Fully Inkjet‐Printed Organic Electrochemical Transistors: A Path Toward All‐Organic Electronics

Organic materials have the potential to be the basis for environmentally friendly, all‐carbon electronics. However, most real devices require additional materials, such as metals for electrodes. Here, we present an example of all‐organic devices: organic electrochemical transistors (OECTs), which are fully printed and do not use metal electrodes. We prove that these OECT devices have state‐of‐the‐art performance and present three applications using poly(benzodifurandione) (PBFDO) for the electrodes and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) for the active material: (i) a PBFDO strain sensor made from a single material, which demonstrates real‐time finger flexion detection; (ii) an OECT‐based ion sensor for monitoring the concentration of sodium chloride (NaCl) in aqueous environments; and (iii) intrinsically stretchable, all‐organic OECTs that can stretch up to 60% without the use of elastomeric additives or structural engineering.