Robust Physically Linked Double-Network Ionogel as a Flexible Bimodal Sensor.

To date, ionogel sensors have aroused the extensive interest as an alternative to hydrogel sensors, as they are promising materials to solve the problems of easy drying and easy freezing. However, the weak mechanical properties of ionogels have seriously hindered their large-scale application. Herein, a robust physically linked double-network ionogel (DN ionogel) was fabricated via interpenetrating a poly(hydroxyethyl acrylate) network into an agarose network in 1-ethyl-3-methylimidazolium chloride. The DN ionogel possessed good mechanical properties, high transparency, extreme temperature tolerance, and excellent self-adhesion. The superior electromechanical properties render the DN ionogel as a perfect candidate to be utilized as a strain sensor to monitor various human activities. In addition, the DN ionogel exhibited reasonably high sensitivity to temperature. Therefore, it is believed that this high performance strain-temperature bimodal sensor offers a promising prospect in flexible intelligent electronics.