Bidirectional model for ultrathin pedot-based trilayer transducers
Résumé
PEDOT-based trilayer ionic polymer exhibits bidirectional electromechanical coupling. For such a material system, application of 2 V produces a strain of 1-2 % and millimeter displacements, while a few millivolts are produced when such a millimeter level displacement is applied. To simulate such a behaviour, this study presents a bidirectional sensing and actuation model for the ultrathin PEDOT-based trilayer transducers. The model consists of three elements: an electrochemical part described by a simple RC circuit, a mechanical part represented using dynamic Euler - Bernoulli beam theory, and an empirical
strain-to-charge ratio coupling charge to strain in actuation and applied stress to voltage in sensing. A self-consistent Bond Graph language is used to give a clear physical and power interpretation of the mechanisms. To confirm the prediction ability of the resulting model, a 17 micrometers thick trilayer transducer is fabricated using a stacking layer method, and a complete dimensional, electrical, electro-chemical and mechanical characterization is performed. Good agreement is obtained between the temporal and frequency simulations and experiments in both sensing and actuation, showing that the modeling approach advances the understanding of the operation principles of the studied transducer devices.