| Affiliation: | 1. University of Oxford, Department of Chemistry, Oxford, OX1 3TA UK;2. Linköping University, Department of Science and Technology, Laboratory of Organic Electronics, Norrköping, SE-60174 Sweden
Wallenberg Wood Science Center, Department of Science and Technology, Linköping University, Norrköping, SE-60174 Sweden;3. Linköping University, Department of Science and Technology, Laboratory of Organic Electronics, Norrköping, SE-60174 Sweden;4. King Abdullah University of Science and Technology (KAUST), Biological Sciences and Engineering Division, Thuwal, 23955–6900 Saudi Arabia;5. George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332 USA;6. King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering Division, Thuwal, 23955–6900 Saudi Arabia;7. Stanford University, Department of Materials Science and Engineering, Stanford, CA, 94305 USA;8. Imperial College London, Department of Chemistry and Center for Plastic Electronics, London, W12 0BZ UK |
| Abstract: | Electrochemically induced volume changes in organic mixed ionic-electronic conductors (OMIECs) are particularly important for their use in dynamic microfiltration systems, biomedical machinery, and electronic devices. Although significant advances have been made to maximize the dimensional changes that can be accomplished by OMIECs, there is currently limited understanding of how changes in their molecular structures impact their underpinning fundamental processes and their performance in electronic devices. Herein, a series of ethylene glycol functionalized conjugated polymers is synthesized, and their electromechanical properties are evaluated through a combined approach of experimental measurements and molecular dynamics simulations. As demonstrated, alterations in the molecular structure of OMIECs impact numerous processes occurring during their electrochemical swelling, with sidechain length shortening decreasing the number of incorporated water molecules, reducing the generated void volumes and promoting the OMIECs to undergo different phase transitions. Ultimately, the impact of these combined molecular processes is assessed in organic electrochemical transistors, revealing that careful balancing of these phenomena is required to maximize device performance. |
