Graphene-based printable conductors for cyclable strain sensors on elastomeric substrates

Printable stretchable devices, which can be used in a wide range of environments, are required for a range of flexible or stretchable electronics applications. Here we present an ink containing liquid exfoliated graphene and natural rubber, which can be printed onto a variety of elastomeric substrates and recover conductance after multiple strains of up to 15%. In addition, the printed composite acts as a strain sensor with a gauge factor of around 7. The robust character of these composites allows for operation at temperatures up to 150 °C. The combination of the effectiveness of the device, along with comparable performance at elevated temperatures while being relatively cheap makes this ideal for integration with automotive components. For applications that require superior conductivity, silver nanowires can be added. The enhanced conductivity composite cannot withstand higher temperatures due to the breakdown of the nanowires. However, at room temperature the material shows similar recovery of conductivity after cycling leading to a highly conductive, room temperature, printable, stretchable composite.