Spatial Adjustment Strategy to Improve the Sensitivity of Ionogels for Flexible Sensors

Abstract

AbstractRecently, ionogels‐based flexible/stretchable sensors have been receiving great attention, which greatly promotes the development of artificial flexible electronics. Except transparency, stretchability, stability, self‐healing, and adhesion, the high conductivity of ionogels and high sensitivity as a sensor still are huge challenges. This work proposes a spatial adjustment strategy to improve sensitivity and conductivity through reducing the spatial hinderance without a change in the compound types and ratio. The addition of space pre‐occupier during the preparation of the ionogel reduces the entanglement of polymer chains for better flowability of the polymer network. After removing the solvent from formed ionogels, the obtained free volume could facilitate the movement of ions and mobility of polymers. Through this way, the sensitivity (up to 1.6 times) and conductivity (up to 1.3 times) of ionogels are successfully improved, while maintaining their excellent transparency, stretchability, stability, and electromechanical properties, such as fast response speed and good repeatability. The detecting ability of movements of different parts of the human body is proved. It is worth mentioning that this simple and effective strategy needs no special requirement for chemical structure, so that it has broad applicability in various systems and opens up a new way for the development of flexible sensors.