Year: 2026
Type: preprint
Abstract: Organic mixed ionic-electronic conductors (OMIECs) couple ionic and electronic signals, enabling energy storage, neuromorphic computing, and bioelectronics. However, how charge relaxes in water once the bias is removed, which determines how long stored states persist, remains unclear. Using operando charge photometry, we tracked charge in OMIEC films during biasing and open-circuit relaxation. Under bias, charges moved as redox fronts. After bias removal, charge instead relaxed uniformly across the channel. Modeling and cryo-electron microscopy indicate that swelling creates connected water-rich pathways through the bulk. These pathways speed ion motion but also let stored charge leak away. Tuning the terminal side chain of a polythiophene controls water uptake and ion trapping. Bulky hydrophobic side chains enable stable programmable states, whereas hydrophilic side chains support fast electrophysiology sensing.
Source: arXiv (Cornell University)
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: Advanced Device Concepts for Next-Generation Photovoltaics, G1435316258, ORGANIC HETEROJUNCTION PHOTOCATALYSTS FOR SOLAR-DRIVEN GREEN HYDROGEN SYNTHESIS FROM WATER, G4137521004, Exploiting spins for new insights into photocatalytic mechanisms for hydrogen generation, Harnessing vibration-induced enhancement of transport in functional materials with soft structural dynamics, Multi-Dimensional Electron Microscope, Probing charge transport in mixed ionic-electronic conductors
OpenAlex ID: W7221092581