Ink Development and Printing of Conducting Polymers for Intrinsically Stretchable Interconnects and Circuits

Printable elastic conductors open up new opportunities in large-area fabrication of wearable electronics and prosthetics. Furthermore, they have the potential to advance health monitoring and continuous diagnostics by implementing sensor arrays in close proximity to the skin. Such devices need to be comfortable to wear and must accommodate strains and deformations such as twisting and stretching. A conductive polymer ink for elastic interconnects and electrodes is introduced. The processability by inkjet printing enables versatile, contactless, and maskless large area processing. The printed PEDOT:PSS-based interconnects have conductivities as high as 700 S cm⁻¹, sustain strains above 100% and show good stability in air (less than 5% change in resistance in 1 month). The conductivity is among the highest reported for inkjet-printed PEDOT:PSS and is interesting not only for stretchable circuits, but also for printed flexible and rigid PEDOT:PSS-based applications such as solar cells, organic light emitting diodes, and electrochemical sensors.