Morphology map-guided identification of bijel ink for producing conductive porous structures

Manufacturing of composites consisting of polymers and electrically conductive fillers is critical for producing wearable conductive materials. Here, we demonstrate the direct ink writing of bijels composed of bicontinuous water and resin phases stabilized by graphene oxide (GO) to fabricate wearable electrically conductive foams with excellent tensile performance. A morphology map was established to illustrate emulsion morphology and ink printability. After printing, conductive foams were readily obtained by resin curing, GO reduction, and water removal. The bijel ink can be printed and processed on different fabrics with excellent adhesion, and the obtained structures present an exceptionally rapid heating response to radio frequency; with only 4.0 wt % loading of nanosheets, temperature increased by 215.4 degrees C in 1.0 s, outperforming previously reported particle/polymer composites. This work provides a roadmap for developing phase behaviors for fluid-fluid systems stabilized by nanoparticles, including printable bijels, and enables the 3D printing of wearable, porous, conductive materials without complicated pre/post-processing.