Poly (3,4-ethylenedioxythiophene): Poly (styrene sulfonate) Modified Laser Scribed Graphene for Flexible and Wearable Bioelectronics¹

The rapid development of flexible and wearable electronic devices has increased the demand for highly flexible, conductive, and durable materials for device circuits. Over the past decade, laser-scribed graphene (LSG) has been widely employed for the contact-free and mask-free fabrication of conductive carbon circuits or patterns from polyimide or other precursors due to its excellent physiochemical properties. On the other hand, conducting polymer poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) has also been extensively studied for fabricating flexible electronics thanks to its excellent electronic/ionic conductivity and flexibility. However, both materials have their limitations, making them still difficult to use directly for manufacturing high-performance electronic devices. For example, the LSG is fragile and easily damaged, and PEDOT: PSS is easily clustered in aqueous solutions, reducing the conductivity. To overcome the limitations, in this paper, we report a facile and cost-effective LSG modifying method with PEDOT: PSS to enhance the performance, which combines the exceptional sensing properties of the PEDOT: PSS with the electronic advantages of the LSG. The modification method can be readily extended using inkjet printing or screen printing. The characterization and comparison experiments demonstrate that the electric conductivity can be improved to three times as that of the original LSG by PEDOT: PSS modification. The modified LSG has better flexibility, which is more suitable for flexible and wearable electronics.