Influence of mechanical stress on flexible electrolyte-gated organic field-effect transistors

Electrolyte-gated organic field-effect transistors (EGOFETs) are attracting great attention for the development of low-cost and flexible sensors. However, in order to progress towards such applications, it is key to understand the stability of these devices in aqueous media and under mechanical deformation. Here, we have fabricated flexible EGOFETs based on two small molecule organic semiconductors blended with polystyrene. These materials have been printed employing a low-cost solution-based technique, obtaining large area crystalline films. The devices revealed a good EGOFET performance in terms of mobility. Finally, the devices were operated under tensile and compressive strain, observing a current increase (decrease) when a compressive (tensile) deformation was applied, revealing large gauge factors. Thus, this work shows the importance of assessing the device response under mechanical deformation when flexible EGOFET-based sensors are developed, in order to achieve a reliable response.