Evaluating and eliminating electrode-induced degradation in organic electrochemical transistors (RPA Pilot / Seed Project)

Organic electrochemical transistors, OECTs, are promising devices for bioelectronics, biosensing, precision agriculture, and low-cost sensors in general. In many applications OECTs serve as electrochemical sensors with built-in amplification, thus improving signal fidelity and reducing the electronic components necessary. A major advantage of OECTs is that they are mechanically flexible, biocompatible, permeable to electrolytes, low cost, and can potentially be biodegradable. As a result of these advantages, OECTs have been used for monitoring brain activity, collecting electrocardiograms, detecting COVID-19, and monitoring plant health. However, the low stability of OECTs currently presents a major challenge for their further development and commercial use. One major source of instability is at the interface between the metallic electrode and conjugated polymer, where the conjugated polymer serves as the ionic and electronic conductor in the OECT. In this research, PI Paterson’s (College of Engineering) OECT device fabrication and characterization will be combined with PI Graham’s (College of Arts and Sciences) electrochemical and photoemission spectroscopies to investigate chemical degradation reactions as a function of the electrode/organic interface in OECTs, and characterize the impact on OECT stability. The project will use both bare metal electrodes and metal electrodes with self-assembled monolayers (SAMs) to determine the impact of the metal/organic interaction on degradation reactions, while also testing the ability of the SAM to improve OECT stability. This seed project will generate data for proposals to federal funding agencies, with an initial target of NSF FuSe with a focus on sustainable and biodegradable electronics.