utilization in advanced bioelectronic devices, including in sensors printed atop commercial contact lenses. These devices allow for the comfortable and continuous monitoring of biomarkers associated with eye function in patients. In this way, we aim to demonstrate how polymer chemistry can be connected to modular device functionality in a direct manner.