Uncovering ion-electron interactions in organic mixed conductors
Organic mixed ionic-electronic conductors (OMIECs) have risen as a promising material choice for bioelectronic devices due to their low impedance, soft mechanical properties, and ability to transduce ionic signals to electronic currents. The ion-electron interactions, which are unique to mixed conductors, have been exploited to produce high performance sensors and electrophysiological recording devices. However, the fundamental interactions between ions and electrons that determine the performance of these materials is still poorly understood, impeding their translation from a research setting to commercial use. This proposal aims to address this gap in knowledge using state-of-the-art analysis of the nanoscale electronic and chemical properties to better understand the macroscale materials performance.
The proposed project consists of three central goals: (1) direct observation of nanoscale ion-electron interactions in OMIECs, (2) identifying the relationship between these interactions to OMIEC materials properties, and (3) leverage the findings to optimise next-generation bioelectronic devices. Spectroscopic scanning transmission electron microscopy (STEM) techniques will be used to study the spatial distribution and electronic structure of ions in OMIEC films during operation with ultra-high spatial resolution. Optical spectroscopy and electronic characterisation will be used to study the transport properties of ionic and electronic charge carriers in OMIECs. The work will be supervised by Prof. Malliaras, an expert in both fundamental physics of OMIECs and their clinical applications, Prof. Ducati, an expert in advanced multidimensional STEM techniques, and Dr. Rao, an expert in optical characterisation of organic semiconductors. The fundamental insights drawn from investigating the ion-electron interactions in OMIECs will inform the design of next-generation bioelectronic materials and devices to advance beyond the lab into commercial and clinical applications.