Rapid Prototyping of Organic Electrochemical Transistors Using Dispenser Printing on Flexible Substrates for Future E-Textiles

Flexible printed electronics play a crucial role in wearable devices, however, to achieve thin and flexible layers their construction often requires multiple fabrication techniques, such as spin coating and evaporation which are challenging for traditional garment manufacturing. Organic electrochemical transistors (OECTs) are similar in principle to field effect transistors but do not require such high-definition manufacturing to achieve a working transistor structure compared with more traditional transistor structures. These OECT devices have been previously demonstrated in applications such as flexible integrated circuits (IC) and biosensors, exploiting the ionic conduction mechanism crucial to their operation. This work presents a method that utilizes screen-printable inks and a dispenser printer to fabricate bespoke OECTs on a flexible substrate, thus allowing rapid prototyping of OECT devices which can subsequently be scaled up via screen printing in the future to make viable e-textile logic and biosensor systems. In this work, dispenser printed OECTs have demonstrated an ON/OFF current ratio of up to 3000, demonstrating the potential of dispenser printing for the rapid prototyping of printed transistor circuits and sensors.