Screen printed silver nanowire and graphene oxide hybrid transparent electrodes for long-term electrocardiography monitoring

Silver nanowires (AgNWs) have attracted considerable attention as the material for emerging flexible, high conductive, and transparent wearable healthcare monitoring. However, due to the high possibility of AgNWs being oxidized in air and the discomfort caused by direct contact between silver nanowires and human skin, there are still some concerns to be taken into account in the direct application of AgNWs to ECG electrodes. Here, we combined AgNWs with graphene oxide (GO), and adopted the screen-printing technology for the fabrication of AgNWs/GO hybrid transparent conductive electrodes. Using the screen-printing technology throughout the whole fabrication process gives the ability to fabricate patterned films easily, and has the advantages of simple control and low cost, which makes it superior in mass production compared to previous studies. By encapsulating the AgNW with the GO layer, the electrodes obtained exhibit excellent optical and electrical properties (transmittance of 83.5% at 550 nm and sheet resistance of 11.9 Ohm/sq). Apart from optical and electrical properties, with GO as a protective layer, the reliability, bio-friendliness and long-term stability of AgNWs/GO hybrid electrodes have been greatly improved. In addition, AgNWs/GO electrodes fabricated on PET substrate also show excellent mechanical flexibility. We anticipate that AgNWs/GO electrodes will be promising materials for the implementation of emerging portable healthcare electronics such as wearable ECG monitoring.