Advanced printing technique for transferring graphene layer into elastomer for stretchable conductors with tunable mechanical and electrical properties

Flexible and stretchable conductors have been widely considered crucial components in future electronic devices, due to their ability to maintain good conductivity while being bent and/or stretched, i.e. combined electrical and mechanical properties. Fabricating these conductors with simple processes and outstanding properties is constantly pursued by many researchers. Herein, 3D printing was used to encapsulate a blade-coated graphene layer into the extruded polymer matrix patterns, which not only simplifies the transfer process but also achieves desirable patterns. The morphology characterization and elemental analysis were conducted to verify the successful transfer of the graphene layer. An elongation of more than 600% without breaking reveals an outstanding mechanical stretchability. Furthermore, we compared various 3D printing settings, and identified rational optimal printing parameters, i.e. ~0.5 mm printing height and ~0.8 mm line spacing, to enable successful transfer with high quality. Finally, the stretchable conductors with various lattice structures were compared to study their effect on the mechanical and electrical properties. This study provides a novel and facile strategy to fabricate stretchable conductors, which not only simplifies the conventional cumbersome steps, but also enables custom-designed patterns for the conductors as well as tunable mechanical and electrical properties.